Effect of timing of coronary angiography on mortality after out-of-hospital cardiac arrest in elderly patients: a substudy of the TOMAHAWK trial

AIMS: The optimal timing of coronary angiography in elderly patients after out-of-hospital cardiac arrest (OHCA) without ST-segment elevations after successful resuscitation remains uncertain. This substudy of the randomized TOMAHAWK trial investigated the prognostic impact of immediate vs. delayed/selective coronary angiography in elderly vs. younger OHCA survivors. METHODS AND RESULTS: A total of 529 patients with successfully resuscitated OHCA of presumed cardiac origin without ST-segment elevations on post-resuscitation electrocardiograms were analysed. Patients had been randomized to immediate or delayed/selective coronary angiography after 24 h at the earliest. Patients were stratified by age: elderly patients defined as >75 years vs. younger patients as ≤75 years. The primary endpoint was 30-day mortality. Multivariable Cox regression models were applied. Elderly patients exhibited a greater burden of cardiovascular comorbidities, had higher 30-day mortality (69% vs. 43%, P < 0.001), and had higher rates of death or severe neurologic deficit (75% vs. 51%, P < 0.001) compared to younger individuals. In adjusted analyses, the timing of coronary angiography was not significantly associated with mortality in either elderly patients (HR 0.96, 95% CI, 0.59-1.56, P = 0.88) or younger patients (HR 0.88, 95% CI, 0.56-1.38, P = 0.57), with no evidence of effect modification by age (P for interaction = 0.758). CONCLUSION: Routine immediate coronary angiography does not appear to modify mortality risk in both elderly and younger OHCA survivors without ST-segment elevations. The results do not support differential treatment strategies across age groups.