- Design
- Multicentre randomised clinical trial, 12-month follow-up (IDEAL-AF)
- Population
- 209 adults with persistent AF and low-voltage zones ≥3 cm² at first ablation, Sweden
- Primary outcome
- Freedom from atrial arrhythmia without antiarrhythmic drugs at 12 months
- Effect
- 67.6% vs 37.4%, difference 30.3% (95% CI 17.4–43.2); OR 3.5
IDEAL-AF mapped 936 patients having first-time ablation for persistent atrial fibrillation at five Swedish centres. The 209 with low-voltage zones of at least 3 cm² after pulmonary vein isolation (median age 72, 52% women) were randomised to additional individualised ablation of those zones or no further ablation.
At 12 months, freedom from atrial arrhythmia off antiarrhythmic drugs (allowing up to two procedures) was 67.6% with low-voltage ablation versus 37.4% with PVI alone — an absolute difference of 30.3 percentage points (95% CI 17.4–43.2). Time to first recurrence after a single procedure also favoured the added ablation (HR 0.4). Quality of life improved more, and serious adverse events were similar.
This is one of the clearer positive results for any strategy beyond PVI in persistent AF, and it applies to a defined group: older patients with substantial atrial scar, in whom PVI alone often fails. It is a moderate-sized, unblinded trial with 12 months' follow-up, so durability is unknown.
- Ask the electrophysiology team whether voltage mapping is done at first ablation for persistent AF.
- Low-voltage zone ablation applies to patients with substantial scar (≥3 cm²) — about one in five of those mapped here.
- Expect PVI alone to fail in more than half of such patients at a year.
- Serious complications were not increased, so the added ablation did not trade safety for efficacy in this trial.
Why it matters
It gives a mapping-guided answer to the persistent-AF patients who most often relapse after pulmonary vein isolation alone.
Don't overread it
One year of follow-up in 209 patients from one country — longer durability and replication are still needed.
The statistics, in plain English
The confidence interval for the absolute difference (17 to 43 percentage points) is wide because the trial is small, but even its lower end is a large benefit.
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