Does Ventricular Substrate Play a Role in Incident Stroke? The Atherosclerosis Risk in Communities (ARIC) Study

Abstract

Background: The goal of the study was to determine an association of ventricular substrate with thrombotic, cardioembolic, and hemorrhagic stroke. Methods: Participants from the Atherosclerosis Risk in Communities study with analyzable ECGs and no history of stroke were included (n=14,479; age 54±6 y; 55% female; 24% black). Ventricular substrate was characterized by cardiac memory [spatial QRS-T angle (QRS-Ta), sum absolute QRST integral (SAIQRST), spatial ventricular gradient magnitude (SVGmag)], premature ventricular contractions (PVC) and tachycardia-dependent intermittent bundle branch block (TD-IBBB) on 12-lead ECG recorded at visits 1-5. Incident strokes were adjudicated by physician reviewers. Cox proportional hazard risk models were constructed. Results: Over a median 24.5 y follow-up, there were 899 thrombotic, 400 cardioembolic, and 187 hemorrhagic strokes. After adjustment for cardiovascular disease (CVD) and its risk factors, atrial fibrillation / atrial substrate, and ECG-left ventricular hypertrophy, PVC (HR 1.72; 95%CI 1.02-2.92), QRS-Ta (HR 1.15; 95%CI 1.03-1.28), SAIQRST (HR 1.20; 95%CI 1.07-1.34) and time-updated SVGmag (HR 1.19; 95%CI 1.08-1.32) associated with cardioembolic stroke. After adjustment for CVD and its risk factors, PVC (HR 1.53; 95%CI 1.03-2.26), QRS-Ta (HR 1.08; 95%CI 1.01-1.16), SAIQRST (HR 1.07; 95%CI 1.01-1.14), and time-updated SVGmag (HR 1.11; 95%CI 1.04-1.19) associated with thrombotic stroke. In fully adjusted time-updated Cox model QRS-Ta (HR 1.20; 95%CI 1.04-1.38), SAI QRST (HR 1.23; 95%CI 1.06-1.43), SVGmag (HR 1.23; 95%CI 1.06-1.43) associated with hemorrhagic stroke, whereas TD-IBBB trended (HR 1.84; 95%CI 0.25-13.33). Conclusions: PVC burden reflected by cardiac memory is associated with ischemic stroke. Transient cardiac memory (likely through TD-IBBB) precedes hemorrhagic stroke.