Initial In-Hospital Visit-to-Visit Heart Rate Variability Is Associated with Higher Risk of Atrial Fibrillation in Patients with Acute Ischemic Stroke

Background: To evaluate the association between the visit-to-visit heart rate variability and the risk of atrial fibrillation (AF) in acute ischemic stroke (AIS). Methods: We analyzed the data of 8179 patients with AIS. Patients without AF on 12-lead electrocardiography underwent further 24 h Holter monitoring. They were categorized into four subgroups according to the visit-to-visit heart rate variability expressed as the coefficient of variation in heart rate (HR-CV). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using the HR-CV < 0.08 subgroup as a reference. Results: The adjusted OR of paroxysmal AF was 1.866 (95% CI = 1.205-2.889) for the HR-CV >= 0.08 and <0.10 subgroup, 1.889 (95% CI = 1.174-3.038) for the HR-CV >= 0.10 and <0.12 subgroup, and 5.564 (95% CI = 3.847-8.047) for the HR-CV >= 0.12 subgroup. The adjusted OR of persistent AF was 2.425 (95% CI = 1.921-3.062) for the HR-CV >= 0.08 and <0.10 subgroup, 4.312 (95% CI = 3.415-5.446) for the HR-CV >= 0.10 and <0.12 subgroup, and 5.651 (95% CI = 4.586-6.964) for the HR-CV >= 0.12 subgroup. Conclusions: HR-CV can facilitate the identification of patients with AIS at a high risk of paroxysmal AF.