Relation of hemodynamics and risk factors to ventricular–vascular interactions in the elderly: the Cardiovascular Health Study


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Abstract

Objective To investigate the interaction between left ventricular (LV) geometry, carotid structure and arterial compliance in relation to hemodynamic stimuli and risk factors (plasma cholesterol, body mass index, insulin resistance, smoking habit, age, sex and race).Design Cross-sectional.Methods Echocardiography and carotid ultrasound were performed in 2375 elderly subjects without signs or history of prevalent cardiovascular disease, diabetes or renal disease (795 men; 298 non-whites; 1215 hypertensive), from the cohort of the Cardiovascular Health Study. Arterial compliance was estimated by the prognostically validated ratio of stroke volume to pulse pressure (SV/PP) as the percent deviation (Δ%) from the value predicted by individual age, heart rate and body weight.Results Intima–medial thickness (IMT) was higher in the presence of LV hypertrophy (LVH) in normotensive and hypertensive subjects and was greatest in the presence of concentric LVH. Maximum carotid lumen diameter (CLD) was also higher in the presence of LVH (and was greatest with eccentric LVH, in association with relatively high values for stroke volume). After adjusting for blood pressure, maximum carotid lumen diameter was directly correlated with stroke volume, and IMT to LV mass (all P< 0.001). Similarly, IMT was also related to maximum carotid lumen diameter, independently of prevalent risk factors (P< 0.001). SV/PP-Δ% was reduced in both groups with concentric LV remodeling (both P< 0.0001) or concentric LVH (both P< 0.05). Adjusting for risk factors did not affect these associations in normotensives, but made them insignificant in hypertensives. In normotensives, IMT was inversely related to SV/PP-Δ% (P< 0.001), independently of risk factors, whereas no significant relation was found in hypertensives.Conclusions The magnitudes of carotid intima–medial thickness and lumen diameter parallel levels of LV mass and geometry, and are directly related to stroke volume and arterial stiffness; this interaction is most evident in the presence of normal blood pressure, whereas it is affected by other cardiovascular risk factors when arterial hypertension is present.

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