Abnormal haemorheology, endothelial function and thrombogenesis in relation to hypertension in acute (ictus < 12 h) stroke patients: the West Birmingham Stroke Project

While the blood vessels are exposed to high pressures in hypertension, the main complications of hypertension (stroke and myocardial infarction) are p aradoxically thrombotic rather than haemorrhagic. To investigate abnormalit ies of haemorheology (plasma viscosity, fibrinogen), endothelial dysfunctio n (von Willebrand factor), platelet activation (soluble P-selectin) and thr ombogenesis (plasminogen activator inhibitor and fibrin D-dimer) in stroke and the effects of concurrent hypertension, we studied 86 consecutive patie nts (58 male, 28 female) aged < 75 years (mean age +/- SD, 64.2 +/- 9.2 yea rs) with acute stroke (ictus < 12 h). Baseline blood tests on admission wer e compared with 46 'hospital controls' (patients with uncomplicated essenti al hypertension; mean age +/- SD, 65.9 +/- 3.8 years) and 24 healthy normot ensive controls (mean age +/- SD, 65 +/- 14.0 years). Further comparisons w ere made between stroke patients with hypertension (systolic blood pressure > 160 mmHg and/or diastolic > 90 mmHg) on admission and those without hype rtension. Mean plasma viscosity (one-way analysis of variance, P = 0.026) a nd fibrinogen levels (P = 0.016) were significantly higher in stroke patien ts and hospital controls, when compared with healthy controls. The von Will ebrand factor, plasminogen activator inhibitor soluble P-selectin and fibri n D-dimer levels were highest in the acute stroke patients, intermediate in hospital controls and lowest in healthy controls (all P less than or equal to 0.001). There were no significant differences in measured indices of ha emorheology, endothelial dysfunction and thrombogenesis between the three s troke pathological subtypes (ischaemic/thrombotic, haemorrhagic or transien t ischaemic attack). There were also no significant differences in the meas ured parameters for stroke patients with or without systolic blood pressure > 160 mmHg or diastolic blood pressures > 90 mmHg using clinical (manual) readings or mean daytime or night-time ambulatory blood pressure monitoring recordings. There were no statistically significant differences between th e measured parameters on admission and at 3 months follow-up in 26 patients (all P = not significant). Plasma viscosity was significantly correlated w ith mean daytime systolic blood pressure (r = 0.314, P = 0.021) and mean ni ght-time systolic blood pressure (r = 0.309, P = 0.025). This study of hype rtension and haemostasis in acute stroke has demonstrated clear abnormaliti es of haemorheology, endothelial dysfunction, platelet activation and throm bogenesis, which do not appear to be affected by the height of the blood pr essure or the presence of hypertension. This is despite the known hypercoag ulable state found in hypertension and the relationship of haemostatic abno rmalities to vascular complications. (C) 2001 Lippincott Williams & Wilkins .