The Influence of Sex on Clinical Outcomes after Surgical Mitral Valve Replacement in Spain (2001–2015)

(1) Background: Mitral regurgitation (MR) is the second most prevalent valvular heart disease in developed countries. Mitral valve (MV) disease is a common cause of heart failure and a leading cause of morbidity and mortality in the U.S.A. and Europe. (2) Methods: We performed a retrospective study using the Spanish National Hospital Discharge Database, 2001–2015. We included patients that had surgical mitral valve replacement (SMVR) listed as a procedure in their discharge report. We sought to (i) examine trends in incidence of SMVR among women and men in Spain, (ii) compare in-hospital outcomes for mechanical and bioprosthetic SMVR by sex, and (iii) identify factors associated with in-hospital mortality (IHM) after SMVR. (3) Results: We identified 44,340 hospitalizations for SMVR (84% mechanical, 16% bioprosthetic). The incidence of SMVR was higher in women (IRR 1.51; 95% CI 1.48–1.54). The use of mechanical SMVR decreased over time in both sexes and the use of bioprosthetic valves increased over time in both sexes. Men who underwent mechanical and bioprosthetic SMVR had higher comorbidity than women. IHM was significantly lower in women who underwent SMVR than in men (10% vs. 12% p < 0.001 for mechanical and 14% vs. 16% p = 0.025 for bioprosthetic valve, respectively). Major adverse cardiovascular and cerebrovascular events (MACCE) were also significantly lower in women who underwent mechanical and bioprosthetic SMVR. A significant reduction in both in-hospital MACCEs and IHM was observed over the study period regardless of sex. After multivariable logistic regression, male sex was associated with increased IHM only in bioprosthetic SMVR (OR 1.28; 95% CI 1.1–1.5). (4) Conclusions: This nationwide analysis over 15 years of sex-specific outcomes after SMVR showed that incidences are significantly higher in women than men for mechanical and bioprosthetic SMVR. IHM and MACCE have improved over time for SMVR in both sexes. Male sex was independently associated with higher mortality after bioprosthetic SMVR.