Adverse cardiovascular outcomes in atrial fibrillation: Validation of the new 2MACE risk score

Abstract

Background: In addition to thromboembolism, atrial fibrillation (AF) may also predispose to major adverse cardiovascular events (MACE) attributable to coronary artery disease (CAD), including myocardial infarction (MI). The 2MACE score (2 points - Metabolic syndrome and Age≥75years, 1 point - MI/revascularization, Congestive heart failure/ejection-fraction <40%, and thrombo-Embolism) was recently proposed to help identify AF patients at risk of MACE. We assessed the predictive validity of the 2MACE score for MACE occurrence in AF patients free of CAD at baseline.

Methods: Non-valvular AF patients (n=794) without CAD (mean-age, 62.5±12.1years, metabolic syndrome, 34.0%; heart failure/ejection-fraction <40%, 25.7%; thromboembolism, 9.7%) were prospectively followed for 5years, or until MACE (composite of non-fatal/fatal MI, revascularization and cardiovascular death). At inclusion, CAD was excluded by medical history, exercise-stress testing and/or coronary angiography. Also, the 2MACE score was determined.

Results: At follow-up, 112 patients experienced MACE (2.8%/year). The 2MACE score demonstrated adequate discrimination (C-statistic, 0.699; 95% confidence interval [CI], 0.648-0.750; P<0.001) and calibration (Hosmer-Lemeshow P=0.79) for MACE. The score was significantly associated with MACE, with the adjusted Hazard Ratio (aHR) of 1.56 (95%CI, 1.35-1.73; P<0.001). As for individual outcomes, the score predicted MI (n=46; aHR, 1.49; 95%CI 1.23-1.80), revascularization (n=32; aHR, 1.41; 95%CI, 1.11-1.80) and cardiovascular death (n=34; aHR, 1.43; 95%CI, 1.14-1.81), all P<0.001.

Conclusions: The 2MACE score successfully predicts future MACE, including incident MI, coronary revascularization and cardiovascular death in AF patients free of CAD at baseline. It may have a role in risk-stratification and primary prevention of MACE in AF patients.

Keywords: Atrial fibrillation; Cardiac death; Major adverse cardiovascular event; Metabolic syndrome; Myocardial infarction; Risk score.