Mortality after mitral regurgitation surgery: importance of clinical and echocardiographic variables

The management of patients with mitral regurgitation (MR) constitutes a challenge due to its heterogeneity in terms of etiology and possible treatment strategies. In the present study, we sought to describe the importance of preoperative echocardiographic and clinical variables in relation to outcome 5 years after surgical treatment of MR.

The echocardiographic reports (transthoracic) from 298 patients were analyzed and the anatomic lesions were classified into one of three main groups (functional, organic degenerated with hypermobile valve or organic degenerated without hypermobility). 5-year cumulative survival was compared with the expected survival in an age- and gender-matched normal population. Risk functions were determined with a Poisson regression model.

Operative mortality was 4.4%, with higher mortality in patients with concomitant coronary artery bypass grafting (CABG) (7.6 vs. 2.2%, P=0.03). Survival after 5 years was 65% in patients with concomitant CABG, compared with the expected 86% (P<0.001), 70 vs. 88% (P<0.001) in patients with preoperative NYHA class III/IV, while survival in patients with NYHA class I/II did not differ from the expected (90 vs. 90%, P=0.56). In patients with a hypermobile valve without CABG, postoperative survival did not differ from the expected (91 vs. 89%, P=0.92). The estimated risk ratio for death, repair versus prosthesis, was 0.57 (95% confidence interval 0.32-1.00, P=0.05).

The present study shows that it is possible, using transthoracic echocardiography and clinical data, to identify patients with an excellent outcome. The adverse effects of severe symptomatology and replacement compared with repair are demonstrated. The findings encourage early intervention before severe symptoms occur, especially if repair is possible.