Abstract
BACKGROUND: Although immediate recurrence of atrial fibrillation (IRAF) after cardioversion has been proposed as a surrogate for atrial substrate vulnerability, its broad definition may insufficiently discriminate patients at highest risk of postablation recurrence. We introduced the concept of ultra-early recurrence of AF (URAF)-defined as recurrence within 10 s after direct current cardioversion (CV) under deep sedation-as a novel marker of advanced remodeling in persistent atrial fibrillation (AF). OBJECTIVE: To evaluate whether URAF independently predicts late recurrence following pulmonary vein isolation (PVI) in patients with persistent or long-standing persistent AF. METHODS: We retrospectively analyzed 104 patients undergoing first-time PVI for persistent AF. Among 93 patients who underwent external CV, URAF, and IRAF were defined as AF recurrence within 10 and 90 s, respectively. Recurrence of atrial arrhythmias was assessed at 12 m postablation. RESULTS: URAF was observed in 10/104 patients (9.6%) and was associated with higher 12-m recurrence compared with URAF-negative patients (50% vs. 18%, p = 0.02), whereas IRAF (20/104, 19.2%) showed no significant difference (30% vs. 19%, p = 0.28). On multivariable logistic regression, URAF (Odds Ratio (OR): 4.8; 95% Confidence Interval (CI): 1.16-19.98; p = 0.029) and long-standing AF (OR: 5.5; 95% CI: 1.70-17.78; p = 0.004) emerged as independent predictors of recurrence. Kaplan-Meier analysis showed worse recurrence-free survival for URAF (log-rank p = 0.02; HR 4.5, 95% CI 1.18-17.41). CONCLUSION: URAF may represent a promising intra-procedural marker associated with post-ablation recurrence in persistent AF, but prospective validation in larger cohorts is required.