They survived an out of hospital cardiac arrest, but don’t have a STEMI.
Nearly 70% of the cardiac deaths in the United States occur out of hospital, usually presenting as sudden cardiac arrest.[1] There is a high prevalence of acute coronary artery occlusions in out-of-hospital cardiac arrest (OHCA) patients with return of spontaneous circulation, especially those whose initial rhythm is ventricular fibrillation (VF) in the setting of ST elevation myocardial infarction (STEMI).
Early access to coronary angiography with revascularization, when significant lesions are identified, has been associated with a significant increase in the odds ratio for survival and, more importantly, functionally favorable survival.[2] Therefore, the American College of Cardiology recommends emergency coronary angiography with prompt opening of the infarct artery in this specific population of OHCA patients with ROSC in the setting of STEMI.[3]
However, in patients with OHCA and ROSC without STEMI, the timing of coronary angiography is still unclear. The presence of a culprit lesion in OHCA patients without STEMI has been reported as 29-33%[4,5] Some observational studies have shown a survival benefit in non-STEMI, OHCA patients who undergo immediate angiography.[6,7] The Coronary Angiography after Cardiac Arrest (COACT) study was designed to specifically investigate the impact of coronary angiography timing in OHCA patients without STEMI.[8]
STUDY DESIGN
COACT was a multicenter, open-label, randomized trial across 19 centers in the Netherlands between 2015-2018, comparing immediate coronary angiography against delayed angiography in cardiac arrest patients who had been successfully resuscitated and did not have STEMI on their screening electrocardiogram (ECG) in the emergency department (ED).
Eligible patients were adults > 18 years, with a GCS <8, who had ROSC after OHCA with initial rhythm of ventricular tachycardia or ventricular fibrillation. Exclusion criteria were STEMI on screening ED ECG (including new LBBB or isolated ST depression in V1-V3 due to a true posterior infarct), hemodynamic instability or shock state (defined as systolic blood pressure <90 mmHg for >30 min), refractory ventricular arrythmia, pregnancy, known or severe renal dysfunction, obvious non-coronary cause of CA, >4 hours between ROSC to screening ECG, known or suspected intracranial hemorrhagic or ischemic stroke, known inability to complete 90 day follow-up, and severe pre-arrest neurologic disability (defined as a cerebral performance category >3).
Patients were randomly assigned in a 1:1 ratio using a Web-based randomization system to either an immediate or delayed strategy. Immediate angiography was performed within two hours of randomization while delayed angiography was performed after neurologic recovery. If a patient in the delayed group decompensated into cardiogenic shock, recurrent arrythmias, or recurrent ischemia/STEMI, urgent angiography was performed.
The primary outcome was survival at 90 days with multiple secondary outcomes including 90-day survival with good cerebral performance or mild or moderate disability (defined as CPC 1 or 2), myocardial injury measured by troponin and creatine-kinase-MB, acute kidney injury, need for renal replacement therapy, time to optimal targeted temperature, markers of shock (including lactate and SVO2 at day 1, 2 and 3), recurrence of ventricular tachycardia needing defibrillation or electrical cardioversion, duration of mechanical ventilation, duration of catecholamine or inotropic support, neurologic status at discharge from the ICU, and TIMI major bleeding.
Five hundred thirty eight patients met inclusion criteria, were enrolled, and had data available for assessment, with 273 randomized to immediate and 265 to delayed angiography. Of the immediate angiography group, 265/273 (97.1%) actually underwent coronary angiography; those who did not were identified as either having been enrolled erroneously, carrying a high bleeding risk, being logistically difficult, or diagnosed with hemoperitoneum, splenic rupture, known congenital heart disease, aortic dissection, or an intracranial pathology.
Study Results
A total of 172/265 (64.9%) of the delayed group actually had angiography performed, with 38 of these having urgent angiography due to cardiac deterioration. The median time from randomization to angiography for the immediate group was 0.8 hr vs. 119.9 hrs for the delayed group. In terms of survival at 90 days, 64.5% of the immediate and 67.2% of the delayed group met this primary outcome, a result that demonstrates no statistically significant difference.
An acute unstable lesion (defined as a stenosis severity of ≥70% and the presence of characteristics of plaque disruption including lesion irregularity, dissection, haziness or thrombus defined by coronary angiography) was identified in 13.6% of immediate angiography patients and 16.9% of delayed angiography patients.
These are surprisingly low numbers of unstable lesions in a presumably high-risk patient population. 3.4% of the immediate group had an acute thrombotic occlusion on angiography. This is to be compared to 7.6% of the delayed group, half of whom represent patients who were “upgraded” for urgent angiography due to cardiac deterioration. PCI was performed in 33% of the immediate group and 24.2% of the delayed group. There was no significant difference between the two groups in terms of the secondary outcomes. The most common cause of death for both groups was neurologic injury.
This is a well-designed and well-executed study. The low frequency of unstable lesions in this study population overall is notable, and about half what has been reported in previous studies.[4,5] Additionally, the overall survival rate was higher than expected. The results surprised the authors themselves, who had anticipated a survival benefit in patients undergoing immediate angiography.
Bottom Line
Based on the results of this study, there is no clear benefit to immediate coronary angiography in OHCA patients with an initial shockable rhythm who do not have STEMI on ECG. That is not to say that these patients shouldn’t undergo angiography at all but calls into question the timing of the angiography.
Additionally, as was mentioned in an accompanying editorial, the individual patient, their specific history and cardiac event circumstances, their clinical course, the resources available at the receiving hospital, and collaboration with invasive cardiologists should ultimately drive the decision regarding the need and timing of coronary angiography.[9]
References:
- O’Gara PT, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013 Jan 29;61(4):e78-e140. PMID: 23256914.
- Larsen JM, Ravkilde J. Acute coronary angiography in patients resuscitated from out-of-hospital cardiac arrest–a systematic review and meta-analysis.Resuscitation. 2012 Dec;83(12):1427-33, PMID: 22960567
- Rab T,et al. Interventional Council, American College of Cardiology. Cardiac Arrest: A Treatment Algorithm for Emergent Invasive Cardiac Procedures in the Resuscitated Comatose Patient. J Am Coll Cardiol. 2015 Jul 7;66(1):62-73.PMID: 26139060.
- Dumas F, et al. Emergency percutaneous coronary intervention in post-cardiac arrest patients without ST-segment elevation pattern: insights from the PROCAT II Registry. JACC Cardiovasc Interv. 2016; 9:1011–1018. PMID:27131438
- Kern KB,et al. INTCAR-Cardiology Registry. Outcomes of comatose cardiac arrest survivors with and without ST-segment elevation myocardial infarction: importance of coronary angiography. JACC Cardiovasc Interv. 2015; 8:1031–1040. PMID: 26117462
- Hollenbeck RD, et al. Early cardiac catheterization is associated with improved survival in comatose survivors of cardiac arrest without STEMI. Resuscitation. 2014 Jan;85(1):88-95. PMID: 23927955.
- Khan MS, et al. Early coronary angiography in patients resuscitated from out of hospital cardiac arrest without ST-segment elevation: A systematic review and meta-analysis. Resuscitation. 2017 Dec;121:127-134. PMID: 29079508.
- Lemkes JS, et al. Coronary Angiography after Cardiac Arrest without ST-Segment Elevation. N Engl J Med. 2019 Apr 11;380(15):1397-1407. PMID: 30883057.
- Abella BS,et al. Coronary Angiography after Cardiac Arrest – The Right Timing or the Right Patients? N Engl J Med. 2019 Apr 11;380(15):1474-1475. PMID: 30883048.
