Hemodynamic and Mechanical Properties of the Proximal Aorta in Young and Middle Aged Adults with Isolated Systolic Hypertension: The Dallas Heart Study

摘要

The aim of this study is to assess characteristic impedance (Zc) of the proximal aorta in young and middle-aged individuals with isolated systolic hypertension (ISH). Zc is an index of aortic stiffness relative to aortic size. In the Dallas Heart Study, 2,001 untreated participants 18 to 64 years of age (mean age 42.3years, 44% black race) were divided into the following groups based on office blood pressure (BP) measurements: 1) optimal BP (systolic BP [SBP]<120 and [DBP]<80 mmHg; n=837); 2) prehypertension (SBP 120–139 and/or DBP 80–89 mmHg; n=821); 3) ISH (SBP ≥140 and DBP <90 mmHg; n=121); 4) isolated diastolic hypertension (IDH: SBP<140 and DBP≥90 mmHg; n=44); and 5) systolic-diastolic hypertension (SDH: SBP≥140 and DBP≥90 mmHg; n=178). Zc, aortic arch pulse wave velocity (PWV), and minimum ascending aortic size were quantified using cardiovascular magnetic resonance. In multivariable-adjusted linear models, Zc was highest in the ISH group compared with the optimal BP, IDH, or SDH groups (103.2±4.0 vs. 68.3±2.1, 75.4±6.0, and 88.9±4.8 dyne*sec/cm⁵, respectively; all P<0.05). The Zc-ISH association did not differ by race. Aortic PWV was highest in the ISH group compared with the optimal BP, IDH, or SDH groups (6.3±0.3 vs. 4.3±0.1, 4.4±0.4 and 5.5±0.3 m/s, respectively; all P<0.05), whereas aortic size was similar across groups (all P > 0.2). Results were similar in a subgroup of 1,551 participants 18 to 49 years of age. In a multiracial population-based sample, we found evidence of a mismatch between proximal aortic stiffness and diameter in young and middle-aged adults with ISH.