A cross-sectional, diurnal, and follow-up study of platelet activation andendothelial dysfunction in malignant phase hypertension

To investigate the hypothesis that abnormalities of thrombogenesis and endo thelial damage/dysfunction are greater in malignant hypertension (MHT) comp ared 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 s ubjects. We also investigated whether there was any diurnal variation in th e measured indices, as well as the effects of good blood pressure (BP) cont rol after 6-month follow-up. Mean plasma fibrinogen and von Willebrand fact or levels were both highest in the MHT group, intermediate in the nonmalign ant hypertension group and lowest in the normotensive control subjects (P < .001). Similarly, mean soluble P-selectin levels were higher in both hyper tensive groups compared to normotensive control subjects (P = .033). There was no significant diurnal variation in plasma fibrinogen, soluble P-select in, and von Willebrand factor levels over the 24-h study period among the M HT 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 sol uble P-selectin (P < .001) and von Willebrand factor (P = .0025) were signi ficantly reduced. In conclusion, malignant hypertension is associated with abnormal endothelial damage (elevated von Willebrand factor), platelet acti vation (soluble P-selectin), and fibrinogen levels, which may be related to the pathogenesis of this condition, as well as the development of complica tions. These abnormalities do not undergo any significant diurnal variation and may be beneficially altered by BP reduction. (C) 2001 American Journal of Hypertension. Ltd.