DISCUSSION
SECONDARY, RECRUITMENT
To date there has not been a double‐blind randomized controlled trial comparing PV isolation to a sham procedure. Given this, physicians have advocated for a sham‐controlled study in patients with AF to fully evaluate the efficacy of PV isolation to account for any placebo effect.In this study, healthcare professionals and physicians post‐procedure will be blinded to treatment strategy. Although previous studies examining catheter ablation for PV isolation have included end point blinded adjudication committees, the lack of blinding of physicians treating patients may confound results. As physicians post‐procedure will be blinded to the treatment received in this study, all patients will be treated equally on the same pathway, thus minimizing bias.The first 3 months post‐procedure constitute the blanking period as recommended by the 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of AF.The study is powered to address the primary hypothesis that AF ablation results in a significant AF burden reduction compared to a sham procedure. Quality of life and AF symptoms will also be assessed as secondary outcomes. The sample size calculation and standard deviations are based on CASTLE‐AF data and the clinical investigators own experience, specifically continuous monitoring data from The Eastbourne District General Hospital AF Ablation Registry.The study is limited to 6 months follow‐up. Previous studies examining PV isolation with a longer follow‐up have had high crossover rates, which affects the interpretation of results for example, In the CABANA trial 9% of patients in the ablation group did not undergo ablation and 22.3% of the patients in the medical therapy group underwent ablation.A challenge of the study to date has been the recruitment of patients during the COVID‐19 pandemic which has delayed study recruitment. However, to limit any potential effect of the COVID‐19 pandemic, recruitment was paused in March 2020 and restarted in July 2021. Protocol changes were made to facilitate follow‐up during the COVID‐19 pandemic. The ILR insertion timing recommendation was reduced to a minimum of 2 weeks before the ablation/sham procedure date. During 2021, there was uncertainty regarding further surges in COVID‐19 and the impact this would have on the study. Thus the ILR insertion was also allowed to be performed at the time of the ablation/sham procedure. This would have reduced the requirement for patients to isolate before entering hospital sites. However to date, this has not been required and all patients have had their ILR inserted before the ablation/sham procedure allowing a pre‐procedure AF burden in all patients.