Long-term survival after mitral valve surgery for post-myocardial infarction papillary muscle rupture

Abstract

Background: Papillary muscle rupture (PMR) is a rare, but dramatic mechanical complication of myocardial infarction (MI), which can lead to rapid clinical deterioration and death. Immediate surgical intervention is considered the optimal and most rational treatment, despite high risks. In this study we sought to identify overall long-term survival and its predictors for patients who underwent mitral valve surgery for post-MI PMR. Methods: Fifty consecutive patients (mean age 64.7 ± 10.8 years) underwent mitral valve repair (n = 10) or replacement (n = 40) for post-MI PMR from January 1990 through May 2014. Clinical data, echocardiographic data, catheterization data, and surgical data were stored in a dedicated database. Follow-up was obtained in June of 2014; mean follow-up was 7.1 ± 6.8 years (range 0.0-22.2 years). Univariate and multivariate Cox proportional hazard regression analyses were performed to identify predictors of long-term survival. Kaplan-Meier curves were compared with the log-rank test. Results: Kaplan-Meier cumulative survival at 1, 5, 10, 15, and 20 years was 71.9 ± 6.4%, 65.1 ± 6.9%, 49.5 ± 7.6%, 36.1 ± 8.0% and 23.7 ± 9.2%, respectively. Univariate and multivariate analyses revealed logistic EuroSCORE ≥40% and EuroSCORE II ≥25% as strong independent predictors of a lower overall long-term survival. After removal of the EuroSCOREs from the model, preoperative inotropic drug support and mitral valve replacement (MVR) without (partial or complete) preservation of the subvalvular apparatus were independent predictors of a lower overall long-term survival. Conclusions: Logistic EuroSCORE ≥40%, EuroSCORE II ≥25%, preoperative inotropic drug support and MVR without (partial or complete) preservation of the subvalvular apparatus are strong independent predictors of a lower overall long-term survival in patients undergoing mitral valve surgery for post-MI PMR. Whenever possible, the subvalvular apparatus should be preserved in these patients.