Eva Verbeek

Objectives: This study aimed to evaluate the long-term efficacy and safety of isolated and hybrid thoracoscopic atrial fibrillation (AF) ablation using a bipolar irrigated radiofrequency clamp in a multicentre registry. Methods: A retrospective multicentre registry of patients undergoing AF ablation using the bipolar clamp was conducted over the past 13 years (2010-2023). The primary efficacy outcome was freedom of atrial tachyarrhythmias (ATAs), with and without the use of Class I/III antiarrhythmic drugs (AADs). Antiarrhythmic drug use during follow-up was not uniformly documented across centres. The primary safety outcome was the rate of periprocedural complications. Results: The cohort of 678 patients consisted of a minority of female patients (17.4%), with most patients having longstanding persistent AF (LSPAF) (66.7%), a mean duration of 61 months of AF duration and 33.3% had undergone prior catheter ablation. Freedom from ATA while allowing Class I/III AAD use was 82.3%, 71.5%, and 52.4% at 1, 3, and 5 years, respectively. Freedom from ATA off Class I/III AAD declined from 71.7% at 1 year to 44.2% at 5 years, underscoring the progressive nature of AF and the need for long-term rhythm strategies. Women presented with a more advanced cardiovascular risk profile than men, including older age (60.3 vs 57.3 years), higher CHA2DS2-VA-scores, and more comorbidities. Despite these differences, there were no significant sex-based differences in long-term ATA freedom. There were no significant unadjusted differences in long-term ATA freedom between paroxysmal AF (PAF) and non-PAF. Major complication rate was low. Conclusions: Isolated and hybrid thoracoscopic AF ablation using the Gemini Clamp demonstrated favourable outcomes with a low complication rate. However, variability in ATA detection methods among centres may have influenced the primary outcome and should be considered when interpreting long-term efficacy results. Clinical trial registry number: METC-number 2022-3561.