Temporary interruption of oral anticoagulation associated with substantial risk of stroke, bleeding

May 6, 2014 – Matthew Sherwood, MD, led the study, which studied data from more than 14,000 patients enrolled in ROCKET-AF.

Temporary interruption of anticoagulation in patients with atrial fibrillation (AF) is associated with greater risk of stroke and bleeding, regardless of the anticoagulant used.

That is the finding of a study by the DCRI’s Matthew Sherwood, MD (pictured); Manesh Patel, MD; Jonathan Piccini, MD, MHS; Anne Hellkamp, MS; Yuliya Lokhnygina, PhD; Rob Califf, MD; and colleagues from other institutions. The study was published this week in the journal Circulation.

matthew-sherwood-newsIn patients with AF, anticoagulation reduces the risk of stroke and embolic events and improves survival. Annually, nearly 250,000 AF patients in the United States alone require temporary interruption of anticoagulation for invasive procedures, acute illness, or bleeding events. Although other studies have examined the risk of these interruptions in AF patients, there has been little research into the long-term outcomes for these patients or the effect of temporary interruptions of newer oral anticoagulants.

To investigate these questions, the researchers used data from the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study. ROCKET-AF compared the safety and efficacy of warfarin with a newer anticoagulant, rivaroxaban. During the course of the trial, many participants required a temporary interruption of their anticoagulant medication. Of the 14,236 who were randomized and received study drug, 4,692 (33 percent) experienced 7,555 episodes of temporary interruption, of which 3,393 occurred in participants treated with rivaroxaban and 4,162 in participants treated with warfarin. Participants with TI were similar to the overall ROCKET AF population in regard to baseline clinical characteristics.

During the at-risk period associated with temporary interruptions, patients had a 30-day stroke/systemic embolism rate of 0.4 percent and a major bleeding rate of 0.9 percent. Rates of stroke and bleeding were similar in the warfarin and rivaroxaban groups, which was consistent with the findings of ROCKET-AF. The use of bridging therapy was infrequent, at 6 percent of all temporary interruptions in the on-treatment safety population despite the moderate to high-risk nature of this group. The researchers posited that this may be due to the blinding of participants and investigators in the ROCKET-AF trial. Often clinicians are hesitant to introduce a second anticoagulant therapy to a patient experiencing temporary interruption if they are unsure of the current status of anticoagulation.

Given the lack of randomized data in this area, the researchers concluded, additional research is needed to determine the safest way to manage both warfarin and newer anticoagulant medications, such as rivaroxaban, during temporary interruptions.