Summary of Important Trial Results for Interventional Cardiology From ACC.19

Summary of Important Trial Results for Interventional Cardiology From ACC.19

COACT: Coronary Angiography After Cardiac Arrest Without ST-Segment Elevation

· The COACT trial (Coronary Angiography after Cardiac Arrest) is the first published randomized clinical trial evaluating the strategy of immediate coronary angiography versus delayed coronary angiography in patients successfully resuscitated after out-of-hospital cardiac arrest with an initial shockable rhythm and no ST-segment elevation on their electrocardiogram.

·  A total of 552 patients was randomized. The primary endpoint was survival at 90 days, at which time 64.5% (176/273) of patients receiving immediate angiography and 67.2% (178/265) of patients in the delayed angiography group were alive (odds ratio 0.89; 95% confidence interval [CI], 0.62-1.27; p = 0.51).

· This is the first report of 9 separate randomized clinical trials examining this issue in post-arrest patients without ST-segment elevation. Over the next decade when all of these trials are completed, more than 4,000 patients will have been studied. The COACT trial was well-done.

·  No difference in the primary endpoint of 90-day survival was found. It should be appreciated that both arms of this trial had excellent survival rates, indeed much higher than the reported 25% post-resuscitation survival rate in the 1990s.

·  A surprising finding was the low incidence of acute coronary thrombotic occlusion found among these resuscitated cardiac arrest patients: only 5% among all those undergoing coronary angiography and just 3.4% among those randomized to immediate angiography.

·  Multiple non-randomized cohort studies involving 3,900 post-arrest patients without ST-segment elevation have found an acutely occluded coronary artery in 31%. This is the difference between only 1 in 25 patients having an acutely occluded coronary versus 1 in 3!

·  Unquestionably, the cohort experience could include a significant selection bias, but the consistency among reports is striking. What is the actual incidence of acute coronary occlusion in the resuscitated patient without ST-segment elevation? That is the critical question we must answer before we can determine the optimal use of coronary angiography among those successfully resuscitated from out-of-hospital cardiac arrest but without associated STEMI.

·  Of note, this group includes nearly 75% of resuscitated out-of-hospital cardiac arrest patients. If the incidence really is less than 5%, then immediate coronary angiography is not necessary. But if 1 in 3 patients has an occluded major coronary artery requiring timely reperfusion to preserve long-term myocardial function, then we need to provide such timely reperfusion even if immediate catheterization does not result in primary percutaneous coronary intervention (PCI) in 2 out of every 3 patients.

·  As the other randomized clinical trials finish and report their findings, we should be able to determine the true incidence of acutely occluded coronaries in those resuscitated but without ST-segment elevation.

·  The real issue is about finding acutely occluded culprit vessels needing timely reperfusion and not just electrocardiographic findings. If timely reperfusion of such a thrombotic coronary is not achieved, heart muscle will be lost. Survival may or may not be significantly impacted, but that should not be the only goal. Quality of life, being able to return to meaningful physical activities without shortness of breath and heart failure (HF), is also an important goal.

By Karl B. Kern, MD, FACC
Sarver Heart Center, University of Arizona, Tucson, AZ, USA