- Email: [email protected]
Comparison of Pulmonary Complications in Patients Undergoing Transcatheter Aortic Valve Implantation Versus Open Aortic Valve Replacement
Comparison of Pulmonary Complications in Patients Undergoing Transcatheter Aortic Valve Implantation Versus Open Aortic Valve Replacement Jamie K. Pettet, MSN, APN, Myra N. McGhee, MSN, APN, S. Timothy McIlrath, MD, and Gordon L. Collins, MD Objective: The purpose of this study was to investigate and compare the differences in postoperative pulmonary complications in patients undergoing aortic valve replacement by open repair (OAVR) versus those undergoing transcatheter aortic valve implantation by the transapical approach (TAVI-A) or transfemoral approach (TAVI-F). Design: A retrospective review of data from aortic valve replacement patients. Setting: A private, non-profit hospital. Participants: Thirty patients with severe aortic stenosis requiring surgical replacement. Interventions: Data collected from TAVI-F, TAVI-A, and OAVR patient charts. Materials and Methods: Patients were divided into 3 groups: 10 patients undergoing OAVR, 10 patients undergoing TAVI-F, and 10 patients undergoing TAVI-A. Pulmonary complications and length of stay were recorded and analyzed. The TAVI-F group had the lowest number of total pulmonary complications per patient (1.0 ⫾ 0.667)
compared to the OAVR group (1.8 ⫾ 0.789, p ¼ 0.04) and TAVI-A group (2.0 ⫾ 1.054, p ¼ 0.02). The most frequent complication was atelectasis. TAVI-F patients spent the least amount of time on the ventilator (TAVI-F median 2.6, IQR 4.8 h, TAVI-A median 4.9, IQR 7.6 h, and OAVR median 6.6, IQR 17.3 h, p ¼ 0.02) and were discharged in half the time of the other groups (TAVI-F median 3.2, IQR 1.3 days, TAVI-A median 5.6, IQR 3.5 days, OAVR median 6.1, IQR 4.6 days, p ¼ 0.008). Conclusions: Due to the high incidence of multiple comorbidities and increased age, it is important to take into consideration the risk of pulmonary complications when choosing the surgical and anesthetic approach to TAVI in this high-risk group of patients. & 2013 Elsevier Inc. All rights reserved.
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differences in postoperative pulmonary complications in patients undergoing OAVR with those undergoing valve replacement by TAVI using the transapical approach (TAVIA) or transfemoral approach (TAVI-F).
S MANY AS FIFTY PERCENT of patients with untreated, symptomatic aortic valve stenosis (AS) are not considered candidates for conventional surgery due to high risk of mortality secondary to coexisting conditions.1-4 Unfortunately, without surgical intervention, severe AS carries up to a fifty percent morbidity and mortality rate within 2 years of onset of symptoms.1,5 Recent successes in transcatheter aortic valve implantation (TAVI), and the Food and Drug Administrationʼs approval for limited use in the United States in 2012, have enabled patients with considerable surgical and anesthetic risk for conventional surgery to have a viable option for improvement in quality of life and survival.1,5-7 Patients undergoing TAVI pose unique challenges for anesthesia providers. Rapid hemodynamic fluctuations in combination with severe AS, advanced age, and multiple comorbidities, can make the care of these patients difficult to manage during general anesthesia.8-10 Complications from the TAVI procedure are well documented and include death, stroke, vascular damage, permanent pacemaker insertion, renal replacement therapy, and aortic regurgitation.5-7 However, a review of the literature revealed no studies specifically addressing pulmonary complications in patients undergoing TAVI. Postoperative pulmonary complications have been shown to increase morbidity and mortality in patients undergoing open aortic valve replacement (OAVR). Complications may be attributed to the diaphragmatic dysfunction caused by surgical intervention in the thoracic region and the systemic inflammation induced by mandatory use of extracorporeal circulation in OAVR patients.11-14 Predictors of the development of postoperative pulmonary and pleural complications in OAVR include postoperative heart failure and bleeding, previous coronary artery surgery, chronic obstructive pulmonary disease (COPD), body mass index (BMI) > 25, age > 80 years, previous pacemaker insertion, and small valve size.14 The purpose of this study was to investigate and compare the
KEY WORDS: transcatheter aortic valve implantation, anesthesia, pulmonary complications, aortic stenosis, aortic valve replacement
MATERIALS AND METHODS A retrospective chart review of patients undergoing aortic valve replacement (AVR) was conducted in a non-profit private hospital after review and approval from the hospitalʼs Institutional Review Board. Patients were divided into 3 groups according to surgical approach: OAVR, TAVI-F, and TAVI-A. At the authorsʼ institution, the decision of which TAVI approach to use was made by the cardiovascular team after the patient was declared ineligible for OAVR. Patients were offered TAVI-A only if they had less than an 8 mm diameter of their femoral and iliac vessels or significant calcifications that made them unsuitable candidates for TAVI-F. Regardless of approach, all TAVI patients had an Edwards SAPIEN heart-valve system implanted (Edwards Lifesciences, Irvine, CA). Inclusion criteria for this study consisted of patients between 60 and 100 years old with severe AS requiring valvular replacement. Patients were excluded from the study if they had coronary artery bypass grafting at the time of their AVR, severe COPD defined as FEV 1 /FVC <0.7 or FEV 1 <50% predicted, or moderate-to-severe mitral valve stenosis or regurgitation. All enrolled study patients underwent general endotracheal anesthesia with use of anesthetic gases administered by qualified nurse
From the Department of Anesthesia, Parkwest Medical Center, Knoxville, TN. Address reprint requests to Jamie K. Pettet, MSN, APN, Parkwest Medical Center, Department of Anesthesia, 501 20th Street, Suite 606, Knoxville, TN 37916. E-mail: [email protected] © 2013 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2013.04.006
Journal of Cardiothoracic and Vascular Anesthesia, Vol ], No ] (Month), 2013: pp ]]]–]]]
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anesthetists under anesthesiologist supervision. Anesthesia was induced with intravenous administration of midazolam, sufentanil or fentanyl, propofol, and vecuronium in OAVR patients and midazolam, fentanyl, etomidate, and vecuronium in TAVI patients. To confirm valve function, transesophageal echocardiography (TEE) was performed by an anesthesiologist prior to valve replacement/deployment and again prior to surgical closure. Each patient was transferred directly to the intensive care unit (ICU) post-procedure. All AVR patients were expected to be extubated as quickly as possible after surgery. Decision to extubate the patient in the operating room (OR) was made based on the patientʼs comorbidities and ability to wean from ventilator support. Any patient unable to be extubated in the OR was placed on a propofol infusion at 25 to 45 μg/kg/min if needed to maintain comfort until they met institutional weaning parameters. Such parameters included spontaneous ventilation >5 mL/kg, FVC 10 to 15 mL/kg, O2 saturation >90% on less than 50% FIO2, ability to lift head off pillow and follow commands, and chest tube output less than 100 mL/h. Data were obtained from the patient's electronic medical record beginning with pre-admission testing through postoperative discharge from the hospital. Patientʼs age, gender, BMI, and presence of diagnosed diabetes, renal insufficiency, and pulmonary disease were collected. Although not yet modeled for TAVI patients, the Society of Thoracic Surgeons (STS) score was calculated on all patients to generate a predicted mortality estimate for comparison. Duration of mechanical ventilation, ICU stay, and postoperative hospital stay were recorded for analysis. Postoperative pulmonary complications were divided into 7 categories: Atelectasis, pneumothorax, pneumonia, pulmonary edema, pleural effusion, respiratory failure (defined as inability to wean from ventilatory support by postoperative day seven), and other. Pulmonary complications documented by hospital radiologists on daily chest x-ray reports or by the attending cardiovascular surgeon in the patientʼs progress notes were recorded for analysis. Use of medications felt to augment pulmonary function were recorded. Such medications included intraoperative use of a local anesthetic nerve block and postoperative use of narcotics, bronchodilators, and diuretics. Data were expressed by mean ⫾ standard deviation (SD) or frequency unless otherwise noted. A p value of <0.05 was considered to be statistically significant. To compare incidence of postoperative pulmonary complications, chi-squared and one-way ANOVA were used. The Kruskal-Wallis test was used to assess differences among surgical groupsʼ time on mechanical ventilation and length of stay in the ICU and hospital. Data for these were reported as median and interquartile range (IQR). Correlation between variables was evaluated using Pearsonʼs R and Kendallʼs tau-b correlation tests. Statistical analysis was performed using SPSS (Version 21.0, IBM SPSS, Chicago, IL). RESULTS
A total of 30 patients were enrolled in the study from 2011 to 2012, 10 patients in each of the OAVR, TAVI-A, and TAVIF groups. Demographic data by group are shown in Table 1. The OAVR group (73.5 ⫾ 6.7 years) was significantly younger than the TAVI-F group (81.9 ⫾ 5.6 years, p ¼ 0.04) and TAVI-A group (81.7 ⫾ 8.4 years, p ¼ 0.03). The TAVI-F group (median 5.5, IQR 2.5) and TAVI-A group (median 4.6, IQR 2.1) had significantly higher STS scores than the OAVR group (median 1.3, IQR 1.1, p ¼ 0.002). There were no significant differences among groups for pre-existing comorbidities or BMI. Pre-existing pulmonary disease included obstructive sleep apnea, mild-to-moderate pulmonary hypertension, asthma, and past history of smoking. No patients were
current smokers at the time of their surgery, and only 1 of the patients with a past history of smoking had a diagnosis confirming existence of any pulmonary disease. The incidence of pulmonary complications for each group is shown in Table 2 and Figure 1. There were significant differences in the total number of pulmonary complications per patient among groups (p ¼ 0.04). The TAVI-F group averaged the lowest number of total complications per patient (1.0 ⫾ 0.67) compared to the OAVR group (1.8 ⫾ 0.79, p ¼ 0.04) and TAVI-A group (2.0 ⫾ 1.05, p ¼ 0.02). Twenty percent of TAVI-F patients had no pulmonary complications. Only 1 patient (TAVI-A group) had more than 3 documented pulmonary complications. Two patients from the OAVR group were discharged home with oxygen. Atelectasis was the most frequent complication across all groups (p ¼ 0.05). The incidence of atelectasis in the TAVI-F group was 50%, whereas the TAVI-A and OAVR groups were higher at 90% each. In all groups, there was a positive correlation between BMI and atelectasis (p ¼ 0.03). No correlations were found between other comorbidities and the development of any pulmonary complication. Patients with a higher number of total pulmonary complications demonstrated increased ICU stays (p ¼ 0.02) and postoperative days in the hospital (p ¼ 0.003) but not hours on the ventilator. TAVI-F patients spent the least amount of time on the ventilator (median 2.6, IQR 4.8 h) compared to the OAVR (median 6.6, IQR 17.3 h, p ¼ 0.006) and TAVI-A groups (median 4.9, IQR 7.6 h, p ¼ 0.13). Three TAVI-F and 2 TAVI-A patients were extubated in the OR, whereas none of the OAVR patients was extubated until after admission to the ICU. No study patients required reintubation. Although not statistically significant, TAVI-A patients averaged the longest time in the ICU (median 1.1, IQR 2.9 days, p ¼ 0.10) (Table 2). Across all groups, development of a pleural effusion positively correlated with longer ICU stays (p ¼ 0.03). Differences in postoperative days in the hospital were significant (p ¼ 0.008), with TAVI-F patients (median 3.2, IQR 1.3 days) being discharged in almost half the time of OAVR (median 6.1,
Table 1. Patient Characteristics and Comorbidities Overall (n ¼ 30)
OAVR (n ¼ 10)
TAVI-A (n ¼ 10)
TAVI-F (n ¼ 10)
Age* 79⫾7.9 73.5⫾6.7 81.9⫾5.6 81.7⫾8.4 BMI 28.2⫾5.2 30.8⫾4.6 27.9⫾5.8 26⫾4.1 Male Gender 20 (67) 8 (80) 6 (60) 6 (60) Pulmonary Disease 13 (43) 6 (60) 4 (40) 3 (30) Renal Insufficiency 8 (27) 2 (20) 4 (40) 2 (20) Diabetes 11 (37) 2 (20) 4 (40) 5 (50) STS Score** 4.4 (4.4) 1.3 (1.1) 4.6 (2.1) 5.5 (2.5)
P value
0.02 0.11 0.55 0.39 0.51 0.37 0.002
Note: Age and BMI are expressed as mean⫾SD. STS Scores are expressed as median (IQR). All other values are expressed as number (percentage); P values represent comparisons among all 3 groups. Abbreviations: OAVR, aortic valve replacement by open repair; TAVI-A, transcatheter aortic valve implantation by transapical approach; TAVI-F, transcatheter aortic valve implantation by transfemoral approach; BMI, body mass index; STS, Society of Thoracic Surgeons. *P value reached significance level <0.05. **P value reached significance level <0.01.
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COMPARISON OF PULMONARY COMPLICATIONS
Table 2. Incidence of Pulmonary Complications and Length of Stay Overall
OAVR
TAVI-A
TAVI-F
(n ¼ 30)
(n ¼ 10)
(n ¼ 10)
(n ¼ 10)
Atelectasis* 23 (77) Pneumothorax 0 (0) Pneumonia 1 (3) Pleural effusion 12 (40) Respiratory 1 (3) failure Pulmonary 7 (23) edema Other 4 (13) 48 Total pulmonary complications* Extubated in 5 (17) operating room 4.8 (6.7) Hours on mechanical ventilation* Days in intensive 1.0 (0.4) care unit Postoperative 5.0 (3.2) days in hospital**
9 0 0 4 1
(90) (0) (0) (40) (10)
9 0 1 5 0
(90) (0) (10) (50) (0)
5 0 0 3 0
P Value
(50) (0) (0) (30) (0)
0.05 N/A 0.36 0.66 0.36
2 (20)
0.83
2 (20)
3 (30)
2 (20) 18
2 (20) 20
0 (0)
2 (20)
3 (30)
0.19
6.6 (17.3) 4.9 (7.6)
2.6 (4.8)
0.02
1.0 (3.3)
1.1 (2.9)
0.9 (0.3)
0.10
6.1 (4.6)
5.6 (3.5)
3.2 (1.3)
0.008
0 (0) 10
0.19 0.04
NOTE: Values are expressed median (IQR) or number (percentage); P values represent comparisons among all 3 groups. Abbreviations: OAVR, aortic valve replacement by open repair; TAVI-A, transcatheter aortic valve implantation by transapical approach; TAVI-F, transcatheter aortic valve implantation by transfemoral approach. *P value reached significance level <0.05. **P value reached significance level <0.01.
IQR 4.6 days, p ¼ 0.01) and TAVI-A (median 5.6, IQR 3.5 days, p ¼ 0.03) patients. No correlations were found between preexisting comorbidities and hours on the ventilator, days in the ICU, and postoperative days in the hospital.
DISCUSSION
It previously has been documented that OAVR is associated with an increased incidence of pulmonary complications attributed to the disruption of normal ventilatory mechanics and use of extracorporeal circulation.11-14 Many studies have suggested the TAVI procedure may improve long-term survival in patients previously considered unsuitable candidates for OAVR, and as such, the TAVI procedure is gaining popularity in the medical community.5-7 However, there is a lack of research specifically evaluating pulmonary complications in patients undergoing OAVR, TAVI-A, and TAVI-F. Due to the high incidence of multiple comorbidities and increased age, it is important to take into consideration risk of pulmonary complications when choosing the best TAVI approach and safest anesthetic for these high-risk patients. In this study, the TAVI-A group had a higher incidence of postoperative pulmonary complications than the TAVI-F and OAVR groups. The average number of complications per patient in the TAVI-A group was twice as many as the TAVI-F group (2.0 v 1.0) and, surprisingly, even more than the OAVR group (2.0 v 1.8). The incidence of atelectasis in TAVI-A patients was comparable to patients undergoing OAVR and significantly higher than TAVI-F patients. Recent studies referenced that mini-thoracotomy may be more painful than open sternotomy due to rib spreading and intercostal nerve injury and showed impaired respiratory function to be an independent risk factor for perioperative morbidity in TAVI-A patients.15,16 One of the contributing factors to the increases in atelectasis and pneumonia seen in the TAVI-A group may be inadequate lung volume expansion secondary to poor pain control. None of the TAVI-F patients in this study received an iliohypogastric/ilioinguinal nerve block for postoperative pain control and intercostal nerve block was documented in only one of the TAVI-A patients. All of the TAVI-A and OAVR patients required intravenous narcotics postoperatively, compared to only 50% of TAVI-F patients. The use of thoracic epidural analgesia has been demonstrated to
Fig 1. This graph shows patients grouped according to how many total pulmonary complications they had. Patients ranged from zero complications to 4 pulmonary complications.
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provide superior pain control and reduced pneumonia and respiratory complications in cardiovascular surgery patients.15,17,18 This may be important for anesthesia personnel to consider with high-risk patients who are undergoing TAVI-A. Use and effectiveness of neuraxial and/or regional technique (ie, intercostal nerve block) among TAVI-A patients needs further research. Prolonged periods of mechanical ventilation following cardiac surgery have been attributed to the development of pulmonary complications.19 As expected in the current study, TAVI-F patients were extubated sooner than OAVR patients. Although it did not reach statistical significance, the TAVI-A groupʼs median mechanical ventilation duration was almost twice as long as the TAVI-F groupʼs (4.9 v 2.6 h). Differences may have been attributed to disruption of normal pulmonary mechanics, pain from the minithoracotomy, and the higher incidence of atelectasis in the TAVI-A group. Unfortunately, general anesthesia and mechanical ventilation are necessary for the TAVI-A procedure. Two recent studies have examined the feasibility of performing TAVI-F under local anesthesia with sedation in efforts to avoid mechanical ventilation.10,20 One caveat of concern is the depth of sedation required to tolerate the procedure without converting to general anesthesia. The deep levels of sedation necessary frequently are associated with depressed ventilation, which may increase atelectasis and worsen pulmonary artery hypertension from resulting hypercapnia. Although both studies showed some advantages to local anesthesia with sedation, they failed to mention the incidence of pulmonary complications and incidence of postoperative respiratory failure requiring mechanical ventilation.10,20 Further research would be necessary to examine if the occurrence of pulmonary complications in patients undergoing sedation with local anesthesia impacted short-term outcomes in TAVI-F patients. In the current study, the development of pulmonary complications seemed to correlate with increased length of stay. TAVIA patients had more total pulmonary complications and longer ICU stays than both the OAVR and TAVI-F groups. The development of pleural effusions positively correlated with longer ICU stays but not longer hospital stays. The TAVI-A group had the highest incidence of pleural effusions at 50%. Surprisingly, the TAVI-A group was similar to the OAVR group in postoperative days in the hospital. On average, TAVIA patients spent nearly double the time in the hospital as TAVIF patients (5.6 v 3.2 days). It may be argued that the TAVI-A
procedure typically is performed on sicker patients with increased comorbidities, such as peripheral vascular disease or aneurysms, that make them unsuitable candidates for TAVI-F. However, in the present study, the modified STS score for predicted mortality was higher in TAVI-F patients than TAVI-A patients (5.5 v 4.6) and the decision between approaches was made strictly on anatomic evaluation. The TAVI procedure is new to the authorsʼ institution and was a contributing factor to the small sample size. A larger, randomized trial significantly powered to see statistical differences in pulmonary outcomes across all 3 groups would be necessary to confirm these results. With this small a sample, it was difficult to distinguish which other variables (such as comorbidities and postoperative pain/sedation) played a part in the development of postoperative pulmonary complications found in this study versus the surgical approach itself. At this point, all of the TAVI procedures at this institution are being performed under general endotracheal anesthesia due to the surgeonsʼ preference to have TEE immediately available at various stages of the procedure. One advantage to the TAVI-F is that it may be performed with local monitored anesthesia care. In future studies, it will be important to include this group to further investigate the role anesthetic choice may play in impacting postoperative pulmonary complications. Additionally, the authors excluded patients with severe preexisting pulmonary disease in an effort to reduce preexisting pulmonary dysfunction as a causative factor in the development of postoperative pulmonary complications. Future studies might include this group to further assess the impact of preexisting conditions on postoperative outcomes. It is imperative that anesthesia providers work closely with the cardiovascular team to ensure a successful outcome with the least number of postoperative complications. Incorporating the expertise of all cardiovascular, surgical, and anesthesia team members during selection of patients and surgical approach may optimize positive outcomes and increase patient satisfaction. ACKNOWLEDGMENTS The authors would like to acknowledge Thomas Pollard, MD, Chadwick Stouffer, MD, Nicholaos Xenopoulos, MD, Thomas Ayres, MD, the East Tennessee Cardiovascular Surgery Group, and the Parkwest Medical Center TAVI team for their outstanding patient care and assistance with this study.
REFERENCES 1. Smith CR, Leon MB, Mack MJ, et al: Transcatheter versus surgical aortic valve replacement in high-risk patients. N Engl J Med 364:2187-2198, 2011 2. Thielmann M, Wendt D, Eggebrecht H, et al: Transcatheter aortic valve implantation in patients with very high risk for conventional aortic valve replacement. Ann Thorac Surg 88:1468-1474, 2009 3. Lung B, Baron G, Butchart EG, et al: A prospective survey of patients with valvular heart disease in Europe: The Euro Heart survey on valvular heart disease. Eur Heart J 24:1231-1243, 2003 4. Rodes-Cabau J, Webb JG, Cheung A, et al: Transcatheter aortic valve implantation for the treatment of severe symptomatic aortic stenosis in patients at very high or prohibitive surgical risk: Acute and late outcomes of the multicenter Canadian experience. J Am Coll Cardiol 55:1080-1090, 2010
5. Leon MB, Smith CR, Mack MJ, et al: Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med 363:1597-1607, 2010 6. Khatri PJ, Webb JG, Rodes-Cabau J, et al: Adverse effects associated with transcatheter aortic valve implantation. Ann Intern Med 158:35-46, 2013 7. Makkar RR, Fontana GP, Jilaihawi H, et al: Transcatheter aorticvalve replacement for inoperable severe aortic stenosis. N Engl J Med 366:1696-1704, 2012 8. Fassl J, Walther T, Groesdonk HV, et al: Anesthesia management for transapical transcatheter aortic valve implantation: A case series. J Cardiothorac Vasc Anesth 23:286-291, 2009 9. Billings FT, Kodali SK, Shanewise JS: Transcatheter aortic valve implantation: Anesthetic considerations. Anesth Analg 108: 1453-1462, 2009
COMPARISON OF PULMONARY COMPLICATIONS
10. Dehedin B, Guinot PG, Ibrahim H, et al: Anesthesia and perioperative management of patients who undergo transfemoral transcatheter aortic valve implantation: An observational study of general versus local/regional anesthesia in 125 consecutive patients. J Cardiothorac Vasc Anesth 25:1036-1043, 2011 11. Yanez-Brage I, Pita-Fernandez S, Juffe-Stein A, et al: Respiratory physiotherapy and incidence of pulmonary complications in offpump coronary artery bypass graft surgery: An observational follow-up study. BMC Pulm Med 9:36, 2009 12. Weissman C: Pulmonary complications after cardiac surgery. Semin Cardiothorac Vasc Anesth 8:185-211, 2004 13. Tenling A, Hachenberg T, Tyden H, et al: Atelectasis and gas exchange after cardiac surgery. Anesthesiology 89:371-378, 1998 14. Mistiaen W, Vissers D: The risk of postoperative pulmonary or pleural complications after aortic valve replacement is low in elderly patients: An observational study. Aust J Physiother 54:119-124, 2008
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15. Amat-Santos IJ, Dumont E, Villeneuve J, et al: Effect of thoracic epidural analgesia on clinical outcomes following transapical transcatheter aortic valve implantation. Heart 98:1583-1590, 2012 16. Kempfert J, Rastan A, Holzhey D, et al: Transapical aortic valve implantation: Analysis of risk factors and learning experience in 299 patients. Circulation 124(11 Suppl):S124-S129, 2011 17. Svircevic V, van Dijk D, Nierich AP, et al: Meta-analysis of thoracic epidural anesthesia versus general anesthesia for cardiac surgery. Anesthesiology 114:271-282, 2011 18. Bignami E, Landoni G, Biondi-Zoccai GG, et al: Epidural analgesia improves outcome in cardiac surgery: A meta-analysis of randomized controlled trials. J Cardiothorac Vasc Anesth 24:586-597, 2010 19. Doyle RL: Assessing and modifying the risk of postoperative pulmonary complications. Chest 115(5 Suppl):S77-S81, 1999 20. Bergmann L, Kahlert P, Eggebrecht H, et al: Transfemoral aortic valve implantation under sedation and monitored anaesthetic care: A feasibility study. Anaesthesia 66:977-982, 2011
compared to the OAVR group (1.8 ⫾ 0.789, p ¼ 0.04) and TAVI-A group (2.0 ⫾ 1.054, p ¼ 0.02). The most frequent complication was atelectasis. TAVI-F patients spent the least amount of time on the ventilator (TAVI-F median 2.6, IQR 4.8 h, TAVI-A median 4.9, IQR 7.6 h, and OAVR median 6.6, IQR 17.3 h, p ¼ 0.02) and were discharged in half the time of the other groups (TAVI-F median 3.2, IQR 1.3 days, TAVI-A median 5.6, IQR 3.5 days, OAVR median 6.1, IQR 4.6 days, p ¼ 0.008). Conclusions: Due to the high incidence of multiple comorbidities and increased age, it is important to take into consideration the risk of pulmonary complications when choosing the surgical and anesthetic approach to TAVI in this high-risk group of patients. & 2013 Elsevier Inc. All rights reserved.
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differences in postoperative pulmonary complications in patients undergoing OAVR with those undergoing valve replacement by TAVI using the transapical approach (TAVIA) or transfemoral approach (TAVI-F).
S MANY AS FIFTY PERCENT of patients with untreated, symptomatic aortic valve stenosis (AS) are not considered candidates for conventional surgery due to high risk of mortality secondary to coexisting conditions.1-4 Unfortunately, without surgical intervention, severe AS carries up to a fifty percent morbidity and mortality rate within 2 years of onset of symptoms.1,5 Recent successes in transcatheter aortic valve implantation (TAVI), and the Food and Drug Administrationʼs approval for limited use in the United States in 2012, have enabled patients with considerable surgical and anesthetic risk for conventional surgery to have a viable option for improvement in quality of life and survival.1,5-7 Patients undergoing TAVI pose unique challenges for anesthesia providers. Rapid hemodynamic fluctuations in combination with severe AS, advanced age, and multiple comorbidities, can make the care of these patients difficult to manage during general anesthesia.8-10 Complications from the TAVI procedure are well documented and include death, stroke, vascular damage, permanent pacemaker insertion, renal replacement therapy, and aortic regurgitation.5-7 However, a review of the literature revealed no studies specifically addressing pulmonary complications in patients undergoing TAVI. Postoperative pulmonary complications have been shown to increase morbidity and mortality in patients undergoing open aortic valve replacement (OAVR). Complications may be attributed to the diaphragmatic dysfunction caused by surgical intervention in the thoracic region and the systemic inflammation induced by mandatory use of extracorporeal circulation in OAVR patients.11-14 Predictors of the development of postoperative pulmonary and pleural complications in OAVR include postoperative heart failure and bleeding, previous coronary artery surgery, chronic obstructive pulmonary disease (COPD), body mass index (BMI) > 25, age > 80 years, previous pacemaker insertion, and small valve size.14 The purpose of this study was to investigate and compare the
KEY WORDS: transcatheter aortic valve implantation, anesthesia, pulmonary complications, aortic stenosis, aortic valve replacement
MATERIALS AND METHODS A retrospective chart review of patients undergoing aortic valve replacement (AVR) was conducted in a non-profit private hospital after review and approval from the hospitalʼs Institutional Review Board. Patients were divided into 3 groups according to surgical approach: OAVR, TAVI-F, and TAVI-A. At the authorsʼ institution, the decision of which TAVI approach to use was made by the cardiovascular team after the patient was declared ineligible for OAVR. Patients were offered TAVI-A only if they had less than an 8 mm diameter of their femoral and iliac vessels or significant calcifications that made them unsuitable candidates for TAVI-F. Regardless of approach, all TAVI patients had an Edwards SAPIEN heart-valve system implanted (Edwards Lifesciences, Irvine, CA). Inclusion criteria for this study consisted of patients between 60 and 100 years old with severe AS requiring valvular replacement. Patients were excluded from the study if they had coronary artery bypass grafting at the time of their AVR, severe COPD defined as FEV 1 /FVC <0.7 or FEV 1 <50% predicted, or moderate-to-severe mitral valve stenosis or regurgitation. All enrolled study patients underwent general endotracheal anesthesia with use of anesthetic gases administered by qualified nurse
From the Department of Anesthesia, Parkwest Medical Center, Knoxville, TN. Address reprint requests to Jamie K. Pettet, MSN, APN, Parkwest Medical Center, Department of Anesthesia, 501 20th Street, Suite 606, Knoxville, TN 37916. E-mail: [email protected] © 2013 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2013.04.006
Journal of Cardiothoracic and Vascular Anesthesia, Vol ], No ] (Month), 2013: pp ]]]–]]]
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anesthetists under anesthesiologist supervision. Anesthesia was induced with intravenous administration of midazolam, sufentanil or fentanyl, propofol, and vecuronium in OAVR patients and midazolam, fentanyl, etomidate, and vecuronium in TAVI patients. To confirm valve function, transesophageal echocardiography (TEE) was performed by an anesthesiologist prior to valve replacement/deployment and again prior to surgical closure. Each patient was transferred directly to the intensive care unit (ICU) post-procedure. All AVR patients were expected to be extubated as quickly as possible after surgery. Decision to extubate the patient in the operating room (OR) was made based on the patientʼs comorbidities and ability to wean from ventilator support. Any patient unable to be extubated in the OR was placed on a propofol infusion at 25 to 45 μg/kg/min if needed to maintain comfort until they met institutional weaning parameters. Such parameters included spontaneous ventilation >5 mL/kg, FVC 10 to 15 mL/kg, O2 saturation >90% on less than 50% FIO2, ability to lift head off pillow and follow commands, and chest tube output less than 100 mL/h. Data were obtained from the patient's electronic medical record beginning with pre-admission testing through postoperative discharge from the hospital. Patientʼs age, gender, BMI, and presence of diagnosed diabetes, renal insufficiency, and pulmonary disease were collected. Although not yet modeled for TAVI patients, the Society of Thoracic Surgeons (STS) score was calculated on all patients to generate a predicted mortality estimate for comparison. Duration of mechanical ventilation, ICU stay, and postoperative hospital stay were recorded for analysis. Postoperative pulmonary complications were divided into 7 categories: Atelectasis, pneumothorax, pneumonia, pulmonary edema, pleural effusion, respiratory failure (defined as inability to wean from ventilatory support by postoperative day seven), and other. Pulmonary complications documented by hospital radiologists on daily chest x-ray reports or by the attending cardiovascular surgeon in the patientʼs progress notes were recorded for analysis. Use of medications felt to augment pulmonary function were recorded. Such medications included intraoperative use of a local anesthetic nerve block and postoperative use of narcotics, bronchodilators, and diuretics. Data were expressed by mean ⫾ standard deviation (SD) or frequency unless otherwise noted. A p value of <0.05 was considered to be statistically significant. To compare incidence of postoperative pulmonary complications, chi-squared and one-way ANOVA were used. The Kruskal-Wallis test was used to assess differences among surgical groupsʼ time on mechanical ventilation and length of stay in the ICU and hospital. Data for these were reported as median and interquartile range (IQR). Correlation between variables was evaluated using Pearsonʼs R and Kendallʼs tau-b correlation tests. Statistical analysis was performed using SPSS (Version 21.0, IBM SPSS, Chicago, IL). RESULTS
A total of 30 patients were enrolled in the study from 2011 to 2012, 10 patients in each of the OAVR, TAVI-A, and TAVIF groups. Demographic data by group are shown in Table 1. The OAVR group (73.5 ⫾ 6.7 years) was significantly younger than the TAVI-F group (81.9 ⫾ 5.6 years, p ¼ 0.04) and TAVI-A group (81.7 ⫾ 8.4 years, p ¼ 0.03). The TAVI-F group (median 5.5, IQR 2.5) and TAVI-A group (median 4.6, IQR 2.1) had significantly higher STS scores than the OAVR group (median 1.3, IQR 1.1, p ¼ 0.002). There were no significant differences among groups for pre-existing comorbidities or BMI. Pre-existing pulmonary disease included obstructive sleep apnea, mild-to-moderate pulmonary hypertension, asthma, and past history of smoking. No patients were
current smokers at the time of their surgery, and only 1 of the patients with a past history of smoking had a diagnosis confirming existence of any pulmonary disease. The incidence of pulmonary complications for each group is shown in Table 2 and Figure 1. There were significant differences in the total number of pulmonary complications per patient among groups (p ¼ 0.04). The TAVI-F group averaged the lowest number of total complications per patient (1.0 ⫾ 0.67) compared to the OAVR group (1.8 ⫾ 0.79, p ¼ 0.04) and TAVI-A group (2.0 ⫾ 1.05, p ¼ 0.02). Twenty percent of TAVI-F patients had no pulmonary complications. Only 1 patient (TAVI-A group) had more than 3 documented pulmonary complications. Two patients from the OAVR group were discharged home with oxygen. Atelectasis was the most frequent complication across all groups (p ¼ 0.05). The incidence of atelectasis in the TAVI-F group was 50%, whereas the TAVI-A and OAVR groups were higher at 90% each. In all groups, there was a positive correlation between BMI and atelectasis (p ¼ 0.03). No correlations were found between other comorbidities and the development of any pulmonary complication. Patients with a higher number of total pulmonary complications demonstrated increased ICU stays (p ¼ 0.02) and postoperative days in the hospital (p ¼ 0.003) but not hours on the ventilator. TAVI-F patients spent the least amount of time on the ventilator (median 2.6, IQR 4.8 h) compared to the OAVR (median 6.6, IQR 17.3 h, p ¼ 0.006) and TAVI-A groups (median 4.9, IQR 7.6 h, p ¼ 0.13). Three TAVI-F and 2 TAVI-A patients were extubated in the OR, whereas none of the OAVR patients was extubated until after admission to the ICU. No study patients required reintubation. Although not statistically significant, TAVI-A patients averaged the longest time in the ICU (median 1.1, IQR 2.9 days, p ¼ 0.10) (Table 2). Across all groups, development of a pleural effusion positively correlated with longer ICU stays (p ¼ 0.03). Differences in postoperative days in the hospital were significant (p ¼ 0.008), with TAVI-F patients (median 3.2, IQR 1.3 days) being discharged in almost half the time of OAVR (median 6.1,
Table 1. Patient Characteristics and Comorbidities Overall (n ¼ 30)
OAVR (n ¼ 10)
TAVI-A (n ¼ 10)
TAVI-F (n ¼ 10)
Age* 79⫾7.9 73.5⫾6.7 81.9⫾5.6 81.7⫾8.4 BMI 28.2⫾5.2 30.8⫾4.6 27.9⫾5.8 26⫾4.1 Male Gender 20 (67) 8 (80) 6 (60) 6 (60) Pulmonary Disease 13 (43) 6 (60) 4 (40) 3 (30) Renal Insufficiency 8 (27) 2 (20) 4 (40) 2 (20) Diabetes 11 (37) 2 (20) 4 (40) 5 (50) STS Score** 4.4 (4.4) 1.3 (1.1) 4.6 (2.1) 5.5 (2.5)
P value
0.02 0.11 0.55 0.39 0.51 0.37 0.002
Note: Age and BMI are expressed as mean⫾SD. STS Scores are expressed as median (IQR). All other values are expressed as number (percentage); P values represent comparisons among all 3 groups. Abbreviations: OAVR, aortic valve replacement by open repair; TAVI-A, transcatheter aortic valve implantation by transapical approach; TAVI-F, transcatheter aortic valve implantation by transfemoral approach; BMI, body mass index; STS, Society of Thoracic Surgeons. *P value reached significance level <0.05. **P value reached significance level <0.01.
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COMPARISON OF PULMONARY COMPLICATIONS
Table 2. Incidence of Pulmonary Complications and Length of Stay Overall
OAVR
TAVI-A
TAVI-F
(n ¼ 30)
(n ¼ 10)
(n ¼ 10)
(n ¼ 10)
Atelectasis* 23 (77) Pneumothorax 0 (0) Pneumonia 1 (3) Pleural effusion 12 (40) Respiratory 1 (3) failure Pulmonary 7 (23) edema Other 4 (13) 48 Total pulmonary complications* Extubated in 5 (17) operating room 4.8 (6.7) Hours on mechanical ventilation* Days in intensive 1.0 (0.4) care unit Postoperative 5.0 (3.2) days in hospital**
9 0 0 4 1
(90) (0) (0) (40) (10)
9 0 1 5 0
(90) (0) (10) (50) (0)
5 0 0 3 0
P Value
(50) (0) (0) (30) (0)
0.05 N/A 0.36 0.66 0.36
2 (20)
0.83
2 (20)
3 (30)
2 (20) 18
2 (20) 20
0 (0)
2 (20)
3 (30)
0.19
6.6 (17.3) 4.9 (7.6)
2.6 (4.8)
0.02
1.0 (3.3)
1.1 (2.9)
0.9 (0.3)
0.10
6.1 (4.6)
5.6 (3.5)
3.2 (1.3)
0.008
0 (0) 10
0.19 0.04
NOTE: Values are expressed median (IQR) or number (percentage); P values represent comparisons among all 3 groups. Abbreviations: OAVR, aortic valve replacement by open repair; TAVI-A, transcatheter aortic valve implantation by transapical approach; TAVI-F, transcatheter aortic valve implantation by transfemoral approach. *P value reached significance level <0.05. **P value reached significance level <0.01.
IQR 4.6 days, p ¼ 0.01) and TAVI-A (median 5.6, IQR 3.5 days, p ¼ 0.03) patients. No correlations were found between preexisting comorbidities and hours on the ventilator, days in the ICU, and postoperative days in the hospital.
DISCUSSION
It previously has been documented that OAVR is associated with an increased incidence of pulmonary complications attributed to the disruption of normal ventilatory mechanics and use of extracorporeal circulation.11-14 Many studies have suggested the TAVI procedure may improve long-term survival in patients previously considered unsuitable candidates for OAVR, and as such, the TAVI procedure is gaining popularity in the medical community.5-7 However, there is a lack of research specifically evaluating pulmonary complications in patients undergoing OAVR, TAVI-A, and TAVI-F. Due to the high incidence of multiple comorbidities and increased age, it is important to take into consideration risk of pulmonary complications when choosing the best TAVI approach and safest anesthetic for these high-risk patients. In this study, the TAVI-A group had a higher incidence of postoperative pulmonary complications than the TAVI-F and OAVR groups. The average number of complications per patient in the TAVI-A group was twice as many as the TAVI-F group (2.0 v 1.0) and, surprisingly, even more than the OAVR group (2.0 v 1.8). The incidence of atelectasis in TAVI-A patients was comparable to patients undergoing OAVR and significantly higher than TAVI-F patients. Recent studies referenced that mini-thoracotomy may be more painful than open sternotomy due to rib spreading and intercostal nerve injury and showed impaired respiratory function to be an independent risk factor for perioperative morbidity in TAVI-A patients.15,16 One of the contributing factors to the increases in atelectasis and pneumonia seen in the TAVI-A group may be inadequate lung volume expansion secondary to poor pain control. None of the TAVI-F patients in this study received an iliohypogastric/ilioinguinal nerve block for postoperative pain control and intercostal nerve block was documented in only one of the TAVI-A patients. All of the TAVI-A and OAVR patients required intravenous narcotics postoperatively, compared to only 50% of TAVI-F patients. The use of thoracic epidural analgesia has been demonstrated to
Fig 1. This graph shows patients grouped according to how many total pulmonary complications they had. Patients ranged from zero complications to 4 pulmonary complications.
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provide superior pain control and reduced pneumonia and respiratory complications in cardiovascular surgery patients.15,17,18 This may be important for anesthesia personnel to consider with high-risk patients who are undergoing TAVI-A. Use and effectiveness of neuraxial and/or regional technique (ie, intercostal nerve block) among TAVI-A patients needs further research. Prolonged periods of mechanical ventilation following cardiac surgery have been attributed to the development of pulmonary complications.19 As expected in the current study, TAVI-F patients were extubated sooner than OAVR patients. Although it did not reach statistical significance, the TAVI-A groupʼs median mechanical ventilation duration was almost twice as long as the TAVI-F groupʼs (4.9 v 2.6 h). Differences may have been attributed to disruption of normal pulmonary mechanics, pain from the minithoracotomy, and the higher incidence of atelectasis in the TAVI-A group. Unfortunately, general anesthesia and mechanical ventilation are necessary for the TAVI-A procedure. Two recent studies have examined the feasibility of performing TAVI-F under local anesthesia with sedation in efforts to avoid mechanical ventilation.10,20 One caveat of concern is the depth of sedation required to tolerate the procedure without converting to general anesthesia. The deep levels of sedation necessary frequently are associated with depressed ventilation, which may increase atelectasis and worsen pulmonary artery hypertension from resulting hypercapnia. Although both studies showed some advantages to local anesthesia with sedation, they failed to mention the incidence of pulmonary complications and incidence of postoperative respiratory failure requiring mechanical ventilation.10,20 Further research would be necessary to examine if the occurrence of pulmonary complications in patients undergoing sedation with local anesthesia impacted short-term outcomes in TAVI-F patients. In the current study, the development of pulmonary complications seemed to correlate with increased length of stay. TAVIA patients had more total pulmonary complications and longer ICU stays than both the OAVR and TAVI-F groups. The development of pleural effusions positively correlated with longer ICU stays but not longer hospital stays. The TAVI-A group had the highest incidence of pleural effusions at 50%. Surprisingly, the TAVI-A group was similar to the OAVR group in postoperative days in the hospital. On average, TAVIA patients spent nearly double the time in the hospital as TAVIF patients (5.6 v 3.2 days). It may be argued that the TAVI-A
procedure typically is performed on sicker patients with increased comorbidities, such as peripheral vascular disease or aneurysms, that make them unsuitable candidates for TAVI-F. However, in the present study, the modified STS score for predicted mortality was higher in TAVI-F patients than TAVI-A patients (5.5 v 4.6) and the decision between approaches was made strictly on anatomic evaluation. The TAVI procedure is new to the authorsʼ institution and was a contributing factor to the small sample size. A larger, randomized trial significantly powered to see statistical differences in pulmonary outcomes across all 3 groups would be necessary to confirm these results. With this small a sample, it was difficult to distinguish which other variables (such as comorbidities and postoperative pain/sedation) played a part in the development of postoperative pulmonary complications found in this study versus the surgical approach itself. At this point, all of the TAVI procedures at this institution are being performed under general endotracheal anesthesia due to the surgeonsʼ preference to have TEE immediately available at various stages of the procedure. One advantage to the TAVI-F is that it may be performed with local monitored anesthesia care. In future studies, it will be important to include this group to further investigate the role anesthetic choice may play in impacting postoperative pulmonary complications. Additionally, the authors excluded patients with severe preexisting pulmonary disease in an effort to reduce preexisting pulmonary dysfunction as a causative factor in the development of postoperative pulmonary complications. Future studies might include this group to further assess the impact of preexisting conditions on postoperative outcomes. It is imperative that anesthesia providers work closely with the cardiovascular team to ensure a successful outcome with the least number of postoperative complications. Incorporating the expertise of all cardiovascular, surgical, and anesthesia team members during selection of patients and surgical approach may optimize positive outcomes and increase patient satisfaction. ACKNOWLEDGMENTS The authors would like to acknowledge Thomas Pollard, MD, Chadwick Stouffer, MD, Nicholaos Xenopoulos, MD, Thomas Ayres, MD, the East Tennessee Cardiovascular Surgery Group, and the Parkwest Medical Center TAVI team for their outstanding patient care and assistance with this study.
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