Over 90% freedom from severe MR twenty years after mitral valve repair

Over 90% freedom from severe MR twenty years after mitral valve repair

90.7% freedom from recurrent severe mitral regurgitation was documented at twenty years after mitral valve repair in a study by David et al [1]. They had prospectively followed up eight hundred and forty patients who underwent mitral valve repair for mitral valve regurgitation due to degenerative disease. All patients were followed up prospectively with clinical and echocardiographic evaluations every two years, upto 26 years, with a mean of 10.4 years.

Age, functional class and left ventricular ejection fraction predicted late cardiac mortality and valve related mortality. In those in functional class IV at the time of surgery, mitral valve repair failed to normalize the life span. The probability of reoperation at twenty years was around six percent. Freedom from moderate or severe mitral regurgitation was around seventy percent.

Predictors of recurrent mitral regurgitation were age, isolated prolapse of anterior mitral leaflet and the severity of myxomatous degeneration in the mitral valve. Longer duration of cardiopulmonary bypass time was also associated with higher risk of recurrent mitral regurgitation. The chance of recurrent mitral regurgitation was reduced by mitral annuloplasty. Thirty eight patients had a repeat mitral valve surgery. Severe recurrent MR was noted in 37 patients and moderate MR in 61 patients on follow up.

So the take home message is to get them repaired before they are in functional class IV with impaired left ventricular function, which could mean fibrosis of ventricular muscle in MR which is a relatively lower afterload, dual left ventricular outlet circuit. So if left ventricular dysfunction has occurred, it may imply irreversible myocardial damage and hence poorer prognosis. This is unlike in aortic stenosis where there is a mechanical obstruction to the left ventricular outflow. Even patients with severe left ventricular dysfunction in aortic stenosis may improve well after aortic valve replacement.

Reference

1. Tirone E David, Susan Armstrong, Brian W McCrindle, Cedric Manlhiot. Late outcomes of mitral valve repair for mitral regurgitation due to degenerative disease. Circulation. 2013;127:1485-1492