Long-Term Outcomes of Bovine versus Porcine Mitral Valve Replacement: A Multicenter Analysis

Abstract

Introduction. Recent national guidelines recommending mitral valve replacement (MVR) for severe secondary mitral regurgitation have resulted in an increased utilization of mitral bioprosthesis. There is a paucity of data on how longitudinal clinical outcomes vary by prosthesis type. We examined long-term survival and risk of reoperation between patients having bovine vs. porcine MVR. Study Design. A retrospective analysis of MVR or MVR + coronary artery bypass graft (CABG) from 2001 to 2017 among seven hospitals reporting to a prospectively maintained clinical registry was conducted. The analytic cohort included 1,284 patients undergoing MVR (801 bovine and 483 porcine). Baseline comorbidities were balanced using 1 : 1 propensity score matching with 432 patients in each group. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation. Results. In the overall cohort, patients receiving porcine valves were more likely to have diabetes (19% bovine vs. 29% porcine; $p<0.001$ ), COPD (20% bovine vs. 27% porcine; $p=0.008$ ), dialysis or creatinine >2 mg/dL (4% bovine vs. 7% porcine; $p=0.03$ ), and coronary artery disease (65% bovine vs. 77% porcine; $p<0.001$ ). There was no difference in stroke, acute kidney injury, mediastinitis, pneumonia, length of stay, in-hospital morbidity, or 30-day mortality. In the overall cohort, there was a difference in long-term survival (porcine HR 1.17 (95% CI: 1.00–1.37; $p=050$ )). However, there was no difference in reoperation (porcine HR 0.56 (95% CI: 0.23–1.32; $p=0.185$ )). In the propensity-matched cohort, patients were matched on all baseline characteristics. There was no difference in postoperative complications or in-hospital morbidity and 30-day mortality. After 1 : 1 propensity score matching, there was no difference in long-term survival (porcine HR 0.97 (95% CI: 0.81–1.17; $p=0.756$ )) or risk of reoperation (porcine HR 0.54 (95% CI: 0.20–1.47; $p=0.225$ )). Conclusions. In this multicenter analysis of patients undergoing bioprosthetic MVR, there was no difference in perioperative complications and risk of reoperation of long-term survival after matching.