Importance of mitral regurgitation in patients undergoing percutaneous coronary intervention for acute myocardial infarction: The Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) Trial

Objectives We sought to determine the prognostic importance of mitral regurgitation (MR) in patients undergoing percutaneous coronary intervention for acute myocardial infarction (AMI). Background Mitral regurgitation has been associated with a poor prognosis in patients treated with thrombolytic therapy for AMI. The prognostic significance of MR in patients undergoing mechanical reperfusion therapy for AMI is unknown. Methods Left ventriculography was performed during the index procedure in 1,976 (95%) of 2,082 non-shock patients enrolled in a prospective, multicenter, randomized trial of mechanical reperfusion strategies in AMI. The severity of operator-assessed MR was divided into four strata: none (n = 1,726), mild (n = 192), and moderate/severe (n = 58). Results Patients with progressively more severe MR were older (p < 0.0001), were more often women (p < 0.0001), and had higher Killip class (p = 0.0007). More severe grades of MR correlated with triple-vessel disease (p < 0.0001) and lower left ventricular ejection fraction (LVEF) as measured during the index procedure (p = 0.0004). Increasingly severe MR was strongly associated with a higher mortality at 30 days (1.4% vs. 3.7% vs. 8.6%, respectively; p < 0.0001) and at one year (2.9%, 8.5%, 20.8%, respectively; p < 0.0001). By multivariate analysis, the presence of even mild MR was an independent predictor of long-term mortality (mild MR, relative risk [RR] = 2.40, p = 0.005; moderate/severe MR, RR = 2.82, p = 0.006). Conclusions Mitral regurgitation of any degree present on the baseline left ventriculogram during the index procedure is a powerful, independent predictor of mortality in patients undergoing mechanical reperfusion therapy for AMI. The presence of MR identifies high-risk patients in whom close out-patient follow-up is warranted, and who may benefit from aggressive adjunctive medical or surgical therapies.