Abstract T P142: Association between Left Atrial Abnormality on ECG and Vascular Brain Injury on MRI in the Cardiovascular Health Study
Background: Atrial fibrillation (AF) has long been recognized as a risk factor for vascular brain injury. Emerging evidence suggests that atrial disease is associated with vascular brain injury even in the absence of AF.
Methods: The Cardiovascular Health Study prospectively enrolled community-dwelling adults ≥65 years of age. Among participants who underwent MRI, we examined associations of left atrial abnormality on a 12-lead electrocardiogram (ECG) with MRI-defined brain infarcts and leukoaraiosis. P-wave terminal force--the product of the duration and depth of the terminal component of the P-wave--in lead V1 (PTFV1) is the most consistently used ECG measure of left atrial abnormality and was our primary predictor; P-wave area and duration were secondary predictors. We excluded participants with AF on their index ECG or a diagnosis of AF prior to the index ECG. Primary outcomes were incident infarcts and worsening leukoaraiosis from initial to follow-up scan approximately 5 years later. Secondary outcomes were prevalent infarcts and degree of leukoaraiosis on initial MRI. Non-lacunar infarcts were separately examined in a secondary analysis. We performed relative risk and linear regression analyses adjusting for vascular risk factors.
Results: Among 3,129 participants with at least one scan, each 1-SD increase in PTFV1 (2160 μV*ms) was associated with a 0.05-point (95% CI, 0.0003-0.10) higher baseline white matter grade on a 10-point scale. PTFV1 was also associated with prevalent infarcts of any type (RR per SD, 1.09; 95% CI, 1.04-1.16), and in particular with prevalent non-lacunar infarcts (RR per SD, 1.22; 95% CI, 1.08-1.38). Among 1,839 participants with two scans, PTFV1 was associated with worsening leukoaraiosis (RR per SD, 1.09; 95% CI, 1.01-1.18), but not incident infarcts (RR per SD, 1.06; 95% CI, 0.93-1.20). Similar results were seen in sensitivity analyses accounting for incident AF diagnosed after the ECG and before the MRI under analysis. P-wave area and duration were not associated with our outcomes.
Conclusions: ECG left atrial abnormality is associated with vascular brain injury even in the absence of AF.
- Atrial fibrillation
- Magnetic resonance imaging
- Atrial function
- Cerebrovascular disorders
Author Disclosures: H. Kamel: Research Grant; Modest; Grant K23NS082367 from NIH/NINDS. T. Bartz: None. W. Longstreth: None. P. Okin: Consultant/Advisory Board; Modest; GE Medical Systems on the topic of new product development. E. Thacker: None. K. Patton: None. P. Stein: None. R. Gottesman: None. S. Heckbert: None. R. Kronmal: None. M. Elkind: Consultant/Advisory Board; Modest; Biogen IDEC, BMS-Pfizer Partnership, Boehringer-Ingelheim, Inc., Daiichi-Sankyo, Janssen Pharmaceuticals, Biotelemetry. Other; Modest; UpToDate. Expert Witness; Significant; Merck/Organon. E. Soliman: None.
- © 2015 by American Heart Association, Inc.