Abstract 13193: Association of Abnormal P-wave Indices With Brain MRI Infarcts: The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

Abstract

Introduction: We recently reported that abnormal P-wave indices (PWI)—ECG markers of atrial cardiomyopathy (AC)—are associated with an increased risk of dementia, independent of atrial fibrillation (AF) and clinical ischemic stroke. The mechanisms, however, remain unclear, but may include silent ischemia. Hypothesis: Abnormal PWI are associated with higher prevalence of cortical infarcts on MRI, suggesting cardioembolism as a potential mechanism. Methods: ARIC-NCS participants (mean age, 72.2±5.3 years; 60% women; 29% black) who underwent 3T brain MRI scans in 2011-2013 were included. Abnormal PWI included P-wave terminal force in lead V1 [(PTFV1) defined as ≥4000 μV*ms] and P-wave duration [(PWD) defined as >120 ms], which were measured from standard 12-lead ECGs. Brain MRI outcomes included cortical infarcts, cerebral microbleeds (CMB), and markers of small vessel disease [white matter hyperintensities (WMH) and lacunar infarcts]. We used weighted multivariable logistic and linear regression analyses. Results: Of the 1,850 participants, 464 had abnormal PTFV1 and 415 had prolonged PWD. After multivariable adjustment including AF, abnormal PTFV1 and PWD were significantly associated with 26-44% increased odds of cortical and lacunar infarcts (Table) . Although PWD was associated with CMB in Model 1, the association was no longer significant after multivariable adjustment. Finally, abnormal PWIs were not associated with WMH after adjusting for stroke and AF (P >0.5). Conclusions: Abnormal PWI are associated with higher prevalence of cortical infarcts, suggesting cardioembolism with silent ischemia as a possible mechanism underlying the association of AC with dementia. More research is needed to evaluate other mechanisms such as cerebral small vessel disease.