Experience and procedural efficacy of pulmonary vein isolation using the fourth and second generation cryoballoon: The shorter, the better?

BACKGROUND: The second-generation cryoballoon (CB2) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome. The novel fourth-generation cryoballoon (CB4) incorporates a 40% shorter distal tip. This design change may translate into an increased rate of PVI real-time signal recording, facilitating an individualized ablation strategy using the time to effect (TTE). METHODS AND RESULTS: Three hundred consecutive patients with paroxysmal or persistent atrial fibrillation were prospectively enrolled. The first 150 consecutive patients underwent CB2 based PVI (CB2 group) and the last 150 consecutive patients were treated with the CB4 (CB4 group). A total of 594/594 (100%, CB4) and 589/594 (99.2%, CB2) pulmonary veins (PVs) were successfully isolated utilizing the CB4 and CB2, respectively (p = .283). The real-time PVI visualization rate was 47% (CB4) and 39% (CB2; p = .005) and the mean freeze cycle duration 200 ± 90 s (CB4) and 228 ± 110 s (CB2; p < .001), respectively. The total procedure time did not differ between the groups (CB4: 64 ± 32 min) and (CB2: 62 ± 29 min, p = .370). No differences in periprocedural complications were detected. CONCLUSIONS: A higher rate of real-time electrical PV recordings are seen using the CB4 as compared to CB2, which may facilitate an individualized ablation strategy using the TTE.