Impact of Arterial Stiffening on Left Ventricular Structure

Abstract

Abstract-Aging of the vasculature results in arterial stiffening and an increase in systolic and pulse pressures. Although pressure load is a stimulus for left ventricular hypertrophy, the extent to which vascular stiffening per se, independent of blood pressure, influences left ventricular structure is uncertain. Two hundred seventy-six subjects (79 normotensive and 197 otherwise healthy hypertensive individuals) underwent echocardiography to assess left ventricular structure. Arterial stiffness was estimated by the pressure-independent stiffness index, ␤, and the pressure-dependent elastic modulus derived from simultaneous carotid ultrasound and applanation tonometry. Systemic arterial compliance (the inverse of stiffness) was estimated by the arterial compliance index. In multivariate analysis, ␤ was related to age (PϽ0.001) and smoking history (PϽ0.01) but not mean pressure, whereas elastic modulus was related to age and mean pressure (both PϽ0.001). The arterial compliance index was only related to age. Whereas systolic and diastolic pressures and the elastic modulus were positively associated with left ventricular mass (all PϽ0.001), primarily because of increases in wall thicknesses, ␤ and the arterial compliance index bore no relation to left ventricular mass. ␤ was inversely related to chamber diameter and directly related to left ventricular relative wall thickness, the ratio of wall thickness to chamber radius. Younger and older hypertensive subjects had comparable left ventricular mass, despite higher systolic and pulse pressures in the older group, whereas older hypertensives had higher mean relative wall thickness, associated with a significant increase in arterial stiffness (␤, 7.06 versus 5.17; elastic modulus, 595 versus 437 dyne/cm 2 ϫ10 Ϫ6) and reduction in the arterial compliance index (0.87 versus 1.05 mL/mm Hg per square meter) (all PϽ0.001). Thus, the extent to which arterial stiffness relates to left ventricular hypertrophy is dependent on the method by which arterial stiffness is estimated. Pressure-dependent methods show an association with left ventricular hypertrophy, whereas the pressure-independent stiffness index, ␤, and the arterial compliance index are most strongly associated with aging and left ventricular concentric remodeling but not hypertrophy.

Impact of age on left ventricular hypertrophy regression during antihypertensive treatment with losartan or atenolol (the LIFE study)

“…1,[6][7][8]25 However, the present study population differed from those previously studied in having higher prevalences of isolated systolic hypertension, LV hypertrophy, and albuminuria. LV geometry has been demonstrated to influence both LV function and prognosis.…”

“…1,2 In hypertensive patients, older age is associated with higher prevalence of LV hypertrophy, but it is uncertain whether this is due to age itself or to age-related increased prevalences of concomitant diseases, including coronary or valvular heart disease, diabetes mellitus, and renal impairment influencing LV structure and function. 3,4 Several treatment trials have demonstrated that reduction of blood pressure induces regression of elevated LV mass in hypertensive patients.…”

Association Between Elevated Pulse Pressure and High Resting Coronary Blood Flow Velocity in Patients With Angiographically Normal Epicardial Coronary Arteries

“…Increased PP exhibits a wide range of values, depending on increased systolic BP, decreased diastolic BP, or both. PP is a raw index of arterial stiffness, since loss of arterial elasticity demands greater force to accommodate blood flow, leading to increased systolic BP, increased cardiac workload, and consequent cardiac4 and vascular remodeling 5. Arterial wall stiffening affects peripheral small arteries and microcirculation 6, 7, 8, 9.…”

A Comparison Between Systolic and Diastolic Pulse Contour Analysis in the Evaluation of Arterial Stiffness

“…14 Changes in amplitude and timing of wave reflections play a key role in aortic hemodynamics and, on a broader level, give us information on how the arterial vasculature affects the heart. [15][16][17][18][19] The SphygmoCor BPAS-1/A device (model SPT-301, PWV Medical Pty Ltd) calculates a number of parameters of ventriculo-arterial coupling and wave reflectance, of which the augmentation index (AIx) is preeminent. 11,20,21 Another approach in analyzing the arterial pulse is to regard the waveform as a basic pattern of exponential decay on which damped oscillations are superimposed, building on the "Grundform" -"Grundschwingung" concept pioneered by Otto Frank.…”