This was in fact two RCT’s.
The primary one was comparing conversion to sinus
rhythm between a drug-before-shock strategy vs. shock only for
cardioversion of acute (<48 hours) atrial fibrillation. The second
was a nested RCT comparing anterioposterior vs. anterolateral pad placement.
They enrolled about 400 patients. Half were randomised to procainamide infusion before an attempt at DC cardioversion. The other half got
matching placebo followed by DC cardioversion.
Both strategies were highly effective in conversion to sinus
rhythm at 96% with drug/shock vs. 92% for shock only (95%CI 0-9;
p=0.07). Pad placement didn’t matter.
Of note, the procainamide worked for half of the
patients and they were able avoid electricity and procedural sedation.
But not emphasized in the paper was the success of doing
nothing. Many patients self-reverted during their ED stay and even with
placebo infusion. Perhaps we should adopt a wait-and-see approach as suggested
by the Dutch and Doyle?
There are a few things to note.
They reported no adverse events at follow up. (But
there was one case of “cardiac arrest” when they forgot to hit the sync button…
woops!) As per prior similar studies, it looks safe.
The cohort was a bit younger (mean age 60) and most
had AF for less than 12 hours. Therefore, care should be taken when extrapolating
this study to older patients with longer duration of AF.
11% of patients returned to the ED with recurrent
AF within 14 days. This very likely underrepresents the amount of
recurrence. Which begs the question of why bother…
There was a trend towards efficacy with the drug shock group
with NNT of 25 for more successful overall conversion. This makes physiological
Of course, the biggest issue is procainamide is not officially
available in Australia and in some other countries. The authors suggest
other antiarrhythmics might be useful.
Overall, I think this is compelling evidence to a consider a
drug/shock strategy. But I still think doing nothing might be even better. Time
for shared decision making.
Steill I, Sivlotti M, Taljaard M, et al. Electrical vs
pharmacological cardioversion for emergency department patients with acute
atrial fibrillation (RAFF2): a partial factorial RCT. Lancet 2020;395:339-49. [link to article]