At-admission risk stratification for in-hospital life-threatening ventricular arrhythmias and death in non-ST elevation myocardial infarction patients.

Identification of patients with non-ST elevation acute myocardial infarction (NSTEMI) at higher risk of in-hospital life-threatening ventricular arrhythmias (LT-VA) and death is crucial for determining appropriate levels of care/monitoring during hospitalisation. We assessed predictors of in-hospital LT-VA and all-cause mortality in a consecutive series of NSTEMI patients. We prospectively studied 1325 consecutive patients (69.7% males, median age 70 (61-79) years) presenting with NSTEMI and undergoing continuous electrocardiographic monitoring. The primary study end-point was the occurrence of spontaneous (unrelated to coronary interventions) in-hospital LT-VA, including sustained ventricular tachycardia and ventricular fibrillation; the secondary end-point was in-hospital mortality from all causes. Of 1325 patients, 21 (1.5%) experienced LT-VA and 62 (4.7%) died from either arrhythmias (n=1) or other causes (n=61). Seven of the 20 patients who survived LT-VA subsequently died of heart failure. Independent predictors of in-hospital LT-VA were the Global Registry of Acute Coronary Events (GRACE) score >140 (odds ratio (OR)=7.5; 95% confidence interval (CI) 1.7-33.3; p=0.008) and left ventricular ejection fraction (LV-EF)<35% (OR=4.1; 95% CI 1.7-10.3; p=0.002). GRACE score >140 (OR=14.6; 95% CI 3.4-62) and LV-EF <35% (OR=4.4; 95% CI 1.9-10) also predicted in-hospital all-cause death. The cumulative probability of in-hospital LT-VA and death was respectively 9.2% and 23% in the 98 (7.4%) patients with GRACE score >140 and LV-EF<35%, while it was respectively 0.2% and 0% among the 627 (47.3%) with GRACE score ≤140 and LV-EF ≥35%. Simple risk stratification at admission based on GRACE score and echocardiographic LV-EF allows early identification of NSTEMI patients at higher risk of both in-hospital LT-VA and all-cause mortality.