Reviwer : Dr. Oğuzhan Birdal

Name of the study: Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation (TOMAHAWK)

Published congress: ESC 2021

Full text link: https://www.nejm.org/doi/full/10.1056/NEJMoa2101909

Introduction :

Patients who develop out-of-hospital cardiac arrest (OHCA) have a poor prognosis and have a mortality rate of up to 65%, even if these patients are successfully resuscitated and admission to the hospital. Myocardial infarction is a common cause of OHCA. However, the benefits of early coronary angiography and revascularization in resuscitated patients without ST-segment elevation on ECG are unclear.

Objective :

In this study, routine emergency coronary angiography and delayed or selective coronary angiography strategies were compared in patients with OHCA who underwent resuscitation and did not have ST-segment elevation on ECG.

Methods :

This randomized, multicenter, open-label study were included 554 patients aged 30 years and older, who underwent successful resuscitation after OHCA and had no ST-segment elevation in the post-resuscitation ECG. The primary endpoint of the study was death from any cause at 30 days.

Results :

The median age in the patient population was 70 years and approximately 30% of patients were female. The median time from cardiac arrest to return of spontaneous circulation was 15 minutes. At 30 days, 143 of 265 patients (54.0%) in the emergency angiography group and 122 of 265 patients (46.0%) in the delayed angiography group died (HR, 1.28; 95% [CI], 1.00-1.63; P=0.06). The secondary endpoint, which included the composite of 30-day all-cause death or severe neurologic deficit, occurred more frequently in the emergency angiography group (in 164 of 255 [64.3%]) than in the delayed angiography group (in 138 of 248 [55.6%]). (relative risk 1.16; 95% [CI] 1.00–1.34). Other secondary endpoints such as length of intensive care unit stay, peak troponin levels, myocardial infarction or rehospitalization for congestive heart failure, did not differ between groups. There was no difference between groups in safety endpoints, which included moderate or severe bleeding, stroke, and acute renal failure requiring renal replacement therapy.

Conclusion:

As a result of the study, it was found that the strategy of performing emergency angiography was not superior to the strategy of delayed or selective angiography regarding the 30-day risk of death from any cause in patients who developed OHCA and did not have ST-segment elevation on ECG.

Interpretation:

The TOMAHAWK study found that early angiography was not superior to the delayed strategy in OHCA patients without ST-segment elevation, similar to the results of the COACT study. The most important difference of this study from the COACT study is that only shockable rhythms were present in the patients included in the COACT study, while approximately half of the patients included in this study did not have a shockable rhythm. When making an emergency angiography decision in OHCA patients without ST-segment elevation, it should be considered that early revascularization of these patients does not have a positive effect on 30-day survival, and even angiographic intervention may be against the patient, and the decision should be made accordingly.