PHILADELPHIA — Patients who survived an out-of-hospital cardiac arrest and did not have signs of ST-elevation myocardial infarction (STEMI) had similar 1-year survival whether they had immediate or delayed coronary angiography, in an extension of the Coronary Angiography After Cardiac Arrest (COACT) trial.
At 1 year, there were also no significant differences in secondary outcomes of myocardial infarction, revascularization, hospitalization due to heart failure, or implantable cardiac defibrillation (ICD) shocks with the two different angiography strategies, said lead author Jorrit S. Lemkes, MD, Amsterdam University Medical Center, the Netherlands, here at the American Heart Association (AHA) Scientific Sessions 2019.
These results extend the 90-day findings from COACT that Lemkes presented at the ACC 2019 Scientific Session (ACC.19) in March, which were simultaneously published in the New England Journal of Medicine. COACT was supported by unrestricted research grants from the Netherlands Heart Institute, Biotronik, and AstraZeneca.
These 1-year outcomes "aren't really surprising," he told theheart.org | Medscape Cardiology, "but I think it is important to report them because I think cardiologists are changing their approach," and delaying angiography for patients such as those in COACT.
The new findings show that delaying angiography in these patients is a "wise decision" not only for short-term outcomes but also for long-term outcomes, he said.
Joaquin Cigarroa, MD, Oregon Health & Science University, Portland, the assigned discussant for the study, agreed.
"These findings should not be surprising," he said, "given the lack of difference in myocardial injury nor evidence of reduction in ischemia, duration of inotropic support, or targeted temperature management during the index hospitalization.
"At present," he added, "these results with regard to primary and secondary outcomes should guide practitioners that angiography remains essential, but that early angiography does not improve outcomes compared to delayed angiography," said Cigarroa.
Same Survival With Early vs Delayed Angiography
For patients who present with STEMI and cardiac arrest, guidelines strongly recommend immediate coronary angiography with percutaneous coronary intervention, Lemkes noted.
However, for patients who have cardiac arrest without STEMI, guidelines advise doing emergency angiography, but this course has only a weak recommendation because it is only based on observational data.
COACT was the first randomized study to investigate immediate versus delayed coronary angiography in such patients.
The trial randomized 552 adults at 19 centers in the Netherlands who had out-of-hospital cardiac arrest secondary to ventricular tachycardia/ventricular fibrillation (VT/VF) with return of spontaneous circulation within 20 minutes and no evidence of STEMI.
"Although revascularization was performed if indicated with lesions greater than 70%, this was not a trial comparing revascularization to no revascularization," Cigarroa pointed out. "It was a trial comparing a strategy of early versus late angiography," he stressed.
Participants were a mean age of 65 years and 80% were men.
The researchers hypothesized that immediate coronary angiography would improve survival by enabling clinicians to identify and treat coronary stenosis and thus prevent further myocardial ischemia.
However, at 90 days, survival was similar in both the immediate and delayed coronary angiography groups (64.7% vs 67.2%).
Secondary outcomes were also similar except for a delay in time to achieving target body temperature during induced hypothermia in the delayed angiography group, as previously reported.
Would 1-Year Outcomes Be Different?
In the meantime, a meta-analysis of several observational studies had suggested that short- and long-term outcomes in patients who survived a cardiac arrest and did not have STEMI would be better if they received immediate angiography.
Therefore, the researchers investigated 1-year outcomes in the randomized COACT trial.
They found that survival at 1 year was similar in the immediate and delayed angiography groups (61.4% vs 64.0%).
Long-term secondary findings were also similar in the two groups, consistent with the short-term outcomes.
"Secondary prevention therapies known to reduce recurrent VT/VF or treat lethal arrhythmias — including beta blockers and ICD implantation — should be administered when appropriate," Cigarroa said.
The challenge remains to identify the small subset of patients who may benefit from early angiography, according to Lemkes.
"If you look at the number of patients who actually have an unstable lesion at the time of angiography, in particular, those with a thrombotic occlusion, those are pretty small numbers, 15% and 5%," he said, "Those are the patients who might benefit most from an early invasive strategy. I think the challenge will be: How can we identify those patients?"
According to Cigarroa, results from future trials, including ACCESS and DISCO, will provide further insights into the potential role of early angiography for certain patients with non-STEMI.
"I hope that maybe in future by combining data we can look for that subset of patients that you can actually help with an early invasive strategy," Lemkes said. "But we're not there yet."
American Heart Association (AHA) Scientific Sessions 2019. Presented November 17, 2019.
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Cite this: COACT at 1 Year: Later Angiography Okay in Non-STEMI Cardiac Arrest - Medscape - Nov 19, 2019.
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