Restrictive annuloplasty for ischemic mitral regurgitation may induce functional mitral stenosis.

OBJECTIVES: The purpose of this study was to evaluate mitral valve hemodynamic performance and functional capacity in patients with ischemic mitral regurgitation (MR) who underwent restrictive mitral valve annuloplasty (MVA).
BACKGROUND: Restrictive MVA combined with coronary artery bypass graft is the conventional approach for the surgical management of patients with ischemic MR. We hypothesized that the restriction of the mitral annulus could cause an obstruction to antegrade mitral flow that may affect the patient's functional capacity.
METHODS: A dobutamine stress echocardiography (DSE) and a 6-min walk test (6MWT) were performed in 24 patients with ischemic MR 13 +/- 3 months after restrictive MVA and coronary artery bypass graft and in 20 control patients with coronary artery disease matched for age, gender, and left ventricular ejection fraction.
RESULTS: None of the 24 MVA patients had significant MR after operation. Compared with control patients, MVA patients had significantly (p < 0.001) higher resting and stress peak gradients (rest: 13 +/- 4 mm Hg vs. 4 +/- 1 mm Hg; DSE: 19 +/- 6 mm Hg vs. 6 +/- 3 mm Hg) and systolic pulmonary arterial pressures (PAP) (rest: 42 +/- 13 mm Hg vs. 27 +/- 8 mm Hg; DSE: 58 +/- 12 mm Hg vs. 38 +/- 11 mm Hg) and lower (p = 0.01) 6MWT distance (358 +/- 95 m vs. 433 +/- 61 m). The resting peak mitral gradient correlated with systolic PAP (r = -0.67; p = 0.001) and 6MWT distance (r = -0.78; p < 0.0001) in the MVA group.
CONCLUSIONS: The results suggest that performing a restrictive MVA in patients with ischemic MR may create a functional mitral stenosis. This hemodynamic sequel is associated with higher PAP and a worse functional capacity.