secondary efficiency endpoints
As shown in table 2, the number of RF lesions delivered for the total AF ablation procedure did not differ between the two treatment groups. In contrast, the RF time per lesion until the target AI was reached was significantly shorter in the HPSD group compared to the controls (HPSD: 18.5 ± 3.4 sec vs. control: 28 ± 3.6; p<0.001).
Early recurrence of atrial fibrillation within the first 12 weeks after ablation was reported in 25% in the control- and 6% in the HPSD group (p=0.007, patient- and primary physician reported outcome data).
thermal oesophageal lesions (primary safety endpoint)
Oesophageal thermal lesions were seen in 2 out of 20 patients (10%) within the standard group and 13 out of 97 patients (13.4%) in the HPSD group (p=0.72; table 3) - 3 patients within the high-power group withdrew consent to perform the post-procedural EGD. The individual lesion characteristics are displayed in table 4. Lesions characteristics differed apparently between the two ablation groups. Both lesions seen in the standard-power group were typical thermal oesophageal lesions previously described after PVI, forming deep ulcerations during follow-up and showed slow regression tendencies starting 2 weeks after the index procedure (figure 2 panel A, B). The 13 lesions seen after HPSD ablation were overall smaller and more shallow: 5 lesions showed merely a detachment of superficial mucosal layers that resolved completely after one week (figure 2, panel C - E), 5 lesions showed small ulcer <=5 mm that resolved within 7-14 days and one larger lesion 7 mm in diameter showed healing tendencies after 2 weeks of follow-up (figure 2, Panel F). One patient developed a large, superficial ulcer 12 mm in diameter, that was followed up over a course of 12 weeks and showed prolonged scarring healing, without evidence of fistula formation (supplemental figure, panel G),. Overall, only 2 out of 97 (2%) of all HPSD treated patients developed clinical significant thermal injuries. HPSD Ablation to the inferior wall was not associated with an increase in EDEL, as only 2 out of 17 patients with additional inferior box lesions developed superficial EDEL (11.7%, n.s.).