Abstract
BACKGROUND: Current guidelines recommend early invasive intervention (<24 hr) for high risk patients with non-ST-segment elevation myocardial infarction (NSTEMI). A delayed invasive strategy (24-72 hr) is considered reasonable for low risk patients. The real-world effectiveness of this strategy is unknown. METHODS: The ARIC Study has conducted hospital surveillance of acute myocardial infarction (MI) since 1987. NSTEMI was classified using a validated algorithm. We limited our study to patients undergoing early (<24 hr of the event onset), or late (≥24 hr) percutaneous coronary intervention (PCI). Patients were stratified into low (TIMI score 2-4), and high risk (TIMI score 5-7, or presence of cardiogenic shock, ventricular fibrillation, or cardiac arrest). Associations between early versus late PCI and mortality were analyzed using multivariable logistic regression adjusted for demographics, hospitalization year, TIMI score, and comorbidities. RESULTS: From 1987 to 2012, 6,746 patients were hospitalized with NSTEMI and underwent PCI. Most were white (79%), male (68%), with mean age 61 years. The 28-day and 1-year mortality were 2% and 5%, respectively. Most revascularizations (65%) were late. After accounting for potential confounders, early PCI was associated with a 58% reduced 28-day mortality (OR = 0.42; 95% CI: 0.21-0.84) for the entire population, and 57% reduced mortality (OR = 0.43; 95% CI: 0.21-0.88) for high risk patients. By 1-year of follow up, there was no significant difference in mortality with respect to early vs. late PCI. CONCLUSION: In hospitalized NSTEMI patients with high risk of clinical events, early PCI is associated with improved 28-day survival.