Direct oral anticoagulants (DOACs) can cut the short-term risk of thromboembolic events in half for patients who have undergone cardioversion of atrial fibrillation (AFib), suggests a meta-analysis published in the Journal of the American College of Cardiology.
Dipak Kotecha, MD, PhD, and colleagues pooled results from three prospective trials containing more than 5,200 patients—2,850 of whom were randomized to receive DOACs and 2,353 of whom were randomized to receive vitamin K antagonists (VKAs). The oral anticoagulants were continued for four to six weeks following cardioversion, with an additional 30 days of follow-up.
A total of 12 patients (0.42 percent) in the DOAC group met the primary composite outcome of stroke, systemic embolism, myocardial infarction or cardiovascular death, compared to 23 patients (0.98 percent) in the VKA group. Relative to VKA treatment, the researchers calculated a pooled risk reduction of 58 percent for DOACs, with no heterogeneity between trials.
“Our analysis suggests that DOAC therapy should be considered the default approach for cardioversion of AF, with one-half the rate of thromboembolic events compared with anticoagulation with warfarin,” wrote Kotecha and coauthors, all with the University of Birmingham Institute of Cardiovascular Sciences in the U.K. “Warfarin and other VKAs should be restricted to those patients who are not eligible for DOAC therapy; for example, those with mechanical heart valves, moderate to severe mitral stenosis, or severe chronic kidney disease.”
A lower rate of stroke and systemic embolism was the primary driver in the difference between groups, with DOAC patients meeting that outcome 67 percent less often.
“We show the safety of DOAC therapy in patients with newly initiated oral anticoagulation, including those requiring rapid cardioversion with imaging guidance, and those undergoing cardioversion after 3 weeks of anticoagulation,” the researchers wrote. “Due to the short onset of action and the predictable dosing of DOACs, clinicians can commence a DOAC immediately without the need for parenteral heparin.”
The authors said further research is necessary to define the optimal timing of anticoagulation and cardioversion therapy to reduce stroke risk.