Incidence, associated factors and evolution of non-severe functional mitral regurgitation in patients with severe aortic stenosis undergoing aortic valve replacement.

INTRODUCTION: In order to improve the prognosis, repair of severe mitral regurgitation should be undertaken at the same time as aortic valve replacement in patients with severe aortic valve stenosis. However, mitral regurgitation may be secondary to pressure overload or ventricular dysfunction and improve after surgery. AIM: To assess the incidence of non-severe functional mitral regurgitation before and after isolated aortic valve replacement and determine its influence on the postoperative course. METHODS: The clinical and surgical characteristics were compared in a cohort of 577 consecutive patients who underwent isolated aortic valve replacement. RESULTS: The mean age was 68.4+/-9.2 years (44% women). Non-severe functional mitral valve regurgitation was detected prior to surgery in 26.5% of the patients. These patients were older (p=0.009), more often had ventricular dysfunction (p=0.005) and pulmonary hypertension (0.002), and had been admitted more frequently for heart failure (0.002), with fewer of them conserving sinus rhythm (p<0.001). Additionally, the pre-surgery existence of mitral regurgitation was associated with greater morbidity and mortality (10.5% vs 5.6%; p=0.025). The mitral regurgitation disappeared or improved prior to hospital discharge in 56.2% and 15.6%, respectively. Independent factors predicting this improvement were the presence of coronary lesions (OR 3.7, p=0.038), and the absence of diabetes (OR 0.28, p=0.011) and pulmonary hypertension (0.33, p=0.046). CONCLUSIONS: The presence of intermediate degree mitral regurgitation in patients undergoing isolated aortic valve replacement increases morbidity and mortality. However, a high percentage of those who do survive experience disappearance or improvement of the mitral regurgitation.