Abstract 16491: Predictors of Incident Conduction System Disease in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

Introduction: Left and right bundle branch block (L and RBBB) have been associated with heightened morbidity and mortality, but risk factors for incident conduction disease remain unknown. Understanding factors that accelerate or delay conduction abnormalities could help identify therapies to treat or prevent this condition. Hypothesis: Clinical variables associated with myocardial fibrosis will increase conduction system disease risk while treatment with lisinopril (an anti-fibrotic) will reduce this risk. Methods: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial was a double-blind clinical trial that randomized 33,357 hypertensive participants ≥ 55 years of age with at least one other cardiovascular risk factor to treatment with amlodipine, lisinopril, or chlorthalidone. An electrocardigram (ECG) was obtained at study enrollment and at every two years of follow up. Conduction system disease was defined as LBBB, RBBB, intraventricular conduction delay, or 1st degree AV bloc...