Michael J. Mack M.D.

Gaudino, M., M. J. Mack and D. P. Taggart (2018). “Additional arterial conduits in coronary artery bypass surgery: Finally coming of age.” J Thorac Cardiovasc Surg 156(2): 541-543.

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At 50 years, CABG has entered a mature phase. It is now time to clarify the effect of procedural characteristics on clinical outcomes and to define the most appropriate strategy for each individual patient. Observational data have intrinsic biases and should only be considered hypothesis-generating. Randomized trials remain the only way to solve the conundrum of arterial grafts. International collaboration will be key to the success of this process. (Excerpt from text, p. 543; no abstract available.)

Kavinsky, C. J., M. F. Poulin and M. J. Mack (2018). “Training in Structural Heart Disease: Call to Action.” Circulation 138(3): 225-228.

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Catheter-based therapies for congenital and structural heart diseases (SHDs) have come a long way since the pioneering work of Terry King in 1976 with the first percutaneous atrial septal defect closure, the first mitral balloon valvuloplasty by Kanji Inoue in 1984, and the first percutaneous valve replacements by Philipp Bonhoeffer and Alain Cribier in the early 2000s. More than 100 000 transcatheter aortic valve replacements (TAVRs) have been performed in the United States, and the yearly number of TAVR implants now exceeds that of isolated surgical aortic valve replacements. If the ongoing TAVR trials for low-risk patients demonstrate equivalence with surgery, we can expect another surge in demand for TAVR procedures. Similarly, percutaneous mitral valve repair procedures have now climbed to >15 000 in the United States.1 In addition, several percutaneous therapies for tricuspid and mitral valve repair and replacement are currently in the pipeline and will fuel continued growth in percutaneous therapies for SHD in the coming years. Recent Food and Drug Administration approvals of devices to close the left atrial appendage and patent foramen ovale further highlight this point. Furthermore, the number of adults with congenital heart disease (CHD) now exceeds the number of affected children, and many of these patients will require additional catheterization procedures. It is paradoxical that this nascent field has been devoid of formalized training paradigms. There is a clear and unmet need for defining the training requirements of physicians intending to perform SHD interventions. We need to ensure that future proceduralists will possess the appropriate cognitive and technical skill sets required to safely and effectively perform these interventions. (Excerpt from text, p. 225; no abstract available.)

Tang, G. H. L., S. Zaid, I. George, O. K. Khalique, Y. Abramowitz, Y. Maeno, R. R. Makkar, H. Jilaihawi, N. Kamioka, V. H. Thourani, V. Babaliaros, J. G. Webb, N. M. Htun, A. Attinger-Toller, H. Ahmad, R. Kaple, K. Sharma, J. A. Kozina, T. Kaneko, P. Shah, S. A. Hirji, N. D. Desai, S. Anwaruddin, D. Jagasia, H. C. Herrmann, S. S. Basra, M. A. Szerlip, M. J. Mack, M. Mathur, C. W. Tan, C. W. Don, R. Sharma, S. Gafoor, M. Zhang, S. R. Kapadia, S. L. Mick, A. Krishnaswamy, N. Amoroso, A. Salemi, S. C. Wong, A. S. Kini, J. Rodes-Cabau, M. B. Leon and S. K. Kodali (2018). “Impact of Aortic Root Anatomy and Geometry on Paravalvular Leak in Transcatheter Aortic Valve Replacement With Extremely Large Annuli Using the Edwards SAPIEN 3 Valve.” JACC Cardiovasc Interv Jun 26. [Epub ahead of print].

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OBJECTIVES: The aim of this study was to determine factors affecting paravalvular leak (PVL) in transcatheter aortic valve replacement (TAVR) with the Edwards SAPIEN 3 (S3) valve in extremely large annuli. BACKGROUND: The largest recommended annular area for the 29-mm S3 is 683 mm(2). However, experience with S3 TAVR in annuli >683 mm(2) has not been widely reported. METHODS: From December 2013 to July 2017, 74 patients across 16 centers with mean area 721 +/- 38 mm(2) (range: 684 to 852 mm(2)) underwent S3 TAVR. The transfemoral approach was used in 95%, and 39% were under conscious sedation. Patient, anatomic, and procedural characteristics were retrospectively analyzed. Valve Academic Research Consortium-2 outcomes were reported. RESULTS: Procedural success was 100%, with 2 deaths, 1 stroke, and 2 major vascular complications at 30 days. Post-dilatation occurred in 32%, with final balloon overfilling (1 to 5 ml extra) in 70% of patients. Implantation depth averaged 22.3 +/- 12.4% at the noncoronary cusp and 20.7 +/- 9.9% at the left coronary cusp. New left bundle branch block occurred in 17%, and 6.3% required new permanent pacemakers. Thirty-day echocardiography showed mild PVL in 22.3%, 6.9% moderate, and none severe. There was no annular rupture or coronary obstruction. Mild or greater PVL was associated with larger maximum annular and left ventricular outflow tract (LVOT) diameters, larger LVOT area and perimeter, LVOT area greater than annular area, and higher annular eccentricity. CONCLUSIONS: TAVR with the 29-mm S3 valve beyond the recommended range by overexpansion is safe, with acceptable PVL and pacemaker rates. Larger LVOTs and more eccentric annuli were associated with more PVL. Longer term follow-up will be needed to determine durability of S3 TAVR in this population.

Sathananthan, J., D. J. Murdoch, B. R. Lindman, A. Zajarias, W. A. Jaber, P. Cremer, D. Wood, R. Moss, A. Cheung, J. Ye, R. T. Hahn, A. Crowley, M. B. Leon, M. J. Mack and J. G. Webb (2018). “Implications of Concomitant Tricuspid Regurgitation in Patients Undergoing Transcatheter Aortic Valve Replacement for Degenerated Surgical Aortic Bioprosthesis: Insights From the PARTNER 2 Aortic Valve-in-Valve Registry.” JACC Cardiovasc Interv 11(12): 1154-1160.

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OBJECTIVES: The aim of this study was to assess the implications of concomitant tricuspid regurgitation (TR) in patients undergoing valve-in-valve (VIV) transcatheter aortic valve replacement. BACKGROUND: Patients undergoing VIV transcatheter aortic valve replacement with concomitant TR may have worse outcomes, and optimal management remains undetermined. METHODS: The multicenter PARTNER 2 (Placement of Aortic Transcatheter Valves) VIV trial enrolled patients with symptomatic degenerated surgical aortic bioprostheses who were at high risk for reoperation. Outcomes were assessed between patients with mild or no TR versus moderate or severe TR. RESULTS: A total of 237 patients underwent VIV procedures (mean age 78.7 +/- 10.8 years, mean Society of Thoracic Surgeons score 9.1 +/- 4.8%). In this cohort, 162 patients (68.4%) had mild or no TR, and 75 patients (31.6%) had moderate or severe TR. Although there was no difference in New York Heart Association functional class III or IV symptomatic status (89.3% vs. 91.4%; p = 0.62) or moderate or severe right ventricular dysfunction (9.4% vs. 16.9%; p = 0.11), patients with moderate or severe TR were more likely to be at high surgical risk, with a Society of Thoracic Surgeons score of >8 (62.7% vs 46.9%; p = 0.02). There was no difference in a composite endpoint of death and rehospitalization between moderate or severe TR and mild or no TR, either at 30 days (10.7% vs. 9.9%; p = 0.85) or at 1-year follow-up (24.1% vs. 23.2%; p = 0.80). There was a significant reduction in overall moderate or severe TR from baseline at 30 days (31.1% vs. 21.1%; p = 0.002), which was sustained at 1-year follow-up (38.0% vs. 22.8%; p = 0.004). CONCLUSIONS: Despite higher predicted surgical risk, the presence of TR was not a predictor of long-term outcomes. Importantly, there was significant reduction in TR severity at both short- and long-term follow-up. In selected patients undergoing VIV transcatheter aortic valve replacement, it may be appropriate to conservatively manage concomitant TR.

Mack, M. J. and D. R. Holmes, Jr. (2018). “RESPONSE: Heart Team Training Results in Improved Care and Lasting Relationships: Room for Growth.” J Am Coll Cardiol 71(23): 2704-2705.

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The multidisciplinary team-based approach to medical care is, of course, not new. There are numerous examples where specialists from different disciplines have collaborated to deliver integrated, disease-based care. Examples include tumor boards where medical oncologists, radiation therapists, surgeons, and other specialties team together to determine best treatment options for individual patients. The field of organ transplantation also includes a collaborative team-based approach with multiple medical specialties focused on delivering best patient care. The multidisciplinary approach to cardiac care is also not new, as we are reminded by Dr. Robert Frye from the Mayo Clinic that interdisciplinary team-based care was standard practice in the 1950s. After decades of underemployment, the “heart team” has re-emerged over the past decade and a half to create an integrated culture of care for various cardiac diseases . . . One of the benefits of this approach that was not obvious in the early stages, at least to us, was its potential effect on cardiac surgical training. Around the same time as the heart team re-emerged in 2007, a new program for training cardiac surgeons was created. The “I-6” pathway was developed with 2 goals: to shorten the time required to complete surgical training, and to focus the trainees’ experience more on cardiac and thoracic diseases and less on general surgery as in the traditional cardiac surgery training programs. As can be seen from the experience detailed above by Drs. Han and Brown, these 2 paradigm shifts, implementation of the heart team and creation of the I-6 programs, have become synergistic in training the new generation of cardiovascular surgeons. The integrated, team-based approach to patient care as a consequence of the heart team has served as an optimal training platform for the latest generation of cardiac surgeons. However, the authors relate that the benefits have exceeded just the educational experience by creating a cultural environment that has also led to the development of close professional and personal relationships. (Excerpt from text, p. 2704; no abstract available.)