Determinants of functional capacity after mitral valve annuloplasty or replacement for ischemic mitral regurgitation

Abstract

ObjectiveTo identify the exercise echocardiographic determinants of long-term functional capacity, in patients with chronic ischemic mitral regurgitation, after restrictive mitral valve annuloplasty (RMA) or mitral valve replacement (MVR). MethodsWe retrospectively analyzed 121 patients with significant chronic ischemic mitral regurgitation, who underwent RMA (n = 62) or MVR (n = 59), between 2005 and 2011. Preoperatively, all patients underwent a resting echocardiographic examination, and a 6-minute walking test (6-MWT) to measure distance. Resting and exercise stress echocardiography, and the 6-MWT were repeated at 41 ± 16.5 months. ResultsAfter surgery, the 6-MWT distance significantly improved in the MVR group, and decreased in the RMA group (+37 ± 39 m vs −24 ± 49 m, respectively; P < .0001). Exercise indexed effective orifice area was significantly higher in the MVR, versus the RMA, group (MVR: change from 1.3 ± 0.2 cm2/m2 to 1.5 ± 0.3 cm2/m2; RMA: change from 1.1 ± 0.3 cm2/m2 to 1.2 ± 0.3 cm2/m2; P = .001). The mean mitral gradients significantly increased from rest to exercise, in both groups, but to a greater extent in the RMA group (change from 4.4 ± 1.4 to 11 ± 3.6 mm Hg; MVR: change from 4.3 ± 1.8 to 9 ± 3.5 mm Hg; P = .006). On multivariate analysis, MVR and exercise indexed effective orifice area were the main independent determinants of postoperative 6-MWT. In the RMA group, 25 patients experienced late mitral regurgitation recurrence, severe in 9 (14%) of them. The rate of postoperative cardiovascular events was significantly higher in the RMA group (21% vs MVR: 8%; P = .03). Follow-up survival was 83% in the RMA group and 88% in the MVR group (P = .54). ConclusionsFor chronic ischemic mitral regurgitation, MVR versus RMA was associated with better postoperative exercise hemodynamic performance and long-term functional capacity.