Restrictive mitral valve annuloplasty versus mitral valve replacement for functional ischemic mitral regurgitation: an exercise echocardiographic study

Abstract

Objective: Mitral valve annuloplasty and mitral valve replacement are common strategies for the management of functional ischemic mitral regurgitation with ischemic cardiomyopathy. However, mitral valve annuloplasty may create some degree of functional mitral stenosis. The purpose of this study was to compare the mitral valve hemodynamics in patients with functional ischemic mitral regurgitation undergoing mitral valve annuloplasty or mitral valve replacement, using exercise echocardiography.

Methods: We performed resting and exercise echocardiography in 70 patients matched for indexed effective orifice area, systolic pulmonary arterial pressure, and left ventricular ejection fraction after mitral valve annuloplasty or mitral valve replacement with coronary artery bypass grafting.

Results: There was no significant difference between the 2 groups regarding baseline demographic and clinical data. Exercise systolic pulmonary arterial pressure was higher in the mitral valve annuloplasty group compared with the mitral valve replacement group (from 36.3 ± 8.1 mm Hg to 55 ± 12 mm Hg, vs mitral valve replacement: 33 ± 6 mm Hg to 42 ± 6.2 mm Hg, P = .0001). Exercise-induced improvement in effective orifice area and indexed effective orifice area was better in the mitral valve replacement group (mitral valve replacement: +0.23 ± 0.04 vs mitral valve annuloplasty: -0.1 ± 0.09 cm², P = .001, for effective orifice area; mitral valve replacement: +0.14 ± 0.03 vs mitral valve annuloplasty: -0.04 ± 0.07 cm²/m², P = .03, for indexed effective orifice area). Exercise indexed effective orifice area was correlated with exercise systolic pulmonary arterial pressure (r = -0.45; P = .01). In a multivariable analysis mitral valve annuloplasty, postoperative indexed effective orifice area and resting mitral peak gradients were independent predictors of elevated systolic pulmonary arterial pressure during exercise.

Conclusions: In patients with functional ischemic mitral regurgitation, mitral valve annuloplasty may cause functional mitral stenosis, especially during exercise. Mitral valve annuloplasty was associated with poor exercise mitral hemodynamic performance, lack of mitral valve opening reserve, and markedly elevated postoperative exercise systolic pulmonary arterial pressure compared with mitral valve replacement.