Association of Childhood Blood Pressure with Left Atrial Size and Function: Study of High Blood Pressure in Pediatrics–Adult Hypertension in Youth (SHIP AHOY)

Objective(s): To evaluate the cross-sectional association of cardiovascular disease risk factors with left atrial (LA) size and function among healthy youth, aged 11-18 years, with a wide range of blood pressures (BPs). Study design: Echocardiographic images of youth enrolled in the Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth study were analyzed for LA measurements. The association of casual BP, ambulatory BP, and other cardiovascular disease risk factors with LA size and function were determined using descriptive statistics and multivariable regression. Regression models adjusting for age, sex, race, and body mass index z score determined the independent association between ambulatory systolic BP indices (mean systolic BP/50th %ile systolic BP) and BP phenotypes with LA outcomes while exploratory analyses investigated for additional predictors of LA outcomes. Results: The study population consisted of 347 youth: median age 15.7 years, 60% male and 40% non-White. Greater-risk casual systolic BP groups had worse cardiometabolic profiles but no differences in LA size and function. Each 0.1 increase in ambulatory systolic BP day or night index was associated with a 9.9 mL/m² increase in LA volume/body surface area (LAV/BSA; 95th% CI 2.8-17.0, P = .006) and a 6.8 mL/m² increase in LAV/BSA (95th% CI 0.8-12.8, P = .03), respectively. Ambulatory hypertension was associated with greater odds of abnormal LAV/BSA, defined as >75th %ile (2014 ambulatory BP monitoring criteria: OR 3.2 [95th% CI 1.4-7.2; P = .002]; 2022 ambulatory BP monitoring criteria: OR 2.1 [95th% CI 1.0-4.1; P = .008]). Conclusions: Increasing ambulatory systolic BP and ambulatory hypertension are independently associated with LAV/BSA.