Study Finds Many Heart Patients Can Safely Stop Blood Thinners

A groundbreaking international study indicates that patients who have undergone successful procedures for correcting irregular heartbeats may no longer need to rely on long-term blood thinning therapy. Co-led by Canadian researchers, the findings suggest a significant shift in the clinical management of atrial fibrillation, a common heart condition affecting millions worldwide.

The study, published in the New England Journal of Medicine, involved over 1,200 patients who had received an ablation for atrial fibrillation. This procedure alters the heart’s electrical signals using a catheter. Researchers compared the outcomes of two groups: one receiving rivaroxaban, a widely used anticoagulant, and the other taking low doses of aspirin.

Dr. Atul Verma, a senior cardiovascular scientist at the McGill University Health Centre and co-leader of the trial, emphasized the importance of these findings. “The guidelines have said that even if your doctor does an ablation and feels it’s successful, you should continue your blood thinners for life,” he explained. “We decided to do this trial to see if this was actually necessary.”

Atrial fibrillation is the most prevalent form of cardiac arrhythmia, impacting approximately 1 percent of all Canadians and 5 percent of those over the age of 65. After monitoring the patients for three years, researchers discovered no significant differences in the rates of stroke and embolism between the two groups.

“We were a little surprised by the results,” Verma stated. “It appears that atrial fibrillation ablation, when successful, not only lowers the amount of atrial fibrillation but also seems to drastically lower the risk of stroke.”

The study also included brain MRIs for patients at the beginning and end of the three-year period to assess signs of silent strokes. The findings indicated low rates of silent strokes across both groups. “The rate of stroke or silent stroke in these patients was really, really low,” Verma noted. “It was so low that we could not detect any difference between continuing blood thinners or going on aspirin.” Remarkably, after three years, 96 percent of patients showed no signs of silent strokes.

Anticoagulants, commonly referred to as blood thinners, are used to prevent the formation of blood clots but can cause serious bleeding complications. Dr. Verma highlighted the concerns many patients have regarding the risks associated with blood thinners. “The first thing they ask is, can I stop this blood thinner? I like to go skiing, I like to work in my garage, I’m at risk of bleeding by taking these things,” he said. “And now for a certain substantial portion of those patients, I think we can say, yes you can.”

Dr. David Birnie, a professor at the University of Ottawa and head of the Ottawa Heart Institute, which participated in the study, described the findings as transformative. “Our results show that one year after a successful ablation, the risk of stroke is so low that the downsides of continuing blood thinners outweigh the benefits, meaning many patients can safely stop,” he stated in a press release.

The extensive research collaboration involved more than 50 cardiovascular research centres across Canada, Europe, China, and Australia, coordinated by Dr. George Wells, the director of cardiovascular research at the Ottawa Heart Institute.

This significant report was first published on November 8, 2025, by The Canadian Press, underscoring the potential to change treatment protocols for millions of patients managing atrial fibrillation.