Haemorheological abnormalities in arterial hypertension and their relation to cardiac hypertrophy

Haemorheological characteristics were measured in a group of 52 patients with essential arterial hypertension (HT), and were compared with those of a group of normotensive subjects. The relationships between the arterial blood pressure (BP), the echocardiographic indices of left ventricular hypertrophy (LVH), and the haemorheological measurements, were studied. The group of hypertensive patients was found to have a hyperviscosity syndrome with significant elevations of blood viscosity at all shear rates (for γ = 0.20/s, 29.6 ± 0.6 versus 28.0 ± 0.3 mPa.s, P<0.01: for γ = 128/s, 4.2 ± 0.05 versus 4.1 ± 0.02 mPa.s, P < 0.02, of plasma viscosity (1.29 ± 0.01 versus 1.22 ± 0.06 cSt, P< 0.001); of erythrocyte aggregation index (17.8 ± 0.06 versus 14.6 ± 0.4, P< 0.001 );of erythrocyte filterability index (13.3 ± 0.5 versus 8.8 ± 0.2, P < 0.001) and plasma fibrinogen level (3.4 ± 0.9 versus 2.8 ± 0.6 g/l, P < 0.02). The haematocrit did not differ from that of normotensive subjects (43.3 ± 0.6 versus 44.7 ± 0.5%, NS). The left ventricular mass was increased and was positively correlated with the blood viscosity at a high shear rate (r = 0.38, P < 0.01) and with the erythrocyte aggregation index (r = 0.47, P < 0.01). Systolic, diastolic, and mean arterial blood pressures were positively correlated with the left ventricular mass (r = 0.34–0.47, P < 0.05) and with the erythrocyte aggregation index (r = 0.42–0.46, P < 0.01). These results confirm the existence of a blood hyperviscosity syndrome in hypertension, with abnormal haemorheological characteristics involving blood, plasma, and erythrocytes. The positive correlations in rheological variables with arterial pressure and with indices of LVH that these changes may play some role in the pathophysiology of hypertension and its complications.