Atrial High-Rate Episodes Mirror Atrial Fibrillation in Stroke Prediction: Evidence From an Indian Prospective Cohort

To assess the risk of stroke/TIA and progression to atrial fibrillation (AF) in Indian patients with device-detected atrial high-rate episodes (AHRE) lasting less than 24 h.

In this single-centre prospective matched cohort study, 109 patients with AHRE < 24 h matched to 109 controls without AHRE on age (+/-5 years), sex, device type, device indication, and CHA2DS2-VASc score. Followed for a minimum of 12 months (mean 18.4 months). The CHA2DS2-VASc score was near-perfectly matched between groups (mean 3.26 vs. 3.29, score distribution chi-square p = 1.00). A stroke or TIA occurred in 7 patients with AHRE versus 1 control (annual rate 4.28% vs. 0.61%; OR 7.41, 95% CI 0.90-61.3; p = 0.020; HR 7.19, 95% CI 0.89-58.48; log-rank p = 0.031). Progression to clinical AF, AHRE ≥ 24 h, atrial flutter, or atrial tachycardia happened in 32 AHRE patients versus 2 controls (annual rate 19.7% vs. 1.2%; OR 22.2, 95% CI 5.17-95.6; HR 19.55, 95% CI 4.6-81.71; log rank p < 0.001). Stroke risk increased with CHA₂DS₂-VASc score: 2.15% (score 3), 4.16% (score 4), 6.66% (score 5), and 9.5% (score ≥ 6).

In this hypothesis-generating study, device-detected AF lasting less than 24 h is associated with a significantly higher risk of stroke/TIA and progression to clinical AF in Indian patients. It requires confirmation in larger studies. Region-specific absolute risks must be considered when applying international anticoagulation guidelines.