Introduction and methods

Coronary Angiography after Cardiac Arrest

Presented at ACC.19 by Jorrit Lemkes (Amsterdam, The Netherlands)

A poor outcome is observed in patients with out-of-hospital cardiac arrest (OHCA), despite advances in the field of resuscitation and intensive care management. Ischemic heart disease is the most frequent observed cause of cardiac arrest and coronary artery disease has been shown in up to 70% of patients after OHCA. In those with myocardial infarction and ST segment elevation as cause of the arrest, immediate coronary angiography (CAG) and subsequent percutaneous coronary intervention (PCI) are recommended by guidelines. Based on observational data emergency CAG is also recommended in OHCA patients without ST elevation, however, randomized data are lacking. The COronary Angiography after Cardiac arresT (COACT) trial therefore examined whether immediate CAG and PCI in NSTEMI patients that are successfully resuscitated after cardiac arrest results in better survival compared to delayed CAG.

The COACT trial was an investigator-initiated, randomized, open-label multicenter trial including 552 OHCA patients (aged >18 years) with return of spontaneous circulation (ROSC) without ST segment elevation on the electrocardiogram that were randomized 1:1 to receive either an immediate CAG or delayed CAG and followed for 3 months.

The primary endpoint was survival at 90 days. Secondary endpoints included among others myocardial injury measured by troponin and CK MB, time to target temperature and major bleeding.

Main results

• Survival at 90 days was not significantly different between patients treated with immediate and delayed CAG (176/273 [64.5%] vs. 178/265 [67.2%], OR: 0.89, 95%CI: 0.62-1.27, P=0.51).
• Time to target temperature was longer in the immediate CAG group compared to those with delayed CAG (median: 5.4 [IQR: 2.9-8.6] vs. 4.7 [IQR: 2.6-7.5], geometric mean: 6.5 (95%CI: 5.9-7.1) vs. 5.5 (95%CI: 5.0-6.0) hours, OR: 1.19, 95%CI: 1.04-1.36).
• TIMI or major bleeding was not significantly different between those who received immediate CAG and those with delayed CAG (7/273 [2.6%] vs. 13/265 [4.9%, OR: 0.51, 95%CI: 0.20-1.30).
• Based on levels of CK, CK-MB and troponin, no difference in myocardial injury was seen between the two groups.

Conclusion

In the COACT trial, immediate CAG did not improve survival at 90 days in NSTEMI patients with ROSC after OHCA, compared with delayed CAG. Target temperature was reached later in those allocated to immediate CAG, compared to delayed CAG. No significant difference in myocardial injury was seen between the two treatment groups.

Discussion

The discussant Quinn Capers IV noted that this study yields important information for practice; in stressful situations, these insights might guide decisions. But it is too early to not do immediate angiography: we need to find out who are the patients in whom immediate angiography still pays off. Acute unstable lesions were seen in 15% of patients, and acute thrombotic lesions, which would need treatment with PCI, were seen in only 5%. Possibly, the patients who would benefit from early intervention might be those over 70, and those with a history of disease. But this remains to be established. For now, these data show that physicians are not necessarily doing the wrong thing if they choose to wait, at least in most of the patients. But doctors will not risk losing a life, so predictors for who needs immediate interventions are highly welcomed.

During the discussion, it was asked whether the delay to hypothermia that was seen in patients who received immediate angiography may have affected neurology. It is not certain how important it is to reach hypothermia, but guidelines recommend that ‘hypothermia should be initiated as soon as possible’. Taking patients to the cathlab may delay reaching hypothermia, and this may affect outcomes. Moreover, the delay in hypothermia may have masked a potential positive effect of immediate angiography, but to date, it is unknown if that is the case.

- Our coverage of ACC.19 is based on the information provided during the congress –

The results of the COACT trial were simultaneously published in NEJM