Wednesday, 24 April 2019

Coronary Angiography after Cardiac Arrest without STEMI


Well regarded guidelines recommend immediate coronary angiography in patients who present with STEMI and cardiac arrest. But what about those that don’t have STEMI? Should they also go to the cath lab?

This RCT conducted in 19 centres in the Netherlands attempted to answer this question.

These researchers randomised 552 patients to immediate vs. delayed angiography.

The inclusion criteria were comatose survivors of out-of-hospital cardiac arrest (OHCA) that had shockable rhythms and return of spontaneous circulation. Patients were excluded if they had STEMI in the ED, shock, or an obvious non-cardiac cause of arrest.

The study was powered to detect a whopping 40% difference between the groups. Of course, it is quite ambitious to think immediate angiography would be so efficacious. Therefore, the study had an “adaptive design” that allowed for an increase in sample size if they detected a trend towards benefit during an interim analysis of the first 400 patients. (Kinda sounds like cheating… but I get it)

Results?

Those Dutch know how to conduct a study (must be something in the Heineken).

Adherence to protocol was fantastic. Median time to angiography was about 45 minutes in the immediate group and about 5 days in the delayed.

Acute thrombotic occlusion of a coronary vessel was found in a small minority of patients. Only 3.4% in the immediate and vs. 7.6% in the delayed. As such PCI and CABG was performed less than a third of the time.

I think you know where this is going… this was a negative study.

At 90 days 64% of the immediate group and 67% of the delayed group were alive.
So what should we conclude?

I think it is safe to say that we should not send all patients with OHCA without STEMI to the cath lab.

But one of the major challenges with evidence-based medicine is extrapolating the results of a study to the individual patient in front of us. 

What about the patient with some degree of hemodynamic or electrical instability? Or what about lots of dynamic ST and T wave changes on the ECG (of course this could also come from intracranial catastrophe)? What if they just smell like a coronary occlusion?

In summary, don’t send all patients to the cath lab. But I think we should still consider it on an individual basis. Now back to my Grolsch...


Covering:

Lemkes JS, Janssens GN, van der Hoeven NW, et al. Coronary Angiography after Cardiac Arrest without ST-Segment Elevation. N Engl J Med 2019;380:1397-1407. [link to article]


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