Cryoballoon Pulmonary Vein Isolation for Atrial Fibrillation with Heart Failure – The POLAR-HF study

Background

Atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) are associated with increased morbidity and mortality. Ablation-based rhythm control has been shown to reduce mortality and heart failure-related rehospitalizations in this patient cohort. While this effect is particularly evident with radiofrequency ablation, data on the efficacy and safety of cryoballoon pulmonary vein isolation (CryoPVI) in patients with HFrEF remain limited.

Methods

Prospective, single-center, non-inferiority, observational study with propensity score matching to evaluate whether CryoPVI in HFrEF patients (LVEF ≤ 40%) is non-inferior to CryoPVI in patients without HFrEF. The primary efficacy endpoint was the first documented recurrence of atrial arrhythmia after a 90-day blanking period, with a prespecified non-inferiority margin of a hazard ratio of 1.39. Safety endpoints included death, cerebrovascular events, or serious procedure-related adverse events.

Results

A total of 1402 patients underwent CryoPVI for first-time AF ablation. 162 propensity score matched pairs were formed in a 1:6 ratio (162 patients with HFrEF and 810 without). Over a mean follow-up of 2 years, the primary efficacy endpoint occurred in 75/162 (46.3%) HFrEF patients and in 338/810 (41.7%) non-HFrEF patients (Kaplan-Meier event rate estimates, HR 1.03; 90%CI 0.83-1.28; P=0.01 for non-inferiority). All-cause mortality was higher in the HFrEF group (8% vs. 3.7%, P=0.01), but no difference was observed in the incidence of procedure-related safety endpoints between HFrEF and non-HFrEF patients (3.7% vs. 4.9%,  P=0.50).

Conclusion

CryoPVI in patients with HFrEF is non-inferior to CryoPVI in patients without HFrEF regarding efficacy in rhythm control. While overall mortality is higher in HFrEF patients, there is no difference in procedural safety between patients with and without HFrEF.