Atrial Ectopic Activity in Cryptogenic Ischemic Stroke and TIA: A Risk Factor for Recurrence

Background: To characterize atrial ectopic activity in patients with cryptogenic ischemic stroke (CIS) or transient ischemic attack (TIA) and determine its prognostic significance. Methods: Retrospective cohort study, in which 184 patients with CIS or TIA who had performed 24-hour Holter electrocardiogram were included. The median follow-up was 27.5 months. Baseline clinical and imagiologic characteristics, etiologic investigation results, and ischemic stroke and TIA recurrences information were collected. Number of atrial premature complexes (APCs) per hour was categorized as less than 10 APCs/hour, 10-30 APCs/hour, and more than 30 APCs/hour. Results: Most of the patients had less than 10 APCs/hour (82.6%), 8.2% had 10-30 APCs/hour, and 9.2% had more than 30 APCs/hour. Patients with more than 30 APCs/hour had a greater median left atrium diameter than patients with 30 APCs/hour or less (42 mm vs. 38 mm; 95% confidence interval [CI], .50-7.00; P = .003). Annual recurrence rate of CIS or TIA was 2.9% in patients with less than 10 APCs/hour, 11.0% in 10-30 APCs/hour, and 22.6% in more than 30 APCs/hour (P = .001). More than 30 APCs/hour were independently associated with recurrence risk in multivariate survival analysis (hazard ratio, 3.40; 95% CI, 1.12-10.32; P = .030). Conclusions: In patients with CIS or TIA, frequent atrial ectopic activity (>30 APCs/h) was independently associated with increased risk of stroke or TIA recurrence. Further studies need to validate frequent atrial ectopic activity as a risk factor for recurrence in cryptogenic stroke and confirm its role as a predictor of occult atrial fibrillation.