Changes in mitral regurgitation after replacement of the stenotic aortic valve

Background. Concomitant mitral regurgitation (MR) is frequently seen in patients undergoing aortic valve replacement (AVR) for aortic stenosis. This study was undertaken to characterize the magnitude of MR in these patients and identify factors associated with significant postoperative change. Methods. Between 2002 and 2006, 391 patients with stenotic AV disease but no structural mitral valve disease underwent AVR without coronary artery bypass grafting. Excluded were 164 patients with combined aortic and mitral intervention, right heart surgery, or moderate to severe aortic insufficiency, to yield a final study group of 227 patients. Follow-up echographic evaluation of MR was obtained in 87 of 219 patients (40%) discharged alive without mitral valve intervention. Results. Overall mortality was 3.5%. After AVR, intraoperative MR severity improved in 66% of patients. Independent predictors of lower postoperative MR were small left atrial size (p = 0.03), the presence of aortic insufficiency (p < 0.01), and preoperative congestive heart failure (p = 0.04). Prosthetic valve type or size was not an independent predictor of postoperative MR. After adjustment for intraoperative underestimation of MR grade, there was no difference between the postprocedural MR grade and the early or late follow- up MR grade (p = 0.6 and p = 0.8, respectively). Conclusions. The results of this study support a conservative, tailored approach to concomitant mitral surgery in patients presenting for correction of aortic stenosis who demonstrate functional mitral regurgitation. Characteristics associated with resolution may allow for identification of patients most likely to benefit from mitral valve repair or replacement.