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This study aimed to evaluate effectiveness and safety of cryoballoon ablation (CBA), an emerging technology for atrial fibrillation (AF) treatment by comparing it with drug treatment and radiofrequency ablation (RFA).
A retrospective cohort study was conducted among AF patients who received either catheter ablation (CBA or RFA) or drug treatment from November 2014 to May 2016 at The First Affiliated Hospital of Xi’an Jiaotong University. All patients were followed up from discharge date to either occurrence of death or August 31, 2016. The primary endpoints were the first-documented clinical failure, including AF recurrence or repeat ablation. Secondary effective endpoints included ablation time, mean ablation temperature, the first re-hospitalization for cardiovascular causes, and quality of life, as evaluated by the SF-36 score. The primary safety endpoints included procedure-related adverse complications, causes of death, incidence of stroke or transient ischemic attack, and hemorrhagic events. All patients signed an informed consent for participation in the research.
One hundred and sixty (160) patients were identified who met the inclusion criteria of having episodes of electrocardiogram (ECG)-documented AF within 2 months prior to hospitalization. Twenty-seven (27) patients were excluded due to predetermined exclusion criteria, nine patients (two in the CBA group, one in the RFA group and six in drug treatment) were lost to follow-up, and one hundred and twenty-four (124) patients (23 in the CBA group, 33 in the RFA group, and 68 in drug treatment group) completed follow-up. The primary efficacy endpoints occurred in eight patients in the CBA group, fourteen patients in RFA group and forty-seven in drug treatment group (1-year Kaplan-Meier event-rate estimates, 32.0%, 43.6%, and 66.5% respectively; CBA VS drug treatment: hazard ratio [HR], 0.43, 95% confidence interval [CI], 0.23 to 0.80, p=0.012; CBA VS RFA: HR, 0.62[0.26 to 1.50], p=0.277). The primary safety endpoints occurred in four patients in CBA group, six patients in the RFA group and eleven in drug treatment (1-year Kaplan-Meier event-rate estimates, 6.3%, 21.2%, and 18.8% respectively; CBA VS drug treatment: HR, 0.29[0.11-1.61], p=0.264; CBA VS RFA: HR, 0.21[0.05 to 1.32]; p=0.094).
In this study, CBA is more effective than drug therapy as a treatment for AF and it showed equivalent efficacy and safety in comparison to RFA. This suggests the potential wide application of CBA in AF treatment, especially in China and other third-world countries, where effective RFA is sometimes not available due to the lack of trained physicians to perform this procedure.