Comparing cerebral microembolisation patterns between high power short duration and pulsed field ablation techniques using artificial intelligence based robotic transcranial doppler monitoring

Abstract Thromboembolism is a rare (<1%) complication of atrial fibrillation (AF) ablation , but the incidence of silent ischaemic lesions (SIL) is 5-15% (1). Artificial intelligence (AI)-based robotic transcranial Doppler (r-TCD) enables real-time cerebral embolisation detection. We aimed to investigate the cerebral microembolization signal (MES) load with r-TCD of patients undergoing PF ablation, comparing the number of detected MES-s between 90 W radiofrequency (RFA) "very high power short duration (vHPSD) ablation" and "pulsed field ablation (PFA)" techniques. Our interim analysis included r-TCD registratums of 26 patients. 16 interventions were performed with VHPSD, 10 with PFA, during which we recorded the flow curve of the arteria cerebri media (ACM) bilaterally with r-TCD and analyzed the MES-s quantitatively and qualitatively with AI-based embolisation detection software. Postoperative cranial MRI exams were performed. Continuous variables were compared between the groups using a two-sample t-test, and categorical variables were compared using a Fisher exact test. The MES load by the different pulmonary veins was compared using Wilcoxon test and Bonferroni correction. A p-value below 0,05 was considered significant. The two groups were comparable regarding baseline parameters (mean age: 63 vs.58 p=0,253; EF:59% vs.62 .2% p=0,33). Ablations with vHPSD were significantly longer compared to PFA (88,7 min vs. 54,7 min p<0,001), left atrial time was significantly shorter with PFA (52,1 min vs. 29 min p<0 001), but the fluoroscopic time was significantly longer (5,4 min vs. 9,3 min p=0,009) during ablation with PFA. Neither solid emboli, nor ischaemic lesion or neurological deficit was detected. During the ablations, we saw an average of 246 gas MES-s with PFA and 138 with RFA (p=0,216). During PFA we analyzed the MES load per pulmonary vein: by the left superior vein we detected a median of 56,5 (IQR: 21,5-116,5), by the left inferior there were a median of 23 MES-s (IQR: 4,5 115,5), by the right inferior a median of 32 (IQR: 12-84,5), and by the right superior a median of 22,5(IQR: 8,5-70) respectively, p=0,03. While comparing each veins to each other, by the right vs. left superior vein, the p value resulted 0,01. On an initial sample,we detected known differences in the procedural parameters of the two interventions. There tended to be more MES-s during PFA, but this difference was not significant. Regarding the MES load by the ablation of different pulmonary veins, we found a significant overall difference between the MES load by the four veins, especially between the left and right superior vein. A larger number of interventions and r-TCD registratums is needed to determine the cerebral safety of PFA compared to RFA.