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Malignant hypertension (MHT) is a rare and severe form of hypertension characterised by arteriolar necrosis and severe vascular damage, leading to stroke, myocardial infarction and death. We hypothesised that in addition to endothelial damage, MHT may be associated with increased oxidative stress. Lipid hydroperoxides (LHP, an index of oxidative damage) and plasma von Willebrand factor (vWf, an index of endothelial damage/dysfunction) were measured in 16 patients with MHT and compared with 16 non-malignant essential hypertensives and 32 normotensive controls. vWf was greater in MHT (mean 117 iU/dL) than in non-malignant hypertensives (97 iU/dL) or normotensive controls (100 iU/dL) (ANOVA P = 0.017). However, although LHP were greater in MHT (mean 10.6 mol/L) than in normo-

An interaction between homocyst(e)ine and the endothelium in hypertensive patients may promote thrombogenesis and atherogenesis, leading to adverse cardiovascular events. We hypothesized that homocyst(e)ine levels are abnormal in patients with essential hypertension, and that this may be related to an adverse effect on the vascular endothelium. Accordingly, we compared plasma levels of homocyst(e)ine and von Willebrand factor (marking endothelial damage) in 83 patients (43 men; mean age 54 +/- standard deviation 15.9 years) with essential hypertension (> 160/90 mm Hg), with levels in 25 healthy normotensive controls (13 men; mean age 56+/-11.8 years). Baseline levels of the markers and other clinical indices were then related to adverse cardiovascular events at follow-up. Plasma homocyst(e)ine (P = .0001) and von Willebrand factor (P = .031) levels were significantly higher in hypertensives compared to controls. After a mean follow-up of 76 patients for 45 months (range, 1 to 66 months), 17 subjects experienced an end point of either cardiovascular death (n = 10) or adverse cardiovascular event (n = 7). Comparing these 17 with the 59 free of an end point, the former were older (P = .0002) and had a longer duration of known hypertension (P = .018). There was a nonsignificant trend toward higher median plasma homocyst(e)ine levels in the patients sustaining a vascular end point (P = .07). In this pilot study, we suggest that essential hypertension may be associated with increased plasma homocyst(e)ine levels, but that this amino acid is unrelated to endothelial damage (von Willebrand factor), clinical indices, or prognosis.

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To investigate the hypothesis that abnormalities of thrombogenesis and endothelial damage/dysfunction are greater in malignant hypertension (MHT) compared with uncomplicated nonmalignant essential hypertension (EHT) > 160/90 mm Hg), we measured markers of endothelial function (von Willebrand factor) platelet activation (soluble P-selectin) and fibrinogen in 18 consecutive patients with MHT, 50 patients with untreated EHT, and 34 healthy control subjects. We also investigated whether there was any diurnal variation in the measured indices, as well as the effects of good blood pressure (BP) control after 6-month follow-up. Mean plasma fibrinogen and von Willebrand factor levels were both highest in the MHT group, intermediate in the nonmalignant hypertension group and lowest in the normotensive control subjects (P < .001). Similarly, mean soluble P-selectin levels were higher in both hypertensive groups compared to normotensive control subjects (P = .033). There was no significant diurnal variation in plasma fibrinogen, soluble P-selectin, and von Willebrand factor levels over the 24-h study period among the MHT patients. At 6-month follow-up and a reduction in mean BP, there was no significant change in mean plasma fibrinogen levels (P = .25), but both soluble P-selectin (P < .001) and von Willebrand factor (P = .0025) were significantly reduced. In conclusion, malignant hypertension is associated with abnormal endothelial damage (elevated von Willebrand factor), platelet activation (soluble P-selectin), and fibrinogen levels, which may be related to the pathogenesis of this condition, as well as the development of complications. These abnormalities do not undergo any significant diurnal variation and may be beneficially altered by BP reduction.