Timing of clinically relevant recurrence or true blanking period?

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Ministry of Health and Welfare of Korea The National Research Foundation of Korea (NRF) which is funded by the Ministry of Science, ICT & Future Planning (MSIP) Background Although early recurrence (ER) within 3 months after atrial fibrillation catheter ablation (AFCA) is reportedly considered as a reliable predictor of late recurrence (LR), those ERs are still counted as benign events. There is no large-scale study showing the time limit of true blanking period, nor the potential mechanisms of clinically relevant recurrences within 3 months. Purpose To explore temporal association of ERs with LRs and the presence of extra-pulmonary vein (ExPV) triggers. Methods This retrospective, single center study included 2,788 patients undergoing de novo AFCA (median 60 years old, 37.4% persistent AF [PeAF]) with isoproterenol provocation at the procedures. ER and LR were defined as any documented atrial arrhythmia >30s occurring (≤3 months), (>3months) after AFCA respectively. We evaluated the risk factors for ER and LR and compared the risk for LR and existence of ExPV triggers according to different timing of ER. Results ER was detected in 783 (28.1%) patients. During a median follow-up of 40 months, LR occurred in 945 (33.9%) patients. PeAF (OR 1.79, 95% CI 1.36-2.34), a larger left atrial (LA) diameter (OR 1.03 per 1 mm increase, 95% CI 1.00-1.05), and the existence of ExPV-triggers (OR 3.02, 95% CI 2.08-4.38) were independently associated with ER. ER (HR 2.55, 95% CI 2.15-3.03); the existence of ExPV-triggers (HR 1.63, 95% CI 1.28-2.08), PeAF (HR 1.39, 95% CI 1.16-1.66), and a larger LA diameter (HR 1.02 per 1 mm increase, 95% CI 1.01-1.04) were independent predictors for LR. When stratified according to the days of ER occurrence, ER occurring earlier showed trends toward higher rates of LR (P for trend=0.047) (Figure 1A). Patients with ER occurring within 1 month after AFCA had a higher incidence of LR than those with ER occurring between 2 and 3 months after AFCA (57.5% vs. 49.6%; log-rank P=0.020) (Figure 2B). ER occurring within 1 month after AFCA, compared with no ER, was independently associated with the existence of ExPV triggers (OR 3.99, 95% CI 2.65-6.02) whereas ERs occurring at different timing were not (Figure 1B). Conclusions ER, regardless of the timing, and the existence of Ex-PV triggers were independently associated with long-term AF recurrence. Especially, ER occurring earlier within 1 month after AFCA, which was associated with Ex-PV triggers, had the worst rhythm outcome.