Michael J. Mack M.D.

Mack, M. J. (2016). “The harder one looks, the more one finds.” J Thorac Cardiovasc Surg 152(1): 5-6.

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The article by Gleason and colleagues in this issue of the Journal reports the risk and extent of neurologic injury in high risk patients with aortic stenosis undergoing either transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). The study reports the rate of stroke at 30 days, 1 year, and 2 years postprocedure in the 750 patients enrolled in the Corevalve High-Risk Study. They found no difference in stroke between the TAVR and SAVR groups at 30 days and 1 year, but a higher incidence of stroke at 2 years in the group undergoing SAVR.

Leon, M. B., C. R. Smith, M. J. Mack, R. R. Makkar, L. G. Svensson, S. K. Kodali, V. H. Thourani, E. M. Tuzcu, D. C. Miller, H. C. Herrmann, D. Doshi, D. J. Cohen, A. D. Pichard, S. Kapadia, T. Dewey, V. Babaliaros, W. Y. Szeto, M. R. Williams, D. Kereiakes, A. Zajarias, K. L. Greason, B. K. Whisenant, R. W. Hodson, J. W. Moses, A. Trento, D. L. Brown, W. F. Fearon, P. Pibarot, R. T. Hahn, W. A. Jaber, W. N. Anderson, M. C. Alu and J. G. Webb (2016). “Transcatheter or surgical aortic-valve replacement in intermediate-risk patients.” N Engl J Med 374(17): 1609-1620.

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BACKGROUND: Previous trials have shown that among high-risk patients with aortic stenosis, survival rates are similar with transcatheter aortic-valve replacement (TAVR) and surgical aortic-valve replacement. We evaluated the two procedures in a randomized trial involving intermediate-risk patients. METHODS: We randomly assigned 2032 intermediate-risk patients with severe aortic stenosis, at 57 centers, to undergo either TAVR or surgical replacement. The primary end point was death from any cause or disabling stroke at 2 years. The primary hypothesis was that TAVR would not be inferior to surgical replacement. Before randomization, patients were entered into one of two cohorts on the basis of clinical and imaging findings; 76.3% of the patients were included in the transfemoral-access cohort and 23.7% in the transthoracic-access cohort. RESULTS: The rate of death from any cause or disabling stroke was similar in the TAVR group and the surgery group (P=0.001 for noninferiority). At 2 years, the Kaplan-Meier event rates were 19.3% in the TAVR group and 21.1% in the surgery group (hazard ratio in the TAVR group, 0.89; 95% confidence interval [CI], 0.73 to 1.09; P=0.25). In the transfemoral-access cohort, TAVR resulted in a lower rate of death or disabling stroke than surgery (hazard ratio, 0.79; 95% CI, 0.62 to 1.00; P=0.05), whereas in the transthoracic-access cohort, outcomes were similar in the two groups. TAVR resulted in larger aortic-valve areas than did surgery and also resulted in lower rates of acute kidney injury, severe bleeding, and new-onset atrial fibrillation; surgery resulted in fewer major vascular complications and less paravalvular aortic regurgitation. CONCLUSIONS: In intermediate-risk patients, TAVR was similar to surgical aortic-valve replacement with respect to the primary end point of death or disabling stroke.

Mack, M. and H. Baumgarten (2016). “Just because you get on a scale doesn’t mean you lose weight: Is meetbaar beter really measurably better?” Eur J Cardiothorac Surg 49(6): 1669-1670.

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The article by van Veghel et al. [1] describes a national initiative in the Netherlands termed ‘Meetbaar Beter’ or in English ‘Measurably Better’. The stated goal of this multicentre effort according to its website ‘aims to improve quality and transparency of care for patients with heart diseases by measuring limited patient-relevant outcome measures’. Those outcomes include survival, degree of health/recovery, time to recovery and return to normal activity, disutility of the care of treatment process, sustainability of health/recovery and nature of recurrences and long-term consequences of the therapy. By doing this, they are proposing to implement a ‘Value Based Healthcare Theory’ by ‘measuring patient relevant outcomes and sharing and adopting each others best practices’.

McCabe, J. M., P. H. Huang, D. J. Cohen, E. H. Blackstone, F. G. Welt, M. J. Davidson, T. Kaneko, M. H. Eng, K. B. Allen, K. Xu, A. M. Lowry, Y. Lei, J. Rajeswaran, D. L. Brown, M. J. Mack, J. G. Webb, C. R. Smith, M. B. Leon and A. C. Eisenhauer (2016). “Surgical versus percutaneous femoral access for delivery of large-bore cardiovascular devices (from the partner trial).” Am J Cardiol 117(10): 1643-1650.

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It is unclear if surgical exposure confers a risk advantage compared with a percutaneous approach for patients undergoing endovascular procedures requiring large-bore femoral artery access. From the randomized controlled Placement of Aortic Transcatheter Valve trials A and B and the continued access registries, a total of 1,416 patients received transfemoral transcatheter aortic valve replacement, of which 857 underwent surgical, and 559 underwent percutaneous access. Thirty-day rates of major vascular complications and quality of life scores were assessed. Propensity matching was used to adjust for unmeasured confounders. Overall, there were 116 major vascular complications (8.2%). Complication rates decreased dramatically during the study period. In unadjusted analysis, major vascular complications were significantly less common in the percutaneous access group (35 [6.3%] vs 81 [9.5%] p = 0.032). However, among 292 propensity-matched pairs, there was no difference in major vascular complications (22 [7.5%] vs 28 [9.6%], p = 0.37). Percutaneous access was associated with fewer total in-hospital vascular complications (46 [16%] vs 66 [23%], p = 0.036), shorter median procedural duration (97 interquartile range [IQR 68 to 166] vs 121 [IQR 78 to 194] minutes, p <0.0001), and median length of stay (4 [IQR 2 to 8] vs 6 [IQR 3 to 10] days, p <0.0001). There were no significant differences in quality of life scores at 30 days. Surgical access for large-bore femoral access does not appear to confer any advantages over percutaneous access and may be associated with more minor vascular complications.

Hamm, C. W., M. Arsalan and M. J. Mack (2016). “The future of transcatheter aortic valve implantation.” European Heart Journal 37(10): 803-U876.

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Since the introduction of transcatheter aortic valve implantation (TAVI) into clinical practice, the treatment of aortic stenosis has changed dramatically. In the past, medical therapy with or without balloon aortic valvuloplasty was the only option for inoperable patients. More recently, TAVI has become the treatment of choice for these patients and the preferred alternative for high-risk operable patients. Surgical aortic valve replacement (SAVR) currently remains the gold standard for patients at low or intermediate operative risk. As randomized trials have demonstrated comparable results between TAVI and SAVR in the high-risk population, there is now a clear trend towards performing TAVI even in intermediate-risk patients while awaiting the results of randomized trials in that population. Nevertheless, there are still questions regarding TAVI involving paravalvular leak (PVL), stroke, pacemaker requirements, and durability that remain to be more definitively answered before TAVI can routinely be performed in a broader, lower risk population. Improvements in patient selection, imaging, and second and third generation devices have decreased the incidence of PVLs and vascular complications that followed the earliest TAVI procedures, but the rates of perioperative stroke and permanent pacemaker implantation must still be addressed. Furthermore, the long-term durability of TAVI devices and a role for post-procedure antithrombotic management remain unanswered. Until these questions are more clearly answered, it is the Heart Team’s task to determine the optimal treatment for each patient based on risk scores, frailty metrics, comorbidities, patient preference, and potential for improvement in quality of life.