Early vs Delayed Invasive Strategy in Non-ST-Elevation Acute Coronary Syndromes
Mortality rates were lower in specific high-risk patients who underwent an early invasive strategy.
An early invasive strategy in patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) does not necessarily reduce mortality compared with a delayed strategy, according to a meta-analysis published in the Lancet.
An international team of researchers selected 8 trials (n=5324 patients) that compared early vs delayed invasive strategies in patients with NSTE-ACS. All-cause mortality was designated as the primary outcome. To determine whether there was a time-dependent effect of invasive strategy, researchers divided the follow-up periods from randomization to hospital discharge and from discharge to the end of follow-up. Of the 8 trials included, there was a median follow-up of 180 days.
There was no significant reduction in mortality in the early invasive group compared with the delayed invasive group (hazard ratio [HR], 0.81; 95% CI, 0.64-1.03; P =.0879). However, an early invasive strategy in high-risk patients resulted in lower mortality: elevated cardiac biomarkers (HR, 0.761; 95% CI, 0.581-0.996), diabetes (HR, 0.67; 95% CI, 0.45-0.99), a GRACE (Global Registry of Acute Coronary Events) risk score of more than 140 (HR, 0.70; 95% CI, 0.52-0.95), and aged 75 years or older (HR, 0.65; 95% CI, 0.46-0.93).
The researchers noted that although nearly 80% of all patients had positive biomarkers, the individual trials were underpowered to detect a significant effect of an early vs delayed invasive strategy on all-cause mortality in these patients. In addition, current guidelines do not factor diabetes into the timing of coronary angiography, nor is diabetes a parameter of the GRACE risk score, but an early invasive strategy could benefit these patients.
"Since this finding is exploratory in nature, a pragmatic large-scale confirmatory trial would be needed to obtain definitive evidence of whether an early invasive strategy is beneficial compared with a delayed invasive strategy in these high-risk subgroups," the researchers concluded.
Other limitations included differences in timing of coronary angiographies among the studies, the potential masking of myocardial reinfarction because of already high cardiac biomarkers in patients who underwent angiography within 24 hours, that no interaction was detected among subgroups, and that different biomarkers and assays were used in each trial to define biomarker positivity.
Jobs A, Mehta SR, Montalescot G, et al. Optimal timing of an invasive strategy in patients with non-ST-elevation acute coronary syndrome: a meta-analysis of randomised trials [published online August 1, 2017]. Lancet. doi:10.1016/S0140-6736(17)31490-3