Restarting warfarin after GI bleeding associated with better outcomes

Patients previously on warfarin who don't resume the therapy soon after a gastrointestinal (GI) bleeding event may have a higher risk for thrombosis and death, according to a new study.

Researchers from Kaiser Permanente Colorado performed a retrospective cohort study to examine time to resumption of anticoagulation and incidence of thrombosis, recurrent GI bleeding and death in the 90 days after a GI bleeding event. Clinical and administrative data were used to identify patients who developed GI bleeding while taking warfarin, stopped the therapy, and then did or did not restart it within 90 days. Outcomes were compared between the “resumed therapy” and “did not resume therapy” groups. The study results were published early online Sept. 17 by Archives of Internal Medicine.

A total of 442 patients with an index event of warfarin-associated GI bleeding were included in the study. Approximately half of the patients were men, and the mean age was 74.2 years. Overall, 46.2% of patients had taken aspirin in the 90 days before their first GI bleeding event.

Two hundred sixty patients (58.8%) resumed warfarin therapy within 90 days of the index event, and 182 (41.2%) did not. Resuming warfarin therapy was associated with a lower adjusted risk for thrombosis and death (hazard ratios, 0.05 [95% CI, 0.01 to 0.58] and 0.31 [95% CI, 0.15 to 0.62], respectively) and did not appear to significantly increase the risk for recurrent GI bleeding (hazard ratio, 1.32 [95% CI, 0.50 to 3.57]).

The authors noted that they could not assess all of the factors involved in physicians' clinical decisions about therapy, that there is potential for confounding, and that they did not have data on aspirin use after the index bleeding event. However, they concluded that thrombosis and death after GI bleeding are more likely in patients who do not resume warfarin therapy within 90 days, and that the benefits of the therapy will outweigh the risk in many cases. They called for further research to determine the optimal interval of warfarin interruption after GI bleeding and to better define which patients can tolerate a longer interruption in therapy.

An accompanying editorial outlined three key findings from the study: Patients and physicians are usually willing to restart warfarin after GI bleeding; anticoagulation was usually restarted within a week of the bleeding event; and recurrent bleeding events, none of which were fatal, occurred at an acceptably low rate.

Based on the available data, the editorialists wrote, “We believe that most patients with warfarin-associated GI bleeding and indications for continued long-term antithrombotic therapy should resume anticoagulation within the first week following the hemorrhage, approximately 4 days afterward.” However, they advised against also continuing antiplatelet therapy in these patients without a “compelling indication” to do so and said that the study's findings should not be applied to patients taking new anticoagulant agents, such as dabigatran and rivaroxaban.