Initial experience and procedural efficacy of pulmonary vein isolation using the fourth-generation cryoballoon – a step forward?

Abstract

Background: Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an established treatment modality for patients suffering from paroxysmal or persistent atrial fibrillation (AF). Recently, the novel fourth-generation cryoballoon (CB4) was introduced which mainly provides a 40% shorter distal tip as compared to the second-generation cryoballoon (CB2). This two-centre analysis sought to assess the primary efficacy of the 28 mm CB4 for PVI and the feasibility of real-time signal recordings from the PVs considering the time-to-isolation (TTI).

Methods and results: Eighty-four patients with paroxysmal or short-standing persistent AF underwent CB4-based PVI at two different hospitals. Individual freeze-cycle duration was set at TTI + 120 seconds. No bonus freeze was applied. A total of 331 pulmonary veins (PVs) including five left common PVs were identified and all PVs were successfully isolated. Mean freeze-cycle duration was 165.7 ± 31.5 seconds. The mean minimal CB temperature was –45.6 ± 7.6 °C with a real-time PVI visualisation rate of 78% (67/84 (79.8%) RSPVs, 55/84 (65.5%) RIPVs, 67/79 (84.8%) LSPVs, 66/79 (83.5%) LIPVs and 2/5 (40%) LCPV). Transient phrenic nerve palsy occurred in 2/84 (2.4%) patients during cryo-application along the RSPV.

Conclusions: The novel CB4 provides both, a high acute efficacy and a high rate of real time electrical PV-recordings, thus facilitating individual ablation strategies based on TTI.

Keywords:

• Atrial fibrillation
• pulmonary vein isolation
• cryoballoon
• time to effect
• fourth generation
• efficacy

Disclosure statement

KH Kuck received travel grants and research grants from Biosense Webster, Stereotaxis, Prorhythm, Medtronic, Edwards, Cryocath, and is a consultant to St. Jude Medical, Biosense Webster, Prorhythm, and Stereotaxis. He received speaker's honoraria from Medtronic. A. Metzner received speaker's honoraria and travel grants from Medtronic, Biosense Webster and Cardiofocus. S. Mathew received speaker's honoraria and travel grants from Medtronic and Biosense Webster. A. Rillig received travel grants from Biosense, Medtronic, St. Jude Medical, Cardiofocus, EP Solutions and Ablamap and lecture and consultant fees from St. Jude Medical, Medtronic, Biosense, Cardiofocus, Novartis and Boehringer Ingelheim.