Randomized study defining the optimum target interlesion distance in ablation index-guided atrial fibrillation ablation: Authors’ reply

We thank the authors for their interest in our study1 and for presenting previously unpublished data from their important trials validating the CLOSE protocol. Gupta et al. criticize the early termination and sample size of our study.2 Based on an interim analysis of the first 42 patients and 84 pulmonary vein (PV) pairs, respectively, the study was terminated early for statistically compelling superiority of the protocol with 3.0–4.0 mm over that with 5.0–6.0 mm target intertag distance. This was in consensus with the local ethics committee and in compliance with common stopping guidelines with the P-value for the primary endpoint of P = 0.000000067 being well below even the most conservative statistical stopping boundaries. Thus, while—as with any clinical trial stopped early for superiority of one treatment—our study may overestimate the difference in treatment effects, it is highly unlikely that the null...