BackgroundComparative studies of outcomes between different biological mitral valve prostheses are scarce. This study compares the late clinical results of valve replacement with the Epic and Mosaic bioprostheses. MethodsPatients undergoing isolated elective mitral valve replacement (MVR) between 2005 and 2019 were eligible for inclusion. Primary outcomes were freedom from mitral valve reintervention and overall survival. Inverse probability of treatment weighting and competing risk analyses were performed. ResultsMVR was performed in 247 (73.7%) patients with the Epic prosthesis and in 88 (26.3%) patients with the Mosaic prosthesis. The median follow-up was 3 (interquartile range, 0.20-5.64) years. At 10 years postoperative, the estimated survival rates were 86.1% (95% CI, 80.5%-91.9%) and 73.5% (95% CI, 60.6%-89.3%) for the Epic and Mosaic groups, respectively (P = .40). On inverse probability of treatment weighted analysis, no significant intergroup difference was found (hazard ratio, 1.20; 95% CI, 0.54-2.66; P = .70]. At 10 years, the cumulative incidence functions of mitral valve reintervention with death as competing risk were 34.4% (95% CI, 32.7%-36.1%) and 17.6% (95% CI, 16.2%-18.9%) for the Epic and Mosaic groups, respectively. On multivariable Fine-Gray analysis, the type of implanted mitral valve prosthesis just failed to reach a statistically significant difference in mitral valve reintervention (hazard ratio, 0.43 for Mosaic valve; 95% CI, 0.18-1.06; P = .067). Structural valve deterioration was an uncommon indication for reintervention in the first 10 years postoperative. ConclusionsClinical results of MVR with the Epic or Mosaic prosthesis are satisfactory. Our results suggest that the Mosaic bioprosthesis might offer better freedom from reintervention.