Blood Pressure Parameters and Carotid Intraplaque Hemorrhage as Measured by Magnetic Resonance Imaging

Abstract

A therosclerotic plaques in the carotid arteries represent an important cause of cerebral ischemia. The composition of an atherosclerotic plaque is an important predictor for plaque rupture and subsequent thromboembolic events. Intraplaque hemorrhage (IPH) is considered as a high-risk component of the vulnerable plaque through contribution of cholesterol to the necrotic core of the plaque and by increasing macrophage infiltration, making the plaque more unstable. 1-3 Several studies have indicated a strong association of IPH with cerebrovascular events. [3][4][5] Furthermore, even in atherosclerotic lesions of asymptomatic subjects, IPH was shown to contribute to plaque progression and destabilization. 6,7 Magnetic resonance imaging (MRI) has emerged as a reliable and accurate tool for discriminating plaque components in vivo and for detecting IPH. 7,8 However, only few studies have investigated determinants of plaque composition in the carotid artery 9,10 and, specifically, studies relating risk factors to IPH are scarce. We recently reported that sex, age, smoking, and hypertension are associated with IPH in the general population. 11 Hypertension is a highly prevalent condition and a major contributor to atherosclerotic cardiovascular disease. However, the pathophysiology of the contribution of high blood pressure to atherosclerotic plaques is still not fully elucidated.For a long time, hemodynamic forces have been linked to atherosclerosis formation and plaque destabilization. 12 Plaque instability is, in part, determined by local factors, but it has been suggested that systemic factors are also important. 13 Atherosclerotic plaques form at positions of disturbed blood flow and concomitant low and oscillating wall shear stress, 14 whereas all structures of the arterial wall are influenced by blood pressure fluctuations.As a continuation of our previous study, 11 the current study was designed to determine the association of various blood pressure parameters with the presence of carotid IPH in a large population-based study.Abstract-Intraplaque hemorrhage (IPH) is a characteristic of the vulnerable atherosclerotic plaque that has been associated with ischemic stroke. Not much is known about determinants of IPH. We studied whether blood pressure parameters are associated with presence of IPH. Within the framework of a prospective population-based cohort study, The Rotterdam Study, the carotid arteries of 1006 healthy participants ≥45 years and with intima-media thickening (≥2.5 mm) on ultrasound were imaged with a 1.5-T magnetic resonance imaging scanner. IPH was defined as a hyperintense signal on a 3D-T1w-GRE magnetic resonance sequence. Generalized estimation equation analysis, adjusted for age, sex, carotid wall thickness, and cardiovascular risk factors, was used to assess the association between blood pressure parameters and IPH. Magnetic resonance imaging of the carotid arteries revealed presence of IPH in 444 of 1860 plaques (24%). Systolic blood pressure and pulse pressure (PP) were significantly asso...

Arterial Stiffness Is Associated With Carotid Intraplaque Hemorrhage in the General Population

“…11 We have previously shown that of several blood pressure components, pulse pressure was the strongest determinant of IPH. 13 When we controlled our current analyses for pulse pressure in model 3, associations attenuated somewhat, but we found PWV to be still associated with both plaque presence and IPH. This indicates that PWV is associated with IPH independent of pulse pressure.…”

“…In a previous study, we showed that a single, cross-sectional measurement of the pulsatile component of blood pressure was associated with IPH. 13 Arterial stiffness is the principal cause of increasing systolic blood pressure and pulsatility of flow, and therefore, PWV may reflect the cumulative damage on the arterial wall. Several studies have investigated the relation between arterial stiffness and aortic or coronary calcifications.…”

Blood Pressure Is a Major Modifiable Risk Factor Implicated in Pathogenesis of Intraplaque Hemorrhage

“…The latter may be more likely in light of recent findings from the Rotterdam Study. In the Rotterdam Study, Selwaness et al 26 also examined association between BP and IPH and noted that pulse pressure was the major component associated with IPH. Sample size difference between the two studies can explain the findings related to pulse pressure, but not those regarding diastolic BP.…”

“…However, one notable difference is the lower rate of antihypertensive use in the Rotterdam sample (54% vs. 79%). No subgroup analysis in subjects with or without antihypertensive treatment was available in the study by Selwaness et al 26 Nonetheless, if patients whose diastolic BP has a larger decrease on antihypertensive treatment are more likely to develop IPH, increased antihypertensive use could contribute to a more distinct relationship. On the other hand, antihypertensives are expected to lower pulse pressure and may weaken the association of IPH with pulse pressure.…”

Arterial Stiffness is an Independent Risk Factor for Anemia After Percutaneous Native Kidney Biopsy

“…As the artery progressively stiffens, the pulse pressure generally increases. The pulsations are not completely absorbed and are enhanced as they extend to the microcirculation of organs such as the brain and kidney [20, 21]. The increased pulsatile stress damages small arteries and tears their endothelial and smooth muscle cells with the disruption of the vessel [10, 22, 23], which was shown in the small arteries of kidneys in a rat model of hypertension [24].…”