Comparison of Valve Annuloplasty and Replacement for Ischemic Mitral Valve Incompetence

Abstract

Mitral incompetence is a chronic sequela of myocardial infarction. It is caused by apical displacement and tethering of the mitral valve leaflets after myocardial infarction, resulting in incomplete coaptation. The consensus is for mitral valve surgery in the presence of significant ischemic mitral regurgitation (IMR). Previously, the only option was mitral valve replacement (MVR) with a mechanical or tissue valve. The suboptimal results obtained prompted the development of several methods of mitral valve repair. Today, the most commonly used repair is undersized annuloplasty. We conducted a retrospective nonrandomized study of all patients who underwent operation for coronary artery disease and IMR between 2000 and 2006. The surgeon chose the surgical method used for the mitral valve procedure. The most commonly used procedures were restrictive mitral valve annuloplasty (MVP) and MVR with a mechanical prosthesis. We collected all pertinent preoperative, intraoperative, and early-postoperative data. We followed up with phone interviews of the patients and their relatives and with complete clinical and echocardiography examinations. We carried out operations on 138 patients during the study period (MVR, 52 patients; MVP, 86 patients). The 2 groups had comparable demographic data and risk factors. The 2 groups were significantly different with respect to mean (+/-SD) New York Heart Association (NYHA) class (MVP, 2.72 +/- 0.62; MVR, 2.48 +/- 0.70; P < .01) and ejection fraction (MVP, 29.01% +/- 11.00%; MVR, 35.87% +/- 11.00%; P </= .01). The 30-day mortality rates for the MVR and MVP groups were significantly different (9.61% and 5.81%, respectively; P < .01). Our follow-up included 83% of the patients and continued for up to 84 months. The 2 groups showed no significant difference in mortality by the end of follow-up; however, the MVR patients had a better ejection fraction (37.79% versus 29.86%) and NYHA functional class (1.88 +/- 0.498 versus 2.36 +/- 0.564; P < .01). Correcting chronic IMR with either repair or replacement produces a good mid-term survival rate (approximately 75%) for survivors in NYHA classes I and II. In our study, mortality rates for the MVP and MVR groups were similar, even though the repair group had a lower mean ejection fraction and a higher NYHA class before and after the operation. We therefore conclude that repair is superior to replacement in treating ischemic mitral insufficiency. A prospective randomized study is needed to better compare these 2 approaches.