Abstract 12809: Abnormal P-Wave Axis is Associated With an Increased Risk of Ischemic Stroke: The Atherosclerosis Risk In Communities (ARIC) Study

Abstract

Introduction: Abnormal P-wave axis (aPWA) has been linked to incident atrial fibrillation (AF) and mortality; however, the relationship between aPWA and stroke has not been reported. Hypothesis: We hypothesized that aPWA is associated with ischemic stroke independent of AF and other stroke risk factors and tested our hypothesis in the Atherosclerosis Risk In Communities (ARIC) study, a community-based prospective cohort study. Methods: We included 15,102 participants (age, 54.2 ± 5.7 yrs, 55.2% women, 26.5% blacks) who attended the baseline exam (1987-89) and without prevalent stroke. We defined aPWA as any value outside 0-75 degrees using 12-lead ECGs obtained during the baseline exam. Incident ischemic stroke was identified by annual phone interviews, hospital discharge records, and death certificates. Each case was classified in accordance with criteria from the National Survey of Stroke by a computer algorithm and adjudicated by physician review. Cox regression was used to estimate hazard ratios and 95% confidence intervals for the association of aPWA with stroke. Results: During a mean follow-up of 20.2 years, there were 1027 incident ischemic stroke cases. aPWA was independently associated with a 1.37-fold (95% CI, 1.11-1.69) increased risk of ischemic stroke in the multivariable model. After further adjustment for AF, aPWA remained independently associated with a 1.30-fold (95% CI,1.05-1.61) increased risk of ischemic stroke. Conclusions: aPWA was independently associated with ischemic stroke. This finding suggests that abnormalities in atrial electrical activation are associated with ischemic stroke independent of AF.