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Beyond the Learning Curve: Transapical Versus Transfemoral Transcatheter Aortic Valve Replacement in the Treatment of Severe Aortic Valve Stenosis Kevin L. Greason, M.D.,* Rakesh M. Suri, M.D.,* Vuyisile T. Nkomo, M.D., M.P.H.,y Charanjit S. Rihal, M.D.,y David R. Holmes, M.D.,y and Verghese Mathew, M.D.y *Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota; and yDivision of Cardiovascular Disease, Mayo Clinic, Rochester, Minnesota ABSTRACT Background: Most studies comparing transapical and transfemoral transcatheter aortic valve replacement include the center’s early operative experience, which may negatively impact the outcomes. This study reports our experience beyond the learning curve with transapical and transfemoral transcatheter aortic valve replacement. Methods: A total of 303 patients underwent transcatheter aortic valve replacement from November 2008 through August 2013. There were 153 patients (50.5%) who received transfemoral valve replacement, 130 (42.9%) received transapical valve replacement, and 20 (6.6%) received transaortic valve replacement. We retrospectively reviewed the outcomes of the most recent 100 consecutive patients each from the transfemoral and transapical valve replacement groups. Results: The median age was 82 years (range, 54 to 95) and 110 patients (55%) were male; STS predicted risk of mortality was 8.1% (0.7 to 27.8) and was similar between groups (p = 0.256). Operative complications occurred in 49 patients (49%) in the transapical replacement group and in 43 (43%) in the transfemoral group (p = 0.478). Vascular complications occurred only in the transfemoral group and included nine patients (9%; p = 0.003). Paravalvular regurgitation at discharge of grade mild–moderate occurred in 23 patients (24.2%) in the transapical group in comparison to 40 (43.5%) in the transfemoral group (p = 0.006). Operative mortality occurred in two patients (2%) in the transapical group and in five (5%) in the transfemoral group (p = 0.445). Conclusions: Transapical transcatheter aortic valve replacement is associated with less prevalence of vascular complications and mild–moderate paravalvular regurgitation in comparison to the transfemoral approach. Further study is necessary to determine if the transapical technique is the preferred option. doi: 10.1111/jocs.12323 (J Card Surg 2014;29:303–307) It is thought that transapical transcatheter aortic valve replacement is a higher-risk procedure than transfemoral transcatheter valve replacement in the treatment of patients with severe aortic valve stenosis.1,2 However, patient characteristics of the two groups are often dissimilar with greater prevalence of arteriosclerosis and higher operative risk in transapical patients.3–5 Furthermore, most reported series include the center’s Conflict of interest: The authors acknowledge no conflict of interest in the submission. Sources of funding: none. Address for correspondence: Kevin L. Greason, M.D., Mayo Clinic, Division of Cardiovascular Surgery, Joseph 5-200, 200 First Street, Southwest, Rochester, MN 55905. Fax: þ1-507-255-7378; e-mail: [email protected]

early operative experience, and that may overemphasize the learning curve associated operative morbidity and mortality.3,6 In addition, the learning curves are different for each of the respective procedures.7–10 We have reviewed our experience with over 300 transcatheter aortic valve replacements. We hypothesize in our most recent experience that transapical valve replacement is not a higher-risk procedure than transfemoral valve replacement. MATERIALS AND METHODS The Institutional Review Board approved this study. The cardiac surgery database was reviewed for all patients operated with transcatheter aortic valve replacement at Mayo Clinic, Rochester, Minnesota.

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There were 303 patients who received operation with the SAPIEN/SAPIEN XT valve (Edwards Lifesciences, Irvine, CA, USA) from November 2008 through August 2013. Vascular access for the valve replacement was transfemoral in 153 patients (50.5%), transapical in 130 (42.9%), and transaortic in 20 (6.6%). One patient refused research authorization and was subsequently excluded from further study. A learning curve has been reported for transcatheter aortic valve replacement.7–10 To compensate for the learning curve associated with transcatheter valve replacement, the last 200 cases were selected for study and included 100 patients each in the transfemoral and transapical access groups. Patients underwent surgery from May 2011 through August 2013. The transaortic patients were excluded from the present study because of the small sample size. Patient records were reviewed and data collected using Society of Thoracic Surgeons Adult Cardiac Surgery Database, version 2.73 criteria. Vascular complication data were based on definitions established by the Valve Academic Research Consortium.11 All patients received transesophageal echocardiography and multidector computed tomography. Valve size was determined primarily by transesophageal echocardiography-derived left ventricular outflow tract diameter early in our experience and included 103 patients (51.5%); computed tomography angiography was used to determine left ventricular outflow tract area in the most recent 97 patients (48.5%). The 23-mm valve was inserted in patients with an echocardiography diameter of 21.5 mm or less or a CT scan area of less than 4.15 cm2. The 26-mm valve was inserted in patients with a diameter of greater than 21.5 mm but less than 25 mm, or an area of greater than 4.15 cm2 and less than 5.3 cm2. The 29 mm valve was implanted in patients with a diameter greater than 25 mm or an area of greater than 5.3 cm2. Vascular access was determined by review of the size of the iliac and femoral arteries as noted on the CT

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scan. For the SAPIEN valve, the minimal artery diameter was 7 mm for the 23-mm valve and 8 mm for the 26-mm valve. For the SAPIEN XT valve the minimum diameter was 6 mm for the 23-mm valve, 6.5 mm for the 26-mm valve, and 7 mm for the 29-mm valve. Patients received the transfemoral procedure if they had adequate arterial access to support valve placement. Patients received the transapical procedure only if they had inadequate arterial access to support transfemoral valve placement. All operations were done under general anesthesia with transesophageal echocardiography. Patients in the transfemoral group received open access of the femoral and/or external iliac artery. In the transapical group, the left ventricular apex was identified with fluoroscopy and a left thoracotomy was performed. The following operative principles were applied to both groups: (a) root angiography was used to position the image intensifier along the orthogonal plane to the nadir of the three aortic valve sinuses; (b) predilation balloon aortic valvuloplasty was done under rapid ventricular pacing; and (c) valve positioning was done with fluoroscopy and angiography. Categorical data are reported as count (percent) and continuous data as median (minimum, maximum). Categorical variables were analyzed using the Fisher’s exact test and continuous variables with the Wilcoxon rank sum test for medians. Event data were summarized by frequencies and log-rank statistics. Survival estimates were calculated with the Kaplan–Meier method. All statistics were held at the a-level of 0.05 and computed using JMP 9.0.1 software. RESULTS Two hundred patients received either transfemoral (n ¼ 100) or transapical (n ¼ 100) transcatheter aortic valve replacement. Patient characteristics of the two groups were generally similar (Table 1). The exceptions

TABLE 1 Baseline Patient Characteristics in the Transapical and Transfemoral Valve Replacement Groups Variable Continuous data Age (years) Last preoperative creatinine (mg/dL) Ejection fraction Society of Thoracic Surgeons predicted risk of mortality (%) Categorical data Sex, male Diabetes Hypertension Chronic lung disease Immunosuppression Peripheral vascular disease Cerebrovascular disease Prior coronary artery bypass graft surgery Prior valve procedure New York Heart Association functional class III/IV Atrial arrhythmia Mitral insufficiency moderate/severe

Transapical Valve Replacement (n = 100)

Transfemoral Valve Replacement (n = 100)

Median (minimum, maximum) 82 (62, 95) 81 (54, 94) 1.2 (0.4, 6.8) 1.1 (0.5, 2.9) 0.61 (0.20, 0.75) 0.60 (0.15, 0.78) 8.3 (1.8, 27.9) 7.6 (0.6, 23.7) Count and percent 52 58 46 38 89 87 54 65 13 14 74 44 37 14 49 30 23 30 81 88 27 25 24 26

P-Value

0.205 0.907 0.642 0.249 0.477 0.316 0.828 0.150 1.000 85%) of which were transapical.4 In the FRANCE 2 registry, moderate/severe paravalvular regurgitation was present in 264 of 1418 transfemoral procedures (18.6%), but in only 30 of 334 transapical procedures (8.9%, post-hoc Fisher’s exact test p < 0.001).5 The association of increased prevalence of paravalvular regurgitation with the transfemoral approach has been minimized.2 Although the present study did not show a survival detriment related to paravalvular regurgitation, the PARTNER trial investigators report reduced survival associated with this finding.15,16 It is unclear as to why the transfemoral procedure would result in a higher prevalence of paravalvular regurgitation. It has been thought that the transapical technique allowed for more accurate placement of the valve. However, data from a study by Dvir and colleagues that quantified SAPIEN valve movement during deployment disputes that theory.17 This study reported that in a group of 68 patients, the device moved 2  1.4 mm into the aorta with valve deployment. There was no difference, however, in the amount of movement between the transfemoral (1.78  1.41 mm) and transapical (2.39  1.43 mm) approaches (p ¼ 0.11). Also of importance, the authors reported no correlation between device position and hemodynamic result. The present study reports similar mortality rates for both the transapical procedure and the transfemoral

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technique. This finding is contrary to that reported in other studies.1,2 However, most of the case series are inclusive of the reporting-center’s entire experience.12,14,18–20 This is an important point because the learning curves of the two techniques may be different. Based on this assumption, the rates of complications and mortality associated with the early operative experience may inordinately affect the reported outcomes. For example, the mortality rate was 10.6% in the 104 transapical patients in the PARTNER trial, but was only 8.8% in the subsequent 975 patients who received operation in the continued access program.6 Although the authors report the difference was not statistically significant (p ¼ 0.54), the trend suggests that this is important since the more the experience with a technique, the better the outcomes. Our study attempts to compensate for the learning curve with transcatheter valve replacement. The reported number of cases required to overcome the learning curve varies from 18 to 100.7–10 Alli et al. reported a shorter learning curve associated with the transapical procedure (18 cases) in comparison to the transfemoral procedure (36 cases)8; while Lichtenstein, D’Ancona, and colleagues reported much greater cases numbers (70 and 100, respectively) required to overcome the learning curve associated with the transapical procedure.9,10 The numbers needed to obtain proficiency are unfortunately not known and not universally accepted. The present study has several limitations, the most important being the small number of patients in the study. There is limited power to detect differences in outcomes between the two transcatheter valve replacement techniques; and the risk of both false positive and false negative results needs to be considered in this context. To address the issue, an adequate sample size of 1141 patients per group would be required to detect a 50% difference in the reported mortality. This is assuming 80% power (test of independent proportions; two-sided alpha ¼ 0.05). Also of concern is that we arbitrarily defined the number of learning curve cases, which made reporting and analyzing the data simpler. Patients in the transapical treatment group have greater prevalence of arteriosclerosis as an operative risk factor, but they have less prevalence of the operative complications of vascular injury and paravalvular regurgitation in comparison to the transfemoral group. In spite of the differences, operative mortality and one-year survival are similar between the two groups. Further study is necessary to corroborate our findings. Given the inherent selection bias associated with current treatment paradigms, a prospective study is needed to determine the best method of transcatheter aortic valve replacement. REFERENCES 1. Li X, Kong M, Jiang D, et al: Comparison 30-day clinical complications between transfemoral versus transapical aortic valve replacement for aortic stenosis: A metaanalysis review. J Cardiothorac Surg 2013;8:168.

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2. Gaasch W, D’Agnostino RS: Transcatheter aortic valve implantation: The transfemoral versus the transapical approach. Ann Cardiothorac Surg 2012;1:200–205. 3. Smith CR, Leon MB, Mack MJ, et al: Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med 2011;364:2187–2198. 4. Moat NE, Ludman P, de Belder MA, et al: Long-term outcomes after transcatheter aortic valve implantation in high-risk patients with severe aortic stenosis. J Am Coll Cardiol 2011;58:2130–2138. 5. Gilard M, Eltchaninoff H, Iung B, et al: Registry of transcatheter aortic-valve implantation in high-risk patients. N Engl J Med 2012;366:1705–1715. 6. Dewey TM, Bowers B, Thourani VH, et al: Transapical aortic valve replacement for severe aortic stenosis: Results from the nonrandomized continued access cohort of the PARTNER trial. Ann Thorac Surg 2013; in press. 7. Alli OO, Booker JD, Lennon RJ, et al: Transcatheter aortic valve implantation. J Am Coll Cardiol Interv 2012;5:72–79. 8. Alli O, Rihal C, Suri R, et al: TCT-747 Transcatheter aortic valve replacement assessment of the learning curve based on the PARTNER trial. J Am Coll Cardiol 2013;62 (18_S1):B227–B228. 9. Lichtenstein KM, Kim JM, Gao M, et al: Surgical risk algorithm as a measure of successful adoption of transapical transcatheter aortic valve implantation. J Thorac Cardiovasc Surg 2013; in press. 10. D’Ancona G, Pasic M, Unbehaun A, et al: Transapical aortic valve implantation: Learning curve with reduced operating time and radiation exposure. Ann Thorac Surg 2013; in press. 11. Kappatein AP, Head SJ, Genereux P, et al: Updated standardized endpoint definitions for transcatheter aortic valve implantation. J Am Coll Cardiol 2012;60:1438–1454. 12. van der Boon RM, Marcheix B, Tchetche D, et al: Transapical versus transfemoral aortic valve implantation:

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A multicenter collaborative study. Ann Thorac Surg 2013; in press. Nakamura M, Chakravarty T, Jilaihawi H, et al: Complete percutaneous approach for arterial access in transfemoral transcatheter aortic valve replacement—A comparison with surgical cutdown and closure. Catheter Cardiovasc Interv 2013; in press. Ewe SH, Delgado V, Ng ACT, et al: Outcomes after transcatheter aortic valve implantation: Transfemoral versus transapical approach. Ann Thorac Surg 2011;92:1244–1251. Kodali SK, Williams MR, Smith CR, et al: Two-year outcomes after transcatheter or surgical aortic-valve replacement. N Engl J Med 2012;366:1686–1695. Hahn RT, Pibarot P, Stewart WJ, et al: Comparison of transcatheter and surgical aortic valve replacement in severe aortic stenosis. J Am Coll Cardiol 2013;61:2514– 2521. Dvir D, Lavi I, Eltchaninoff H, et al: Multicenter evaluation of Edwards SAPIEN positioning during transcatheter aortic valve implantation with correlates for device movement during final deployment. J Am Coll Cardiol Interv 2012;5:563–570. Bleizifier S, Ruge H, Mazzitelli D, et al: Survival after transapical and transfemoral valve implantation: Talking about two different patient populations. J Thorac Cardiovasc Surg 2009;138:1073–1080. Himbert D, Descoutures F, Al-Attar N, et al: Results of transfemoral or transapical aortic valve implantation following a uniform assessment in high-risk patients with aortic stenosis. J Am Coll Cardiol 2009;54:303– 311. Johansson M, Nozohoor S, Kimblad PO, et al: Transapical versus transfemoral aortic valve implantation: A comparison of survival and safety. Ann Thorac Surg 2011;91: 57–63.

Beyond the learning curve: transapical versus transfemoral transcatheter aortic valve replacement in the treatment of severe aortic valve stenosis.

Most studies comparing transapical and transfemoral transcatheter aortic valve replacement include the center's early operative experience, which may ...
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