Periodic Repolarization Dynamics Predicts Newly Detected Atrial Fibrillation After Stroke

Background Periodic repolarization dynamics (PRD) is a novel ECG‐derived biomarker reflecting sympathetic activity‐associated oscillations in cardiac repolarization. We hypothesized that elevated PRD identifies patients after acute ischemic stroke who are at increased risk of developing atrial fibrillation detected after ischemic stroke or transient ischemic attack (AFDAS). Methods Between February 22, 2021 and May 5, 2023, 263 patients with acute ischemic stroke from the STROKE‐CARD cohort were prospectively enrolled. All patients were in sinus rhythm at baseline without prior or current atrial fibrillation. Within 5 days after acute ischemic stroke, patients underwent a standardized 30‐minute high‐resolution ECG to assess PRD, heart rate variability, and supraventricular premature complexes per hour. AFDAS was identified through continuous in‐hospital monitoring, 6‐month follow‐ups, and electronic health record review. The CHASE‐LESS score, a clinical score comprising coronary heart disease, heart failure, age, stroke severity, hyperlipidemia, diabetes, and prior stroke/transient ischemic attack, served as the clinical risk model for AFDAS. Results During a median follow‐up of 17 (interquartile range, 12–26) months, AFDAS occurred in 25 of 263 patients (9.5%). Patients with AFDAS exhibited higher PRD values than those without (5.80 versus 2.93 deg 2 , P =0.005). In multivariable Cox regression, PRD independently predicted AFDAS (hazard ratio [HR], 1.27 [95% CI, 1.03–1.44]; P =0.037), alongside supraventricular premature complexes frequency (HR, 1.02 [95% CI, 1.01–1.03]; P <0.001). A model comprising PRD and supraventricular premature complexes per hour showed better discrimination than the CHASE‐LESS score alone, with an area under the curve of 0.82 versus 0.67, respectively ( P =0.005). Conclusions Increased PRD and supraventricular premature complexes frequency independently predicted AFDAS and significantly improved risk prediction compared with the clinical CHASE‐LESS score.