Survival prognosis and surgical management of ischemic mitral regurgitation

Abstract

Background: Ischemic mitral regurgitation (IMR) has an adverse prognosis, but survival characteristics and management are controversial. This study reviewed a 20-year series of IMR patients managed with multiple approaches to assess and refine surgical strategies.

Methods: Patients having surgery for primary coronary disease from 1986 to 2006 were divided into group 1 (no IMR; bypass grafting only; n = 16,209), group 2a (IMR; bypass only; n = 3,181), group 2b (IMR; mitral repair; n = 416), and group 2c (IMR; mitral replacement; n = 106). Cox proportional hazards modeling adjusted for baseline differences, and therapeutic adequacy was quantified by area under each survival curve expressed as a percentage of group 1.

Results: Group 2 patients were older than group 1 patients and had worse baseline characteristics. Group 2a had less severe MR and group 2b had the most comorbidity. Assuming group 1 provided the best adjusted outcome at a given baseline risk, group 2a achieved 97.7%, 2b achieved 93.7%, and 2c achieved 79.1% of potential survival (hazard ratio 1.1, 1.4, and 1.6, respectively; p < 0.003). Most of the survival difference was perioperative.

Conclusions: Worse baseline risk is a major factor reducing long-term survival in IMR. Current algorithms in which mild to moderate IMR is managed with bypass only (group 2a) generally produced good late results. In patients with moderate and severe IMR, repair achieved 93.7% of full survival potential; valve replacement was less satisfactory, primarily owing to higher operative mortality. Future therapeutic refinement, emphasizing reparative procedures and better perioperative care, could enhance the surgical prognosis of IMR.