Immediate angiography after resuscitation from out-of-hospital cardiac arrest does not improve survival compared to delaying angiography until neurologic recovery in patients with no evidence of ST-segment elevation myocardial infarction, according to data presented at the annual meeting of the American College of Cardiology.
The Coronary Angiography after Cardiac Arrest (COACT) trial involved 552 patients who had been successfully resuscitated after out-of-hospital cardiac arrest, without signs of ST-segment elevation myocardial infarction. The study also excluded patients with shock and severe renal dysfunction, and was not blinded, so this may have influenced treatment decisions.
Patients were randomized either to immediate coronary angiography after resuscitation, while still unconscious, or delayed coronary angiography until they had recovered neurologically, which was generally after discharge from intensive care.
Overall, 97.1% of patients in the immediate angiography group and 64.9% of the delayed angiography group underwent coronary angiography, with the median time until angiography being 0.8 hours in the immediate group and 119.9 hours in the delayed group.
In the immediate angiography group, 3.4% of patients were found to have an acute coronary occlusion, while in the delayed group that figure was 7.6%. Percutaneous coronary intervention was performed in 33% of the immediate angiography group and 24.2% of the delayed angiography group.
Survival rates at 90 days were not significantly different between the two groups; 64.5% of the immediate angiography group and 67.2% of the delayed angiography group survived to 90 days (OR 0.89, P = 0.51). The two groups also did not significantly differ in the secondary endpoints of survival with good cerebral performance or mild-to-moderate disability (62.9% vs. 64.4%).
“Our findings do not corroborate findings of previous observational studies, which showed a survival benefit with immediate coronary angiography in patients who had cardiac arrest without STEMI,” wrote Dr. Jorrit S. Lemkes, from the department of cardiology at Amsterdam University Medical Center VUmc, and co-authors. “This difference could be related to the observational nature of the previous studies, which may have resulted in selection bias that favored treating patients who had a presumed better prognosis with a strategy of immediate angiography.”
They also suggested the lack of benefit from early coronary angiography could relate to the fact that majority of those who died did so as a result of neurological complications, as has been seen in other studies of resuscitation.
The authors did note that the vast majority of patients in the study had stable coronary artery lesions, and only 5% showed thrombotic occlusions. They suggested this could explain their results, as percutaneous coronary intervention was not associated with improved outcomes in patients with stable coronary artery lesions – only in patients with acute thrombotic coronary occlusions.
However, they did see the suggestion of a treatment effect in patients over 70 years old and those with a history of coronary artery disease.
The study also revealed differences in subsequent treatment between patients who underwent immediate coronary angiography and those who had delayed angiography. Those in the delayed group were significantly more likely to be treated with salicylates or a P2Y12 inhibitor than those in the immediate angiography group.
“This observation illustrates how the result of immediate coronary angiography can influence treatment, since patients who did not have evidence of coronary artery disease on angiography do not require antiplatelet therapy,” the authors wrote.
Conversely, patients in the immediate angiography were more likely to receive a glycoprotein IIb/IIIa inhibitor. However the authors said these different strategies did not translate to any significant difference in major bleeding.
The COACT trial results were published in the New England Journal of Medicine simultaneously with Dr.Lemkes's presentation.
COACT was supported by the Netherlands Heart Institute, Biotronik and AstraZeneca. Two authors declared grants and support from the study supporters, both in and outside the context of the study. One author declared grants from private industry outside the study. No other conflicts of interest were declared.
SOURCE: Lemkes J et al. NEJM, 2019, March 18. DOI: 10.1056/NEJMoa1816897