Long-term mitral valve repair outcomes and hospital volume: 15 years’ analysis of an administrative dataset

Background Procedural volume has been documented as an important contributor to operative outcomes for most complex surgical procedures. Mitral valve repair (MVRep) has been associated with excellent results, and it is increasingly adopted in many cardiac surgical centers. We sought to investigate if procedural volume is associated with better clinical long-term outcomes after MVRep. Methods We analyzed the 10-year outcomes after MVRep by procedural volume for each cardiac surgery center in an Italian Region, Lazio, during the last 15 years, using a regional administrative dataset. Results Between 2006 and 2020, 4961 patients were treated in seven cardiac surgery centers for an isolated mitral valve surgery (2677 underwent MVRep). At multivariate analysis, mitral valve replacement (MVR) (vs. MVRep) resulted one of the independent predictors of 30-day mortality [adjusted odds ratio (OR) 3.40; 95% confidence interval (CI) 1.96 – 5.90; P < 0.0001]. Notably, a clear association between hospital volume of mitral valve surgery (>40 per year) and high rate of MVRep (>50%) was found. At 10 years, the incidence of mortality and the rate of death and rehospitalization for heart failure after MVRep were significantly lower in high-volume vs. low-volume hospitals. Conclusion Our data suggest that hospital volume is associated with a high rate of MVRep and long-term benefits in terms of mortality and recurrence of heart failure.