Abstract MP42: Do Adult Ambulatory BP Cut-points Predict Target Organ Damage Better Than Pediatric ABP Percentiles?

Abstract

Ambulatory hypertension (HT) is more strongly related to cardiac target organ damage (TOD) than clinic BP. Therefore, correct classification of ambulatory blood pressure (ABP) phenotype is needed to determine which patients to refer for imaging. Pediatric ABPM interpretation is based on percentiles of ABP while adult ABPM interpretation is based on static cut-points. We sought to determine which ABP classification system was the best predictor of TOD in adolescents. We measured adiposity, LV mass index (LVMI), systolic and diastolic function (strain, E/e’ ratio) in 315 adolescents (15.9 + 1.4 years, 64% white, 59% male). BP phenotype was determined by mean of 6 casual aneroid SBPs, and 24-hour SBP on ABP (Spacelabs Inc., Snoqualmie, WA) 1) by age, sex and height specific pediatric cut-points and 2) by adult ABPM cut-points (day <130, night < 110, 24-hour < 125 mmHg). We evaluated concordance in classification and prevalence of TOD with Chi square and kappa statistic for agreement. For daytime SBP, 5% of all subjects (16 of 315) reclassified from normotensive (NT) to masked hypertension (MH) and 8% (24 of 315) reclassified from white coat (WC) to HT. Results were similar for night and 24-hour ABP. Fewer NT and WC subjects had any form of TOD by adult vs pediatric cut-point (NT 32 vs 36%, WC 8 vs 13%; chi square < 0.0001, kappa 0.73). The only significant differences in cardiac TOD by ABP phenotype were found using adult ABP cut-points (LVMI higher and strain lower HT vs NT, diastolic E/e’ higher HT and MH vs NT all p <=0.05). We conclude that classification of ABP by adult cut-points is superior in identifying adolescents at risk for cardiac TOD. These findings may inform future pediatric ABP guidelines.