A heart procedure performed more than 500,000 times a year worldwide did not improve patients' quality of life any more than a convincing fake version of the same procedure, according to a trial presented at the European Society of Cardiology Congress in Munich and published simultaneously in The Lancet.
The finding matters because symptom relief is the main reason most people with atrial fibrillation are offered catheter ablation in the first place. American patients who have been told the procedure will help them feel better now have large blinded evidence testing that specific promise, and the result did not come out the way most cardiologists expected.
The trial did not find that ablation does nothing. It reduced atrial fibrillation episodes substantially. What it failed to show is that the reduction in episodes translated into a measurably better quality of life compared with patients who went through the same hospital experience without the actual ablation.
Inside a Sham Controlled Heart Procedure Trial
Sham-controlled trials of procedures are rare because they are difficult to justify and difficult to fill. In PVI-SHAM-AF, the European Society of Cardiology summarized the trial's main findings: 262 patients with symptomatic paroxysmal or persistent atrial fibrillation at nine hospitals in Germany and Poland were randomly assigned in a two-to-one ratio to receive real catheter ablation or a sham procedure.
Patients in the sham group received conscious sedation for the same length of time and in the same setting as the real procedure, and vascular access was obtained. No catheter was placed. Neither the patients nor the staff assessing their symptoms afterward knew which group they were in.
Both groups filled out the Atrial Fibrillation Effect on Quality of Life questionnaire, known as AFEQT, at the start and again six months later. The change in that score from baseline to six months was the trial's primary endpoint, and it is the standard instrument cardiologists use to measure how much atrial fibrillation is interfering with a patient's daily life.
The Numbers Behind the Split Result
Quality of life improved in both groups. AFEQT summary scores rose from 61.3 to 81.1 among patients who received real ablation and from 59.2 to 74.9 among patients who received the sham. The difference between those improvements was not statistically significant, with a p-value of 0.36.
The rhythm results told a different story. Freedom from atrial fibrillation at six months reached 73 percent in the ablation group compared with 52 percent in the sham group. The procedure clearly worked on the arrhythmia itself.
Safety numbers were similar between arms. There were five vascular access complications overall, three in the ablation group and two in the sham group. Serious adverse events related or possibly related to the procedure occurred in six ablation patients and four sham patients.
Two earlier sham-controlled trials, SHAM-PVI in the United Kingdom and PFA-SHAM in the Czech Republic, had pointed the other way on symptoms. As two earlier sham-controlled trials reached a different conclusion, both were smaller and used different ablation methods and patient selection, which is part of why the field now has a genuine disagreement to resolve rather than a settled answer. The trial was also listed among the late-breaking science in the American Heart Association's congress science summary.
The full results appear in The Lancet, and the trial is registered as NCT05119231.
Patients Weighing Ablation Now Face a Different Conversation
For a household where someone is scheduled for ablation, this is not a reason to cancel. It is a reason to ask a more specific question at the next appointment.
Ablation still reduces atrial fibrillation episodes, and rhythm control has value beyond how a patient feels on a given Tuesday. Fewer episodes can mean fewer emergency department visits, less medication adjustment, and slower progression from occasional atrial fibrillation to the persistent form. Those are real benefits that this trial did not test and did not contradict.
What changes is the expectation being set. If a cardiologist is recommending ablation mainly on the basis that it will make a patient feel dramatically better, this trial suggests some of that improvement may come from other sources, including the attention, the medication review, and the reassurance that surround any major procedure.
Cost is part of the calculation too. Catheter ablation is an expensive hospital procedure, and coverage, deductibles and out of pocket maximums vary widely across commercial plans and Medicare. Patients weighing the decision can reasonably ask their care team what the procedure is expected to accomplish, what the alternatives are, and what the total expected cost will be.
Limits That Keep This from Being the Final Word
The investigators flagged a significant limitation themselves. Of 1,199 patients invited to participate, 937 declined. Patients willing to accept a coin flip that might land them on a fake procedure may be systematically different from patients who insist on the real thing.
Professor Nikolaos Dagres of the German Heart Centre at Charite University Medical Centre Berlin, who co led the trial, said accepting sham allocation "may have selected patients with different symptom burden, treatment expectations or preferences." Patients with the most severe symptoms may have been the most likely to refuse, which would blunt the measurable difference between groups.
Professor Rolf Wachter of the University of Leipzig Medical Center, the trial's other lead investigator, framed the practical takeaway carefully. He said most of the improvement patients report after the procedure "is not attributable to the catheter ablation, but to other factors," which could include a placebo effect or optimization of other therapies. He added that ablation still delays progression of the arrhythmia.
The trial was sponsored by Leipzig University and funded by Helios Gesundheit, a German hospital operator. Wachter and Dagres both disclosed extensive research funding and consulting relationships across the cardiovascular device and drug industry.
Professional societies will now weigh this result against the earlier sham trials that pointed the other way. Guideline committees typically take months to years to respond to a single trial, and no guidance has changed yet. Patients should not stop anticoagulation, antiarrhythmic drugs, or any other prescribed treatment based on this study without speaking to the clinician who prescribed it.
Key Questions Answered
What did the trial actually find? Catheter ablation reduced atrial fibrillation recurrence compared with a sham procedure, but the improvement in atrial fibrillation-related quality of life was not significantly greater than the improvement seen after the sham.
Does this mean ablation does not work? No. The procedure clearly reduced arrhythmia episodes, with 73 percent of ablation patients free from atrial fibrillation at six months versus 52 percent after sham. The trial questioned the size of the symptom benefit, not whether ablation affects the rhythm.
Should someone cancel a scheduled ablation? Not on the basis of this trial. Anyone with questions should raise them with their cardiologist before the procedure date rather than canceling independently.
What is a sham procedure? Patients undergo sedation, vascular access, and the full hospital experience of the real procedure, but the therapeutic step is never performed. It is the procedural equivalent of a placebo pill and allows researchers to separate the effect of the treatment from the effect of being treated.
Why do earlier trials disagree with this one? Two previous sham-controlled trials found a quality of life benefit. They were smaller and differed in how patients were selected, which ablation technique was used, and how blinding was handled. The field has not resolved which design best reflects real practice.
Who is most affected by this finding? Adults with symptomatic paroxysmal or persistent atrial fibrillation who are considering a first ablation, particularly those whose main goal is symptom relief rather than rhythm control for other reasons.
When might treatment guidelines change? No guidance has changed. Guideline committees generally evaluate a single trial in the context of the full body of evidence, a process that typically takes months or longer.
