Warfarin Interruption for Invasive Procedures in VTE Patients | Journal Scan
What are the rates of clinically relevant bleeding and recurrent venous thromboembolism (VTE) among patients treated with warfarin for secondary VTE prevention, who have warfarin interrupted for an invasive procedure?
A retrospective cohort study was conducted at Kaiser Permanente Colorado. Between 2006 and 2012, consecutive patients treated with warfarin for secondary prevention of VTE for whom warfarin therapy was interrupted for an invasive procedure were analyzed. Data were analyzed based on the use of bridging therapy during the warfarin interruption. The primary outcomes were 30-day clinically relevant bleeding, recurrent VTE, and all-cause mortality. Outcomes were manually verified by review of medical records.
Among 1,178 secondary VTE prevention patients with a warfarin interruption for 1,812 procedures, the mean age was 66.1 years (standard deviation, 12.7 years), and 830 (45.8%) of procedures were in men. Warfarin was most commonly used for treatment of deep venous thrombosis. Only 24 patients (1.3%) had a warfarin interruption within 3 months of VTE diagnosis. Most patients (1,431 procedures [79.0%]) were considered at low risk for VTE recurrence at the time of warfarin interruption, based on the American College of Chest Physicians consensus guidelines. Clinically relevant bleeding occurred within 30 of the procedures in 15 (2.7%) patients who received bridging therapy and two patients (0.2%) who did not receive bridging therapy (hazard ratio, 17.2; 95% confidence interval, 3.9-75.1). There was no significant difference in the rate of recurrent VTE between patients who were bridged and not bridged (0 vs. 3, respectively). No deaths occurred in either group.
The authors concluded that use of bridging therapy in patients treated with warfarin for secondary prevention of VTE is associated with an increased risk of bleeding. The authors also concluded that bridging therapy is unlikely to offer benefit for VTE recurrence prevention.
This large, single-center study provides important data about the outcomes associated with periprocedure interruption of warfarin for patients with a prior VTE. However, it is important to note that over 95% of the studied patients had received >12 months of treatment for their VTE and therefore were considered low-risk for VTE recurrence. While they were unable to report on any recurrent VTE in the high-risk patients, the total number of patients (57) was quite small. Nonetheless, this study provides additional support to the notion that bridging therapy for the majority of warfarin-treated patients should be used judiciously.
Keywords: Anticoagulants, Cohort Studies, Hemorrhage, Medical Records, Mortality, Recurrence, Retrospective Studies, Secondary Prevention, Venous Thromboembolism, Venous Thrombosis, Warfarin
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