In patients with persistent atrial fibrillation (AF), standard treatment with pulmonary vein isolation (PVI) ablation resulted in similar outcomes to more extensive ablation in other areas of the heart—as per results from the SUPPRESS-AF randomised controlled trial (RCT), which were presented at this year’s European Society of Cardiology (ESC) congress (30 August–2 September, London, UK).
“In our multicentre trial, the addition of further ablation targeting low-voltage areas that trigger rhythm abnormalities did not reduce the recurrence of AF at one year in the overall cohort, but showed promising results in an important subgroup with advanced left atrial enlargement, which affects around half of patients with persistent AF,” said lead author Masaharu Masuda (Kansai Rosai Hospital, Hyogo, Japan). “The results of this trial will likely change practice by shifting the focus to shorter and more effective pulmonary vein ablation alone without the addition of other ablation at the present time. Further research on more effective methods and patient selection to increase the effectiveness of additional ablations is expected.”
Despite PVI ablation’s ability to treat abnormal heart rhythms, rates of recurrence of AF after the procedure remain high. And, in patients with persistent AF, there is no established ablation strategy in addition to PVI. Nevertheless, low-voltage-area (LVA) ablation—in which areas with low bipolar voltage that trigger rhythm abnormalities are targeted—is widely performed, though its efficacy is not fully known.
To find out more, the SUPPRESS-AF trial enrolled 1,347 patients with persistent AF undergoing their first ablation at eight cardiovascular centres in Japan. Of these, 343 patients (25.5%) with an average age of 74 years, and 49% of whom were female, were found to have left atrial LVAs (covering ≥5cm² of left atrial surface) and were randomised in a 1:1 ratio to receive conventional PVI alone (171 patients) or with the addition of LVA ablation after PVI (170 patients). Recurrence of arrhythmias was identified using 24-hour continuous electrocardiography (ECG) monitoring at six and 12 months after ablation, and twice-daily home ECG recordings for one year.
Regarding the primary endpoint of recurrence of AF and atrial tachycardia (AT) without antiarrhythmic drugs at one year, there was no significant difference between the groups, with 61% of patients who had the additional LVA ablation and 50% of standard treatment patients in the control group being recurrence free. Similarly, freedom from AF/AT recurrence with antiarrhythmic drugs was not different between the two groups (LVA ablation, 63% versus controls, 55%).
However, in the subgroup of patients with left atrium enlargement (diameter ≥45mm)—when one of the heart’s upper chambers becomes larger than normal due to factors like high blood pressure or heart valve issues—LVA ablation reduced AF/AT recurrence by 40%. The researchers report that there was no difference in the rate of serious complications like stroke, which were very low in both groups (1.7% vs 1.8%) in SUPPRESS-AF.
“Ablation targeting the diseased myocardium is widely performed, but our results show that routine addition to PVI is not recommended,” Masuda noted. “This ablation should be performed only in cases of advanced atrial remodelling. An important next step will be to try to understand how this procedure can be improved for patients with the persistent type of AF.”
