Michael J. Mack M.D.

Friedman, D. J., J. P. Piccini, T. Wang, J. Zheng, S. C. Malaisrie, D. R. Holmes, R. M. Suri, M. J. Mack, V. Badhwar, J. P. Jacobs, J. G. Gaca, S. C. Chow, E. D. Peterson and J. M. Brennan (2018). “Association Between Left Atrial Appendage Occlusion and Readmission for Thromboembolism Among Patients With Atrial Fibrillation Undergoing Concomitant Cardiac Surgery.” JAMA 319(4): 365-374.

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Importance: The left atrial appendage is a key site of thrombus formation in atrial fibrillation (AF) and can be occluded or removed at the time of cardiac surgery. There is limited evidence regarding the effectiveness of surgical left atrial appendage occlusion (S-LAAO) for reducing the risk of thromboembolism. Objective: To evaluate the association of S-LAAO vs no receipt of S-LAAO with the risk of thromboembolism among older patients undergoing cardiac surgery. Design, Setting, and Participants: Retrospective cohort study of a nationally representative Medicare-linked cohort from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2012). Patients aged 65 years and older with AF undergoing cardiac surgery (coronary artery bypass grafting [CABG], mitral valve surgery with or without CABG, or aortic valve surgery with or without CABG) with and without concomitant S-LAAO were followed up until December 31, 2014. Exposures: S-LAAO vs no S-LAAO. Main Outcomes and Measures: The primary outcome was readmission for thromboembolism (stroke, transient ischemic attack, or systemic embolism) at up to 3 years of follow-up, as defined by Medicare claims data. Secondary end points included hemorrhagic stroke, all-cause mortality, and a composite end point (thromboembolism, hemorrhagic stroke, or all-cause mortality). Results: Among 10524 patients undergoing surgery (median age, 76 years; 39% female; median CHA2DS2-VASc score, 4), 3892 (37%) underwent S-LAAO. Overall, at a mean follow-up of 2.6 years, thromboembolism occurred in 5.4%, hemorrhagic stroke in 0.9%, all-cause mortality in 21.5%, and the composite end point in 25.7%. S-LAAO, compared with no S-LAAO, was associated with lower unadjusted rates of thromboembolism (4.2% vs 6.2%), all-cause mortality (17.3% vs 23.9%), and the composite end point (20.5% vs 28.7%) but no significant difference in rates of hemorrhagic stroke (0.9% vs 0.9%). After inverse probability-weighted adjustment, S-LAAO was associated with a significantly lower rate of thromboembolism (subdistribution hazard ratio [HR], 0.67; 95% CI, 0.56-0.81; P < .001), all-cause mortality (HR, 0.88; 95% CI, 0.79-0.97; P = .001), and the composite end point (HR, 0.83; 95% CI, 0.76-0.91; P < .001) but not hemorrhagic stroke (subdistribution HR, 0.84; 95% CI, 0.53-1.32; P = .44). S-LAAO, compared with no S-LAAO, was associated with a lower risk of thromboembolism among patients discharged without anticoagulation (unadjusted rate, 4.2% vs 6.0%; adjusted subdistribution HR, 0.26; 95% CI, 0.17-0.40; P < .001), but not among patients discharged with anticoagulation (unadjusted rate, 4.1% vs 6.3%; adjusted subdistribution HR, 0.88; 95% CI, 0.56-1.39; P = .59). Conclusions and Relevance: Among older patients with AF undergoing concomitant cardiac surgery, S-LAAO, compared with no S-LAAO, was associated with a lower risk of readmission for thromboembolism over 3 years. These findings support the use of S-LAAO, but randomized trials are necessary to provide definitive evidence.

Bapat, V., V. Rajagopal, C. Meduri, R. S. Farivar, A. Walton, S. J. Duffy, R. Gooley, A. Almeida, M. J. Reardon, N. S. Kleiman, K. Spargias, S. Pattakos, M. K. Ng, M. Wilson, D. H. Adams, M. Leon, M. J. Mack, S. Chenoweth and P. Sorajja (2018). “Early Experience With New Transcatheter Mitral Valve Replacement.” J Am Coll Cardiol 71(1): 12-21.

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BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a potential therapy for patients with symptomatic, severe mitral regurgitation (MR). The feasibility of this therapy remains to be defined. OBJECTIVES: The authors report their early experience with TMVR using a new valve system. METHODS: The valve is a self-expanding, nitinol valve with bovine pericardial leaflets that is placed using a transapical delivery system. Patients with symptomatic MR who were deemed high or extreme risk by the local heart teams were enrolled in a global pilot study at 14 sites (United States, Australia, and Europe). RESULTS: Fifty consecutively enrolled patients (mean age: 73 +/- 9 years; 58.0% men; 84% secondary MR) underwent TMVR with the valve. The mean Society for Thoracic Surgery score was 6.4 +/- 5.5%; 86% of patients were New York Heart Association functional class III or IV, and the mean left ventricular ejection fraction was 43 +/- 12%. Device implant was successful in 48 patients with a median deployment time of 14 min (interquartile range: 12 to 17 min). The 30-day mortality was 14%, with no disabling strokes, or repeat interventions. Median follow-up was 173 days (interquartile range: 54 to 342 days). At latest follow-up, echocardiography confirmed mild or no residual MR in all patients who received implants. Improvements in symptom class (79% in New York Heart Association functional class I or II at follow-up; p < 0.0001 vs. baseline) and Minnesota Heart Failure Questionnaire scores (56.2 +/- 26.8 vs. 31.7 +/- 22.1; p = 0.011) were observed. CONCLUSIONS: TMVR with the valve was feasible in a study group at high or extreme risk for conventional mitral valve replacement. These results inform trial design of TMVR in lower-risk patients with severe mitral valve regurgitation (Evaluation of the Safety and Performance of the Twelve Intrepid Transcatheter Mitral Valve Replacement System in High Risk Patients with Severe, Symptomatic Mitral Regurgitation - The Twelve Intrepid TMVR Pilot Study.

Sorajja, P., S. Vemulapalli, T. Feldman, M. Mack, D. R. Holmes, Jr., A. Stebbins, S. Kar, V. Thourani and G. Ailawadi (2017). “Outcomes with transcatheter mitral valve repair in the united states: An sts/acc tvt registry report.” J Am Coll Cardiol 70(19): 2315-2327.

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BACKGROUND: Post-market surveillance is needed to evaluate the real-world clinical effectiveness and safety of U.S. Food and Drug Administration-approved devices. OBJECTIVES: The authors examined the commercial experience with transcatheter mitral valve repair for the treatment of mitral regurgitation. METHODS: Data from the Society of Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy Registry on patients commercially treated with transcatheter mitral valve repair were analyzed. The study population consisted of 2,952 patients treated at 145 hospitals between November 2013 and September 2015. In 1,867 patients, data were linked to patient-specific Centers for Medicare and Medicaid Services administrative claims for analyses. RESULTS: The median age was 82 years (55.8% men), with a median Society of Thoracic Surgery predicted risk of mortality of 6.1% (interquartile range: 3.7% to 9.9%) and 9.2% (interquartile range: 6.0% to 14.1%) for mitral repair and replacement, respectively. Overall, in-hospital mortality was 2.7%. Acute procedure success occurred in 91.8%. Among the patients with Centers for Medicare and Medicaid Services linkage data, the mortality at 30 days and at 1 year was 5.2% and 25.8%, respectively, and repeat hospitalization for heart failure at 1 year occurred in 20.2%. Variables associated with mortality or rehospitalization for heart failure after multivariate adjustment were increasing age, lower baseline left ventricular ejection fraction, worse post-procedural mitral regurgitation, moderate or severe lung disease, dialysis, and severe tricuspid regurgitation. CONCLUSIONS: Our findings demonstrate that commercial transcatheter mitral valve repair is being performed in the United States with acute effectiveness and safety. Our findings may help determine which patients have favorable long-term outcomes with this therapy.

Yoon, S. H., T. Schmidt, S. Bleiziffer, N. Schofer, C. Fiorina, A. J. Munoz-Garcia, E. Yzeiraj, I. J. Amat-Santos, D. Tchetche, C. Jung, B. Fujita, A. Mangieri, M. A. Deutsch, T. Ubben, F. Deuschl, S. Kuwata, C. De Biase, T. Williams, A. Dhoble, W. K. Kim, E. Ferrari, M. Barbanti, E. M. Vollema, A. Miceli, C. Giannini, G. F. Attizzani, W. K. F. Kong, E. Gutierrez-Ibanes, V. A. Jimenez Diaz, H. C. Wijeysundera, H. Kaneko, T. Chakravarty, M. Makar, H. Sievert, C. Hengstenberg, B. D. Prendergast, F. Vincent, M. Abdel-Wahab, L. Nombela-Franco, M. Silaschi, G. Tarantini, C. Butter, S. M. Ensminger, D. Hildick-Smith, A. S. Petronio, W. H. Yin, F. De Marco, L. Testa, N. M. Van Mieghem, B. K. Whisenant, K. H. Kuck, A. Colombo, S. Kar, C. Moris, V. Delgado, F. Maisano, F. Nietlispach, M. J. Mack, J. Schofer, U. Schaefer, J. J. Bax, C. Frerker, A. Latib and R. R. Makkar (2017). “Transcatheter aortic valve replacement in pure native aortic valve regurgitation.” J Am Coll Cardiol 70(22): 2752-2763.

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BACKGROUND: Limited data exist about safety and efficacy of transcatheter aortic valve replacement (TAVR) in patients with pure native aortic regurgitation (AR). OBJECTIVES: This study sought to compare the outcomes of TAVR with early- and new-generation devices in symptomatic patients with pure native AR. METHODS: From the pure native AR TAVR multicenter registry, procedural and clinical outcomes were assessed according to VARC-2 criteria and compared between early- and new-generation devices. RESULTS: A total of 331 patients with a mean STS score of 6.7 +/- 6.7 underwent TAVR. The early- and new-generation devices were used in 119 patients (36.0%) and 212 patients (64.0%), respectively. STS score tended to be lower in the new-generation device group (6.2 +/- 6.7 vs. 7.6 +/- 6.7; p = 0.08), but transfemoral access was more frequently used in the early-generation device group (87.4% vs. 60.8%; p < 0.001). Compared with the early-generation devices, the new-generation devices were associated with a significantly higher device success rate (81.1% vs. 61.3%; p < 0.001) due to lower rates of second valve implantation (12.7% vs. 24.4%; p = 0.007) and post-procedural AR >/= moderate (4.2% vs. 18.8%; p < 0.001). There were no significant differences in major 30-day endpoints between the 2 groups. The cumulative rates of all-cause and cardiovascular death at 1-year follow-up were 24.1% and 15.6%, respectively. The 1-year all-cause mortality rate was significantly higher in the patients with post-procedural AR >/= moderate compared with those with post-procedural AR /= moderate was independently associated with 1-year all-cause mortality (hazard ratio: 2.85; 95% confidence interval: 1.52 to 5.35; p = 0.001). CONCLUSIONS: Compared with the early-generation devices, TAVR using the new-generation devices was associated with improved procedural outcomes in treating patients with pure native AR. In patients with pure native AR, significant post-procedural AR was independently associated with increased mortality.

O’Gara, P. T., T. M. Sundt, M. A. Acker, T. E. David, R. E. Michler, M. A. Borger, G. Ailawadi, V. H. Thourani, A. M. Gillinov, R. J. Damiano, M. J. Mack, R. Lee, E. A. Rose, T. J. Gardner, M. A. Miller, R. D. Weisel and A. C. Gelijns (2017). “The cardiothoracic surgical trials network: Implications for clinical practice.” J Thorac Cardiovasc Surg 154(6): 1938-1956.

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Background: Postoperative recurrence (POR) of Crohn’s disease (CD) is common. Guidelines on POR management have recently been issued, but clinical practice may vary. Aims:To examine the current clinical practice of POR management in the USA Methods: A web-based survey was sent to all members of the American Gastroenterological Association and the American College of Gastroenterology. The survey consisted of multiple-choice questions with clinical scenarios to assess how participants manage POR. Results: A total of 189 responses were received from practices in 34 states. 44% of participants were from academic settings. The median number of CD patients seen each month was 20–30 patients per participant. The majority of participants considered smoking, prior intestinal surgery, penetrating disease, perianal fistula, early disease onset, and long extent of disease as high-risk factors for POR. To diagnose and grade endoscopic recurrence, 57% of participants used an endoscopic scoring system; 86% defined clinical recurrence using a combination of symptoms and endoscopic findings; and 79% of participants routinely performed colonoscopy after surgery. In high-risk patients, 65% offered medical prophylaxis—most often biologics and/or immunomodulators—immediately after surgery, while 34% offered medical prophylaxis regardless of the patient’s risk of POR. 64% of participants never stopped medical prophylaxis once initiated. Conclusions: Most gastroenterologists routinely perform colonoscopy to guide POR management. The majority of these providers continue medical prophylaxis indefinitely regardless of subsequent endoscopic findings. Further research is needed to determine the risks and benefits of continuing versus deescalating therapy in patients with potentially surgically induced remission.