Coronary Angiography in Cardiac Arrest: Does Timing Matter?

Mr. Sampson, a 67-year-old man, was making coffee in his kitchen when he suddenly collapsed and became unresponsive. His wife was present and called 911. Mr. Sampson has a known history of coronary artery disease. An ECG performed by the paramedics showed ventricular fibrillation. Resuscitation was initiated, and shocks were applied. Although spontaneous circulation was restored, Mr. Sampson remained unconscious. The ECG showed no ST-segment elevation. En route to the emergency department, the paramedics notified the interventional cardiologist and asked, “Should we come directly to the cath lab for emergent coronary angiography?”

Despite the best resuscitation efforts in patients who remain unconscious after out-of-hospital cardiac arrest, survival rates are low, and a large proportion of survivors have significant long-term neurological complications. Although we know that many of these patients have underlying coronary artery disease, the question of whether urgent coronary angiography leads to improved survival or long-term neurologic and cardiac outcomes is uncertain, particularly when a patient has no evidence of ST-segment elevation to suggest acute coronary occlusion. 

Lemkes et al. addressed this question in a multicentre randomized trial recently published in NEJM. Participants who were unconscious after resuscitation from cardiac arrest and had no evidence of ST-segment–elevation myocardial infarction (STEMI) were randomized to undergo immediate coronary angiography after resuscitation or delayed coronary angiography during hospitalization. Percutaneous coronary intervention was performed in both groups if indicated. The results showed that 90-day survival did not differ between the immediate- and delayed-coronary angiography groups, suggesting that coronary angiography does not need to be performed immediately in this setting.

The following NEJM Journal Watch summary further explains the study and findings:

The COACT trial found no difference in survival with immediate versus delayed angiography.

The benefit of immediate coronary angiography and percutaneous coronary intervention (PCI) after cardiac arrest in the absence of ST-segment–elevation myocardial infarction (STEMI) is not known. In the Coronary Angiography after Cardiac Arrest (COACT) trial, investigators from the Netherlands randomized 552 such patients to either immediate or delayed (after neurologic recovery) coronary angiography — and, for both, PCI if indicated. The primary endpoint was 90-day survival (NTR4973).

The average age of the participants was 65, about 80% were men, a third had prior known coronary artery disease, and about two thirds had signs of ischemia on the electrocardiogram. The arrest was witnessed in about three quarters of participants; median time to basic life support was 2 minutes, and time to return of spontaneous circulation was 15 minutes. The mean baseline pH was 7.2, and the APACHE IV score was 106.

Coronary angiography was performed in 97% of the immediate group versus 65% of the delayed group. An acute thrombotic occlusion was found in 3.4% versus 7.6%. Survival at 90 days was 64.5% versus 67.2%, and survival with good cerebral performance was 62.9% vs. 64.4%; neither difference was significant. Median time to target temperature was 5.4 hours in the immediate group and 4.7 hours in the delayed group, a significant difference. The most common cause of death was neurologic injury, which accounted for about two thirds of deaths; cardiogenic shock and arrhythmias accounted for about 17%.

Comment: In the COACT trial, immediate coronary angiography and PCI, if indicated, for people with cardiac arrest in the absence of STEMI was not better than a delayed strategy. The finding may be explained by the low rate of occlusive thrombus and the fact that neurologic injury was the most common cause of death. There is more to come; editorialists note that two additional trials of this population are under way.

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Angela is a 2018-2019 NEJM editorial fellow. She is an endocrine fellow who trained at Flinders Medical Centre and the Royal Adelaide Hospital. Angela recieved her medical degree from the University of Adelaide, and masters of public health from the University of Sydney. Her clinical and research interests are in the areas of glucocorticoid and cardiovascular endocrinology and diabetes medicine.