Usefulness of the CHADS₂ score for prognostic stratification of patients with acute myocardial infarction

The Thrombolysis In Myocardial Infarction (TIMI) score and Global Registry of Acute Coronary Events (GRACE) score have been validated as predictors of major adverse cardiovascular events (MACE) in patients with acute myocardial infarction (AMI). This study was undertaken to determine whether the CHADS₂ score had good accuracy for predicting clinical outcome in patients with AMI and to compare the discriminatory performance of the 3 risk scores (RSs). We calculated the TIMI RS, GRACE RS, and CHADS₂ score for 747 consecutive patients with AMI. The study end point was the combined occurrence of MACE, including death, nonfatal myocardial infarction, and ischemic stroke. All patients were followed up for at least 3 years or until the occurrence of a major event. The area under the receiver operating characteristic curve was used to evaluate the predictive ability of each score at different time points. Higher CHADS₂ scores were associated with adverse outcome at discharge and 1-year and 3-year follow-ups (chi-square test for linear trend, p <0.001). Both CHADS₂ score and GRACE RS demonstrated better discrimination than TIMI RS in predicting 1-year and 3-year MACE (p <0.001). Multivariate Cox regression analysis revealed that the CHADS₂ score was an independent predictor of future MACE in patients with AMI (hazard ratio 1.349, 95% confidence interval 1.196 to 1.522). In conclusion, the CHADS₂ score provides potentially valuable prognostic information on clinical outcome when applied to patients with AMI.