Comparison of Cool Tip Versus 8‐mm Tip Catheter in Achieving Electrical Isolation of Pulmonary Veins for Long‐Term Control of Atrial Fibrillation: A Prospective Randomized Pilot Study

OBJECTIVE: To compare safety and efficacy of 8-mm versus cooled tip catheter in achieving electrical isolation (EI) of pulmonary veins (PV) for long-term control of atrial fibrillation (AF). BACKGROUND: There is paucity of studies comparing safety/efficacy of 8-mm and cooled tip catheters in patients undergoing AF ablation. METHODS AND RESULTS: This was a randomized and patient-blinded study. Subjects were followed by clinic visits (at 6 weeks and 6 months) and transtelephonic monitoring (3-week duration) done around each visit. Primary endpoints were: (1) long-term AF control (complete freedom and/or >90% reduction in AF burden on or off antiarrhythmic drugs at 6 months after a single ablation), and (2) occurrence of serious adverse events (cardiac tamponade, stroke, LA-esophageal fistula, and/or death). Eighty-two patients (age 56 +/- 9 years, 60 males, paroxysmal AF = 59) were randomized (42 patients to 8-mm tip and 40 patients to cooled tip). EI of PVs was achieved in shorter time by the 8-mm tip as compared with cooled tip catheter (40 +/- 23 minutes vs 50 +/- 30 minutes; P < 0.05) but long-term AF control was not different between the two (32 patients 78% vs 28 patients 70%, respectively; P = NS). One serious adverse event occurred in each group (LA-esophageal fistula and stroke, respectively) and no significant PV stenosis was observed in either. CONCLUSION: EI of PVs using either 8-mm or cooled tip catheter results in long-term AF control in the majority after a single ablation procedure, with comparable efficacy and safety.