Study Reveals Many No Longer Need Blood Thinners After Heart Procedure

A significant shift in the management of atrial fibrillation may be on the horizon, as a recent international study indicates that many patients who undergo successful corrective procedures for irregular heartbeats may no longer require long-term blood-thinning therapy. The findings, co-led by researchers from Canada, were published in the New England Journal of Medicine and could impact millions globally.

The randomized trial involved over 1,200 patients who had undergone an ablation procedure for atrial fibrillation. This procedure modifies the heart’s electrical signals using a catheter. Participants were divided into two groups: one received rivaroxaban, a widely prescribed anticoagulant, while the other group was prescribed low doses of aspirin.

Dr. Atul Verma, a senior cardiovascular scientist at the McGill University Health Centre, noted, “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. We decided to do this trial to see if this was actually necessary.”

Atrial fibrillation, the most prevalent form of cardiac arrhythmia, affects approximately 1 percent of all Canadians and 5 percent of those over the age of 65. After monitoring the patients for three years, researchers found no significant difference 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.”

As part of the study, brain MRIs were conducted on patients at the beginning and again three years later to detect signs of silent strokes. The results showed low rates of silent strokes across both groups. Verma highlighted that after three years, 96 percent of patients exhibited no signs of silent strokes.

Anticoagulants, or blood thinners, are designed to prevent blood clots but can lead to serious bleeding complications. Many patients express a desire to discontinue these medications due to the risks associated with potential accidents. Verma remarked, “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. And now for a certain substantial portion of those patients, I think we can say, yes you can.”

Dr. David Birnie, a professor in the Department of Medicine at the University of Ottawa and head of the Ottawa Heart Institute, characterized the findings as a “game-changer.” He explained, “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.”

The study involved collaboration among over 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 report by The Canadian Press was first published on November 8, 2025.