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Safety of Noncardiac Surgery in Patients With Hypertrophic Obstructive Cardiomyopathy at a Tertiary Care Center
Safety of Noncardiac Surgery in Patients With Hypertrophic Obstructive Cardiomyopathy at a Tertiary Care Center David W. Barbara, MD,* Joseph A. Hyder, MD, PhD,* Travis L. Behrend, MD,* Martin D. Abel, MD,* Hartzell V. Schaff, MD,† and William J. Mauermann, MD* Objectives: This study’s purpose was to review noncardiac surgery (NCS) in patients with hypertrophic obstructive cardiomyopathy (HOCM) to examine perioperative management and quantify postoperative mortality and worsening heart failure. Design: Retrospective review. Setting: A single tertiary care center. Participants: The study included 57 adult patients with HOCM who underwent NCS from January 1, 1996, through January 31, 2014. Interventions: Noncardiac surgery. Measurements and Main Results: The authors identified 57 HOCM patients who underwent 96 NCS procedures. Vasoactive medications were administered to the majority of NCS patients. Three patients (3%) died within 30 days of NCS, but causes of death did not appear to be cardiac in nature. Death after NCS was not significantly associated
with preoperative left ventricular ejection fraction (p ¼ 0.2727) or peak instantaneous systolic resting gradient (0.8828), but was associated with emergency surgery (p ¼ 0.0002). Three patients experienced worsening heart failure postoperatively, and this was significantly associated with preoperative New York Heart Association Class III-IV symptoms compared with I-II symptoms (p ¼ 0.0008). Conclusions: HOCM patients safely can undergo NCS at multidisciplinary centers experienced in caring for these patients. The mortality rate in this study was less than that reported in the majority of other studies. Postoperative complications, including increasing heart failure, may occur, especially in patients with more severe preoperative cardiac symptoms. & 2015 Elsevier Inc. All rights reserved.
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database was searched16 from January 1, 1996, through January 31, 2014, to identify patients with HOCM listed as a diagnosis or in their past medical histories. Pediatric patients (age o18 years), individuals not consenting to use of their record for research purposes, and those who had undergone surgical treatment for HOCM (ie, alcohol ablation or surgical myectomy) before NCS were not included. Patients were then crossreferenced with a surgical database to include only those HOCM patients who had undergone NCS requiring general anesthesia or neuraxial anesthesia at the Mayo Clinic, Rochester, MN. Resulting individual patient records were reviewed by a single author (TLB) to verify presence of HOCM and NCS. Similar to guidelines defining severity of regurgitant and stenotic cardiac valvular lesions,17 guidelines exist that differentiate HCM from HOCM.18 These guidelines, general consensus, and published studies consider a peak instantaneous left ventricular systolic gradient ≥30 mmHg by continuous-wave Doppler echocardiography indicative of obstruction and adverse outcomes in population-based studies.5-7,18,19 The authors delineated HOCM from non-obstructive HCM by using a lower limit peak instantaneous left ventricular systolic outflow gradient (either resting or provoked) of ≥30 mmHg as
YPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HOCM) is an autosomal dominant disease consisting of asymmetric left ventricular hypertrophy that leads to systolic anterior motion of the mitral valve, left ventricular obstruction, and mitral regurgitation.1,2 It may present at any age.3 Patients with classic HOCM have hypertrophy of the left ventricular basal septum. Other variants of HOCM involve obstruction at the apical or midventricular regions.1,3,4 Patients may experience heart failure, palpitations, diastolic dysfunction, stroke, arrhythmias, syncope, and sudden cardiac death. Surgical treatment of HOCM is known to improve long-term survival compared with patients who do not undergo surgery.5 HOCM should be differentiated from non-obstructive hypertrophic cardiomyopathy (HCM), which involves left ventricular hypertrophy without evidence of obstruction, and is associated with a lower mortality compared with HOCM.5-7 Patients with HOCM may present for noncardiac surgery (NCS) without having undergone prior surgical repair of their cardiac disease. Prior retrospective series reported mortality or adverse events in HCM patients undergoing NCS, ranging from 0% to 40%.8-11 However, 3 of these studies included patients with HOCM and non-obstructive HCM,8,10,11 and the other study from 1985 included a relatively small number of HOCM patients.9 The purpose of this study was to retrospectively review NCS in patients with HOCM at a single tertiary care institution that serves as a large referral center for HOCM patients. The authors hypothesized that HOCM patients safely can undergo NCS with low risk of mortality or major adverse cardiac events, such as myocardial infarction or heart failure, at experienced centers. Specifics related to anesthetic and hemodynamic management of these patients previously have been reviewed.12-15 METHODS
This study was approved by the Mayo Foundation Institutional Review Board. All patients gave consent to use of their records for research purposes. The electronic medical record
KEY WORDS: hypertrophic obstructive cardiomyopathy, non-cardiac surgery, anesthesia, mortality, heart failure
From the *Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN; and †Department of Cardiovascular Surgery, Mayo Clinic College of Medicine, Rochester, MN. Acknowledgments: This study used only departmental funding and resources. The authors would like to acknowledge contributions made in designing and performing the patient data search for this project from Gregory A. Wilson, RRT, and the Anesthesiology Clinical Research Group at Mayo Clinic, Rochester, MN. Address reprint requests to William J. Mauermann, MD, Department of Anesthesiology, Mayo Clinic, 200 First St. S.W., Rochester, MN 55905. E-mail: [email protected] © 2015 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2015.08.017
Journal of Cardiothoracic and Vascular Anesthesia, Vol ], No ] (Month), 2015: pp ]]]–]]]
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determined by echocardiography before NCS. The authors chose to include patients with latent obstruction (o30 mmHg) at rest who demonstrated obstruction (≥30 mmHg) with provocation (Valsalva maneuver or inhaled amyl nitrite administration), given the labile nature of the obstruction that may be provoked under the hemodynamically altering effects of anesthesia. However, patients with apical-variant HOCM and those without resting or provokable left ventricular systolic peak instantaneous gradients of ≥30 mmHg were excluded. Preoperative and demographic information collected included patient age at NCS, sex, hemoglobin values, creatinine values, cardiac rhythm on electrocardiogram, New York Heart Association (NYHA) heart failure classification, history of cardiac arrest, history of syncope, history of congestive heart failure, history of stroke or transient ischemic attack, presence of diabetes mellitus requiring insulin, and chronic kidney disease with creatinine 42 mg/dL. Preoperative echocardiographic data recorded included left ventricular ejection fraction, resting left ventricular outflow tract (LVOT) gradient, provoked (Valsalva maneuver or inhaled amyl nitrite administration) LVOT gradient, left ventricular basal septum thickness, and mitral regurgitation severity. The intraoperative anesthetic records and surgical notes were reviewed for type of surgery, emergency versus nonemergency surgery, anesthesia type (general v neuraxial), duration of anesthesia (as determined from the documented anesthesia start and stop times), whether care was provided by a cardiac anesthesiologist (defined as an anesthesiologist who completed a cardiac anesthesiology fellowship), presence of invasive monitors (arterial, central venous, and pulmonary artery lines), use of transesophageal echocardiography, intraoperative cardiac arrest, the use of vasoactive medications (phenylephrine, ephedrine, vasopressin, esmolol, and metoprolol), and estimated blood loss (as documented in the anesthetic record). Postoperative records for the 30 days after NCS were searched for death (and cause of death when present), hospital readmission (and reason for readmission), cardiac arrest, stroke (as defined as having received a new diagnosis of stroke in the postoperative period), myocardial infarction, and increasing heart failure (defined as notation in the postoperative documentation of worsening heart failure). Hospital length of stay also was noted. Statistical analysis consisted of mean, standard deviation, median, and range determination for continuous variables and percent quantification for categorical variables. As exploratory analyses, the authors performed tests for associations between preoperative echocardiographic characteristics of HOCM (ejection fraction and resting left ventricular systolic peak instantaneous gradient) and death as well as emergency surgery and death. In addition, the authors performed a test for association between preoperative NYHA heart failure classifications (I-II compared with III-IV) and occurrence of postoperative heart failure. In this population with a small number of events and clustering within patients, associations between the categorical variables emergency surgery and death ideally would be tested with an exact test that also accounts for clustering. The largest cluster sizes exceeded two admissions, so no methods have been developed for this purpose.20 Thus, the authors calculated
BARBARA ET AL
Fig 1. Selection process for patients with hypertrophic obstructive cardiomyopathy undergoing noncardiac surgery. HOCM, hypertrophic obstructive cardiomyopathy; NCS, noncardiac surgery.
statistical significance with the Rao-Scott test and present p values for these tests. Given the limitations of this test, the authors also calculated statistical significance using the Fisher’s test (which is an exact test) and by using robust standard errors (PROC GENMOD; SAS Institute, Cary, NC).21 In all instances, p values were very similar. Analyses were performed using SAS, version 9.3 (SAS Institute). RESULTS
Search of the electronic medical database after exclusion of patients with non-obstructive HCM resulted in 57 HOCM patients undergoing 96 NCS (Fig 1). Mean age was 62 ± 16 years, and 52 of the 96 NCS (54%) were performed on men. Other demographic and preoperative information, including echocardiographic findings, are shown in Table 1. The majority (89.6%) of patients were NYHA classification I or II before NCS. Patients underwent a variety of types of NCS (Table 2). Eight surgeries (8%) were emergency procedures. All surgeries were performed with the patient under general anesthesia, except for 1 patient (1%) who underwent uneventful revision hip arthroplasty under spinal anesthesia with concomitant sedation. Intraoperative findings for the 96 NCS are listed in Table 2. A cardiac anesthesiologist cared for the patient in 16 NCS (17%). Arterial and central venous lines were present in 24 (25%) and 9 (9%) of NCS, respectively. A pulmonary artery catheter and transesophageal echocardiography were each used for 1 NCS (in separate surgeries). Red blood cell transfusions were administered in 15 NCS (16%). No patient experienced cardiac arrest intraoperatively. Within 30 days of NCS, 3 deaths occurred (3%). Two deaths occurred secondary to perioperative aspiration events, and 1 was secondary to bowel ischemia not amenable to surgical intervention. Additional details related to these deaths are listed in Table 3. Statistical analysis revealed only
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Table 1. Demographic Information and Preoperative Findings for 96 Noncardiac Surgery Procedures in 57 Patients Age (y) LVEF (%) Resting gradient (mmHg)* Provoked gradient (mmHg)† Basal septal thickness (mm) Mitral regurgitation severity
Hemoglobin (g/dL) Creatinine (mg/dL) Preoperative ECG rhythm
New York Heart Association Classification
History of cardiac arrest History of syncope History of congestive heart failure History of stroke/TIA Diabetes mellitus requiring insulin Chronic kidney disease with creatinine 4 2 mg/dL
62 ± 16, median 65, range 30-94 71 ± 7, median 72, range 40-82 39 ± 28, median 29, range 3-130 75 ± 32, median 76, range 30-196 19 ± 4, median 19, range 13-28 29 (30%) none/trivial 36 (37.5%) mild 19 (20%) moderate 12 (12.5%) severe 12.2 ± 2.3, median 12.6, range 7.3-18.9 1.5 ± 1.2, median 1.2, range 0.4-8.9 61 (64%) normal sinus 15 (16%) normal sinus with first-degree AV block 10 (10%) atrial fibrillation or atrial flutter 5 (5%) sinus bradycardia with first-degree AV block 3 (3%) ventricular paced 1 (1%) sinus bradycardia 1 (1%) sinus tachycardia 54 (56.3%) class I 32 (33.3%) class II 9 (9.4%) class III 1 (1.0%) class IV 2 (2%) 6 (6%) 7 (7%) 7 (7%) 10 (10%)
III or IV symptoms was significantly greater than for patients with preoperative NYHA class I or II symptoms (2/10 v 1/86, respectively; p ¼ 0.0008). DISCUSSION
The main findings of this study were that (1) HOCM patients, especially those with preoperative NYHA class I and II symptoms, tolerated anesthesia and a wide variety of NCS relatively safely; (2) the majority of patients required vasoactive medications intraoperatively; (3) the observed mortality rate was lower than that reported in most other series examining NCS in patients with HCM; (4) preoperative echocardiographic findings related to HOCM were not significantly associated with 30-day mortality; and (5) HOCM patients with preoperative NYHA class III and IV symptoms were more likely to experience worsening heart failure symptoms after NCS compared with patients with NYHA class I and II symptoms. Limited retrospective series and several case reports have examined NCS in patients with HCM.8-11,15,22-27 The largest series involved 227 patients with HCM (based on ICD-9-CM codes) and did not quantify the degree of left ventricular systolic obstruction or differentiate non-obstructive HCM from HOCM.8 In this study, 6.7% of patients died before hospital discharge and the odds of death, after matching with controls, were increased nearly 2-fold in patients with HCM (95% CI, 1.46-1.77; p o0.001). The odds of myocardial infarction were significantly increased in patients with HCM as well (2.2% v 0.3% for controls; p o0.001). Haering et al reviewed 77 patients with asymmetric septal hypertrophy (30 with left ventricular outflow tract gradients ≥10 mmHg on echocardiography who underwent NCS).10 Although no patients died, 1% experienced myocardial Table 2. Procedure Type and Intraoperative Findings for 96 Noncardiac Surgeries Procedure type
17 (18%)
Abbreviations: AV, atrioventricular; ECG, electrocardiogram; LVEF, left ventricular ejection fraction; TIA, transient ischemic attack. *Performed in 56 of 57 patients. †Performed in 37 of 57 patients; 29 of 57 patients (51%) had latent obstruction (defined as a peak instantaneous left ventricular systolic outflow gradient o30 mmHg at rest and ≥30 mmHg with provocation with Valsalva maneuver or inhaled amyl nitrite administration).
emergency surgery to be significantly associated with death after NCS (Table 4). No patient experienced cardiac arrest within 30 days of NCS. After NCS, 2 strokes (2%), 2 myocardial infarctions (2%), and 3 cases of increasing heart failure symptoms (3%) were noted. Mean hospital length of stay was 8.2 ± 12.3 days (median 3, range 1-52 days). Readmission was required in 4 instances (4%) within 30 days of NCS, and 1 readmission was for worsening heart failure (see Table 3). Of 10 patients with preoperative NYHA heart failure classification III or IV symptoms, 2 experienced worsening heart failure symptoms in the postoperative period. The rate of worsening heart failure postoperatively among patients with preoperative NYHA class
Surgical duration (min) Estimated blood loss (cc)† Phenylephrine bolus Vasopressin bolus Ephedrine bolus Esmolol bolus Esmolol infusion received Metoprolol bolus
27 (28.1%) intra-abdominal 24 (25.0%) orthopedic (extremity or joint) 13 (13.5%) endoscopy/superficial/ cystoscopy 9 (9.4%) otorhinolaryngology/dental 6 (6.3%) gynecologic 5 (5.2%) intrathoracic 4 (4.2%) intracranial 3 (3.1%) endovascular 3 (3.1%) transplantation* 1 (1.0%) cesarean section 1 (1.0%) spine 195 ± 103, median 163, range 25-454 47 Not documented 49 Documented (303 ± 455, median 200, range 5-3,000) 67 (70%) 1 (1%) 33 (34%) 16 (17%) 2 (2%) 12 (12.5%)
*Two kidney transplantations and one pancreas transplantation were performed. †As documented in the anesthesia record.
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Table 3. Deaths and Unplanned Readmissions Within 30 Days of Noncardiac Surgery/Procedure Deaths
Patient
80 y female with recurrent bowel obstructions 87 y male with obstructing gastric mass 76 y female with lymphoma and necrotic bowel
Preoperative Echocardiogram and NYHA Functional Classification
LVEF, 75% resting gradient,* 51 mmHg Basal septal thickness, 18 mm NYHA class II LVEF, 40% resting gradient,* 52 mmHg Basal septal thickness, 23 mm NYHA class III LVEF, 70% Resting gradient,* 9 mmHg Provoked gradient,* 49 mmHg Basal septal thickness, 18 mm NYHA class II
Procedure
Emergency Surgery
Likely Cause of Death
Exploratory laparotomy, lysis of adhesions, umbilical hernia repair
Yes
Aspiration on postoperative day 2
Esophagogastroduodenoscopy
No
Aspiration during procedure†
Exploratory laparotomy‡
Yes
Preoperative septic shock with postoperative withdrawal of support at family’s request
Unplanned Readmissions Preoperative Echocardiogram and NYHA Patient
95 y female
88 y female
76 y male
51 y male
Emergency
Functional Classification
LVEF, 40% Resting gradient,* 36 mmHg Basal septal thickness, 19 mm NYHA class III LVEF, 65% Resting gradient,* 68 mmHg Basal septal thickness, 16 mm NYHA class II LVEF, 74% Resting gradient,* 92 mmHg Basal septal thickness, 18 mm NYHA class II LVEF, 68% Resting gradient 25,* mmHg Provoked gradient,* 77 mmHg Basal septal thickness, 20 mm NYHA class III
Procedure
Surgery
Reason for Readmission
Left hip hemiarthroplasty
No
Worsening heart failure
Left hip hemiarthroplasty
No
Subdural hematoma
Right parathyroidectomy
No
Urosepsis
Exploratory laparotomy, removal of infected mesh with primary abdominal closure
No
Nonhealing abdominal wound
Abbreviations: LVEF, left ventricular ejection fraction; NYHA, New York Heart Association. *“Gradient” refers to peak instantaneous left ventricular systolic gradient as determined by continuous-wave Doppler echocardiography. †The esophagogastroduodenoscopy initially was planned to be performed with monitored anesthesia care. However, after administration of sedation, the patient vomited 1-2 L of bilious gastric contents and aspirated. The patient’s trachea immediately was intubated, and bronchoscopy revealed copious bilious liquid, predominantly on the right-sided airways, that was removed with suctioning. The procedure was performed with the patient under general anesthesia, and the patient was transferred to the intensive care unit intubated, sedated, and mechanically ventilated after the procedure. He experienced progressive hypoxic respiratory failure. On postoperative day 3, the patient’s family requested withdrawal of support, and the patient died. ‡The explorative laparotomy revealed ischemia of the entire small bowel in the setting of underlying recurrent lymphoma. Additional surgical intervention was deemed futile, the incision closed, and the patient was transferred to the intensive care unit. After discussion with the family, support was withdrawn and the patient died.
infarction and 16% experienced congestive heart failure perioperatively. The authors concluded that regardless of the presence of obstruction, patients with asymmetric septal hypertrophy experienced frequent perioperative morbidity. Thompson et al retrospectively examined the perioperative courses of 35 patients with HOCM (diagnosed by presence of obstruction on cardiac catheterization or echocardiographic findings of mitral valve systolic anterior motion in conjunction with asymmetric septal hypertrophy who underwent NCS).9 Three patients (9%) died postoperatively, but none of the deaths was attributed to cardiac causes. Perioperatively, 14% experienced hypotension
requiring vasopressors, 14% experienced atrial arrhythmias, 9% experienced ventricular arrhythmias, 3% experienced myocardial infarction, and 3% experienced angina. Xuan et al published a series reporting on 24 patients with HCM (mean LVOT peak gradient, 30 ± 19 mmHg; 29% of patients had mitral valve systolic anterior motion who underwent NCS).11 Postoperatively, 1 patient (4%) experienced a myocardial infarction and died. One published study of HCM patients reported a mortality r ate of 0%10; however, only 39% of these patients had gradients ≥10 mmHg, in contrast to all patients in this study having gradients ≥30 mmHg. Consistent with the aforementioned
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Table 4. Statistical Analysis of Associations Between Hypertrophic Obstructive Cardiomyopathy Patients and Death Within 30 Days After Non-cardiac Surgery Variable
Survivors (n ¼ 93)
Nonsurvivors (n ¼ 3 )
p Value
Left ventricular ejection fraction (mean) Peak instantaneous systolic resting gradient (mean) Emergency surgery
71.5% 39.1 mmHg 6 patients (6.5%)
61.7% 37.3 mmHg 2 patients (66.7%)
0.2727 0.8828 0.0002
studies, myocardial infarction was noted in 2% of patients after NCS in this study. The authors noted worsening heart failure symptoms postoperatively after NCS for 3% of patients, compared with as high as 16% of patients in a prior study.10 The mortality (3%) observed in the series described here was lower than the 4% to 9% reported in the majority of other studies, which typically included patients with non-obstructive HCM.8,9,11 Review of the patients in this study who died revealed that mortality most likely was due to noncardiac factors. The observed mortality rate in this study was nearly equivalent to the 3.1% 30day mortality rate of a control group undergoing NCS reported in a recently published study from the authors’ institution.28 The analyses presented here did not identify any statistically significant associations between preoperative echocardiographic findings and mortality. Presence of outflow tract obstruction (defined as gradient ≥30 mmHg) is known to increase mortality in patients with HCM; however, the likelihood of death is not increased with progressive elevations greater than 30 mmHg.6 In addition, the statistically significant association in this study between emergency surgery and 30-day mortality may validate the study sample because emergency surgery is known to be a strong predictor of mortality across patient and surgery types.29,30 Although definitive cause of mortality was difficult to determine given the retrospective nature of this study, the 3 instances of death after NCS appeared most likely to be attributed to causes not directly related to HOCM. Finally, the statistically significant association between preoperative NYHA class III and IV compared with class I and II symptoms and the development of increasing heart failure symptoms after NCS was consistent with preoperative congestive heart failure being a known predictor of postoperative cardiac complications, including heart failure.28,31 Noncardiac anesthesiologists safely cared for the majority of patients in this series. The authors believe that more important than the formal training of the anesthesiologist is an in-depth understanding of the pathophysiology of HOCM in caring for these patients. The authors’ institution serves as a major referral center for HOCM patients, and there is a broad knowledge base for understanding this disease process throughout the institution. In addition, patients at the authors’ institution typically receive perioperative care from multidisciplinary teams, including cardiologists, anesthesiologists, and intensivists familiar with HOCM patients. As highlighted by the majority of patients requiring intraoperative vasoactive medication use, careful attention to and prompt treatment of hemodynamic alterations during NCS are necessary when caring for HOCM patients. Consistent with prior series reporting the use of invasive blood pressure monitoring in 8% to 29% of HOCM patients undergoing NCS, 25% of patients in this series underwent invasive blood pressure monitoring intraoperatively.9-11 For NCS with a high likelihood of substantial blood loss or hemodynamic alterations, invasive blood pressure
monitoring may be prudent, given the hemodynamic sensitivity of HOCM patients to changes in preload, afterload, and heart rate. Similarly, even in patients without preoperative evidence of HOCM or known cardiac disease, hemodynamic perturbations associated with fluid shifts, positive-pressure ventilation and induction, maintenance, and emergence from anesthesia may unmask latent HOCM physiology.7,25-27 A high degree of vigilance and index of suspicion are required to appropriately diagnose and treat this subset of HOCM patients to mitigate adverse sequelae. Finally, intraoperative transesophageal echocardiography can yield immediate information on the degree of outflow tract obstruction, secondary mitral regurgitation, ventricular filling and function, and the results of any intervention. This series included only one parturient with HOCM. Prior publications have reviewed management of these patients.32-34 Although the majority of HOCM patients tolerate pregnancy and childbirth without complication, overall maternal mortality is increased in parturients with HOCM compared with the general population, and higher peak instantaneous LVOT gradients appear to be associated with worse outcomes.33,34 Both general and neuraxial anesthesia have been used safely in HOCM patients undergoing cesarean section. In addition, vaginal and cesarean section deliveries both have been reported. Parturients with HOCM, especially in severe cases, may be managed best by multidisciplinary teams at high-risk obstetric centers with experience in managing these patients. Limitations of this study included all those inherent to a retrospective series. Charting inaccuracies may have been present, and reasons for management cannot always be found. By definition, the authors excluded patients with non-obstructive HCM. In addition, the authors defined “obstruction” as a resting or provoked peak instantaneous left ventricular systolic gradient of ≥30 mmHg as determined using continuous-wave Doppler echocardiography. Therefore, patients who may have had clinical signs of HOCM with lesser measured gradients were excluded. In addition, patients with undiagnosed HOCM at the time of NCS that was later diagnosed were not included. Finally, the hypothesis testing reported here did not adjust for potential confounders. The small number of deaths precluded the meaningful use of statistical methods for adjustment. Moreover, deaths were most likely due to noncardiac factors, so the use of a comparison group would be unlikely to clarify the role of HOCM as potentially causal for mortality or shed light on the main findings of the study.35 The p values reported, however, did account for clustered data and were thus conservative. CONCLUSIONS
In the current series, patients with HOCM underwent a variety of NCS with an observed mortality rate of 3%. Death after NCS was not significantly associated with preoperative echocardiographic findings but was associated with emergency
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surgery. The authors’ analysis suggested that mortality likely was due to noncardiac factors. Postoperative acutely worsening heart failure was significantly greater among patients with preoperative NYHA III and IV symptoms compared to those with lesser symptoms. Intraoperative vasoactive medications
were required in most patients. HOCM patients safely may undergo NCS at multidisciplinary centers with experience in caring for these patients, but clinicians should be aware of the potential for complications, especially among severely symptomatic patients.
REFERENCES 1. Wigle ED, Rakowski H, Kimball BP, et al: Hypertrophic cardiomyopathy. Clinical spectrum and treatment. Circulation 92:1680-1692, 1995 2. Nishimura RA, Holmes DR Jr: Clinical practice. Hypertrophic obstructive cardiomyopathy. N Engl J Med 350:1320-1327, 2004 3. Maron BJ: Hypertrophic cardiomyopathy: A systematic review. JAMA 287:1308-1320, 2002 4. Kunkala MR, Schaff HV, Nishimura RA, et al: Transapical approach to myectomy for midventricular obstruction in hypertrophic cardiomyopathy. Ann Thorac Surg 96:564-570, 2013 5. Ommen SR, Maron BJ, Olivotto I, et al: Long-term effects of surgical septal myectomy on survival in patients with obstructive hypertrophic cardiomyopathy. J Am Coll Cardiol 46:470-476, 2005 6. Maron MS, Olivotto I, Betocchi S, et al: Effect of left ventricular outflow tract obstruction on clinical outcome in hypertrophic cardiomyopathy. N Engl J Med 348:295-303, 2003 7. Schaff HV, Dearani JA, Ommen SR, et al: Expanding the indications for septal myectomy in patients with hypertrophic cardiomyopathy: Results of operation in patients with latent obstruction. J Thorac Cardiovasc Surg 143:303-309, 2012 8. Hreybe H, Zahid M, Sonel A, et al: Noncardiac surgery and the risk of death and other cardiovascular events in patients with hypertrophic cardiomyopathy. Clin Cardiol 29:65-68, 2006 9. Thompson RC, Liberthson RR, Lowenstein E: Perioperative anesthetic risk of noncardiac surgery in hypertrophic obstructive cardiomyopathy. JAMA 254:2419-2421, 1985 10. Haering JM, Comunale ME, Parker RA, et al: Cardiac risk of noncardiac surgery in patients with asymmetric septal hypertrophy. Anesthesiology 85:254-259, 1996 11. Xuan TM, Zeng Y, Zhu WL: Risk of patients with hypertrophic cardiomyopathy undergoing noncardiac surgery. Chin Med Sci J 22: 211-215, 2007 12. Mittnacht AJ, Fanshawe M, Konstadt S: Anesthetic considerations in the patient with valvular heart disease undergoing noncardiac surgery. Semin Cardiothorac Vasc Anesth 12:33-59, 2008 13. Gajewski M, Hillel Z: Anesthesia management of patients with hypertrophic obstructive cardiomyopathy. Prog Cardiovasc Dis 54: 503-511, 2012 14. Robertson A: Intraoperative management of liver transplantation in patients with hypertrophic cardiomyopathy: A review. Transplant Proc 42:1721-1723, 2010 15. Sahoo RK, Dash SK, Raut PS, et al: Perioperative anesthetic management of patients with hypertrophic cardiomyopathy for noncardiac surgery: A case series. Ann Card Anaesth 13:253-256, 2010 16. Holtby H, Skowno JJ, Kor DJ, et al: New technologies in pediatric anesthesia. Paediatr Anaesth 22:952-961, 2012 17. Nishimura RA, Otto CM, Bonow RO, et al: 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 129: e521-643, 2014 18. Gersh BJ, Maron BJ, Bonow RO, et al: 2011 ACCF/AHA Guideline for the Diagnosis and Treatment of Hypertrophic Cardiomyopathy: A report of the American College of Cardiology Foundation/ American Heart Association Task Force on Practice Guidelines. Developed in collaboration with the American Association for Thoracic Surgery, American Society of Echocardiography, American Society of
Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 58:e212-260, 2011 19. Maron BJ, McKenna WJ, Danielson GK, et al: American College of Cardiology/European Society of Cardiology clinical expert consensus document on hypertrophic cardiomyopathy. A report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines. J Am Coll Cardiol 42: 1687-1713, 2003 20. Kang SH, Chung SJ, Ahn CW: Exact tests for one sample correlated binary data. Biom J 47:188-193, 2005 21. Spiegelman D, Hertzmark E: Easy SAS calculations for risk or prevalence ratios and differences. Am J Epidemiol 162:199-200, 2005 22. Cywinski JB, Argalious M, Marks TN, et al: Dynamic left ventricular outflow tract obstruction in an orthotopic liver transplant recipient. Liver Transpl 11:692-695, 2005 23. Popescu WM, Perrino AC Jr: Critical cardiac decompensation during laparoscopic surgery. J Am Soc Echocardiogr 19(1074): e1075-1076, 2006 24. Kojima T, Imai Y, Tsushima K, et al: Temporary dual-chamber pacing can stabilize hemodynamics during noncardiac surgery in a patient with left ventricular hypertrophy and outflow obstruction. J Cardiothorac Vasc Anesth 28:124-127, 2014 25. Angelotti T, Fuller A, Rivera L, et al: Anesthesia for older patients with hypertrophic cardiomyopathy: Is there cause for concern? J Clin Anesth 17:478-481, 2005 26. Lanier W, Prough DS: Intraoperative diagnosis of hypertrophic obstructive cardiomyopathy. Anesthesiology 60:61-63, 1984 27. Fayad A: Left ventricular outflow obstruction in a patient with undiagnosed hypertrophic obstructive cardiomyopathy. Can J Anaesth 54:1019-1020, 2007 28. Tashiro T, Pislaru SV, Blustin JM, et al: Perioperative risk of major non-cardiac surgery in patients with severe aortic stenosis: A reappraisal in contemporary practice. Eur Heart J 35:2372-2381, 2014 29. Mangano DT: Perioperative cardiac morbidity. Anesthesiology 72:153-184, 1990 30. Fleisher LA, Beckman JA, Brown KA, et al: 2009 ACCF/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: A report of the American college of cardiology foundation/American heart association task force on practice guidelines. Circulation 120:e169-276, 2009 31. Lee TH, Marcantonio ER, Mangione CM, et al: Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 100:1043-1049, 1999 32. Stergiopoulos K, Shiang E, Bench T: Pregnancy in patients with pre-existing cardiomyopathies. J Am Coll Cardiol 58:337-350, 2011 33. Autore C, Conte MR, Piccininno M, et al: Risk associated with pregnancy in hypertrophic cardiomyopathy. J Am Coll Cardiol 40: 1864-1869, 2002 34. Thaman R, Varnava A, Hamid MS, et al: Pregnancy related complications in women with hypertrophic cardiomyopathy. Heart 89: 752-756, 2003 35. Greenland S, Morgenstern H: Confounding in health research. Annu Rev Public Health 22:189-212, 2001
with preoperative left ventricular ejection fraction (p ¼ 0.2727) or peak instantaneous systolic resting gradient (0.8828), but was associated with emergency surgery (p ¼ 0.0002). Three patients experienced worsening heart failure postoperatively, and this was significantly associated with preoperative New York Heart Association Class III-IV symptoms compared with I-II symptoms (p ¼ 0.0008). Conclusions: HOCM patients safely can undergo NCS at multidisciplinary centers experienced in caring for these patients. The mortality rate in this study was less than that reported in the majority of other studies. Postoperative complications, including increasing heart failure, may occur, especially in patients with more severe preoperative cardiac symptoms. & 2015 Elsevier Inc. All rights reserved.
H
database was searched16 from January 1, 1996, through January 31, 2014, to identify patients with HOCM listed as a diagnosis or in their past medical histories. Pediatric patients (age o18 years), individuals not consenting to use of their record for research purposes, and those who had undergone surgical treatment for HOCM (ie, alcohol ablation or surgical myectomy) before NCS were not included. Patients were then crossreferenced with a surgical database to include only those HOCM patients who had undergone NCS requiring general anesthesia or neuraxial anesthesia at the Mayo Clinic, Rochester, MN. Resulting individual patient records were reviewed by a single author (TLB) to verify presence of HOCM and NCS. Similar to guidelines defining severity of regurgitant and stenotic cardiac valvular lesions,17 guidelines exist that differentiate HCM from HOCM.18 These guidelines, general consensus, and published studies consider a peak instantaneous left ventricular systolic gradient ≥30 mmHg by continuous-wave Doppler echocardiography indicative of obstruction and adverse outcomes in population-based studies.5-7,18,19 The authors delineated HOCM from non-obstructive HCM by using a lower limit peak instantaneous left ventricular systolic outflow gradient (either resting or provoked) of ≥30 mmHg as
YPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HOCM) is an autosomal dominant disease consisting of asymmetric left ventricular hypertrophy that leads to systolic anterior motion of the mitral valve, left ventricular obstruction, and mitral regurgitation.1,2 It may present at any age.3 Patients with classic HOCM have hypertrophy of the left ventricular basal septum. Other variants of HOCM involve obstruction at the apical or midventricular regions.1,3,4 Patients may experience heart failure, palpitations, diastolic dysfunction, stroke, arrhythmias, syncope, and sudden cardiac death. Surgical treatment of HOCM is known to improve long-term survival compared with patients who do not undergo surgery.5 HOCM should be differentiated from non-obstructive hypertrophic cardiomyopathy (HCM), which involves left ventricular hypertrophy without evidence of obstruction, and is associated with a lower mortality compared with HOCM.5-7 Patients with HOCM may present for noncardiac surgery (NCS) without having undergone prior surgical repair of their cardiac disease. Prior retrospective series reported mortality or adverse events in HCM patients undergoing NCS, ranging from 0% to 40%.8-11 However, 3 of these studies included patients with HOCM and non-obstructive HCM,8,10,11 and the other study from 1985 included a relatively small number of HOCM patients.9 The purpose of this study was to retrospectively review NCS in patients with HOCM at a single tertiary care institution that serves as a large referral center for HOCM patients. The authors hypothesized that HOCM patients safely can undergo NCS with low risk of mortality or major adverse cardiac events, such as myocardial infarction or heart failure, at experienced centers. Specifics related to anesthetic and hemodynamic management of these patients previously have been reviewed.12-15 METHODS
This study was approved by the Mayo Foundation Institutional Review Board. All patients gave consent to use of their records for research purposes. The electronic medical record
KEY WORDS: hypertrophic obstructive cardiomyopathy, non-cardiac surgery, anesthesia, mortality, heart failure
From the *Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN; and †Department of Cardiovascular Surgery, Mayo Clinic College of Medicine, Rochester, MN. Acknowledgments: This study used only departmental funding and resources. The authors would like to acknowledge contributions made in designing and performing the patient data search for this project from Gregory A. Wilson, RRT, and the Anesthesiology Clinical Research Group at Mayo Clinic, Rochester, MN. Address reprint requests to William J. Mauermann, MD, Department of Anesthesiology, Mayo Clinic, 200 First St. S.W., Rochester, MN 55905. E-mail: [email protected] © 2015 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2015.08.017
Journal of Cardiothoracic and Vascular Anesthesia, Vol ], No ] (Month), 2015: pp ]]]–]]]
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determined by echocardiography before NCS. The authors chose to include patients with latent obstruction (o30 mmHg) at rest who demonstrated obstruction (≥30 mmHg) with provocation (Valsalva maneuver or inhaled amyl nitrite administration), given the labile nature of the obstruction that may be provoked under the hemodynamically altering effects of anesthesia. However, patients with apical-variant HOCM and those without resting or provokable left ventricular systolic peak instantaneous gradients of ≥30 mmHg were excluded. Preoperative and demographic information collected included patient age at NCS, sex, hemoglobin values, creatinine values, cardiac rhythm on electrocardiogram, New York Heart Association (NYHA) heart failure classification, history of cardiac arrest, history of syncope, history of congestive heart failure, history of stroke or transient ischemic attack, presence of diabetes mellitus requiring insulin, and chronic kidney disease with creatinine 42 mg/dL. Preoperative echocardiographic data recorded included left ventricular ejection fraction, resting left ventricular outflow tract (LVOT) gradient, provoked (Valsalva maneuver or inhaled amyl nitrite administration) LVOT gradient, left ventricular basal septum thickness, and mitral regurgitation severity. The intraoperative anesthetic records and surgical notes were reviewed for type of surgery, emergency versus nonemergency surgery, anesthesia type (general v neuraxial), duration of anesthesia (as determined from the documented anesthesia start and stop times), whether care was provided by a cardiac anesthesiologist (defined as an anesthesiologist who completed a cardiac anesthesiology fellowship), presence of invasive monitors (arterial, central venous, and pulmonary artery lines), use of transesophageal echocardiography, intraoperative cardiac arrest, the use of vasoactive medications (phenylephrine, ephedrine, vasopressin, esmolol, and metoprolol), and estimated blood loss (as documented in the anesthetic record). Postoperative records for the 30 days after NCS were searched for death (and cause of death when present), hospital readmission (and reason for readmission), cardiac arrest, stroke (as defined as having received a new diagnosis of stroke in the postoperative period), myocardial infarction, and increasing heart failure (defined as notation in the postoperative documentation of worsening heart failure). Hospital length of stay also was noted. Statistical analysis consisted of mean, standard deviation, median, and range determination for continuous variables and percent quantification for categorical variables. As exploratory analyses, the authors performed tests for associations between preoperative echocardiographic characteristics of HOCM (ejection fraction and resting left ventricular systolic peak instantaneous gradient) and death as well as emergency surgery and death. In addition, the authors performed a test for association between preoperative NYHA heart failure classifications (I-II compared with III-IV) and occurrence of postoperative heart failure. In this population with a small number of events and clustering within patients, associations between the categorical variables emergency surgery and death ideally would be tested with an exact test that also accounts for clustering. The largest cluster sizes exceeded two admissions, so no methods have been developed for this purpose.20 Thus, the authors calculated
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Fig 1. Selection process for patients with hypertrophic obstructive cardiomyopathy undergoing noncardiac surgery. HOCM, hypertrophic obstructive cardiomyopathy; NCS, noncardiac surgery.
statistical significance with the Rao-Scott test and present p values for these tests. Given the limitations of this test, the authors also calculated statistical significance using the Fisher’s test (which is an exact test) and by using robust standard errors (PROC GENMOD; SAS Institute, Cary, NC).21 In all instances, p values were very similar. Analyses were performed using SAS, version 9.3 (SAS Institute). RESULTS
Search of the electronic medical database after exclusion of patients with non-obstructive HCM resulted in 57 HOCM patients undergoing 96 NCS (Fig 1). Mean age was 62 ± 16 years, and 52 of the 96 NCS (54%) were performed on men. Other demographic and preoperative information, including echocardiographic findings, are shown in Table 1. The majority (89.6%) of patients were NYHA classification I or II before NCS. Patients underwent a variety of types of NCS (Table 2). Eight surgeries (8%) were emergency procedures. All surgeries were performed with the patient under general anesthesia, except for 1 patient (1%) who underwent uneventful revision hip arthroplasty under spinal anesthesia with concomitant sedation. Intraoperative findings for the 96 NCS are listed in Table 2. A cardiac anesthesiologist cared for the patient in 16 NCS (17%). Arterial and central venous lines were present in 24 (25%) and 9 (9%) of NCS, respectively. A pulmonary artery catheter and transesophageal echocardiography were each used for 1 NCS (in separate surgeries). Red blood cell transfusions were administered in 15 NCS (16%). No patient experienced cardiac arrest intraoperatively. Within 30 days of NCS, 3 deaths occurred (3%). Two deaths occurred secondary to perioperative aspiration events, and 1 was secondary to bowel ischemia not amenable to surgical intervention. Additional details related to these deaths are listed in Table 3. Statistical analysis revealed only
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Table 1. Demographic Information and Preoperative Findings for 96 Noncardiac Surgery Procedures in 57 Patients Age (y) LVEF (%) Resting gradient (mmHg)* Provoked gradient (mmHg)† Basal septal thickness (mm) Mitral regurgitation severity
Hemoglobin (g/dL) Creatinine (mg/dL) Preoperative ECG rhythm
New York Heart Association Classification
History of cardiac arrest History of syncope History of congestive heart failure History of stroke/TIA Diabetes mellitus requiring insulin Chronic kidney disease with creatinine 4 2 mg/dL
62 ± 16, median 65, range 30-94 71 ± 7, median 72, range 40-82 39 ± 28, median 29, range 3-130 75 ± 32, median 76, range 30-196 19 ± 4, median 19, range 13-28 29 (30%) none/trivial 36 (37.5%) mild 19 (20%) moderate 12 (12.5%) severe 12.2 ± 2.3, median 12.6, range 7.3-18.9 1.5 ± 1.2, median 1.2, range 0.4-8.9 61 (64%) normal sinus 15 (16%) normal sinus with first-degree AV block 10 (10%) atrial fibrillation or atrial flutter 5 (5%) sinus bradycardia with first-degree AV block 3 (3%) ventricular paced 1 (1%) sinus bradycardia 1 (1%) sinus tachycardia 54 (56.3%) class I 32 (33.3%) class II 9 (9.4%) class III 1 (1.0%) class IV 2 (2%) 6 (6%) 7 (7%) 7 (7%) 10 (10%)
III or IV symptoms was significantly greater than for patients with preoperative NYHA class I or II symptoms (2/10 v 1/86, respectively; p ¼ 0.0008). DISCUSSION
The main findings of this study were that (1) HOCM patients, especially those with preoperative NYHA class I and II symptoms, tolerated anesthesia and a wide variety of NCS relatively safely; (2) the majority of patients required vasoactive medications intraoperatively; (3) the observed mortality rate was lower than that reported in most other series examining NCS in patients with HCM; (4) preoperative echocardiographic findings related to HOCM were not significantly associated with 30-day mortality; and (5) HOCM patients with preoperative NYHA class III and IV symptoms were more likely to experience worsening heart failure symptoms after NCS compared with patients with NYHA class I and II symptoms. Limited retrospective series and several case reports have examined NCS in patients with HCM.8-11,15,22-27 The largest series involved 227 patients with HCM (based on ICD-9-CM codes) and did not quantify the degree of left ventricular systolic obstruction or differentiate non-obstructive HCM from HOCM.8 In this study, 6.7% of patients died before hospital discharge and the odds of death, after matching with controls, were increased nearly 2-fold in patients with HCM (95% CI, 1.46-1.77; p o0.001). The odds of myocardial infarction were significantly increased in patients with HCM as well (2.2% v 0.3% for controls; p o0.001). Haering et al reviewed 77 patients with asymmetric septal hypertrophy (30 with left ventricular outflow tract gradients ≥10 mmHg on echocardiography who underwent NCS).10 Although no patients died, 1% experienced myocardial Table 2. Procedure Type and Intraoperative Findings for 96 Noncardiac Surgeries Procedure type
17 (18%)
Abbreviations: AV, atrioventricular; ECG, electrocardiogram; LVEF, left ventricular ejection fraction; TIA, transient ischemic attack. *Performed in 56 of 57 patients. †Performed in 37 of 57 patients; 29 of 57 patients (51%) had latent obstruction (defined as a peak instantaneous left ventricular systolic outflow gradient o30 mmHg at rest and ≥30 mmHg with provocation with Valsalva maneuver or inhaled amyl nitrite administration).
emergency surgery to be significantly associated with death after NCS (Table 4). No patient experienced cardiac arrest within 30 days of NCS. After NCS, 2 strokes (2%), 2 myocardial infarctions (2%), and 3 cases of increasing heart failure symptoms (3%) were noted. Mean hospital length of stay was 8.2 ± 12.3 days (median 3, range 1-52 days). Readmission was required in 4 instances (4%) within 30 days of NCS, and 1 readmission was for worsening heart failure (see Table 3). Of 10 patients with preoperative NYHA heart failure classification III or IV symptoms, 2 experienced worsening heart failure symptoms in the postoperative period. The rate of worsening heart failure postoperatively among patients with preoperative NYHA class
Surgical duration (min) Estimated blood loss (cc)† Phenylephrine bolus Vasopressin bolus Ephedrine bolus Esmolol bolus Esmolol infusion received Metoprolol bolus
27 (28.1%) intra-abdominal 24 (25.0%) orthopedic (extremity or joint) 13 (13.5%) endoscopy/superficial/ cystoscopy 9 (9.4%) otorhinolaryngology/dental 6 (6.3%) gynecologic 5 (5.2%) intrathoracic 4 (4.2%) intracranial 3 (3.1%) endovascular 3 (3.1%) transplantation* 1 (1.0%) cesarean section 1 (1.0%) spine 195 ± 103, median 163, range 25-454 47 Not documented 49 Documented (303 ± 455, median 200, range 5-3,000) 67 (70%) 1 (1%) 33 (34%) 16 (17%) 2 (2%) 12 (12.5%)
*Two kidney transplantations and one pancreas transplantation were performed. †As documented in the anesthesia record.
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Table 3. Deaths and Unplanned Readmissions Within 30 Days of Noncardiac Surgery/Procedure Deaths
Patient
80 y female with recurrent bowel obstructions 87 y male with obstructing gastric mass 76 y female with lymphoma and necrotic bowel
Preoperative Echocardiogram and NYHA Functional Classification
LVEF, 75% resting gradient,* 51 mmHg Basal septal thickness, 18 mm NYHA class II LVEF, 40% resting gradient,* 52 mmHg Basal septal thickness, 23 mm NYHA class III LVEF, 70% Resting gradient,* 9 mmHg Provoked gradient,* 49 mmHg Basal septal thickness, 18 mm NYHA class II
Procedure
Emergency Surgery
Likely Cause of Death
Exploratory laparotomy, lysis of adhesions, umbilical hernia repair
Yes
Aspiration on postoperative day 2
Esophagogastroduodenoscopy
No
Aspiration during procedure†
Exploratory laparotomy‡
Yes
Preoperative septic shock with postoperative withdrawal of support at family’s request
Unplanned Readmissions Preoperative Echocardiogram and NYHA Patient
95 y female
88 y female
76 y male
51 y male
Emergency
Functional Classification
LVEF, 40% Resting gradient,* 36 mmHg Basal septal thickness, 19 mm NYHA class III LVEF, 65% Resting gradient,* 68 mmHg Basal septal thickness, 16 mm NYHA class II LVEF, 74% Resting gradient,* 92 mmHg Basal septal thickness, 18 mm NYHA class II LVEF, 68% Resting gradient 25,* mmHg Provoked gradient,* 77 mmHg Basal septal thickness, 20 mm NYHA class III
Procedure
Surgery
Reason for Readmission
Left hip hemiarthroplasty
No
Worsening heart failure
Left hip hemiarthroplasty
No
Subdural hematoma
Right parathyroidectomy
No
Urosepsis
Exploratory laparotomy, removal of infected mesh with primary abdominal closure
No
Nonhealing abdominal wound
Abbreviations: LVEF, left ventricular ejection fraction; NYHA, New York Heart Association. *“Gradient” refers to peak instantaneous left ventricular systolic gradient as determined by continuous-wave Doppler echocardiography. †The esophagogastroduodenoscopy initially was planned to be performed with monitored anesthesia care. However, after administration of sedation, the patient vomited 1-2 L of bilious gastric contents and aspirated. The patient’s trachea immediately was intubated, and bronchoscopy revealed copious bilious liquid, predominantly on the right-sided airways, that was removed with suctioning. The procedure was performed with the patient under general anesthesia, and the patient was transferred to the intensive care unit intubated, sedated, and mechanically ventilated after the procedure. He experienced progressive hypoxic respiratory failure. On postoperative day 3, the patient’s family requested withdrawal of support, and the patient died. ‡The explorative laparotomy revealed ischemia of the entire small bowel in the setting of underlying recurrent lymphoma. Additional surgical intervention was deemed futile, the incision closed, and the patient was transferred to the intensive care unit. After discussion with the family, support was withdrawn and the patient died.
infarction and 16% experienced congestive heart failure perioperatively. The authors concluded that regardless of the presence of obstruction, patients with asymmetric septal hypertrophy experienced frequent perioperative morbidity. Thompson et al retrospectively examined the perioperative courses of 35 patients with HOCM (diagnosed by presence of obstruction on cardiac catheterization or echocardiographic findings of mitral valve systolic anterior motion in conjunction with asymmetric septal hypertrophy who underwent NCS).9 Three patients (9%) died postoperatively, but none of the deaths was attributed to cardiac causes. Perioperatively, 14% experienced hypotension
requiring vasopressors, 14% experienced atrial arrhythmias, 9% experienced ventricular arrhythmias, 3% experienced myocardial infarction, and 3% experienced angina. Xuan et al published a series reporting on 24 patients with HCM (mean LVOT peak gradient, 30 ± 19 mmHg; 29% of patients had mitral valve systolic anterior motion who underwent NCS).11 Postoperatively, 1 patient (4%) experienced a myocardial infarction and died. One published study of HCM patients reported a mortality r ate of 0%10; however, only 39% of these patients had gradients ≥10 mmHg, in contrast to all patients in this study having gradients ≥30 mmHg. Consistent with the aforementioned
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Table 4. Statistical Analysis of Associations Between Hypertrophic Obstructive Cardiomyopathy Patients and Death Within 30 Days After Non-cardiac Surgery Variable
Survivors (n ¼ 93)
Nonsurvivors (n ¼ 3 )
p Value
Left ventricular ejection fraction (mean) Peak instantaneous systolic resting gradient (mean) Emergency surgery
71.5% 39.1 mmHg 6 patients (6.5%)
61.7% 37.3 mmHg 2 patients (66.7%)
0.2727 0.8828 0.0002
studies, myocardial infarction was noted in 2% of patients after NCS in this study. The authors noted worsening heart failure symptoms postoperatively after NCS for 3% of patients, compared with as high as 16% of patients in a prior study.10 The mortality (3%) observed in the series described here was lower than the 4% to 9% reported in the majority of other studies, which typically included patients with non-obstructive HCM.8,9,11 Review of the patients in this study who died revealed that mortality most likely was due to noncardiac factors. The observed mortality rate in this study was nearly equivalent to the 3.1% 30day mortality rate of a control group undergoing NCS reported in a recently published study from the authors’ institution.28 The analyses presented here did not identify any statistically significant associations between preoperative echocardiographic findings and mortality. Presence of outflow tract obstruction (defined as gradient ≥30 mmHg) is known to increase mortality in patients with HCM; however, the likelihood of death is not increased with progressive elevations greater than 30 mmHg.6 In addition, the statistically significant association in this study between emergency surgery and 30-day mortality may validate the study sample because emergency surgery is known to be a strong predictor of mortality across patient and surgery types.29,30 Although definitive cause of mortality was difficult to determine given the retrospective nature of this study, the 3 instances of death after NCS appeared most likely to be attributed to causes not directly related to HOCM. Finally, the statistically significant association between preoperative NYHA class III and IV compared with class I and II symptoms and the development of increasing heart failure symptoms after NCS was consistent with preoperative congestive heart failure being a known predictor of postoperative cardiac complications, including heart failure.28,31 Noncardiac anesthesiologists safely cared for the majority of patients in this series. The authors believe that more important than the formal training of the anesthesiologist is an in-depth understanding of the pathophysiology of HOCM in caring for these patients. The authors’ institution serves as a major referral center for HOCM patients, and there is a broad knowledge base for understanding this disease process throughout the institution. In addition, patients at the authors’ institution typically receive perioperative care from multidisciplinary teams, including cardiologists, anesthesiologists, and intensivists familiar with HOCM patients. As highlighted by the majority of patients requiring intraoperative vasoactive medication use, careful attention to and prompt treatment of hemodynamic alterations during NCS are necessary when caring for HOCM patients. Consistent with prior series reporting the use of invasive blood pressure monitoring in 8% to 29% of HOCM patients undergoing NCS, 25% of patients in this series underwent invasive blood pressure monitoring intraoperatively.9-11 For NCS with a high likelihood of substantial blood loss or hemodynamic alterations, invasive blood pressure
monitoring may be prudent, given the hemodynamic sensitivity of HOCM patients to changes in preload, afterload, and heart rate. Similarly, even in patients without preoperative evidence of HOCM or known cardiac disease, hemodynamic perturbations associated with fluid shifts, positive-pressure ventilation and induction, maintenance, and emergence from anesthesia may unmask latent HOCM physiology.7,25-27 A high degree of vigilance and index of suspicion are required to appropriately diagnose and treat this subset of HOCM patients to mitigate adverse sequelae. Finally, intraoperative transesophageal echocardiography can yield immediate information on the degree of outflow tract obstruction, secondary mitral regurgitation, ventricular filling and function, and the results of any intervention. This series included only one parturient with HOCM. Prior publications have reviewed management of these patients.32-34 Although the majority of HOCM patients tolerate pregnancy and childbirth without complication, overall maternal mortality is increased in parturients with HOCM compared with the general population, and higher peak instantaneous LVOT gradients appear to be associated with worse outcomes.33,34 Both general and neuraxial anesthesia have been used safely in HOCM patients undergoing cesarean section. In addition, vaginal and cesarean section deliveries both have been reported. Parturients with HOCM, especially in severe cases, may be managed best by multidisciplinary teams at high-risk obstetric centers with experience in managing these patients. Limitations of this study included all those inherent to a retrospective series. Charting inaccuracies may have been present, and reasons for management cannot always be found. By definition, the authors excluded patients with non-obstructive HCM. In addition, the authors defined “obstruction” as a resting or provoked peak instantaneous left ventricular systolic gradient of ≥30 mmHg as determined using continuous-wave Doppler echocardiography. Therefore, patients who may have had clinical signs of HOCM with lesser measured gradients were excluded. In addition, patients with undiagnosed HOCM at the time of NCS that was later diagnosed were not included. Finally, the hypothesis testing reported here did not adjust for potential confounders. The small number of deaths precluded the meaningful use of statistical methods for adjustment. Moreover, deaths were most likely due to noncardiac factors, so the use of a comparison group would be unlikely to clarify the role of HOCM as potentially causal for mortality or shed light on the main findings of the study.35 The p values reported, however, did account for clustered data and were thus conservative. CONCLUSIONS
In the current series, patients with HOCM underwent a variety of NCS with an observed mortality rate of 3%. Death after NCS was not significantly associated with preoperative echocardiographic findings but was associated with emergency
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surgery. The authors’ analysis suggested that mortality likely was due to noncardiac factors. Postoperative acutely worsening heart failure was significantly greater among patients with preoperative NYHA III and IV symptoms compared to those with lesser symptoms. Intraoperative vasoactive medications
were required in most patients. HOCM patients safely may undergo NCS at multidisciplinary centers with experience in caring for these patients, but clinicians should be aware of the potential for complications, especially among severely symptomatic patients.
REFERENCES 1. Wigle ED, Rakowski H, Kimball BP, et al: Hypertrophic cardiomyopathy. Clinical spectrum and treatment. Circulation 92:1680-1692, 1995 2. Nishimura RA, Holmes DR Jr: Clinical practice. Hypertrophic obstructive cardiomyopathy. N Engl J Med 350:1320-1327, 2004 3. Maron BJ: Hypertrophic cardiomyopathy: A systematic review. JAMA 287:1308-1320, 2002 4. Kunkala MR, Schaff HV, Nishimura RA, et al: Transapical approach to myectomy for midventricular obstruction in hypertrophic cardiomyopathy. Ann Thorac Surg 96:564-570, 2013 5. Ommen SR, Maron BJ, Olivotto I, et al: Long-term effects of surgical septal myectomy on survival in patients with obstructive hypertrophic cardiomyopathy. J Am Coll Cardiol 46:470-476, 2005 6. Maron MS, Olivotto I, Betocchi S, et al: Effect of left ventricular outflow tract obstruction on clinical outcome in hypertrophic cardiomyopathy. N Engl J Med 348:295-303, 2003 7. Schaff HV, Dearani JA, Ommen SR, et al: Expanding the indications for septal myectomy in patients with hypertrophic cardiomyopathy: Results of operation in patients with latent obstruction. J Thorac Cardiovasc Surg 143:303-309, 2012 8. Hreybe H, Zahid M, Sonel A, et al: Noncardiac surgery and the risk of death and other cardiovascular events in patients with hypertrophic cardiomyopathy. Clin Cardiol 29:65-68, 2006 9. Thompson RC, Liberthson RR, Lowenstein E: Perioperative anesthetic risk of noncardiac surgery in hypertrophic obstructive cardiomyopathy. JAMA 254:2419-2421, 1985 10. Haering JM, Comunale ME, Parker RA, et al: Cardiac risk of noncardiac surgery in patients with asymmetric septal hypertrophy. Anesthesiology 85:254-259, 1996 11. Xuan TM, Zeng Y, Zhu WL: Risk of patients with hypertrophic cardiomyopathy undergoing noncardiac surgery. Chin Med Sci J 22: 211-215, 2007 12. Mittnacht AJ, Fanshawe M, Konstadt S: Anesthetic considerations in the patient with valvular heart disease undergoing noncardiac surgery. Semin Cardiothorac Vasc Anesth 12:33-59, 2008 13. Gajewski M, Hillel Z: Anesthesia management of patients with hypertrophic obstructive cardiomyopathy. Prog Cardiovasc Dis 54: 503-511, 2012 14. Robertson A: Intraoperative management of liver transplantation in patients with hypertrophic cardiomyopathy: A review. Transplant Proc 42:1721-1723, 2010 15. Sahoo RK, Dash SK, Raut PS, et al: Perioperative anesthetic management of patients with hypertrophic cardiomyopathy for noncardiac surgery: A case series. Ann Card Anaesth 13:253-256, 2010 16. Holtby H, Skowno JJ, Kor DJ, et al: New technologies in pediatric anesthesia. Paediatr Anaesth 22:952-961, 2012 17. Nishimura RA, Otto CM, Bonow RO, et al: 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 129: e521-643, 2014 18. Gersh BJ, Maron BJ, Bonow RO, et al: 2011 ACCF/AHA Guideline for the Diagnosis and Treatment of Hypertrophic Cardiomyopathy: A report of the American College of Cardiology Foundation/ American Heart Association Task Force on Practice Guidelines. Developed in collaboration with the American Association for Thoracic Surgery, American Society of Echocardiography, American Society of
Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol 58:e212-260, 2011 19. Maron BJ, McKenna WJ, Danielson GK, et al: American College of Cardiology/European Society of Cardiology clinical expert consensus document on hypertrophic cardiomyopathy. A report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines. J Am Coll Cardiol 42: 1687-1713, 2003 20. Kang SH, Chung SJ, Ahn CW: Exact tests for one sample correlated binary data. Biom J 47:188-193, 2005 21. Spiegelman D, Hertzmark E: Easy SAS calculations for risk or prevalence ratios and differences. Am J Epidemiol 162:199-200, 2005 22. Cywinski JB, Argalious M, Marks TN, et al: Dynamic left ventricular outflow tract obstruction in an orthotopic liver transplant recipient. Liver Transpl 11:692-695, 2005 23. Popescu WM, Perrino AC Jr: Critical cardiac decompensation during laparoscopic surgery. J Am Soc Echocardiogr 19(1074): e1075-1076, 2006 24. Kojima T, Imai Y, Tsushima K, et al: Temporary dual-chamber pacing can stabilize hemodynamics during noncardiac surgery in a patient with left ventricular hypertrophy and outflow obstruction. J Cardiothorac Vasc Anesth 28:124-127, 2014 25. Angelotti T, Fuller A, Rivera L, et al: Anesthesia for older patients with hypertrophic cardiomyopathy: Is there cause for concern? J Clin Anesth 17:478-481, 2005 26. Lanier W, Prough DS: Intraoperative diagnosis of hypertrophic obstructive cardiomyopathy. Anesthesiology 60:61-63, 1984 27. Fayad A: Left ventricular outflow obstruction in a patient with undiagnosed hypertrophic obstructive cardiomyopathy. Can J Anaesth 54:1019-1020, 2007 28. Tashiro T, Pislaru SV, Blustin JM, et al: Perioperative risk of major non-cardiac surgery in patients with severe aortic stenosis: A reappraisal in contemporary practice. Eur Heart J 35:2372-2381, 2014 29. Mangano DT: Perioperative cardiac morbidity. Anesthesiology 72:153-184, 1990 30. Fleisher LA, Beckman JA, Brown KA, et al: 2009 ACCF/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: A report of the American college of cardiology foundation/American heart association task force on practice guidelines. Circulation 120:e169-276, 2009 31. Lee TH, Marcantonio ER, Mangione CM, et al: Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 100:1043-1049, 1999 32. Stergiopoulos K, Shiang E, Bench T: Pregnancy in patients with pre-existing cardiomyopathies. J Am Coll Cardiol 58:337-350, 2011 33. Autore C, Conte MR, Piccininno M, et al: Risk associated with pregnancy in hypertrophic cardiomyopathy. J Am Coll Cardiol 40: 1864-1869, 2002 34. Thaman R, Varnava A, Hamid MS, et al: Pregnancy related complications in women with hypertrophic cardiomyopathy. Heart 89: 752-756, 2003 35. Greenland S, Morgenstern H: Confounding in health research. Annu Rev Public Health 22:189-212, 2001