Timing of Percutaneous coronary intervention in non-ST elevation acute coronary syndrome- Meta-analysis and systematic review of literature

Abstract Background Percutaneous coronary intervention (PCI) is the standard procedure of care for most patients with Non-ST elevation acute coronary syndrome (NSTE-ACS). However, the timing of PCI remains unclear. We performed this meta-analysis with available Randomized Controlled Trials (RCTs) to compare early versus late coronary intervention in patients with NSTE-ACS. Method A total of 13 RCTs were selected through PubMed/MEDLINE via OVID, EMBASE via OVID and Cochrane Central Register of Controlled Trials (inception to October 2018) search. Outcomes were analyzed using the relative risk (RR) and 95% CI. Pooled RRs were determined using M-H random-effects model, which can account for between study heterogeneity. Results We included 13 RCTs with 11,972 patients were included. There were 7101 patients were randomized into early invasive group and 4871 in late invasive group. There was a significant decrease in myocardial infarction with long-term follow up in early invasive group compared to the delayed invasive group (RR 0.847 [95% CI 0.74–0.95], p = .009) with no difference in mortality between early and late invasive group (5.41% vs 6.49%, RR 0.882 [95% CI, 0.76–1.02]). On subgroup analysis, data was available from 6 RCTs for GRACE (Global Registry of Acute Coronary Events) score and 8 RCTs for elevated troponin. Early intervention led to decrease in adverse events in patients with elevated GRACE score > 140, (Mantel-Haenszel pooled RR 0.88 [95% CI 0.82–0.95], p-value 0.002 but no difference was seen in patients with elevated troponin. Conclusion It can be postulated from these results that early invasive strategy leads to decrease in myocardial infarction but without significant decrease in mortality. In patients with elevated GRACE score (>140), early intervention did show a trend towards decrease in major adverse cardiac events, whereas in patients with elevated troponin alone, similar association was not observed. However, adequately powered randomized controlled trial is necessary to validate these findings.