Direct oral anticoagulants generally outperform traditional vitamin K antagonists across various risk groups for treating atrial fibrillation, though the benefit varies by patient profile. A study published in JACC Advances suggests that while DOACs are the superior choice for most patients, the modest absolute benefit for low-risk individuals might justify using warfarin when cost is a prohibitive barrier.
Researchers evaluated 58,634 patients, comparing warfarin with DOACs based on the TIMI-AF risk scores. They identified specific factors associated with increased risk for adverse outcomes, including all-cause death, disabling stroke, and intracranial bleeding.
Older age (adjusted hazard ratio 1.55), male sex (1.30), impaired kidney function (2.21), lower BMI (1.25), vitamin K antagonist-naïve status (1.17), and nonparoxysmal atrial fibrillation (1.31) were all linked to worse results. The study stratified patients into three groups, finding an annualized adverse-outcome rate of 3.5% in the low-risk group, 7.6% in the intermediate-risk group, and 12.9% in the high-risk group.
Related: Guideline Issued for Sleep Apnea in Pregnancy
Although standard-dose DOACs reduced risk in all three categories, the authors described the absolute benefit in the low-risk group as “modest” at 0.3%. This smaller margin of improvement means that for a patient with very low risk, the difference between a drug and a cheaper alternative might not justify the higher price tag.
Why Warfarin Still Has a Place
Robert P. Giugliano, MD, a senior investigator with the Thrombolysis in Myocardial Infarction Study Group, noted that warfarin remains a reasonable option when access to DOACs is limited. He explained that while one should generally pick a DOAC, the cost in the United States often makes it impossible for some patients to afford.
Georgios Syros, MD, a cardiac electrophysiologist at Mount Sinai Fuster Heart Hospital, confirmed that patients frequently face hundreds of dollars in out-of-pocket expenses for DOACs. He said he can now tell patients at lower risk that they can safely use warfarin if they cannot afford the newer medication.
However, Dr. Giugliano highlighted a troubling paradox: older patients, who often have lower income and rely on government insurance, derive the most benefit from DOACs. “Unfortunately, it’s our older patients that are less likely to work and less likely to have commercial insurance, so they’re relying on the government,” he said.
Related: All-Stars Reject MLB Salary Cap Seek Deal
Practical Considerations for Clinicians
Even with the data suggesting warfarin is acceptable for low-risk patients, experts generally recommend DOACs as the first-line treatment for nonvalvular atrial fibrillation. The convenience factor plays a major role in this preference.
Warfarin requires strict dietary restrictions due to vitamin K content and frequent blood draws to monitor International Normalized Ratio (INR) levels. Rajesh Kabra, MD, a professor at the University of Tennessee Health Science Center, noted that the median time in therapeutic range among patients in the warfarin arm was 65%, which would likely be lower in real-world settings.
Dr. Syros emphasized that the need to restrict a patient’s diet and manage frequent monitoring makes DOACs a more manageable option for daily life. Despite the study’s findings, Dr. Kabra stated that he continues to recommend DOACs over warfarin for patients who can afford them, across all risk groups.