COACT: Delayed Angiography Safe in Selected Non-STEMI Resuscitated Cardiac Arrest

March 21, 2019

NEW ORLEANS — Immediate coronary angiography may offer no survival advantage over a delayed-angiography approach in adults resuscitated but unconscious after out-of-hospital cardiac arrest with no sign of ST-segment elevation myocardial infarction (STEMI), suggests a randomized trial with more than 500 patients.

Survival at 90 days, the Coronary Angiography After Cardiac Arrest Trial (COACT) primary end point, was similar at about 66% in both the immediate- and delayed-cath groups. And there was no significant difference in the secondary end point of neurologic status at intensive-care-unit (ICU) discharge..

Even so, there were signs that immediate angiography came at the cost of a significant 16% delay in time to achieving target body temperature during induced hypothermia.

Sending such patients right to the cath lab "we now know will not improve outcomes, and we saw that it delays a treatment that is one of the cornerstones of treating post-cardiac-arrest patients," Jorrit S. Lemkes, MD, Amsterdam University Medical Centre, told theheart.org | Medscape Cardiology.

"Routine immediate angiography in this patient population is not necessary," Lemkes said. "We might have to decide not to send them to the cath lab, but send them right to the ICU for target-temperature management. I think that's an important finding."

Lemkes presented COACT here at the ACC 2019 Scientific Session (ACC.19) and is lead author on the report published online the same day in the New England Journal of Medicine.

"As we tell our trainees, sometimes the wisest course of action is to be thoughtful and delay," said Quinn Capers IV, MD, Ohio State University, Columbus, not associated with COACT, at a media briefing on the trial.

Pending more clarity from other trials, Capers said, "I think its nice to know that in cardiac arrest without ST-segment elevation, you're not necessarily doing the wrong thing by saying let's wait, for maybe the majority of these patients."

Timothy D. Henry, MD, said at panel discussion on the trial at ACC.19: "I think this is unbelievably helpful from the standpoint of taking care of patients."

It suggests that "If you have no ST-segment elevation and you're hemodynamically stable, you should do cooling and see if they recover, and then find out if you have ischemia later," said Henry, from Cedars-Sinai Medical Center, Los Angeles.

But, "it's a very specific population, don't forget that." For example, he noted, it excluded patients with STEMI or signs of posterior-wall infarction.

Speaking on the same panel, Judith S. Hochman, MD, New York University School of Medicine, New York City, explained that a posterior-wall infarction can be pathophysiologically like a STEMI and call for immediate catheterization, even though it won't show up as STEMI on the electrocardiogram (ECG).

"Just clinically, I think people should rule out whether it's a posterior STEMI before saying it's not a STEMI," Hochman urged.

"Fundamental Limitation"

"The COACT trial represents an important step forward in the care of patients after a cardiac arrest, and the results suggest that for the majority of comatose patients who have had a cardiac arrest without evidence of STEMI, coronary angiography need not be performed immediately," observes an accompanying editorial.

However, write Benjamin S. Abella, MD, MPhil, University of Pennsylvania, and David F. Gaieski, MD, Jefferson Medical College, both in Philadelphia, "it is important to highlight a fundamental limitation." Namely, fewer than a fifth of the trial's patients had acute unstable coronary lesions at angiography.

"That is, the majority of patients who had cardiac arrest and underwent angiography did not have clinically significant coronary lesions, and thus only a small fraction of the trial population would be affected by the timing of coronary angiography — or the performance of coronary angiography at all. Therefore, the results of the trial should be interpreted with caution."

The published report acknowledges the point, further noting that only 5% of the patients had thrombotic occlusions. "This might explain our results, since PCI is associated with improved outcomes in patients with acute thrombotic coronary occlusion," they write, "but not in patients with stable coronary artery disease.

Time to Target Hypothermia Temperature

Also, the immediate-angiography strategy might have led to better results, conceivably besting delayed angiography, had there not been delays to achieving target hypothermia temperatures, Lemkes acknowledged for theheart.org | Medscape Cardiology.

"But we really don't know," he said. "I'd think a lesson that we can learn from this is, if the patient has to go to the cath lab — for instance, if he has STEMI — you should still start to cool the patient as soon as possible, preferably in the emergency department, but also in the cath lab."

The editorialists agree that "whether this delay attenuated a potential survival benefit of immediate coronary angiography remains unknown." But it is possible. Importantly, they continue, "most in-hospital deaths that occur among patients who have been resuscitated after cardiac arrest are due to neurologic injury rather than to cardiac complications."

Timing of Delayed Angiography

COACT randomly assigned 552 adults with resuscitated out-of-hospital cardiac arrest and no sign of STEMI, intracranial hemorrhage, or stroke to one of the two cath strategies at 19 centers in the Netherlands. More than three-quarters were men.

Those assigned to the delayed-angiography group underwent the procedure after neurologic recovery, a median of about 5 days after their arrest and usually after ICU discharge, the report notes. The corresponding time was 2.3 hours in the immediate-angiography group.

Coronary angiography was performed in 97% of the 273 assigned to the immediate-angiography group and in 65% of the 365 assigned to delayed angiography (that is, in those who survived to be discharged).

At 90 days, 64.5% of the immediate-cath group and 67.2% of those assigned to delayed cath were alive (odds ratio, 0.89; 95% CI, 0.62 -1.27); P = .51).

There were no significant differences in any secondary end point, save time to target hypothermia temperature. The others included 90-day survival "with good cerebral performance or mild or moderate disability," myocardial injury by troponins and other biomarkers, catecholamine support, recurrent ventricular tachycardia, mechanical ventilation, major bleeding, and acute kidney injury.

Median time to target hypothermia temperature was 5.4 hours for those assigned to immediate angiography and 4.7 hours in the delayed-angiography group (effect size, 1.19; 95% CI, 1.04 - 1.36).

"Certainly the final word isn't in yet," said Claire Duvernoy, MD, not associated with COACT, at the media briefing.

Duvernoy, from the University of Michigan and Veterans Affairs Ann Arbor Healthcare System, pointed out that a number of other relevant clinical trials are currently underway.

As noted by the editorialists, they include the Direct or Subacute Coronary Angiography in Out-of-Hospital Cardiac Arrest (DISCO) trial, with an estimated enrollment of more than 1000 patients, and ACCESS, which will have an estimated 864 patients. Both have entry criteria similar to COACT.

COACT was supported by unrestricted research grants from the Netherlands Heart Institute, Biotronik, and AstraZeneca, from which Lemkes discloses receiving grants; disclosures for the other authors are at nejm.org. Abella reports receiving grants from the Medtronic Foundation; grants and personal fees from Becton Dickinson and Stryker; personal fees from Mallinckrodt; and having other relationships with JDP Pharmaceuticals, CPR Ready, and MD Ally. Gaieski reports receiving personal fees from BrainCool, Stryker, and PhysioControl; grants from Bard; and "nonfinancial support from Getinge outside the submitted work."

N Engl J Med. Published online March 12, 2019. Full text, Editorial

American College of Cardiology (ACC) 2019 Scientific Session: Abstract 410-10. Presented March 18, 2019.

Follow Steve Stiles on Twitter: @SteveStiles2. For more from theheart.org | Medscape Cardiology, follow us on Twitter and Facebook.

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