Effect of Beta-blocker therapy on survival in patients with severe mitral regurgitation and normal left ventricular ejection fraction.

Chronic volume overload from chronic severe mitral regurgitation (MR) results in neuroendocrine activation similar to the heart failure syndrome despite normal left ventricular (LV) ejection fraction (EF). Hence, the hypothesis that beta-blocker (BB) therapy may have a beneficial effect in these patients was tested using a large observational cohort. Our echocardiographic database was searched for patients with severe MR and normal LVEF. Full chart reviews were conducted for clinical and pharmacologic data. Survival was analyzed as a function of BB therapy. The search produced 895 patients aged 68 +/- 17 years, 44% men, with LVEF 66 +/- 7%. Of these, 32% were on BB therapy. Use of a BB was associated with a significantly decreased mortality hazard of 0.62 (95% confidence interval 0.46 to 0.83, p = 0.002), which was unchanged after adjusting for age, gender, LVEF, coronary artery disease, diabetes mellitus, hypertension, and cardiac valve surgery. The independent beneficial effect of BBs was seen in patients with or without coronary artery disease, those with or without hypertension, and patients managed both medically and surgically. In conclusion, use of BB therapy was associated with a significant independent survival benefit in patients with chronic severe MR with normal LVEF. This benefit was seen in patients with or without coronary artery disease, as well as patients managed both medically and surgically. Use of BBs in patients with severe MR despite normal LVEF is suggested.