Keeping patients with atrial fibrillation on rather than off warfarin therapy during radiofrequency catheter ablation reduced the risk of periprocedural stroke in a randomized trial. The results were published online April 17 in Circulation.

Thromboembolic and hemorrhagic events such as stroke and bleeding are potential complications in ablation procedures. Luigi Di Biase, MD, PhD, of the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center in Austin, Texas, and colleagues compared two periprocedural anticoagulation management strategies to assess their role in preventing these complications.

They enrolled 1,584 patients with atrial fibrillation between 2009 and 2012 who were to be treated with a catheter ablation procedure into a prospective, randomized, multicenter study. All patients had a CHADS2 score of 1 or greater.

Patients were randomized to a strategy of warfarin discontinuation (790 patients) or warfarin continuation (794 patients). Patients in the discontinuation group stopped warfarin therapy two or three days before the ablation and were bridged with low molecular weight heparin. Secondary endpoints were bleeding complications.

The warfarin group had lower rates of periprocedural thromboembolic events compared with the bridged group, at 0.25 percent vs. 4.9 percent. The relative risk reduction was 95 percent in favor of warfarin continuation vs. discontinuation, and the benefit was seen across subgroups.

A multivariable analysis showed warfarin discontinuation was a strong predictor of periprocedural thromboembolic events.

Incidence of major bleeding complications was not statistically different between the two groups but the incidence of minor bleeding complications was much lower in the warfarin group, at 4.1 percent vs. 22 percent for the bridged group.

“This is the first randomized study showing that performing catheter ablation of atrial fibrillation without warfarin discontinuation and with a therapeutic INR [international normalized ratio] in patients at high risk of stroke significantly reduces the occurrence of periprocedural stroke/TIA [transient ischemic attack] and minor bleeding complications,” Di Biase and colleagues wrote.

They added that the results apply to warfarin only and not new oral anticoagulant drugs such as dabigatran (Pradaxa, Boehringer Ingelheim), rivaroxaban (Xarelto, Bayer Healthcare), apixaban (Xarelto, Bristol-Myers Squibb/Pfizer) and edoxaban (Daiichi Sankyo).