April 2024 Stroke Highlights

FIBRILLATION DETECTION AFTER CRYPTOGENIC STROKEOccult atrial fibrillation (AF) is a common cause of cryptogenic stroke.AF can be detected by various methods of cardiac monitoring, including ECG, 24-hour Holter monitoring, 30-day event recorders, wearable devices, and implantable cardiac monitors (ICM).Identifying patients with cryptogenic stroke at high risk of having underlying AF is crucial for optimizing evaluation, treatment, and prevention strategies.In this multicenter observational study in Japan, investigators sought to identify the relationship between the frequency of premature atrial contractions (PACs) and AF detected by ICM in patients with cryptogenic stroke.Of 381cryptogenic patients included in the study (mean age, 70 years), AF was detected in 31% at an average of 76 days after ICM implantation.Patients were divided into groups based on frequency of PACs on 24-hour Holter monitoring before ICM implantation.Those with a high frequency of PACs (n=62) were older and with higher CHADS 2 scores.Moreover, those in the high frequency group had an AF detection rate of 71.4%/y (compared with 15.5% in the low frequency group) and AF burden of 40.3% (compared with 10.1% in the low frequency group).After adjustment, high frequency of PACs was associated with ≈3-fold risk of AF detection and 4-fold risk of high AF burden compared with low frequency of PACs.In the sensitivity analysis grouping patients into tertiles, quartiles, and quintiles based on PAC burden, there was a similar dose-dependent relationship with PAC frequency and AF detection and burden.This study highlights frequent PACs as a potential marker for underlying AF in patients with cryptogenic stroke, suggesting that long-term cardiac monitoring with ICM for AF detection should be strongly encouraged in this patient population.See p 946.