01.03 Carotid Plaque, Arterial Stiffness Gradient, and Bending Strain in Hypertension

Abstract

Background

Plaque rupture may involve shearing strain of the arterial wall in the longitudinal direction. We previously determined a longitudinal gradient of arterial strain, named bending strain (BS), along the common carotid artery (CCA), with two distinct patterns (Paini et al. Stroke 2007): Pattern A (outward BS; larger radial strain at the plaque level than adjacent CCA) and Pattern B (inward BS), more often observed in dyslipidemic and type 2 diabetic patients.

Aim

To determine the influence of essential hypertension on patterns of bending strain.

Method

92 patients with an atherosclerotic plaque on the CCA were included: 66 patients with essential hypertension (HT), either treated or not, and 26 normotensives (NT). A novel non-invasive echotracking system (ArtLab^®) was used to measure intima-media thickness, diameter, pulsatile strain, and distensibility at 128 sites on a 4 cm long CCA segment.

Results

NT and HT did not differ except for BP values and an older age (5 years). Pattern A was less frequently observed in HT than in NT. The plaque exhibiting Pattern A were characterized by an inward remodeling whereas plaques exhibiting Pattern B grew according to an outward remodeling (increased external diameter and no change in internal diameter). In multivariate logistic regression analysis, Pattern B was influenced by essential hypertension (OR = 6.8[1.35–34.9], P<0.02), independently of outward remodeling (OR = 4.6[1.6–13.4], P<0.005) and lack of RAAS inhibitors (OR = 4.7[1.1–20.4], P<0.05).

Conclusion

Patients with essential hypertension had a stiffer carotid at the level of the plaque than in adjacent CCA, leading to an inward bending stress.