- Email: [email protected]
Short- and Long-Term Outcomes of Patients With Hypertrophic Cardiomyopathy After Noncardiac Surgery: A Single-Center Retrospective Study
Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
Contents lists available at ScienceDirect
Journal of Cardiothoracic and Vascular Anesthesia journal homepage: www.jcvaonline.com
Original Article
Short- and Long-Term Outcomes of Patients With Hypertrophic Cardiomyopathy After Noncardiac Surgery: A Single-Center Retrospective Study Tomoaki Yatabe, MD, PhDn,1, Toru Kubo, MD, PhD†, Hiroaki Kitaoka, MD, PhD†, Masataka Yokoyama, MD, PhD* n
Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School, Kochi, Japan † Department of Cardiology and Geriatrics, Kochi Medical School, Kochi, Japan
Objective: Although several studies have demonstrated that noncardiac surgery in patients with hypertrophic cardiomyopathy (HCM) is safe, the long-term outcomes remain unclear. Therefore, the authors investigated the postoperative long-term outcomes of patients with HCM who underwent noncardiac surgery at their hospital. Design: Retrospective review. Setting: Single university hospital. Participants: Seventy-two consecutive patients with HCM who underwent noncardiac surgery. Intervention: No intervention. Measurements and Main Results: The incidence of HCM-related events during the patient’s hospital stay were evaluated as the short-term outcomes, and HCM-related events after discharge were evaluated as the long-term outcomes. HCM-related events were defined as sudden death, implantable cardioverter-defibrillator discharge with successful recovery from cardiopulmonary arrest, death due to heart failure, hospitalization for heart failure, myocardial infarction, and thrombosis caused by atrial fibrillation. The median postoperative follow-up was 1,382 days (3.8 years). Short-term mortality and morbidity rates were both 1.3%, whereas long-term mortality and morbidity rates were 4.2% and 15%, respectively. The 5-year event-free rate was 76%, whereas the postoperative HCM-related mortality rate was 4.2%. Conclusions: This study suggests that noncardiac surgery in patients with HCM is safe in terms of both short- and long-term outcomes. To confirm the findings, additional studies, such as prospective, multicenter, observational studies, should be conducted. & 2018 Elsevier Inc. All rights reserved.
Key Words: hypertrophic cardiomyopathy; noncardiac surgery; long-term outcome
HYPERTROPHIC CARDIOMYOPATHY (HCM) is defined as increased left ventricular wall thickness that is not explained solely by abnormal loading conditions.1 HCM causes several symptoms, such as palpitations, heart failure, stroke, and sudden cardiac death.2–4 In addition, approximately 20% of patients with HCM have systolic left 1 Address reprint requests to Tomoaki Yatabe, MD, PhD, Kochi Medical School, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan. E-mail address: [email protected] (T. Yatabe).
ventricular outflow tract (LVOT) obstruction, referred to as hypertrophic obstructive cardiomyopathy (HOCM), which is independently associated with adverse HCM-related outcomes.5,6 Previous reviews have recommended that anesthesiologists should be aware of the potential life-threatening nature of HCM and provide optimal treatments during the perioperative period.4 Thus, recently the influence of noncardiac surgery in patients with HCM has attracted attention. A previous study in the United States revealed that the inhospital mortality rate of patients with HCM who underwent
https://doi.org/10.1053/j.jvca.2018.03.004 1053-0770/& 2018 Elsevier Inc. All rights reserved.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
2
noncardiac surgery was significantly higher than that of patients without HCM (6.7% v 2.5%; p o 0.001).3 Two recent retrospective studies in the United States suggested that noncardiac surgery might be safe because the 30-day mortality rates of patients with HCM and HOCM who underwent noncardiac surgery were 4% and 3%, respectively.2,5 However, patients with HCM are considered to have a higher risk of composite events compared with those without HCM. In fact, the incidence of postoperative complications, such as congestive heart failure, has been reported to be significantly higher in patients with HCM.5 However, the long-term outcomes of patients with HCM who undergo noncardiac surgery remain unclear because previous studies did not conduct a long-term follow-up. Therefore, the authors of the present study conducted a single-center, retrospective study to investigate the postoperative long-term outcomes of patients with HCM who undergo noncardiac surgery. Methods Study Design This study was approved by the Ethics Committee of Kochi Medical School (No. 28-69). The requirement for informed consent was waived because of the retrospective nature of the study. Study participants were consecutive patients with HCM who underwent noncardiac surgery for HCM from January 2007 through September 2015. Of these, those age o 18 years and those who refused the use of their records at hospitalization were excluded from the study. The electronic medical record database of the authors’ hospital was searched for the terms “hypertrophic cardiomyopathy” or “hypertrophic obstructive cardiomyopathy” to identify potential patients for analysis (first screening). Two authors (TY and TK) independently reviewed these potential patients to confirm the diagnosis of HCM or HOCM and the surgical procedures performed (second screening). Diagnosis of HCM and HOCM The diagnosis of HCM was based on the echocardiographic demonstration of a hypertrophied, nondilated left ventricle (maximum left ventricular wall thickness Z 15 mm) in the absence of systemic hypertension or other cardiac disease (eg, aortic stenosis) capable of producing clinically evident hypertrophy at some point in the clinical course.7 HOCM was defined as the presence of basal left ventricular outflow gradient Z 30 mmHg at rest.7 Echocardiographic reports and the clinical course were available through electrical medical records to confirm the diagnosis. Subsequently, patients with a previously incorrect diagnosis of HCM (second screening) were excluded from the final analysis. Data Collection Age, height, body weight, presence of LVOT obstruction, and preoperative and postoperative HCM-related events were
collected from patients’ medical records. In addition, intraoperative data, including anesthetic method, use of vasopressor agents, and intraoperative fluid balance, were collected from anesthesia records. Definition of HCM-Related Events HCM-related events were defined as sudden death, implantable cardioverter-defibrillator (ICD) discharge with successful recovery from cardiopulmonary arrest, death due to heart failure, hospitalization for heart failure, myocardial infarction, and thrombosis caused by atrial fibrillation in reference to the previous studies.2,3,5,8,9 Two authors (TY and TK) independently reviewed the HCM-related events from patients’ medical records, including reference letters from primary physicians and the Kochi prefecture cancer registry database. Even if the patients visited other hospitals or clinics, the authors were aware of the HCM-related events because physicians in those hospitals and clinics sent reference letters to the authors’ hospital or input data in the cancer registry database. The follow-up time was defined as the duration between the surgical day and March 31, 2016. Preoperative HCM-related events were defined as HCM-related events occurring between the diagnosis of HCM or initiation of follow-up at the authors’ hospital and the day before surgery. Evaluation of Short- and Long-Term Outcomes The mortality rate and incidence of HCM-related events during the hospital stay were evaluated as the short-term outcomes. The mortality rate and incidence of HCM-related events between the surgical day and March 31, 2016, were evaluated as the long-term outcomes. Data Analysis Data are expressed as mean 7 standard deviation or median. Each of the parameters was assessed using the Mann-Whitney U or chi-square test. A p value o 0.05 was considered to be statistically significant. Event-free curves were constructed using the Kaplan-Meier method. Statistical analysis was performed using JMP 9.00 (SAS Institute Japan, Tokyo, Japan). Results A total of 124 patients were identified through the first screening of medical records. Of these, 72 were included and 52 were excluded after the second screening. Patient Characteristics and Intraoperative Data Table 1 shows the patient characteristics. The mean patient age was 67 7 11 years, and 35% were female. The proportion of patients with HOCM was 19%, and 17% of patients experienced preoperative HCM-related events, including ICD discharge and heart failure admission in 1 patient, heart failure admission in 8 patients, and embolic events in 3 patients.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
3
Table 1 Patient Background
Female, n (%) Age (y) Height (cm) Weight (kg) Preoperative HCM-related events, n (%) General anesthesia, n (%) TIVA, n (%) Surgical procedure Abdominal surgery, n (%) Craniotomy and neck, n (%) Limb surgery, n (%) Duration of anesthesia (min) Duration of surgery (min) Use of invasive blood pressure monitor, n (%) Use of epidural catheter, n (%) Intraoperative minimum systolic blood pressure (mmHg) Intraoperative minimum mean blood pressure (mmHg) Use of phenylephrine, n (%) Use of ephedrine, n (%) Use of remifentanil, n (%) Use of noradrenaline, n (%) Use of dopamine, n (%) Use of patient-controlled analgesia, n (%) Intraoperative fluid balance (mL) Postoperative ICU admission, n (%)
Overall (n ¼ 72)
Non-HOCM (n ¼ 58)
HOCM (n ¼ 14)
p Value
25 (35) 67 7 11 160 7 9 62 7 11 12 (17) 48 (67) 12 (25)
17 (29) 69 7 9 161 7 8 63 7 11 11 (18) 41 (71) 8 (14)
8 (57) 62 7 16 155 7 8 57 7 12 1 (7) 7 (50) 4 (29)
0.05 0.03* 0.01* 0.11 0.29 0.14 0.18 0.09
16 (22) 13 (18) 12 (17) 216 7 133 155 7 109 35 (48) 14 (19) 92 7 26 65 7 18 14 (19) 26 (36) 29 (40) 2 (3) 3 (4) 25 (35) 1,145 7 1,037 10 (14)
15 (26) 12 (21) 8 (14) 234 7 134 168 7 110 30 (52) 11 (19) 92 7 25 65 7 18 9 (16) 24 (41) 25 (43) 1 (2) 3 (5) 21 (36) 1,203 7 1,082 8 (14)
1 (7) 1 (7) 4 (29) 144 7 104 101 7 90 5 (36) 3 (21) 92 7 31 62 7 21 5 (36) 2 (14) 4 (29) 1 (7) 0 (0) 4 (29) 901 7 808 2 (14)
0.02* 0.04* 0.28 0.83 0.92 0.64 0.09 0.06 0.32 0.27 0.38 0.59 0.33 0.96
Abbreviations: HCM, hypertrophic cardiomyopathy; HOCM, hypertrophic obstructive cardiomyopathy; ICU, intensive care unit; TIVA, total intravenous anesthesia. n p o 0.05
General anesthesia was administered in 67% of the patients. Of these, 75% received the inhalation agent sevoflurane. Abdominal surgery (22%) was the most common procedure, followed by craniotomy (18%). An intra-arterial catheter for invasive blood pressure monitoring was inserted in 48% of the patients. Intraoperative minimum systolic and mean blood pressures were 92 7 26 mmHg and 65 7 18 mmHg, respectively. The duration of anesthesia and intraoperative fluid balance was 216 7 133 minutes and 1,145 7 1,037 mL, respectively. After surgery, 14% of the patients were admitted to the intensive care unit. Short-Term Outcomes Two patients (2.8%) experienced intraoperative and postoperative HCM-related events (Table 2). One male patient with HOCM died during the hospital stay due to infection and heart failure. Therefore, the in-hospital mortality rate was 1.4%. A female patient with HOCM experienced intraoperative heart failure and postoperative HCM-related events after discharge. The details regarding these 2 patients are described later in the article (cases 1 and 6). Long-Term Outcomes The median length of hospital stay and duration of postoperative follow-up were 15 and 1,382 days (3.8 years),
respectively (see Table 2). Postoperative HCM-related events occurred in 11 patients (15%). Of these, 3 died suddenly (cases 2, 4, and 8). The 5-year event-free rate was 76%. The postoperative event-free rate in all patients is shown in Figure 1.
Details of Severe HCM-Related Events Case 1: Postoperative Death (Postoperative Day 71) The patient was a 72-year-old man with HOCM. He underwent transhiatal esophagectomy under general anesthesia. The duration of surgery was 340 minutes, and total blood loss was 360 mL. Although he was transferred to a general ward from the intensive care unit on postoperative (POD) 2, severe hypoxia developed due to aspiration pneumonitis on POD 3. Thereafter, he was readmitted to the intensive care unit. On POD 11, heart failure occurred after paroxysmal atrial fibrillation. The patient died on POD 71 due to catheter-related bloodstream infection, pneumonia, and heart failure.
Case 2: Sudden Death (POD 596) The patient was a 58-year-old woman with HCM. On POD 197, she was admitted to the hospital emergently due to heart failure. She was discharged 2 weeks later after treatment with diuretics. Thereafter, her condition was stable. However, she died suddenly on POD 596 while taking a bath.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
4 Table 2 Outcome Data
Median postoperative follow-up (d) In-hospital mortality, n (%) Median hospital stay (d) Perioperative HCM-related events, n (%) Intraoperative events, n (%) Heart failure, n (%) Postoperative events during hospital stay, n (%) Heart failure, n (%) Postoperative HCM-related events after discharge, n (%) Sudden death, n (%) ICD shock, n (%) Successful CPR, n (%) Unexpected HCM-related hospitalization, n (%)
Overall (n ¼ 72)
Non-HOCM (n ¼ 58)
HOCM (n ¼ 14)
p Value
1,382 1 (1) 15 2 (3) 1 (1) 1 (1) 1 (1) 1 (1) 11 (15)† 3 (4) 3 (4) 1 (1) 6 (8)‡
1,279 0 (0) 15 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 8 (14) 3 (5) 2 (3) 0 (0) 5 (9)
1,709 1 (7) 13 2 (14) 1 (7) 1 (7) 1 (7) 1 (7) 3 (23) 0 (0) 1 (8) 1 (8) 1 (8)
0.10 0.04* 0.88 0.004*
0.18
Abbreviations: CPR, cardiopulmonary resuscitation; HCM, hypertrophic cardiomyopathy; HOCM, hypertrophic obstructive cardiomyopathy; ICD, implantable cardioverter-defibrillator. n p o 0.05 † Total number of patients was 71 because 1 patient died during hospital stay. ‡ Before sudden death and implantable cardioverter-defibrillator shock, 2 patients were admitted to the hospital because of heart failure.
Case 3: ICD Shock (POD 311) The patient was a 58-year-old woman with HCM (dilated phase) and ICD implantation. On POD 291, she was admitted to the hospital emergently due to heart failure. She was discharged 10 days later after treatment with diuretics. On POD 311, she suddenly lost consciousness. ICD shock was delivered immediately, and her condition became stable. Case 4: Sudden Death (POD 1,755) The patient was a 70-year-old woman with HCM. Although she was admitted to the hospital several times for examination and treatment of angina after total hip arthroplasty, her condition was stable. She died suddenly on POD 1,755. Case 5: Successful Cardiopulmonary Resuscitation (POD 454) The patient was a 49-year-old woman with HOCM. Although her condition was stable, she suddenly lost consciousness after taking a bath on POD 454. Her son performed cardiopulmonary resuscitation, after which she was admitted to the hospital. She recovered without any complications after
several treatments, including percutaneous cardiopulmonary support. Case 6: Intraoperative Heart Failure and ICD Shock (POD 324) The patient was a 26-year-old woman with HOCM. She underwent elective cesarean section with epidural anesthesia at 38 weeks of gestation. After administration of oxytocin for uterine contraction, heart failure and pulmonary edema occurred. She was admitted to the intensive care unit and received diuretic agents and a nasal high-flow device. She was discharged 12 days later. On POD 271, she received an ICD for primary prevention of sudden death. On POD 324, she suddenly lost consciousness while walking. ICD shock was delivered immediately after loss of consciousness. Case 7: ICD Shock (POD 1,615) The patient was a 49-year-old man with HCM. Although his condition was stable after total thyroidectomy, he received an ICD for primary prevention of sudden death because he felt faint while jogging on POD 1,615. After ICD implantation, the ICD discharged 4 times. Case 8: Sudden Death (POD 1,257) The patient was a 58-year-old man with HCM (dilated phase). He underwent tympanoplasty under general anesthesia. Although his physician recommended ICD implantation due to high risk of sudden death, he declined. He died suddenly on POD 1,257. Discussion
Fig 1. Postoperative event-free rate in all patients.
The authors conducted a retrospective analysis to clarify the short- and long-term outcomes of patients with HCM who undergo noncardiac surgery. The study revealed that the
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
short-term outcomes, namely in-hospital mortality rate and HCM-related nonfatal morbidity rate, were both only 1.4%. On the other hand, the 5-year event-free rate, considered as a long-term outcome, was 76%, and the postoperative HCMrelated mortality rate was 4.2%.
Short-Term Mortality Several reviews have reported that patients with HCM undergoing noncardiac surgery commonly experience adverse perioperative outcomes, such as myocardial ischemia and congestive heart failure.4,6 A recent study also reported that patients with HCM have a 4.23-fold higher risk of 30-day composite events compared with patients without HCM.5 Another recent review reported that up to 40% to 60% of patients with HCM experience perioperative cardiac events, such as myocardial infarction and congestive heart failure.8,10 On the other hand, very low rates of mortality, myocardial infarction, and stroke have been reported in patients both with and without HCM.5 Furthermore, another study concluded that patients with HOCM can safely undergo noncardiac surgery because the mortality rate was 3% and the causes of mortality did not appear to be cardiac in nature.2 The present study demonstrated that the rates of in-hospital mortality and perioperative HCM-related events were 1% and 3%, respectively. These were relatively low compared with those reported in the previous studies (Table 3). Although study design, period, and sex seemed not to affect this difference, the proportion of HOCM was associated with it. The proportion of HOCM of the present study was lower compared with other previous studies (19% v 39%-100%). In the present study, the 2 patients who experienced intraoperative and postoperative events (cases 1 and 6) had LVOT obstruction. Thus, the rates of mortality and incidence of heart failure in HOCM were both
5
7%. These values are similar to those in the other HOCM studies.2 Therefore, patients with HOCM should be monitored carefully during the perioperative period. Previous studies and a review suggested that the duration of intraoperative systolic blood pressure o90 mmHg might be associated with short-term adverse events.2,4,5 In the present study, intraoperative minimum systolic and mean blood pressures were 92 mmHg and 65 mmHg, respectively. Therefore, the authors consider that noncardiac surgery in patients with HCM might be safe if anesthesiologists pay attention to the hemodynamic status with or without invasive blood pressure monitoring.
Postoperative Events After Discharge Although a long-term follow-up study was performed in a general HCM population,9 there has been no study of patients who underwent noncardiac surgery. The data in the present study show that postoperative HCM-related events occurred in 15% of patients after discharge and that the 5-year event-free rate was 76%. Furthermore, the postoperative mortality rate was 4.2%. Eleven percent of patients experienced sudden death or near sudden death, and ICD shock was delivered and successful cardiopulmonary resuscitation was performed in survivors. The 5-year event-free rate could not compared with other studies because there were few reports on the incidence of HCM-related events according to the definition in the present study. However, a previous review reported that ventricular fibrillation and rapid ventricular tachycardia occurred in 20% of high-risk patients with HCM over a mean follow-up of approximately 4 years.11 Because the incidence of HCM-related events in 4 to 5 years was similar, the authors consider that the patients in the present study should be deemed low risk. For this reason, the authors believe that
Table 3 Summary of Previous and Present Studies
Design Follow-up period Number Age (y) Female (%) HOCM (%) General anesthesia (%) Duration of surgery (min) Perioperative complication Death (%) Heart failure (%) Myocardial infarction (%) Fatal arrhythmia (%)
Haering (1996)8
Hreybe (2006)3
Barbara (2016)2
Dhillon (2016)5
Present Study
Retrospective Perioperative period 77
Retrospective Discharge* 227
Retrospective 30 d 57
Observational cohort† 30 d 92
Retrospective 3.8 y‡ 72
71 7 13 57 39§ 81 151 7 102
68 7 19 62 NA NA NA
62 7 16 9 100 98 195 7 103
67 46 58 89 243
67 7 11 35 19 67 155 7 109
0 16 1 1
6.7 NA 2.2 NA
3 7 4 NA
4 18 1 NA
1¶ 1¶ 0 0
Abbreviations: HOCM, hypertrophic obstructive cardiomyopathy; NA, not available. n Prospectively entered records and extracted by manual review. † Hospital discharge ‡ Median follow-up duration. § Outflow gradient Z10 mmHg. ¶ 7% of HOCM patients. Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
6
noncardiac surgery might be safe because the in-hospital mortality rate was only 1% in the present study. A study of a general HCM population reported that the 10year survival rate, free of death and severe symptoms, for patients with LVOT velocity at rest 4 4 m/s was significantly lower than that of patients with peak LVOT velocity o 4 m/s.9 In the present study, although the short-term HCM-related event rate was significantly higher in patients with HOCM, the long-term event rates were similar in patients with and without HOCM. Additional observational studies of noncardiac surgery comparing patients with and without HOCM are necessary.
was 3.8 years. On the contrary, that of the other larger series of general HCM patients was 9.3 years, and LVOT velocity was associated with an undesirable outcome.9 Therefore, the authors cannot deny that the duration of follow-up affected the data. In this regard, future prospective, multicenter, observational studies or the establishment of a registry system are necessary to confirm the present study’s results. In conclusion, this study suggests that noncardiac surgery in patients with HCM is safe in terms of both short- and longterm outcomes. To confirm the findings, additional studies, such as prospective, multicenter, observational studies, should be conducted.
Limitations
References
This study has several limitations. First, the number of patients was small. Thus, some of the statistical analyses, such as comparison between patients with HCM and HOCM, might have been affected. HCM patients who underwent noncardiac surgery were not so prevalent. In fact, the number of patients in almost all the previous studies and present study was less than 100 (see Table 3). The authors could not conclude whether surgical procedures and anesthesia influenced mortality and morbidity. Second, the present study was retrospective in design. Although the medical records, reference letters from primary physicians, and cancer registry database were checked carefully to evaluate the long-term outcomes, 3 patients were lost to follow-up. These data might have affected the results. Third, all clinical records were surveyed until a single date. Therefore, the follow-up period of each patient was different. Although this could influence the incidence rates, the followup period was more than 6 months in 93% of patients. Fourth, the morbidity rate may have been underestimated. However, 2 independent authors carefully reviewed the patient records in this study. In addition, in general, patients visited the hospital when severe HCM-related events occurred. Therefore, the authors believe that the data are similar to “true” values. Fifth, individual anesthesiologists decided on anesthetic management, such as the use of invasive blood pressure monitoring and choice of vasopressor agents, because the authors’ hospital does not have a standard anesthetic protocol for patients with HCM. Finally, the median follow-up duration of this study
1 Authors/Task Force members, Elliott PM, Anastasakis A, Borger MA, et al. 2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy: The Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC). Eur Heart J 2014;35:2733–79. 2 Barbara DW, Hyder JA, Behrend TL, et al. Safety of noncardiac surgery in patients with hypertrophic obstructive cardiomyopathy at a tertiary care center. J Cardiothorac Vasc Anesth 2016;30:659–64. 3 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 2006;29:65–8. 4 Poliac LC, Barron ME, Maron BJ. Hypertrophic cardiomyopathy. Anesthesiology 2006;104:183–92. 5 Dhillon A, Khanna A, Randhawa MS, et al. Perioperative outcomes of patients with hypertrophic cardiomyopathy undergoing non-cardiac surgery. Heart 2016;102:1627–32. 6 Vives M, Roscoe A. Hypertrophic cardiomyopathy: Implications for anesthesia. Minerva Anestesiol 2014;80:1310–9. 7 Kubo T, Baba Y, Hirota T, et al. Differentiation of infiltrative cardiomyopathy from hypertrophic cardiomyopathy using high-sensitivity cardiac troponin T: A case-control study. BMC Cardiovasc Disord 2015;15:53. 8 Haering JM, Comunale ME, Parker RA, et al. Cardiac risk of noncardiac surgery in patients with asymmetric septal hypertrophy. Anesthesiology 1996;85:254–9. 9 Sorajja P, Nishimura RA, Gersh BJ, et al. Outcome of mildly symptomatic or asymptomatic obstructive hypertrophic cardiomyopathy: A long-term follow-up study. J Am Coll Cardiol 2009;54:234–41. 10 Hensley N, Dietrich J, Nyhan D, et al. Hypertrophic cardiomyopathy: A review. Anesth Analg 2015;120:554–69. 11 Maron BJ. Risk stratification and role of implantable defibrillators for prevention of sudden death in patients with hypertrophic cardiomyopathy. Circ J 2010;74:2271–82.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
Contents lists available at ScienceDirect
Journal of Cardiothoracic and Vascular Anesthesia journal homepage: www.jcvaonline.com
Original Article
Short- and Long-Term Outcomes of Patients With Hypertrophic Cardiomyopathy After Noncardiac Surgery: A Single-Center Retrospective Study Tomoaki Yatabe, MD, PhDn,1, Toru Kubo, MD, PhD†, Hiroaki Kitaoka, MD, PhD†, Masataka Yokoyama, MD, PhD* n
Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School, Kochi, Japan † Department of Cardiology and Geriatrics, Kochi Medical School, Kochi, Japan
Objective: Although several studies have demonstrated that noncardiac surgery in patients with hypertrophic cardiomyopathy (HCM) is safe, the long-term outcomes remain unclear. Therefore, the authors investigated the postoperative long-term outcomes of patients with HCM who underwent noncardiac surgery at their hospital. Design: Retrospective review. Setting: Single university hospital. Participants: Seventy-two consecutive patients with HCM who underwent noncardiac surgery. Intervention: No intervention. Measurements and Main Results: The incidence of HCM-related events during the patient’s hospital stay were evaluated as the short-term outcomes, and HCM-related events after discharge were evaluated as the long-term outcomes. HCM-related events were defined as sudden death, implantable cardioverter-defibrillator discharge with successful recovery from cardiopulmonary arrest, death due to heart failure, hospitalization for heart failure, myocardial infarction, and thrombosis caused by atrial fibrillation. The median postoperative follow-up was 1,382 days (3.8 years). Short-term mortality and morbidity rates were both 1.3%, whereas long-term mortality and morbidity rates were 4.2% and 15%, respectively. The 5-year event-free rate was 76%, whereas the postoperative HCM-related mortality rate was 4.2%. Conclusions: This study suggests that noncardiac surgery in patients with HCM is safe in terms of both short- and long-term outcomes. To confirm the findings, additional studies, such as prospective, multicenter, observational studies, should be conducted. & 2018 Elsevier Inc. All rights reserved.
Key Words: hypertrophic cardiomyopathy; noncardiac surgery; long-term outcome
HYPERTROPHIC CARDIOMYOPATHY (HCM) is defined as increased left ventricular wall thickness that is not explained solely by abnormal loading conditions.1 HCM causes several symptoms, such as palpitations, heart failure, stroke, and sudden cardiac death.2–4 In addition, approximately 20% of patients with HCM have systolic left 1 Address reprint requests to Tomoaki Yatabe, MD, PhD, Kochi Medical School, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan. E-mail address: [email protected] (T. Yatabe).
ventricular outflow tract (LVOT) obstruction, referred to as hypertrophic obstructive cardiomyopathy (HOCM), which is independently associated with adverse HCM-related outcomes.5,6 Previous reviews have recommended that anesthesiologists should be aware of the potential life-threatening nature of HCM and provide optimal treatments during the perioperative period.4 Thus, recently the influence of noncardiac surgery in patients with HCM has attracted attention. A previous study in the United States revealed that the inhospital mortality rate of patients with HCM who underwent
https://doi.org/10.1053/j.jvca.2018.03.004 1053-0770/& 2018 Elsevier Inc. All rights reserved.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
2
noncardiac surgery was significantly higher than that of patients without HCM (6.7% v 2.5%; p o 0.001).3 Two recent retrospective studies in the United States suggested that noncardiac surgery might be safe because the 30-day mortality rates of patients with HCM and HOCM who underwent noncardiac surgery were 4% and 3%, respectively.2,5 However, patients with HCM are considered to have a higher risk of composite events compared with those without HCM. In fact, the incidence of postoperative complications, such as congestive heart failure, has been reported to be significantly higher in patients with HCM.5 However, the long-term outcomes of patients with HCM who undergo noncardiac surgery remain unclear because previous studies did not conduct a long-term follow-up. Therefore, the authors of the present study conducted a single-center, retrospective study to investigate the postoperative long-term outcomes of patients with HCM who undergo noncardiac surgery. Methods Study Design This study was approved by the Ethics Committee of Kochi Medical School (No. 28-69). The requirement for informed consent was waived because of the retrospective nature of the study. Study participants were consecutive patients with HCM who underwent noncardiac surgery for HCM from January 2007 through September 2015. Of these, those age o 18 years and those who refused the use of their records at hospitalization were excluded from the study. The electronic medical record database of the authors’ hospital was searched for the terms “hypertrophic cardiomyopathy” or “hypertrophic obstructive cardiomyopathy” to identify potential patients for analysis (first screening). Two authors (TY and TK) independently reviewed these potential patients to confirm the diagnosis of HCM or HOCM and the surgical procedures performed (second screening). Diagnosis of HCM and HOCM The diagnosis of HCM was based on the echocardiographic demonstration of a hypertrophied, nondilated left ventricle (maximum left ventricular wall thickness Z 15 mm) in the absence of systemic hypertension or other cardiac disease (eg, aortic stenosis) capable of producing clinically evident hypertrophy at some point in the clinical course.7 HOCM was defined as the presence of basal left ventricular outflow gradient Z 30 mmHg at rest.7 Echocardiographic reports and the clinical course were available through electrical medical records to confirm the diagnosis. Subsequently, patients with a previously incorrect diagnosis of HCM (second screening) were excluded from the final analysis. Data Collection Age, height, body weight, presence of LVOT obstruction, and preoperative and postoperative HCM-related events were
collected from patients’ medical records. In addition, intraoperative data, including anesthetic method, use of vasopressor agents, and intraoperative fluid balance, were collected from anesthesia records. Definition of HCM-Related Events HCM-related events were defined as sudden death, implantable cardioverter-defibrillator (ICD) discharge with successful recovery from cardiopulmonary arrest, death due to heart failure, hospitalization for heart failure, myocardial infarction, and thrombosis caused by atrial fibrillation in reference to the previous studies.2,3,5,8,9 Two authors (TY and TK) independently reviewed the HCM-related events from patients’ medical records, including reference letters from primary physicians and the Kochi prefecture cancer registry database. Even if the patients visited other hospitals or clinics, the authors were aware of the HCM-related events because physicians in those hospitals and clinics sent reference letters to the authors’ hospital or input data in the cancer registry database. The follow-up time was defined as the duration between the surgical day and March 31, 2016. Preoperative HCM-related events were defined as HCM-related events occurring between the diagnosis of HCM or initiation of follow-up at the authors’ hospital and the day before surgery. Evaluation of Short- and Long-Term Outcomes The mortality rate and incidence of HCM-related events during the hospital stay were evaluated as the short-term outcomes. The mortality rate and incidence of HCM-related events between the surgical day and March 31, 2016, were evaluated as the long-term outcomes. Data Analysis Data are expressed as mean 7 standard deviation or median. Each of the parameters was assessed using the Mann-Whitney U or chi-square test. A p value o 0.05 was considered to be statistically significant. Event-free curves were constructed using the Kaplan-Meier method. Statistical analysis was performed using JMP 9.00 (SAS Institute Japan, Tokyo, Japan). Results A total of 124 patients were identified through the first screening of medical records. Of these, 72 were included and 52 were excluded after the second screening. Patient Characteristics and Intraoperative Data Table 1 shows the patient characteristics. The mean patient age was 67 7 11 years, and 35% were female. The proportion of patients with HOCM was 19%, and 17% of patients experienced preoperative HCM-related events, including ICD discharge and heart failure admission in 1 patient, heart failure admission in 8 patients, and embolic events in 3 patients.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
3
Table 1 Patient Background
Female, n (%) Age (y) Height (cm) Weight (kg) Preoperative HCM-related events, n (%) General anesthesia, n (%) TIVA, n (%) Surgical procedure Abdominal surgery, n (%) Craniotomy and neck, n (%) Limb surgery, n (%) Duration of anesthesia (min) Duration of surgery (min) Use of invasive blood pressure monitor, n (%) Use of epidural catheter, n (%) Intraoperative minimum systolic blood pressure (mmHg) Intraoperative minimum mean blood pressure (mmHg) Use of phenylephrine, n (%) Use of ephedrine, n (%) Use of remifentanil, n (%) Use of noradrenaline, n (%) Use of dopamine, n (%) Use of patient-controlled analgesia, n (%) Intraoperative fluid balance (mL) Postoperative ICU admission, n (%)
Overall (n ¼ 72)
Non-HOCM (n ¼ 58)
HOCM (n ¼ 14)
p Value
25 (35) 67 7 11 160 7 9 62 7 11 12 (17) 48 (67) 12 (25)
17 (29) 69 7 9 161 7 8 63 7 11 11 (18) 41 (71) 8 (14)
8 (57) 62 7 16 155 7 8 57 7 12 1 (7) 7 (50) 4 (29)
0.05 0.03* 0.01* 0.11 0.29 0.14 0.18 0.09
16 (22) 13 (18) 12 (17) 216 7 133 155 7 109 35 (48) 14 (19) 92 7 26 65 7 18 14 (19) 26 (36) 29 (40) 2 (3) 3 (4) 25 (35) 1,145 7 1,037 10 (14)
15 (26) 12 (21) 8 (14) 234 7 134 168 7 110 30 (52) 11 (19) 92 7 25 65 7 18 9 (16) 24 (41) 25 (43) 1 (2) 3 (5) 21 (36) 1,203 7 1,082 8 (14)
1 (7) 1 (7) 4 (29) 144 7 104 101 7 90 5 (36) 3 (21) 92 7 31 62 7 21 5 (36) 2 (14) 4 (29) 1 (7) 0 (0) 4 (29) 901 7 808 2 (14)
0.02* 0.04* 0.28 0.83 0.92 0.64 0.09 0.06 0.32 0.27 0.38 0.59 0.33 0.96
Abbreviations: HCM, hypertrophic cardiomyopathy; HOCM, hypertrophic obstructive cardiomyopathy; ICU, intensive care unit; TIVA, total intravenous anesthesia. n p o 0.05
General anesthesia was administered in 67% of the patients. Of these, 75% received the inhalation agent sevoflurane. Abdominal surgery (22%) was the most common procedure, followed by craniotomy (18%). An intra-arterial catheter for invasive blood pressure monitoring was inserted in 48% of the patients. Intraoperative minimum systolic and mean blood pressures were 92 7 26 mmHg and 65 7 18 mmHg, respectively. The duration of anesthesia and intraoperative fluid balance was 216 7 133 minutes and 1,145 7 1,037 mL, respectively. After surgery, 14% of the patients were admitted to the intensive care unit. Short-Term Outcomes Two patients (2.8%) experienced intraoperative and postoperative HCM-related events (Table 2). One male patient with HOCM died during the hospital stay due to infection and heart failure. Therefore, the in-hospital mortality rate was 1.4%. A female patient with HOCM experienced intraoperative heart failure and postoperative HCM-related events after discharge. The details regarding these 2 patients are described later in the article (cases 1 and 6). Long-Term Outcomes The median length of hospital stay and duration of postoperative follow-up were 15 and 1,382 days (3.8 years),
respectively (see Table 2). Postoperative HCM-related events occurred in 11 patients (15%). Of these, 3 died suddenly (cases 2, 4, and 8). The 5-year event-free rate was 76%. The postoperative event-free rate in all patients is shown in Figure 1.
Details of Severe HCM-Related Events Case 1: Postoperative Death (Postoperative Day 71) The patient was a 72-year-old man with HOCM. He underwent transhiatal esophagectomy under general anesthesia. The duration of surgery was 340 minutes, and total blood loss was 360 mL. Although he was transferred to a general ward from the intensive care unit on postoperative (POD) 2, severe hypoxia developed due to aspiration pneumonitis on POD 3. Thereafter, he was readmitted to the intensive care unit. On POD 11, heart failure occurred after paroxysmal atrial fibrillation. The patient died on POD 71 due to catheter-related bloodstream infection, pneumonia, and heart failure.
Case 2: Sudden Death (POD 596) The patient was a 58-year-old woman with HCM. On POD 197, she was admitted to the hospital emergently due to heart failure. She was discharged 2 weeks later after treatment with diuretics. Thereafter, her condition was stable. However, she died suddenly on POD 596 while taking a bath.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
4 Table 2 Outcome Data
Median postoperative follow-up (d) In-hospital mortality, n (%) Median hospital stay (d) Perioperative HCM-related events, n (%) Intraoperative events, n (%) Heart failure, n (%) Postoperative events during hospital stay, n (%) Heart failure, n (%) Postoperative HCM-related events after discharge, n (%) Sudden death, n (%) ICD shock, n (%) Successful CPR, n (%) Unexpected HCM-related hospitalization, n (%)
Overall (n ¼ 72)
Non-HOCM (n ¼ 58)
HOCM (n ¼ 14)
p Value
1,382 1 (1) 15 2 (3) 1 (1) 1 (1) 1 (1) 1 (1) 11 (15)† 3 (4) 3 (4) 1 (1) 6 (8)‡
1,279 0 (0) 15 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 8 (14) 3 (5) 2 (3) 0 (0) 5 (9)
1,709 1 (7) 13 2 (14) 1 (7) 1 (7) 1 (7) 1 (7) 3 (23) 0 (0) 1 (8) 1 (8) 1 (8)
0.10 0.04* 0.88 0.004*
0.18
Abbreviations: CPR, cardiopulmonary resuscitation; HCM, hypertrophic cardiomyopathy; HOCM, hypertrophic obstructive cardiomyopathy; ICD, implantable cardioverter-defibrillator. n p o 0.05 † Total number of patients was 71 because 1 patient died during hospital stay. ‡ Before sudden death and implantable cardioverter-defibrillator shock, 2 patients were admitted to the hospital because of heart failure.
Case 3: ICD Shock (POD 311) The patient was a 58-year-old woman with HCM (dilated phase) and ICD implantation. On POD 291, she was admitted to the hospital emergently due to heart failure. She was discharged 10 days later after treatment with diuretics. On POD 311, she suddenly lost consciousness. ICD shock was delivered immediately, and her condition became stable. Case 4: Sudden Death (POD 1,755) The patient was a 70-year-old woman with HCM. Although she was admitted to the hospital several times for examination and treatment of angina after total hip arthroplasty, her condition was stable. She died suddenly on POD 1,755. Case 5: Successful Cardiopulmonary Resuscitation (POD 454) The patient was a 49-year-old woman with HOCM. Although her condition was stable, she suddenly lost consciousness after taking a bath on POD 454. Her son performed cardiopulmonary resuscitation, after which she was admitted to the hospital. She recovered without any complications after
several treatments, including percutaneous cardiopulmonary support. Case 6: Intraoperative Heart Failure and ICD Shock (POD 324) The patient was a 26-year-old woman with HOCM. She underwent elective cesarean section with epidural anesthesia at 38 weeks of gestation. After administration of oxytocin for uterine contraction, heart failure and pulmonary edema occurred. She was admitted to the intensive care unit and received diuretic agents and a nasal high-flow device. She was discharged 12 days later. On POD 271, she received an ICD for primary prevention of sudden death. On POD 324, she suddenly lost consciousness while walking. ICD shock was delivered immediately after loss of consciousness. Case 7: ICD Shock (POD 1,615) The patient was a 49-year-old man with HCM. Although his condition was stable after total thyroidectomy, he received an ICD for primary prevention of sudden death because he felt faint while jogging on POD 1,615. After ICD implantation, the ICD discharged 4 times. Case 8: Sudden Death (POD 1,257) The patient was a 58-year-old man with HCM (dilated phase). He underwent tympanoplasty under general anesthesia. Although his physician recommended ICD implantation due to high risk of sudden death, he declined. He died suddenly on POD 1,257. Discussion
Fig 1. Postoperative event-free rate in all patients.
The authors conducted a retrospective analysis to clarify the short- and long-term outcomes of patients with HCM who undergo noncardiac surgery. The study revealed that the
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
short-term outcomes, namely in-hospital mortality rate and HCM-related nonfatal morbidity rate, were both only 1.4%. On the other hand, the 5-year event-free rate, considered as a long-term outcome, was 76%, and the postoperative HCMrelated mortality rate was 4.2%.
Short-Term Mortality Several reviews have reported that patients with HCM undergoing noncardiac surgery commonly experience adverse perioperative outcomes, such as myocardial ischemia and congestive heart failure.4,6 A recent study also reported that patients with HCM have a 4.23-fold higher risk of 30-day composite events compared with patients without HCM.5 Another recent review reported that up to 40% to 60% of patients with HCM experience perioperative cardiac events, such as myocardial infarction and congestive heart failure.8,10 On the other hand, very low rates of mortality, myocardial infarction, and stroke have been reported in patients both with and without HCM.5 Furthermore, another study concluded that patients with HOCM can safely undergo noncardiac surgery because the mortality rate was 3% and the causes of mortality did not appear to be cardiac in nature.2 The present study demonstrated that the rates of in-hospital mortality and perioperative HCM-related events were 1% and 3%, respectively. These were relatively low compared with those reported in the previous studies (Table 3). Although study design, period, and sex seemed not to affect this difference, the proportion of HOCM was associated with it. The proportion of HOCM of the present study was lower compared with other previous studies (19% v 39%-100%). In the present study, the 2 patients who experienced intraoperative and postoperative events (cases 1 and 6) had LVOT obstruction. Thus, the rates of mortality and incidence of heart failure in HOCM were both
5
7%. These values are similar to those in the other HOCM studies.2 Therefore, patients with HOCM should be monitored carefully during the perioperative period. Previous studies and a review suggested that the duration of intraoperative systolic blood pressure o90 mmHg might be associated with short-term adverse events.2,4,5 In the present study, intraoperative minimum systolic and mean blood pressures were 92 mmHg and 65 mmHg, respectively. Therefore, the authors consider that noncardiac surgery in patients with HCM might be safe if anesthesiologists pay attention to the hemodynamic status with or without invasive blood pressure monitoring.
Postoperative Events After Discharge Although a long-term follow-up study was performed in a general HCM population,9 there has been no study of patients who underwent noncardiac surgery. The data in the present study show that postoperative HCM-related events occurred in 15% of patients after discharge and that the 5-year event-free rate was 76%. Furthermore, the postoperative mortality rate was 4.2%. Eleven percent of patients experienced sudden death or near sudden death, and ICD shock was delivered and successful cardiopulmonary resuscitation was performed in survivors. The 5-year event-free rate could not compared with other studies because there were few reports on the incidence of HCM-related events according to the definition in the present study. However, a previous review reported that ventricular fibrillation and rapid ventricular tachycardia occurred in 20% of high-risk patients with HCM over a mean follow-up of approximately 4 years.11 Because the incidence of HCM-related events in 4 to 5 years was similar, the authors consider that the patients in the present study should be deemed low risk. For this reason, the authors believe that
Table 3 Summary of Previous and Present Studies
Design Follow-up period Number Age (y) Female (%) HOCM (%) General anesthesia (%) Duration of surgery (min) Perioperative complication Death (%) Heart failure (%) Myocardial infarction (%) Fatal arrhythmia (%)
Haering (1996)8
Hreybe (2006)3
Barbara (2016)2
Dhillon (2016)5
Present Study
Retrospective Perioperative period 77
Retrospective Discharge* 227
Retrospective 30 d 57
Observational cohort† 30 d 92
Retrospective 3.8 y‡ 72
71 7 13 57 39§ 81 151 7 102
68 7 19 62 NA NA NA
62 7 16 9 100 98 195 7 103
67 46 58 89 243
67 7 11 35 19 67 155 7 109
0 16 1 1
6.7 NA 2.2 NA
3 7 4 NA
4 18 1 NA
1¶ 1¶ 0 0
Abbreviations: HOCM, hypertrophic obstructive cardiomyopathy; NA, not available. n Prospectively entered records and extracted by manual review. † Hospital discharge ‡ Median follow-up duration. § Outflow gradient Z10 mmHg. ¶ 7% of HOCM patients. Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004
T. Yatabe et al. / Journal of Cardiothoracic and Vascular Anesthesia ] (]]]]) ]]]–]]]
6
noncardiac surgery might be safe because the in-hospital mortality rate was only 1% in the present study. A study of a general HCM population reported that the 10year survival rate, free of death and severe symptoms, for patients with LVOT velocity at rest 4 4 m/s was significantly lower than that of patients with peak LVOT velocity o 4 m/s.9 In the present study, although the short-term HCM-related event rate was significantly higher in patients with HOCM, the long-term event rates were similar in patients with and without HOCM. Additional observational studies of noncardiac surgery comparing patients with and without HOCM are necessary.
was 3.8 years. On the contrary, that of the other larger series of general HCM patients was 9.3 years, and LVOT velocity was associated with an undesirable outcome.9 Therefore, the authors cannot deny that the duration of follow-up affected the data. In this regard, future prospective, multicenter, observational studies or the establishment of a registry system are necessary to confirm the present study’s results. In conclusion, this study suggests that noncardiac surgery in patients with HCM is safe in terms of both short- and longterm outcomes. To confirm the findings, additional studies, such as prospective, multicenter, observational studies, should be conducted.
Limitations
References
This study has several limitations. First, the number of patients was small. Thus, some of the statistical analyses, such as comparison between patients with HCM and HOCM, might have been affected. HCM patients who underwent noncardiac surgery were not so prevalent. In fact, the number of patients in almost all the previous studies and present study was less than 100 (see Table 3). The authors could not conclude whether surgical procedures and anesthesia influenced mortality and morbidity. Second, the present study was retrospective in design. Although the medical records, reference letters from primary physicians, and cancer registry database were checked carefully to evaluate the long-term outcomes, 3 patients were lost to follow-up. These data might have affected the results. Third, all clinical records were surveyed until a single date. Therefore, the follow-up period of each patient was different. Although this could influence the incidence rates, the followup period was more than 6 months in 93% of patients. Fourth, the morbidity rate may have been underestimated. However, 2 independent authors carefully reviewed the patient records in this study. In addition, in general, patients visited the hospital when severe HCM-related events occurred. Therefore, the authors believe that the data are similar to “true” values. Fifth, individual anesthesiologists decided on anesthetic management, such as the use of invasive blood pressure monitoring and choice of vasopressor agents, because the authors’ hospital does not have a standard anesthetic protocol for patients with HCM. Finally, the median follow-up duration of this study
1 Authors/Task Force members, Elliott PM, Anastasakis A, Borger MA, et al. 2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy: The Task Force for the Diagnosis and Management of Hypertrophic Cardiomyopathy of the European Society of Cardiology (ESC). Eur Heart J 2014;35:2733–79. 2 Barbara DW, Hyder JA, Behrend TL, et al. Safety of noncardiac surgery in patients with hypertrophic obstructive cardiomyopathy at a tertiary care center. J Cardiothorac Vasc Anesth 2016;30:659–64. 3 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 2006;29:65–8. 4 Poliac LC, Barron ME, Maron BJ. Hypertrophic cardiomyopathy. Anesthesiology 2006;104:183–92. 5 Dhillon A, Khanna A, Randhawa MS, et al. Perioperative outcomes of patients with hypertrophic cardiomyopathy undergoing non-cardiac surgery. Heart 2016;102:1627–32. 6 Vives M, Roscoe A. Hypertrophic cardiomyopathy: Implications for anesthesia. Minerva Anestesiol 2014;80:1310–9. 7 Kubo T, Baba Y, Hirota T, et al. Differentiation of infiltrative cardiomyopathy from hypertrophic cardiomyopathy using high-sensitivity cardiac troponin T: A case-control study. BMC Cardiovasc Disord 2015;15:53. 8 Haering JM, Comunale ME, Parker RA, et al. Cardiac risk of noncardiac surgery in patients with asymmetric septal hypertrophy. Anesthesiology 1996;85:254–9. 9 Sorajja P, Nishimura RA, Gersh BJ, et al. Outcome of mildly symptomatic or asymptomatic obstructive hypertrophic cardiomyopathy: A long-term follow-up study. J Am Coll Cardiol 2009;54:234–41. 10 Hensley N, Dietrich J, Nyhan D, et al. Hypertrophic cardiomyopathy: A review. Anesth Analg 2015;120:554–69. 11 Maron BJ. Risk stratification and role of implantable defibrillators for prevention of sudden death in patients with hypertrophic cardiomyopathy. Circ J 2010;74:2271–82.
Please cite this article as: Yatabe T, et al. (2018), https://doi.org/10.1053/j.jvca.2018.03.004