Is the association of QTc with atrial fibrillation and stroke in cohort studies a matter of time?

• Published in: Open heart 2022-09, Vol.9 (2), p.e002080
• Main Authors: Radnahad, Navid, Ehrlinder, Hanne, Leander, Karin, Engdahl, Johan, Wallén, Håkan, Gigante, Bruna
• Format: Article
• Language: English
• Subjects: atrial fibrillation; Blood pressure; Cardiac arrhythmia; Cardiac Risk Factors and Prevention; Cardiovascular disease; Codes; Cohort analysis; Diabetes; Heart rate; Hypertension; Ischemia; Medical records; Medical screening; Medicin och hälsovetenskap; Patients; Questionnaires; risk factors; Self report; Stroke; Women
• ISSN: 2053-3624; 2398-595X; 2053-3624
• DOI: 10.1136/openhrt-2022-002080

ObjectivesTo investigate the association of the heart rate-corrected QT interval (QTc) with the risk of atrial fibrillation (AF) and ischaemic stroke.MethodsWe estimated the risk of AF and ischaemic stroke associated with QTc duration (ms) by Cox regression in study participants from the cohort of 60-year-old men and women from Stockholm (60YO) (n=4232). Univariate and multivariate adjusted risk estimates were expressed as HR and 95% CI. Main results were validated in elderly patients with AF, included in the Carebbean-e study, where an ECG in sinus rhythm (SR) (ECG-SR) recorded before the ECG diagnostic for (ECG-AF) was available (n=803). We estimated the correlation between the time interval (years) between the ECG-SR and ECG-AF with the QTc duration, by the Spearman correlation coefficient (rho).ResultsIn the 60YO, the highest QTc duration quartile (>427 ms) associated with the AF risk (n=435) with a multivariable adjusted HR of 1.68 and 95% CI (1.26 to 2.24). No association was observed with ischaemic stroke. In the Carebbean-e study, no significant association was observed between the QTc duration measured on the ECG-SR and risk of ischaemic stroke during follow-up. QTc duration showed an inverse correlation (rho: −0.26, p