Does mitral valve repair offer an advantage over replacement in patients undergoing aortic valve replacement?

Background: Concomitant aortic and mitral valve (MV) operations have more than doubled over the past decade. We utilized the Society of Thoracic Surgeons Adult Cardiac Surgery Database (ACSD) to evaluate outcomes for patients undergoing combined aortic valve replacement (AVR) and MV repair or replacement.

Methods: From 1993 to 2007, 23,404 patients undergoing concomitant AVR+MV surgery were identified. Patients with mitral stenosis, emergent or salvage status, and endocarditis were excluded. Outcomes were expressed as unadjusted operative mortality, adjusted odds ratio (OR) for mortality, and a composite of mortality and major complications.

Results: The MV repair was performed in 46.0% and replacement in 54.0% of AVR patients. The rate of MV repair increased from 22.5% in 1993 to 59.1% in 2007 (p<0.0001). Compared with the AVR+MV replacement group, the AVR+MV repair group was older (69.7±11.5 vs 67.2±12.7 years, p<0.0001), had worse ejection fraction (0.449±0.153 vs 0.495±0.139, p<0.0001), and more concomitant coronary artery bypass grafting (CABG) (50.5% vs 40.9%, p<0.0001). Unadjusted operative mortality was lower in the AVR+MV repair group (8.2% vs 11.6%, p<0.0001). Predictors of operative mortality by multivariable analysis included the following: age (OR 1.21, p<0.0001); concomitant CABG (OR 1.49, p<0.0001); diabetes mellitus (OR 1.56, p<0.0001); reoperation (OR 1.53, p<0.0001); and renal failure with dialysis (OR 3.57, p<0.0001). Patients undergoing MV repair had a lower independent risk of operative mortality (OR 0.61, p<0.0001), and mortality also independently improved over time (2003 to 2007 vs 1993 to 1997, OR 0.79, p<0.002).

Conclusions: When feasible, MV repair remains the most optimal method of correcting mitral regurgitation during concomitant AVR. Continued efforts to improve MV repair rates in this setting seem warranted.