Predictors of late atrial fibrillation recurrence after cryoballoon-based pulmonary vein isolation: a meta-analysis

BACKGROUND: The recurrence rate of atrial fibrillation (AF) after cryoballoon ablation in drug refractory AF patients is high. Late-recurrence of AF has various predictors. AIM: The aim of the study was to explore the related risk factors that can effectively predict late AF recurrence after cryoballoon-based pulmonary vein isolation. METHODS: The PubMed and Web of Science databases were searched from 1 January 2013 to 1 August 2016, and studies were chosen that met the pre-stated inclusion criteria. The reference lists of the retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies. The strength of the relationship between different risk factors and late recurrence was assessed by the adjusted hazard ratio. RESULTS: A total of 16 papers met the inclusion criteria and were included in the meta-analysis. The hazard ratio of late atrial arrhythmia recurrence in patients with early recurrence was 4.19 compared with the reference group (95% CI 2.73-6.44, p < 0.00001); that of increased left atrial diameter was 1.25 (95% CI 1.12-1.3, p < 0.0001); that of a long duration of AF before ablation was 1.10 (95% CI 1.04-1.17, p < 0.0009); and that of persistent AF was 2.44 (95% CI 1.30-4.58, p < 0.006). However, there exists significant heterogeneity for each indicator, and a slight publication bias was observed. CONCLUSIONS: Our study suggests that early recurrence in the blanking period, increased left atrial size, a longduration of AF before ablation and persistent AF are independent predictors of late recurrence after cryoballoon ablation.