Bovine pericardial versus porcine mitral valve replacement: a propensity-matched analysis of mid-term durability outcomes

OBJECTIVES The optimal choice of bioprosthetic valve for mitral valve replacement (MVR) remains controversial, with prior studies reporting inconsistent outcomes. This study aimed to compare mid-term clinical performance between bovine pericardial and porcine bioprostheses using a hierarchical composite end-point reflecting both durability and clinical relevance, including cardiac death, reoperation, and haemodynamic structural valve deterioration (SVD). METHODS This retrospective study included 304 patients (152 per group) who underwent bioprosthetic MVR between 2007 and 2020, following 1:1 propensity score matching. The primary outcome was a hierarchical composite of cardiac death, reoperation for SVD, and echocardiographic diagnosis of haemodynamic SVD. Secondary outcomes included overall survival and perioperative complications. RESULTS The median clinical follow-up durations were 7.3 years in the bovine group and 5.3 years in the porcine group. The win ratio was 1.49 (95% CI: 1.21–1.83; P < 0.001), indicating a statistically significant difference favouring the bovine group. While overall survival and freedom from cardiac death were comparable between groups, the cumulative incidence of reoperation for SVD and haemodynamic SVD diagnosis were significantly higher in the porcine group (Gray’s P = 0.031 and 0.037, respectively). CONCLUSIONS In this propensity-matched analysis, bovine pericardial valves showed a modest, consistent mid-term durability signal on SVD-related components, with similar overall survival. These findings are hypothesis-generating and should inform individualised prosthesis selection rather than dictate device choice; model-specific prospective studies, ideally randomized controlled trials, are needed for definitive guidance.