Limitations
Several limitations should be acknowledged. This was an observational and non-randomised study, however it is unlikely that a randomised trial will ever be performed of NOAC versus VKA in HCM patients undergoing AF ablation. Whilst our data are non-randomised it is hoped that they will be a useful point of reference for others considering this approach. Given the small sample size, this study was underpowered to demonstrate non-inferiority of NOAC vs. VKA for most of the study comparisons (which referred to events with a rate <10%). However, our multicentre data constitute the largest cohort of HCM patients undergoing AF ablation, and this is the first study to investigate the use of NOAC in this setting. An interrupted oral anticoagulation strategy with heparin bridging is no longer the standard of care and was used in a few patients in this series. However, the observed numerical differences were maintained even in sub-analyses excluding such patients. We could not provide data on silent cerebral infarction, as patients did not routinely undergo brain magnetic resonance imaging post-ablation. Only a limited number of patients were on edoxaban or dabigatran.