Abnormalities of vascular function in resistant hypertension

Abstract

We aimed to evaluate markers of vascular dysfunction in patients with resistant hypertension (RH). A group of 144 patients (61 years, 42% women) with essential RH were divided in two groups based on ambulatory blood pressure monitoring (ABPM). True RH (72%) was considered when 24-h blood pressure (BP) was ≥ 130 and/or 80 mmHg. Otherwise, patients were classified as white coat RH (28%). Hyperemia-induced forearm vasodilation (HIFV), serum inflammatory biomarkers (hs-CRP, s-ICAM-1, s-VCAM-1, e-selectin, p-selectin and MCP-1) and large (C1) and small arterial (C2) compliance (HDI/Pulse Wave CR 2000) were determined in all individuals. In comparison with patients with white coat RH, and after adjustment for age, office systolic BP and diabetes status, those with true RH had a more impaired HIFV (201 ± 159 vs 436 ± 157%; p < 0.001), increased e-selectin (53.1 ± 29.8 vs 40.7 ± 23.5 ng/ml; p = 0.035), and MCP-1 (445 ± 120 vs 386 ± 126 ng/ml; p = 0.027). No significant differences were observed in arterial compliance. Maximal HIFV inversely correlated with urinary albumin excretion (Rho: - 0.278; p = 0.004) and with some inflammatory biomarkers (MCP-1: - 0.441; p < 0.001, e-selectin: - 0.468; p < 0.001 and p-selectin: - 0.329; p = 0.001). We conclude that true RH, diagnosed by ABPM, is associated with a more severe degree of vascular dysfunction, as measured by HIFV and serum biomarkers, whereas other types of vascular alterations, such as compliance, are not directly linked with the level of BP.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

“…Physiological aberrations in RH include vascular disease/dysfunction as evidenced by high rates of peripheral 39 and carotid artery atherosclerosis, 42 impaired endothelial function, 51,52 reduced arterial compliance, and raised systemic vascular resistance, 40 all of which may be more pronounced in RH compared with non-RH. The normal nocturnal decline in BP is also attenuated in a high proportion (43%−65%) of individuals with RH.…”

Resistant hypertension: patient characteristics, risk factors, co-morbidities and outcomes

“…Concretely, patients with true RH have a higher prevalence of left ventricular hypertrophy, as measured either by electrocardiogram 3 or by echocardiography, 11,35 higher levels of urinary albumin excretion, 3,5,11,20,35 decreased estimated glomerular filtration rate, 5,20 carotid intima-media thickening and more carotid plaques, 35 as well as a more severe degree of vascular dysfunction as assessed by impaired forearm vasodilation function and increased levels of serum inflammatory biomarkers. 36 Not only subclinical organ damage, but also adverse cardiovascular outcomes are more likely to occur in patients with RH. This was shown in the retrospective analysis of Daugherty et al 6 where after adjustment for several variables, patients with RH had an increased risk to experience adverse cardiovascular outcomes as compared with patients with controlled BP.…”

Clinical situations associated with difficult-to-control hypertension

“…RHT, meanwhile, is associated with higher prevalence of subclinical target organ damage with respect to normotensive patients or those with well controlled BP. This is true in relation to left ventricular hypertrophy [7,8,10], microalbuminuria [8][9][10]14,23], impaired renal function [10,14], and vascular involvement manifested by carotid intimamedia thickening [7] and endothelial dysfunction [42]. More important, however, is the evidence that RHT patients, confirmed by 24h-ABPM, are more at risk of developing cardiovascular complications than patients with controlled BP [2][3][4][5].…”