Should a Regurgitant Mitral Valve Be Replaced Simultaneously with a Stenotic Aortic Valve?

Mitral valve regurgitation frequently accompanies aortic valve stenosis. It has been suggested that mitral regurgitation improves after aortic valve replacement alone and that the mitral valve need not be replaced simultaneously. Furthermore, mitral regurgitation associated with coronary artery disease, particularly in patients with poor left ventricular function, shows immediate improvement after coronary artery bypass grafting. We studied 60 consecutive patients with aortic stenosis and mitral regurgitation to determine the degree of improvement in mitral regurgitation after aortic valve replacement alone versus aortic valve replacement combined with coronary artery bypass grafting. Thirty-six of the patients had normal coronary arteries (Group 1); the other 24 had symptomatic coronary artery disease requiring bypass surgery (Group 2). Echocardiography was performed preoperatively, 1 week postoperatively, and at follow-up. In Group 1, left ventricular ejection fraction did not improve early or at 2.5 months postoperatively, but mitral regurgitation improved gradually during follow-up. In Group 2, mitral regurgitation showed improvement 1 week postoperatively (p <0.001), and left ventricular ejection fraction was improved at 2.5 months. We conclude that patients with aortic valve stenosis and mild-to-severe mitral regurgitation, without echocardiographic signs of chordal or papillary muscle rupture and without coronary artery disease, should undergo aortic valve replacement alone. The mitral regurgitation will remain the same or improve. For patients with coexisting coronary artery disease, simultaneous aortic valve replacement and coronary artery bypass grafting are imperative; however, the mitral valve again requires no intervention, since mitral regurgitation improves significantly after the other 2 procedures.