International guidelines recommend early invasive strategy (<24hrs) for patients with NSTEMI w/high risk factors defined by a GRACE score >140
A recent meta-analysis based on 7 RCTs & 4 observational studies demonstrated an inconclusive survival benefit with an early invasive strategy
Heterogeneity across multiple studies including timing of intervention, definition of MI, patients' risk profiles, major bleeding, and sample size make the interpretation of survival results difficult
Based on the most recent data the optimal timing of intervention remains unclear and a more definite RCT is warranted to guide clinical practice
References
Navarese E, et al. Optimal Timing of Coronary Invasive Strategy in Non-ST-Segment Elevation Acute Coronary Syndromes. Ann Intern Med. 2013;158:261-270.