Predictors of Short and Long Term Recurrences of Paroxysmal AF after Radiofrequency Ablation. Is Blanking Period Really Benign?

BACKGROUND: Following pulmonary vein isolation for paroxysmal atrial fibrillation (PAF), early recurrences of atrial arrhythmias (ERAA) are frequent, classified benign as a part of a blanking period. But recently it seems that there is increased incidence of late recurrences in patients with ERAA but mechanism is still unknown. PURPOSE: To assess the incidence and risk factors for early and late AF recurrences post AF ablation and the impact of these ERAA on long-term success. METHODS: Thirty-six consecutive patients (age 45 ± 11 years, 72% males) undergoing RF ablation for PAF. They were followed up in hospital for 2 days post ablation then every week for one month. Subsequent follow-up visits consisted of clinical interview, ECGs, and 24h Holter monitoring every 3 months were done for one year. Extended Holter monitoring was done for patients with palpitations. Any episode of symptomatic or asymptomatic documented atrial tachyarrhythmia > 30 seconds was considered recurrence. RESULTS: Prevalence of ERAA during first 3 months was 47.2%, while late AF recurrence was 25%. 35% of patients with ERAA had late AF recurrence. ≥ 2 attacks of ERAA during the blanking period had significant diagnostic performance in prediction of late AF with sensitivity 44% and specificity 100% (p value=0.05) and also long procedural time ( with sensitivity 89% and specificity 63% (p value=0.049). Multivariate logistic regression showed that frequent ERAA attacks was the only significant factor that increases the risk of late AF recurrence (p value =0.008, OR= 4.39, 95% CI=1.48-12.99). CONCLUSION: ERAA in blanking period may be associated with increased risk for late AF recurrence. Frequent episodes of early recurrences (≥ 2 attacks) is a strong predictor for late AF recurrence. These data should be considered during follow up of the patients with paroxysmal AF after ablation.