Long-Term Outcomes of Mosaic Versus Perimount Mitral Replacements: 17-Year Follow-Up of 940 Implants

Background. The objective of this study was to compare long-term outcomes of Mosaic (Medtronic, Minneapolis, MN) porcine mitral valves to Carpentier-Edwards (Edwards Lifesciences, Irving, CA) bovine pericardial mitral valves. Methods. From 2001 through 2017 at a single institution, 940 patients received a mitral bioprosthesis, of which 463 (49.3%) were porcine and 477 (50.7%) were bovine pericardial. Retrospective review of the procedure and the postoperative clinical course, including echocardiography, through August 2018 were analyzed. All consecutive mitral valve replacements over the study period were included. Follow-up was 99% (929 patients) complete for a total of 6045 patient-years (mean, 6.4 +/- 4.5 years). A propensity-matched cohort of 802 mitral bioprosthesis was used for outcome analyses. Results. Operative mortality of the 940 patients was 5.4% (n = 51) and incidence of postoperative stroke was 2.1% (n = 20). Overall survival of the propensitymatched patients at 10 and 15 years was 49.7% (95% confidence interval [CI] 45.5%-53.7%) and 23.3% (95% CI 17.9%-29.3%), respectively. Survival at 15 years was 24.0% (95% CI 18.0%-30.5%) for porcine and 16.5% (95% CI 5.5%-32.6%) for bovine implants, which was not significantly different (P = .67). Overall cumulative incidence for reoperative structural valve deterioration at 15 years was 7.9% (95% CI 4.7%- 12.3%) for porcine valves versus 13.2% (95% CI 8.1%-19.5%) for pericardial valves (P <.001). For patients age younger than 65 years, structural valve deterioration at 15 years was 15.8% (95% CI 7.4%-27.0%) versus 30.2% (95% CI 15.1%-46.8%) for porcine and pericardial valves, respectively (P = .009). Overall average time to reoperation for structural valve deterioration for porcine valves was 11.1 +/- 2.3 years vs 6.8 +/- 2.3 years for bovine pericardial valves (P <.001). Conclusions. In long-term follow-up, of patients younger than 65 years of age undergoing mitral valve replacement, bovine pericardial valves experienced earlier and more frequent structural valve deterioration than porcine valves. (C) 2020 by The Society of Thoracic Surgeons.