Acute hemodynamic effects of restrictive mitral annuloplasty in patients with end-stage heart failure: analysis by pressure-volume relations.

OBJECTIVE: Recent studies show beneficial long-term effects of restrictive mitral annuloplasty in patients with end-stage heart failure. However, concerns are raised about possible adverse effects on early postoperative systolic and diastolic function, which might limit application of this approach in patients with heart failure. Therefore we evaluated the acute effects of restrictive mitral annuloplasty on left ventricular function by using load-independent pressure-volume relations.

METHODS: In 23 patients (heart failure, n = 10; control, n = 13) we determined left ventricular systolic and diastolic function before and after surgical intervention by means of pressure-volume analysis with a conductance catheter. All patients with heart failure underwent stringent restrictive mitral annuloplasty (2 sizes smaller than the measured size), and 4 received additional coronary artery bypass grafting. Transesophageal echocardiography was used for evaluation of valve repair. Patients with preserved left ventricular function who underwent isolated coronary artery bypass grafting served as control subjects.

RESULTS: Restrictive mitral annuloplasty (ring size, 25 +/- 1) restored leaflet coaptation (8.0 +/- 0.2 mm) with normal pressure gradients (2.9 +/- 1.8 mm Hg). Restrictive mitral annuloplasty did not change cardiac output (5.0 +/- 1.8 to 5.3 +/- 0.9 L/min, P = .516), left ventricular ejection fraction (29% +/- 5% to 32% +/- 8%, P = .315), or end-systolic elastance (0.86 +/- 0.50 to 0.99 +/- 1.05 mm Hg/mL, P = .688). After restrictive mitral annuloplasty, end-diastolic volume tended to decrease (237 +/- 89 to 226 +/- 52 mL, P = .564), whereas end-diastolic pressure remained unchanged (14 +/- 6 to 15 +/- 5 mm Hg, P = .356). Diastolic chamber stiffness tended to increase (0.027 +/- 0.035 to 0.041 +/- 0.047 mL -1 , P = .542) but not significantly. Peak left ventricular wall stress was unchanged (356 +/- 91 to 346 +/- 85 mm Hg, P = .668). Baseline values in the control group were different, but changes in most parameters after surgical intervention showed similar nonsignificant trends.

CONCLUSION: Mitral valve repair by means of restrictive mitral annuloplasty effectively restores mitral valve competence without inducing significant acute changes in left ventricular systolic or diastolic function in patients with end-stage heart failure.