Aims: An invasive approach is superior to medical management for the treatment of patients with acute coronary syndromes without ST-segment elevation (NSTE-ACS), but the optimal timing of coronary angiography and subsequent intervention, if indicated, has not been settled.
Methods and results: We conducted a meta-analysis of randomized trials addressing the optimal timing (early vs. delayed) of coronary angiography in NSTE-ACS. Four trials with 4013 patients were eligible (ABOARD, ELISA, ISAR-COOL, TIMACS), and data for longer follow-up periods than those published became available for this meta-analysis by the ELISA and ISAR-COOL investigators. The median time from admission or randomization to coronary angiography ranged from 1.16 to 14 h in the early and 20.8-86 h in the delayed strategy group. No statistically significant difference of risk of death [random effects risk ratio (RR) 0.85, 95% confidence interval (CI) 0.64-1.11] or myocardial infarction (MI) (RR 0.94, 95% CI 0.61-1.45) was detected between the two strategies. Early intervention significantly reduced the risk for recurrent ischaemia (RR 0.59, 95% CI 0.38-0.92, P = 0.02) and the duration of hospital stay (by 28%, 95% CI 22-35%, P < 0.001). Furthermore, decreased major bleeding events (RR 0.78, 95% CI 0.57-1.07, P = 0.13), and less major events (death, MI, or stroke) (RR 0.91, 95% CI 0.82-1.01, P = 0.09) were observed with the early strategy but these differences were not nominally significant.
Conclusion: Early coronary angiography and potential intervention reduces the risk of recurrent ischaemia, and shortens hospital stay in patients with NSTE-ACS.