Abstract 10587: Frequency and Outcomes of Bradyarrhythmias in the Community

Introduction: Bradyarrhythmias, diseases characterized by slow heart rates, are associated with substantial morbidity. Contemporary estimates of the frequency of bradyarrhythmias and associated outcomes in the community are needed. Methods: We examined the prevalence and incidence of bradyarrhythmias in a multi-institutional electronic health record cohort comprised of individuals receiving primary care. We used an automated tool to ascertain diagnoses from 12-lead electrocardiogram (ECG) diagnostic statements. We defined bradyarrhythmia groups based on location and severity of disease. We tested associations between clinical risk factors and incident bradyarrhythmia groups using multivariable proportional hazards regression. To characterize potential associations between bradyarrhythmias and major adverse cardiovascular events (MACE, a composite of myocardial infarction, heart failure, stroke, and death), we matched incident bradyarrhythmia and non-bradyarrhythmia individuals 1:1 on age, sex, and duration of preceding follow-up, and included bradyarrhythmia exposure in multivariable regression with MACE as the outcome. Results: Of a total of 520,868 individuals (mean age 48, 62% female, 3.5 million ECGs), the prevalence of any bradyarrhythmia was 10%. After excluding individuals with prevalent bradyarrhythmia, a total of 49,513 events occurred in 440,370 individuals as shown in Figure 1. Bradyarrhythmias were associated with common modifiable cardiovascular risk such as diabetes (HR 1.26, 95% CI [1.22-1.29]) and hypertension (HR 1.24, 95% CI [1.22-1.27]). Bradyarrhythmias were significantly associated with MACE in the atrioventricular delay (HR 1.07, 95% CI [1.01-1.14]) and conduction delay groups (HR 1.19, 95% CI [1.13-1.25]). Conclusions: Bradyarrhythmias are common and increase with older age and male sex. Incident bradyarrhythmias are associated with cardiovascular risk factors and may be associated with MACE.