Purpose: Catheter-tissue contact is critical for effective lesion creation in radiofrequency catheter ablation (RFCA). In a multicenter prospective study, we assessed the relationship between catheter contact force (CF) during RFCA for paroxysmal atrial fibrillation (AF) and clinical recurrences over a mid-term follow-up.
Methods: All patients underwent RFCA for paroxysmal AF by antral pulmonary vein (PV) isolation, aiming at entry and exit conduction block in all PVs. A new open-irrigated tip catheter with CF sensing (SmartTouch(TM), Biosense Webster Inc. CA) was used. All patients were followed for at least 12 months and the relationship between CF and clinical outcomes assessed.
Results: One year follow-up was available in 92/95 of the patients enrolled. Acute PV isolation was achieved in 100 % of the veins. Mean CF during RFCA was 12.2 ± 3.9 g. Mean force-time integral (FTI) was 733 ± 505 gs. Following the 3-month blanking period, 17 (18 %) patients experienced at least 1 atrial tachyarrhythmia relapse. There was no statistical difference in mean CF (13 ± 3.4 g vs 12 ± 4 g, p = 0.32) and mean FTI (713 ± 487 gs vs 822 ± 590 gs, p = 0.42) between patients with and without arrhythmia recurrences. Recurrences were recorded in 22 % of patients achieving a mean FTI value below the median of 544 gs and in 15 % of patients with a mean FTI value above the median (p = 0.64).
Conclusions: RFCA with CF data during PV isolation for paroxysmal AF improves physician's knowledge on catheter-tissue contact. In the present dataset, however, higher CF values did not impact mid-term clinical RFCA outcome.