Direct oral anticoagulants (DOACs) typically demonstrate superior outcomes versus warfarin across TIMI-AF risk categories, though low-risk patients experience only marginal absolute benefit. A JACC Advances study indicates that in instances where DOAC affordability is restricted, warfarin may serve as a viable option for atrial fibrillation (AF) patients with low-risk profiles for adverse events.
Study author Robert P. Giugliano, MD, said that while DOACs are preferred, warfarin may be suitable for low-risk patients who cannot access DOACs due to cost. The study evaluated the TIMI-AF risk scores of 58,634 patients with AF, with half taking warfarin and half taking a DOAC.
Factors Influencing Outcomes with Warfarin
The investigators identified several factors that influence outcomes with warfarin, including older age, male sex, impaired kidney function, lower BMI, vitamin K antagonist-naïve status, and nonparoxysmal AF. These factors had an independent association with increased risk for adverse outcomes, including all-cause death, disabling or fatal stroke, or intracranial bleeding.
The study authors stratified patients into three groups based on TIMI-AF scores: low-risk, intermediate-risk, and high-risk. In the low-risk group, the annualized rate of adverse outcomes was 3.5%, compared with 7.6% in the intermediate-risk group and 12.9% in the high-risk group.
DOACs and Warfarin
While standard-dose DOACs reduced the risk of adverse outcomes in all three groups, the authors described the absolute benefit of DOACs in the low-risk group as modest, with a difference of 0.3% and a 95% confidence interval of 0.1% to 0.6%.
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Georgios Syros, MD, a cardiac electrophysiologist, noted that it is not uncommon for his patients to have to pay hundreds of dollars out of pocket for a DOAC. He said that the study’s findings are promising for low-risk patients, as they allow him to offer warfarin as a safe and affordable alternative.
Access Issues with DOACs
Despite the study’s findings, DOACs remain the preferred option for preventing adverse outcomes in AF, especially in people with intermediate to high risk scores. Dr. Giugliano pointed out that access issues with DOACs pose a greater threat to high-risk patients who have poorer outcomes on vitamin K antagonists.
Rajesh Kabra, MD, governor-elect of the Kansas Chapter of the American College of Cardiology, noted that DOACs are more convenient for both patients and clinicians. He said that he would still recommend DOACs over warfarin for his nonvalvular AF patients who can afford it, across all risk groups.
In practice, the study’s findings mean that low-risk patients who cannot access DOACs due to cost may be able to safely take warfarin instead. This could be particularly beneficial for patients who are struggling to afford the newer medication, as it would provide them with a more affordable alternative for managing their AF.
The study’s authors and experts agree that DOACs are the preferred option, but access issues must be addressed to ensure that all patients can receive the best possible care. Dr. Giugliano noted that it is the older patients who benefit the most from DOACs, but they are also the ones who are less likely to have access to them due to cost.