Nikolaou NI, Netherton S, Welsford M, et al. - By performing this systematic review and meta-analysis, researchers assessed how early coronary angiography (CAG) can influence key clinical results in comatose patients following return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest of presumed cardiac origin. Eligible studies were those that compared patients receiving early CAG vs patients with late or no CAG. These were selected from PubMED, EMBASE, CINAHL, ERIC and Cochrane Central Register of Controlled Trials databases. There were 3738 screened citations, of these, 3 randomized trials and 41 observational studies were included. As per randomized data, there was no advantage from early vs late CAG across all critical results of survival and survival with favourable neurologic outcome for undifferentiated cases and for patient subgroups without ST-segment-elevation on post ROSC ECG and shockable initial rhythm. Overall, findings of this study do not lend support to routine early CAG in undifferentiated comatose patients as well as those without STE on post ROSC ECG following OHCA.