The ICE-AFIB trial: A multicenter prospective investigational device exemption (IDE) trial using cryosurgical ablation for atrial fibrillation during concomitant cardiac surgery.

OBJECTIVE

Surgical treatment for atrial fibrillation (AF) has transitioned from cut-and-sew to cryothermal and radiofrequency ablation. ICE-AFIB is the first prospective, multicenter investigational device exemption trial to evaluate cryothermy as a sole energy source to perform concomitant Cox-maze III procedures for patients with nonparoxysmal AF.

METHODS

ICE-AFIB is a single-arm, Bayesian adaptive design, investigational device exemption study (NCT03732794). Patients ≥18 years with persistent/longstanding persistent atrial fibrillation underwent concomitant cryosurgical Cox-maze III. Primary effectiveness was freedom from AF/atrial flutter/atrial tachycardia from 6 to 12 months after the procedure. Primary safety was composite major adverse event (myocardial infarction, stroke, major bleeding, death) rate within 30 days. Rhythm assessment was with periodic 24-hour Holter monitoring.

RESULTS

One hundred fifty patients were treated at 14 sites, with median age 69.0 (standard deviation [SD], 8.85) years, median body mass index 31.0 (SD 6.90) kg/m2, CHA2DS2-VASc = 3.0 (SD 1.67), and median left atrial diameter 5.2 (SD 0.83) cm. In total, 66.0% were male, and median current/most recent AF episode was 5.7 (SD 25.86) months in duration (63.3% persistent AF, 36.7% long-standing persistent AF). Concomitant procedures were mitral valve (67.3%), tricuspid valve (42.0%), coronary artery bypass grafting (29.3%), and aortic valve (18.7%); 59.3% had multiple concomitant procedures. Primary effectiveness was met with 70% freedom from AF/atrial flutter/atrial tachycardia from 6 through 12-months (posterior probability: 0.9997; 95% credible interval, 62%-77%) and 77% (95% confidence interval, 68.7%-84.5%) at 12 months off class I/III AADs. Primary safety at 30 days was achieved with a major adverse event rate of 9.3% (posterior probability: 0.974; 95% credible interval, 14.2%), including 2.7% stroke, 5.3% major bleeding, 2% operative mortality, all unrelated to surgical ablation/device.

CONCLUSIONS

The ICE-AFIB trial demonstrated safety and effectiveness of single procedure cryothermal-only cryomaze procedure in patients with persistent and longstanding persistent atrial fibrillation.