The purpose of this study is to examine trends in mitral valve (MV) repair and replacement
surgery using The Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS
The study population included isolated mitral valve operations performed between January
2000 and December 2007 at 910 hospitals participating in the STS ACSD. Patients with
endocarditis, prior cardiac operation, shock, emergency operation, and concomitant
coronary artery bypass graft or aortic valve surgery were excluded.
During the 8-year study period, 58,370 patients underwent isolated primary MV operations.
For patients with isolated mitral regurgitation (n = 47,126), the rate of MV repair
(versus replacement) increased from 51% to 69% (p < 0.0001). Among patients having
replacement (n = 24,404), there has been a pronounced decline in the use of mechanical
valves: 68% to 37% (p < 0.0001). The operative mortality for MV replacement was consistently
higher than that for repair (3.8% versus 1.4%), a finding that persisted after risk-adjustment
(adjusted odds ratio 0.52, 95% confidence interval: 0.45 to 0.59; p < 0.0001). Among
patients having elective isolated MV repair (n = 28,140), the operative mortality
was 1.2%. For asymptomatic (class I) patients, operative mortality was 0.6%.
This study documents several important trends in MV surgery, including the progressive
adoption of mitral valve repair and increasing use of bioprosthetic replacement valves.
Operative risks of MV repair are significantly lower than those for MV replacement.
Operative mortality for isolated elective mitral valve repair is 1% in contemporary