The impact of the mechanism of mitral regurgitation on clinical outcomes after mitral valve surgery.

BACKGROUND Mitral regurgitation (MR) is the second most frequent indication for valve surgery. There are few studies addressing mitral valve (MV) surgery in the context of etiology of MR. AIMS We aimed to compare postoperative outcomes in the context of the etiological mechanism of MR in patients after MV surgery. METHODS The study group included 337 consecutive patients with severe MR. Preoperative comorbidities, postoperative clinical course, and predictors of in-hospital mortality were assessed. RESULTS Primary etiology of MR was observed in 72% of patients, and of secondary, in 28% (P < 0.001). Among the primary MR group, the most common etiological factor was fibroelastic deficiency (79%), followed by Barlow disease (16%) and rheumatic disease (5%) (P < 0.001). Secondary MR was seen in ischemic heart disease (67%) and dilated cardiomyopathy (33%) (P < 0.001). The incidence of death and complications following surgery did not differ between the groups. Univariate analysis revealed that higher risk of death was associated with older age, severe heart failure symptoms, impaired left ventricular ejection fraction, previous percutaneous coronary interventions, cardiopulmonary bypass time, low cardiac output syndrome, and wound infections (P = 0.004, P < 0.001, P = 0.005, P = 0.009, P = 0.002, P = 0.006, and P = 0.03, respectively). Also MV replacement with concomitant other valve surgery increased the risk of mortality (P = 0.049). CONCLUSIONS This study indicates that the clinical outcomes and in-hospital mortality in patients with severe MR correlate with the type of procedure and concomitant perioperative comorbidities rather than the etiological mechanism of MR itself.