Efficacy comparison of high and very high power short duration pulmonary vein isolation: the HPSD remap study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Other. Main funding source(s): An investigator-initiated study. Research grant received from Biosense Webster (IIS 653). BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. The high power short duration ablation has shown good efficacy and safety profile. Recently, very high power short duration has been introduced, but initial efficacy results were discouraging. PURPOSE: The goal of this study was to compare the long-term durability of PVI performed with a 90W vs. 50W power setting. METHODS: Patients were randomized in a 1:1 fashion to undergo PVI either with 90W or 50W power. The ablation protocol was the following: in the case of 50W, the ablation index target values were 400 on the posterior wall and 500 on the anterior wall, and the inter-lesion distance was <5 mm; while in the case of 90W, a 4 seconds application was delivered at each site, with an inter-lesion distance <5 mm (preferably <4 mm anteriorly). At the index procedure, PVI was demonstrated by entrance and exit block after a 20-minute waiting period. All patients underwent a protocol-mandated repeat electrophysiology study after 3 months, regardless of symptoms. At the repeat study, all sites of PV reconnection were identified and re-ablated. RESULTS: A total of 40 patients were included in the study (20-20 on each treatment arm). Age was 65±8 years, 19 were females, BMI was 30±3.5, and 23 patients had paroxysmal AF. The most frequent comorbidities were hypertension (n=32) and diabetes (n=14). Procedure time (75 min vs. 84 min, p=0.02), left atrial dwelling time (63 min vs. 71 min, p=0.01), and radiofrequency time (335 sec vs. 1035 sec, p<0.0001) were shorter in procedures performed with 90W compared to 50W. On the other hand, the number of radiofrequency applications was higher in the case of 90W compared to 50W (85 vs. 70, p=0.09). There was no difference in the first-pass isolation rate (80% vs. 85%, p=1.0) and in the acute reconnection rate (5% vs. 15%, p=0.6) between the 90W and 50W power settings. At the repeat electrophysiology study, PV reconnection was seen in 4 and 7 patients in the 90W and 50W groups, respectively (p=0.5). The durable isolation on a per vein basis was 92% in the 90W group and 88% in the 50W group (p=0.4). CONCLUSIONS: A similarly high rate of durable PVI can be achieved both with 90W and 50W power settings if a slightly smaller inter-lesion distance is targeted on the anterior wall in case of 90W. Procedure time, left atrial dwelling time, and radiofrequency time is shorter with a 90W power setting compared to 50W.