Optimal Timing of Coronary Invasive Strategy in Non-ST-Segment Elevation Acute Coronary Syndromes: A Systematic Review and Meta-Analysis

Study Questions:

What is the evidence for early versus delayed invasive therapy in patients with non–ST-segment elevation acute coronary syndrome (NSTE-ACS)?


The authors performed a meta-analysis of all available randomized, controlled trials (RCTs) and observational studies comparing early versus delayed intervention in patients with NSTE-ACS. Data were extracted for populations, interventions, outcomes, and risk of bias. The prespecified primary endpoint was all-cause mortality, and the longest follow-up available in each study was chosen.


The meta-analysis included seven randomized (5,370 patients) and four observational studies (77,499 patients). Early intervention was defined as invasive therapy less than 20 hours after hospitalization or randomization for RCTs and 24 hours or less for observational studies. No survival benefit was noted in association with an early invasive strategy in the randomized studies (odds ratio [OR], 0.83; 95% confidence interval [CI], 0.64-1.09; p = 0.180) or in the observational data. In the RCTs, an early invasive strategy was not associated with any difference in the odds of myocardial infarction (OR, 1.15; CI, 0.65-2.01; p = 0.63) or major bleeding (OR, 0.76; 95% CI, 0.56-1.04; p = 0.090).


The authors concluded that there is insufficient evidence either in favor of or against an early invasive approach in the NSTE-ACS population.


The optimal approach to NSTE-ACS remains controversial, with studies suggesting that an early invasive approach is better than or no different from a delayed invasive approach. This meta-analysis comes to the same conclusion and essentially confirms that either approach is effective. Hospitals need to develop a standardized approach to treatment of NSTE-ACS with the recognition that either early or delayed invasive therapy would be equally effective.

Clinical Topics: Acute Coronary Syndromes, Invasive Cardiovascular Angiography and Intervention, Interventions and ACS

Keywords: Myocardial Infarction, Acute Coronary Syndrome, Cardiology, Bias (Epidemiology), Cardiovascular Diseases, Confidence Intervals, Angioplasty, Balloon, Coronary, Hospitalization

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