Abstract WMP70: Young Adults With Cryptogenic Ischemic Stroke Have Longer Corrected QT Intervals Than Healthy Controls

Abstract

Introduction: In cryptogenic ischemic stroke, no definite etiology is found and high-risk cardiac sources of embolism are excluded. However, it has been hypothesized that many cryptogenic strokes could be cardioembolic especially in younger patients. We assessed whether resting ECG could reveal cardiac differences in young patients with cryptogenic ischemic stroke, as compared to healthy controls. Methods: We recruited prospectively 477 patients with cryptogenic ischemic stroke at age 18-49 and 455 controls at 19 European tertiary centers. We obtained vast clinical data and resting 12-lead ECG (at subacute phase from patients). From the ECGs we measured heart rate, presence of conduction blocks, QRS transition zone in precordial leads, presence of abnormal T-wave inversions, presence of ST depression and corrected QT-interval (QTc). We constructed multivariate models for each ECG parameter, adjusting for demographic and clinical data, using binomial logistic regression. Results: Median age for both patients and controls was 41 years, with 54.0% of patients and 54.6% of controls being men. Compared to controls, patients had higher prevalence of hypertension (38.8% vs. 30.0%, P=0.005) and obesity (38.8% vs. 30.1%, P=0.005), were more frequently heavy drinkers (14.6% vs. 7.6%, P<0.001), and were more likely to smoke (34.1% vs. 17.5%, P<0.001). Patients with cryptogenic ischemic stroke had longer QTc interval than controls (median QTc 416ms vs. 409ms, P<0.001). After adjustments, longer QTc interval was associated with stroke (odds ratio 1.12 per 10ms increase, P<0.001). There were no statistically significant differences in other ECG-abnormalities between patients and controls. Conclusion: Young patients with cryptogenic ischemic stroke have a longer corrected QT interval than healthy controls. The reason for this novel finding is unclear, and could reflect both underlying cardiogenic and neurogenic reasons.