Predictors of in-hospital mortality after mitral valve surgery for post-myocardial infarction papillary muscle rupture

Background: Papillary muscle rupture (PMR) is a rare, but often life-threatening mechanical complication of myocardial infarction (MI). Immediate surgical intervention is considered the optimal and most rational treatment for acute PMR, but carries high risks. At this point it is not entirely clear which patients are at highest risk. In this study we sought to determine in-hospital mortality and its predictors for patients who underwent mitral valve surgery for post-MI PMR. Methods: Between January 1990 and December 2012, 48 consecutive patients (mean age 64.9 +/- 10.8 years) underwent mitral valve repair (n = 10) or replacement (n = 38) for post-MI PMR. Clinical data, echocardiographic data, catheterization data, and surgical reports were reviewed. Univariate and multivariate logistic regression analyses were performed to identify predictors of in-hospital mortality. Results: Intraoperative mortality was 4.2% and in-hospital mortality was 25.0%. Univariate and multivariate logistic regression analyses revealed the logistic EuroSCORE and EuroSCORE II as independent predictors of in-hospital mortality. Receiver operating characteristics curves showed an optimal cutoff value of 40% for the logistic EuroSCORE (area under the curve 0.85, 95% CI 0.71-1.00, P < 0.001) and of 25% for the EuroSCORE II (area under the curve 0.83, 95% CI 0.68-0.99, P = 0.001). After removal of the EuroSCOREs from the model, complete PMR and intraoperative intra-aortic balloon pump (IABP) requirement were independent predictors of in-hospital mortality. Conclusions: The logistic EuroSCORE (optimal cutoff = 40%), EuroSCORE II (optimal cutoff = 25%), complete PMR, and intraoperative IABP requirement are strong independent predictors of in-hospital mortality in patients undergoing mitral valve surgery for post-MI PMR. These predictors may aid in surgical decision making and they may help improve the quality of informed consent.