Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study

Abstract

BackgroundThe second‐generation cryoballoon significantly improves outcome of pulmonary vein isolation (PVI) but may cause more complications than the first generation. Currently, no consensus regarding optimal cryoballoon application time exists. The 123‐study aimed to assess the minimal cryoballoon application duration necessary to achieve PVI (primary endpoint) and the effect of application duration on prevention of phrenic nerve injury (PNI).MethodsPatients <75 years of age with paroxysmal atrial fibrillation, normal PV anatomy, and left atrial size <40 cc/m² or <50 mm were randomized to two applications of different duration: “short,” “medium,” or “long.” A total of 222 patients were enrolled, 74 per group.ResultsDuration per application was 105 (101‐108), 164 (160‐168), and 224 (219‐226) s and isolation was achieved in 79, 89, and 90% (P < 0.001) of the PVs after two applications in groups short, medium, and long, respectively. Only for the left PVs, the success rate of the short group was significantly less compared to the medium‐ and long‐duration groups (P < 0.001). PNI during the procedure occurred in 19 PVs (6.5%) in the medium and in 20 PVs (6.8%) in the long duration groups compared to only five PVs (1.7%) in the short duration group (P < 0.001).ConclusionsShort cryoballoon ablation application times, less than 2 min, did affect the success for the left PVs but not for the right PVs and resulted in less PNI. A PV tailored approach with shorter application times for the right PVs might be advocated.

Impact of cryoballoon applications on lesion gaps detected by magnetic resonance after pulmonary vein isolation

“…Although cryoablation is effective and safe in patients with paroxysmal AF undergoing ablation, 2 the optimal freezing strategy to induce durable lesions while minimizing complications is still under discussion. In previous studies, shorter applications decreased success in achieving PVI 9 . On the other hand, some studies have shown that prolonging freezing time does not improve outcomes.…”

“…However, the optimal freezing strategy is still under debate 3–7 . Prolonged freezing cycles may achieve more durable PVI at the cost of longer procedures and an increased risk of injury to extracardiac structures (eg, phrenic nerve, esophagus, bronchial tree) 8–10 . Conversely, insufficient times may be associated with greater recurrence 9 …”

“…[3][4][5][6][7] Prolonged freezing cycles may achieve more durable PVI at the cost of longer procedures and an increased risk of injury to extracardiac structures (eg, phrenic nerve, esophagus, bronchial tree). [8][9][10] Conversely, insufficient times may be associated with greater recurrence. 9 Late-gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) offers a promising tool for noninvasive characterization of atrial myocardial fibrosis.…”

“…[8][9][10] Conversely, insufficient times may be associated with greater recurrence. 9 Late-gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) offers a promising tool for noninvasive characterization of atrial myocardial fibrosis. Scarring after RF ablation has been well characterized by LGE-CMR [11][12][13] and ablation discontinuities ("gaps") have been shown to predict recurrent AF.…”

Relationship between time‐to‐isolation and freeze duration: Computational modeling of dosing for Arctic Front Advance and Arctic Front Advance Pro cryoballoons

“…As an example, it would be expected that TTI ED is extended when the cryoballoon is ablating along a thickened cardiac anatomy such as the ridge between PV and left atrial appendage. Ultimately, our computational model data might further progress dosing strategies and algorithms that continue to attempt to shorten the cryoablation freeze duration …”