The novel PolarX cryoballoon was noninferior to the Arctic Front cryoballoon for recurrence of atrial tachyarrhythmia (HR 0.85; 95% CI 0.56-1.30; P=0.03 for noninferiority).
RCT (n=201)
1:1
Yes
Does pulmonary vein isolation using the PolarX cryoballoon reduce recurrence of atrial tachyarrhythmia compared to the Arctic Front cryoballoon in patients with symptomatic paroxysmal AF?
The novel PolarX cryoballoon is noninferior to the Arctic Front cryoballoon for efficacy in paroxysmal AF ablation but is associated with a significantly higher rate of phrenic nerve palsy.
Effect estimate: HR 0.85 (95% CI 0.56-1.30)
Absolute Event Rate: 41.6% vs 47.1%
p-value: p=0.03 for noninferiority
BACKGROUND: Pulmonary vein isolation is an effective treatment for atrial fibrillation (AF). Cryoballoon ablation using the Arctic Front cryoballoon (Medtronic) was found to be superior to antiarrhythmic drug treatment. Recently, a novel cryoballoon system was introduced (PolarX, Boston Scientific). OBJECTIVES: The purpose of this study was to compare the efficacy and safety of the 2 cryoballoons in a randomized controlled trial. METHODS: Patients with symptomatic paroxysmal AF were enrolled in 2 centers and randomized 1:1 to pulmonary vein isolation using the PolarX or the Arctic Front cryoballoon. All patients received an implantable cardiac monitor. The primary endpoint was first recurrence of atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia AT) between days 91 and 365. Procedural safety was assessed by a composite of tamponade, phrenic nerve palsy lasting >24 hours, vascular complications, stroke/transient ischemic attack, atrioesophageal fistula or death up to 30 days. RESULTS: A total of 201 patients were enrolled. At 1 year, recurrence of atrial tachyarrhythmia had occurred in 41 of 99 patients (41.6%) assigned to the PolarX group and in 48 of 102 patients (47.1%) assigned to the Arctic Front group (HR: 0.85 95% CI: 0.56-1.30; P = 0.03 for noninferiority; P = 0.46 for superiority). The safety endpoint occurred in 5 patients (5%) in the PolarX group (n = 5 phrenic nerve palsies lasting >24 hours), whereas no safety endpoints occurred in the Arctic Front group (P = 0.03). CONCLUSIONS: In this randomized controlled trial using implantable cardiac monitors for continuous rhythm monitoring, the novel PolarX cryoballoon was noninferior compared with the Arctic Front cryoballoon regarding efficacy. However, the PolarX balloon resulted in significantly more phrenic nerve palsies. (Comparison of PolarX and the Arctic Front Cryoballoons for PVI in Patients With Symptomatic Paroxysmal AF COMPARE-CRYO; NCT04704986).
Reichlin et al. (Wed,) conducted a rct in symptomatic paroxysmal AF (n=201). PolarX cryoballoon vs. Arctic Front cryoballoon was evaluated on first recurrence of atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia [AT]) between days 91 and 365 (HR 0.85, 95% CI 0.56-1.30, p=0.03 for noninferiority). The novel PolarX cryoballoon was noninferior to the Arctic Front cryoballoon for recurrence of atrial tachyarrhythmia (HR 0.85; 95% CI 0.56-1.30; P=0.03 for noninferiority).