Abstract 062: Aortic Stiffness, Blood Pressure Progression and Incident Hypertension: The Framingham Heart Study

Background: Increased vascular stiffness and excessive blood pressure (BP) pulsatility are important risk factors for age-related morbidity. Vascular stiffness and BP pulsatility are related, with a prevailing view that hypertension antedates and contributes to premature vascular aging and a secondary increase in vascular stiffness. However, temporal relations between comprehensive vascular measures and BP elevation have not been fully delineated in a large community-based sample. Methods: We examined longitudinal relations of BP and 3 measures of vascular stiffness and pressure pulsatility derived from arterial tonometry (carotid-femoral pulse wave velocity [CFPWV], forward wave amplitude and augmentation index) over a 7-year period in 1,898 Framingham Offspring participants (mean age 60 yrs, 1,057 women). We also examined relations between measures of microvascular and endothelial function derived from brachial artery Doppler and future progression of BP or vascular stiffness. Results: In multivariable-adjusted regression models, baseline tonometry measures were separately and jointly associated with higher systolic and pulse pressure and incident hypertension ( Table ). Conversely, higher baseline BP was associated with higher forward wave amplitude and augmentation index (all p<0.05) but not CFPWV at follow-up. Higher baseline resting brachial artery flow and lower flow-mediated dilation were associated with incident hypertension in models that included BP and tonometry measures ( Table ). Conclusion: Higher aortic stiffness (CFPWV), pressure pulsatility (forward wave amplitude), and wave reflection (augmentation index) and lower flow-mediated dilation are associated with blood pressure progression and incident hypertension. Our findings support the notion of aortic stiffness as a precursor of hypertension and further suggest a vicious cycle of increasing pressure pulsatility with advancing age. Table. Correlates of incident hypertension. Predictor Variables (baseline) OR 95% CI P Systolic BP 3.24 (2.17; 4.84) <0.0001 Diastolic BP 1.47 (1.13; 1.92) 0.0042 CFPWV 1.30 (1.02; 1.67) 0.037 Forward wave amplitude 1.66 (1.32; 2.09) <0.0001 Augmentation index 1.78 (1.45; 2.17) <0.0001 Brachial artery baseline flow 1.23 (1.05; 1.45) 0.013 Flow-mediated dilation 0.83 (0.70; 0.98) 0.029 Results of a single multivariable model that further adjusted for age,sex, BMI, height and triglycerides in 1,019 participants free of hypertension at baseline who experienced 337 cases of incident hypertension during follow-up. OR expressed per 1 SD of the independent variable.