Predictive value of inter-atrial block for new onset or recurrent atrial fibrillation: A systematic review and meta-analysis

Background and objectives Inter-atrial block (IAB) is characterized by a delay of inter-atrial conduction and is defined electrocardiographically by a P-wave duration (PWD) > 120 ms. Several studies have implicated IAB in the development of new onset atrial fibrillation (AF), whereas others have reported no significant associations. Moreover, there has been no systematic evaluation of the predictive value of IAB in AF recurrence. Therefore, we conducted a systematic review and meta-analysis to examine whether IAB predicts new onset AF or AF recurrence. Methods PubMed and Embase databases were searched through 30th July 2017 for studies investigating the relationship between IAB and AF. Results The initial search identified 260 studies, of which 16 studies met the inclusion criteria. This meta-analysis included 18,204 patients (mean age 56 ± 13, 48% male) with a mean follow-up period of 15.1 years. IAB significantly predicted new onset AF (hazard ratio [HR]: 2.42, 95% confidence interval [CI]: 1.44 to 4.07, P = 0.001; 84%). For partial IAB, the risk of new onset AF did not reach statistical significance (HR: 1.42, 95% CI: 0.85 to 2.34; P = 0.18; I² = 13%). Contrastingly, advanced IAB was a significant predictor of new onset AF with a pooled HR of 2.58 (95% CI: 1.35 to 4.96; P < 0.01; I² = 67%). IAB also predicted AF recurrence after ablation (HR: 2.59, 95% CI: 1.35 to 4.96; P < 0.01; I² = 67%). Conclusions IAB is a significant predictor of both new onset AF and AF recurrence.