Introduction Radiofrequency (RF) ablation for atrial fibrillation (AF) has traditionally been performed under general anaesthesia (GA) to improve procedure tolerance and efficacy, but this has been compromised during the COVID-19 pandemic due to a reduction in GA availability. A very high-power short duration (vHPSD) energy delivery protocol may reduce RF delivery times and hence overall procedure duration, potentially obviating the need for GA when using such an approach. However, the use of vHPSD under conscious sedation has not previously been reported.

We sought to evaluate first-time AF ablation using a vHPSD approach during the COVID-19 pandemic by comparing the procedural metrics and same day discharge (SDD) rates of vHPSD against cryoballoon ablation.

Methods Procedural data was collected from consecutive patients undergoing first-time AF ablation at two UK centres from September 2020 to February 2021 using either the QDot Micro catheter (Biosense Webster) or the Arctic Front Advance Pro cryoballoon (Medtronic). In the QDot group, vHPSD ablation (90W, 4 second lesions) was mandated for pulmonary vein isolation (PVI), while Ablation-Index guided 50W ablation was allowed for additional lesions. Procedures were performed under mild conscious sedation with opiates and benzodiazepines, with a default strategy of SDD in the absence of clinical concerns or adverse events.

Results 78 patients were evaluated, with 39 patients undergoing vHPSD and 39 receiving cryoablation. The procedural metrics of both groups are shown in the table 1. 34 out of 39 (87%) vHPSD procedures were under conscious sedation, and the 5 GA cases were all from the initial 2 months of experience with the Qdot catheter. The duration of RF energy delivery to achieve PVI using vHPSD was significantly shorter than the equivalent duration of cryothermy. Overall fluoroscopy times were shorter using vHPSD, while procedure duration was longer. There was failure to achieve isolation of all pulmonary veins in 3 (7.7%) cryoablation patients versus none when using vHPSD ablation. In the vHPSD group. 3 patients received adjunctive ablation beyond PVI: 1 had roof and floor lines; 1 cavotricuspid isthmus line, and 1 received a mitral isthmus line. No adjunctive ablation was performed in the cryoablation group. SDD rates were similar in in both groups.

Conclusion A vHPSD approach can be used with conscious sedation to achieve same-day discharge rates for AF ablation that are comparable to cryoablation. There are advantages in fluoroscopy time and the required duration of ablation delivery, as well as the versatility to handle variations in pulmonary venous anatomy and additional ablation beyond PVI.

Conflict of Interest GAN - Fellowship support from Biosense Webster and Abbott, consultancy fees from Biosense Webster and Catheter Precision. DG - institutional research grants and speaker fees from Biosense Webster, Medtronic and Boston Scientific. Others - Nil