Catheter ablation after a stroke didn't cut second-stroke risk, a Japanese trial found

Catheter ablation — a procedure that uses heat or cold to scar small areas of heart tissue and interrupt the abnormal electrical signals behind atrial fibrillation — is often added to blood thinners in patients who have already had a stroke, on the reasoning that eliminating the arrhythmia itself should further cut the odds of a second one. A Japanese randomized trial published online 2 March in JAMA Neurology tested that reasoning directly, and did not find the benefit clinicians have generally assumed was there [s1].

What the trial did

The Stroke Secondary Prevention With Catheter Ablation and Edoxaban for Patients With Nonvalvular Atrial Fibrillation (STABLED) trial was an open-label, parallel-group, randomized study conducted at 45 sites across Japan [s1]. Patients with nonvalvular atrial fibrillation who had recently had an ischemic stroke were assigned either to catheter ablation added to the anticoagulant edoxaban, or to edoxaban alone [s1]. Enrollment ran from January 2018 to March 2021, with patients followed until March 2024 [s1] — a long enough horizon to capture recurrent events that take years to show up, not just the immediate post-procedure period.

The primary outcome was a composite of stroke recurrence and other major cardiovascular events, tracked as a per-person-year rate to account for differences in how long individual patients were followed [s1].

What it found

The two groups ended up close to indistinguishable. The primary composite outcome occurred at a rate of 4.9% per person-year in the ablation-plus-anticoagulation group, compared with 5.6% per person-year in the anticoagulation-alone group [s1] — a gap small enough, and a trial modest enough in size, that the result reads as no clear added benefit from ablation rather than a demonstrated one [s1]. The study's authors and outside commentary describe the finding the same way: routinely adding catheter ablation to standard anticoagulant therapy did not significantly reduce the risk of recurrent stroke or major cardiovascular events in this population [s1] [s2].

That is a narrower and more specific claim than "ablation doesn't work for atrial fibrillation." STABLED was not testing ablation as a general treatment for the arrhythmia — plenty of trial evidence supports ablation for reducing AF symptoms and hospitalizations in appropriately selected patients. It was testing one specific proposition: that stacking ablation on top of anticoagulation, in patients who have already had a stroke, buys additional protection against a second one. In a single 45-site Japanese trial with several years of follow-up, it did not.

Why the distinction matters

Anticoagulation is already the standard, well-established therapy for preventing stroke recurrence in atrial fibrillation; the question STABLED was built to answer is whether adding a second, more invasive intervention meaningfully improves on that baseline. Catheter ablation is not a trivial add-on — it carries procedural risks, including bleeding and, rarely, more serious complications, and it is resource-intensive relative to a once-daily anticoagulant. A trial that finds no clear incremental benefit is informative for exactly that reason: it suggests that in this specific secondary-prevention setting, the additional risk and cost of ablation may not be buying additional protection beyond what anticoagulation already provides.

The result should be read with normal caution about a single trial. It was open-label, meaning patients and clinicians knew which treatment was assigned, which can introduce bias in how outcomes are assessed or managed. Japanese trial populations do not always generalize cleanly to other ethnic and health-system contexts, and the enrollment window — 2018 to 2021 — predates some refinements in ablation technique that have occurred since. The absolute event rates in both arms were also relatively low, which limits the trial's statistical power to detect a modest but real difference between groups.

What to watch

STABLED adds to a broader body of cardiology evidence that has, in recent years, repeatedly tested whether adding invasive rhythm-control procedures to standard drug therapy improves outcomes beyond what the drugs achieve on their own — with results that are frequently more modest than clinical intuition suggests. Whether this particular finding changes practice will depend on how it is weighed alongside other ablation trials and professional society guidelines, which have generally supported ablation for symptom control rather than as a stroke-prevention strategy in its own right. For patients already taking anticoagulants after an AF-related stroke, the trial is not evidence that ablation is unsafe or ineffective for its established uses — it is evidence that, in this specific trial, it did not add measurable protection against a second stroke.

Sources

• Catheter Ablation and Oral Anticoagulation for Secondary Stroke Prevention in Atrial Fibrillation: The STABLED Randomized Clinical Trial — JAMA Neurology, published online 2 March 2026
• Trial finds no clear added benefit of catheter ablation for preventing recurrent stroke in atrial fibrillation patients — EurekAlert! / Medical Xpress, 2 March 2026