Warfarin tablets
New research suggests patients with venous thromboembolism (VTE) have similar safety outcomes whether they receive direct oral anticoagulants (DOACs) or warfarin.
The population-based study showed there was no significant difference in the risk of major bleeding and all-cause mortality at 90 days whether patients received warfarin or DOACs (apixaban, dabigatran, and rivaroxaban).
Brenda R. Hemmelgarn, MD, PhD, of the University of Calgary in Alberta, Canada, and her colleagues reported results from this study in The BMJ.
The researchers noted that recent clinical trials have shown similar effectiveness and a reduced or similar risk of major bleeding complications for DOACs compared with warfarin. However, clinical trials involve a highly selected group of patients, so the rate of safety events reported in trials may not reflect those seen in everyday clinical practice.
With this in mind, Dr Hemmelgarn and her colleagues conducted a population-based study to determine the safety of DOAC and warfarin use in adults diagnosed with VTE between January 1, 2009, and March 31, 2016.
Using healthcare data from 6 jurisdictions in Canada and the US, the researchers identified 59,525 adults with a new diagnosis of VTE and a prescription for a DOAC (n=12,489) or warfarin (n=47,036) within 30 days of diagnosis.
Participants were followed for an average of 85.2 days. Of the 59,525 participants, 1967 (3.3%) had a major bleed, and 1029 (1.7%) died during the follow-up period.
Bleeding rates at 30 days ranged between 0.2% and 2.9% for DOACs and 0.2% and 2.9% for warfarin.
Bleeding rates at 60 days ranged between 0.4% and 4.3% for DOACs and 0.4% and 4.3% for warfarin.
The hazard ratio for major bleeding at 90 days was 0.92 (favoring DOACs). The hazard ratio for all-cause mortality at 90 days was 0.99.
The researchers said there was no evidence of heterogeneity across treatment centers, between patients with and without chronic kidney disease, across age groups, or between male and female patients.
The team noted that this is an observational study, so no firm conclusions can be drawn about cause and effect. And they could not rule out the possibility that their results may be due to confounding factors.
