EFFECT OF ENALAPRIL ON HEMORHEOLOGY IN HYPERTENSIVE PATIENTS WITH RENAL-DISEASE

An open, prospective study was undertaken to investigate the effects o f enalapril on hemorheology in patients with renal disease and complic ating hypertension. Cellular and plasma determinants of brood viscosit y and renal function were measured in 19 patients at baseline and 2, 6 0 and 120 days after treatment with enalapril (mean dose 5.4; range 2. 5-20 mg/day). Within 2 days of starting enalapril there was a signific ant decrease in apparent blood viscosity measured at high shear rate ( -0.15 mPa.s; p<0.05) which fell further by day 60. The decrease in blo od viscosity was primarily the result of hemodilution, as evidenced by a concurrent fall in plasma albumin concentration and plasma viscosit y. A small, but significant decrease, in hemoglobin concentration (-7. 4g/l; p=0.03), and a trend of improved red blood cell (RBC) and white blood cell (WBC) rheological properties may have also contributed to t he decrease in blood viscosity. We conclude that enalapril had a benef icial effect on hemorheology in patients with renal disease. The mecha nism of the rheotogical changes appeared to be multifactorial and woul d be expected to decrease vascular resistance to blood flow.