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Effects of Losartan and Enalapril on Renal Function
and Hemodynamics in CHF |
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The aim of investigation was the evaluation of Enalapril (E) and Losartan (L) influence on electrolyte and water excreation, renal function and renal hemodynamics in pts with congestive heart failure (CHF) in accordance with initial hemodynamic status. 83 male pts, aged 44 to 67, with CHF (II-III NYHA classification) due to chronic forms of coronary heart disease were examined. The pts were divided in 3 groups depending on the treatment: I group (29 pts) received cardiac glycosides and diuretics; E 10 mg bid was administered to 28 pts (II group) and L 12,5 mg once daily, titrated to 25 mg, and up to 50 mg once daily was administered – to 26 pts (III group). Acute pharmacological test followed by six-month course of E or L treatment was performed in each pts. Renal function was assessed by endogenous creatinine clearance, renal hemodynamics parameters – by cardiotrast clearance. Sodium and potassium ion concentration was determined by biochemical analyzer, sodium and water excretion was calculated by formula. Central hemodynamic was determined by echocardiography, tetrapolar rheography. After six-month of treatment both E and L improved NYHA class, 6-minute walk distance, and quality-of-life scores (all p<0,05 from baseline), and there were no differences between the 2 treatments. Increased glomerular filtration rate (GFR) and effective renal blood flow (ERBF) were observed in the course of treatment with E (GFR – 68+1 ml/min before treatment vs. 71+2 ml/min after treatment, p<0,05; ERBF – 621+16 ml/min vs. 781+12 ml/min, p<0,01, respectively). E increased renal sodium and water excretion accordingly by 32.1-74.3% and 21.3-64.6%. The renal vascular resistance decreased by 16.2%. The change in the L group was significantly greater than in the E group, especially about concerning ERBF and renal vascular resistance. Our results show, that beneficial effects of E or L on renal function and hemodynamic parameters were due to direct renal action of the drugs (selective renal vasodilation due to angiotensin II inhibition). Improved natriuresis and diuresis, decreased the rigidity of vessel’s wall, which was marked in CHF due to high sodium concentration, and also decreased the compression of vessels due to interstitial edema. Decreased renal vascular resistance. This course the potentiation of vasodilation. After six-month E and L treatment subjective complaints and objective symptoms of CHF decreased and tolerance to physical activity increased. Both drugs treatment reduced the functional class of CHF, which helps the rehabilitation of pts. |
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