Prognostic Value of Burst Pacing Inducibility Post-Radiofrequency Versus Cryoablation for Paroxysmal Atrial Fibrillation.

Background: Atrial fibrillation (AF) inducibility with burst pacing (BP) after radiofrequency ablation (RFA) has been reported to be associated with AF recurrence. In contrast, the relevance of inducibility and recurrence after cryoablation (CRA) is unclear.

Methods: We investigated 367 patients undergoing initial ablation for paroxysmal AF (RFA: 174, CRA: 193). Propensity score matching was conducted, retaining 134 patients in each group. Following pulmonary vein isolation (PVI), the inducibility by BP was tested. Inductions at 250 ppm were defined as low-frequency burst pacing (LFBP) positive, and those at 300 ppm were classified as medium-frequency burst pacing (MFBP) positive. They were followed for 600 days.

Results: Forty-eight patients (18%) had AF recurrence. There was no significant difference in the recurrence rate between RFA and CRA (17% vs. 19%, Log-rank p = 0.79). In RFA, significant differences were observed for both LFBP (Log-rank p < 0.001) and MFBP (Log-rank p < 0.001). In contrast, in CRA, there were no significant differences for either LFBP (Log-rank p = 0.39) or MFBP (Log-rank p = 0.19). Multivariable analysis revealed that LFBP-positive (hazards ratio [HR] = 5.75, 95% confidence interval [CI] 2.41-13.7, p < 0.001) was an independent predictor for recurrence with RFA. Acute reconnection (HR = 2.73, 95% CI 1.13-6.56, p = 0.025) was an independent predictor for recurrence with CRA.

Conclusion: The inducibility by BP after RFA predicted recurrence at both low and medium frequencies. LFBP-positive was an independent predictor of recurrence in multivariable analysis. In contrast, the inducibility by BP after CRA was not a predictor of recurrence.

Trail registration: This study did not require clinical trial registration.