[Erythrocyte aggregation in vascular disease. Influence++ of hypertension].

In vascular diseases, when the vasomotor reserve is exhausted, microcirculation is strongly dependent on blood fluidity. For patients with vascular disorders, it was therefore decided to evaluate red blood cells (RBC) aggregation and disaggregation (SEFAM erythro-aggregometer) which are important factors determining blood viscosity in low flow areas. Our results show that, in essential hypertension (EH), RBC aggregation is significantly increased (+15%), and disaggregation is decreased (-20%). The highest frequency of troubles was found in EH. This observation led to exclusion of EH subjects in all the other studied pathological groups. When EH is excluded from a group of 70 patients with cerebrovascular disorders (CVD), we did not observe significant changes in RBC aggregation. However, in essential and post-thrombotic venous insufficiency there remains a significant increase in RBC aggregation (+10%) and a decrease in disaggregation (-13%). In diabetes, disaggregation is more disabled than for controls (-16%). In all these pathologies presence of EH magnifies the abnormalities, or makes them appear like in CVD. This study underlines the critical importance of taking the influence of hypertension into consideration when evaluating RBC aggregation in vascular pathology. The increase in RBC aggregability and in the shear resistance of the aggregates, when present in vascular pathology, is likely to add a burden to the circulatory system already hindered by a deficient vasomotor regulation system.