International Journal of Cardiology, 29 (1990) 55-61 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFED Elsevier 55 CARD10 11206 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Sustained beneficial effects of enalapril in Africans with congestive heart failure A.A. Ajayi and M.O. Balogun Departmeni of Medicine, Faculty of Health Sciences, Obajemi Awolowo University, Ile-Ije, Nigeria (Received 16 November 1989; revision accepted 24 April 1990) Ajayi AA, Balogun MO. Sustained beneficial effects of enalapril in Africans with congestive heart failure. Int J Cardiol 1990;29:55-61. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA A single blind, placebo controlled, dose-ranging 3 month study of the effects of enalapril on cardiovascu- lar parameters, clinical status and self-paced exercise capacity was undertaken in 12 Nigerians with chronic heart failure. Enalapril exerted only a modest reduction in blood pressure and heart rate but significantly improved functional capacity zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA (P < O.Ol), and prolonged self-paced exercise thne (P < 0.05) compared to the placebo baseline. The pressure rate product and the double product corrected for exercise time, an index of myocardial oxygen demand, exhibited a significant and sustained reduction on enalapril treatment (P -z 0.01). Concentration of sodium in the serum was significantly increased (P < 0.05) but concentrations of potassium and creatinine were unaltered. These results demonstrate the sustained efficacy of enalapril in black Africans with heart failure and indicate no important racial difference in the response to inhibition of angiotensin converting enzyme in congestive heart failure. Key words: Congestive heart failure; Africans; Enalapril; Self-paced walk test; ACE inhibition Introduction Inhibitors of angiotensin converting enzyme are of established value as balanced vasodilators in the therapy of congestive heart failure [l]. Re- cently, in the Cooperative Northern Scandinavian Enalapril Survival Study [2], enalapril was shown to exert beneficial amelioration of symptoms and to reduce mortality in severe congestive heart failure. The pharmacodynamic effects and the clinical response to converting enzyme inhibition, however, may be dependent on plasma renin activ- Correspondence to: A.A. Ajayi, M.B., Ph.D., FWACP., Dept. of Medicine, Obafemi Awolowo University, Ile-Ife, Nigeria. ity [3], which exhibits interracial differences, and is low in people of African descent [4,5]. There remain, therefore, important unanswered ques- tions regarding the worldwide clinical utility of inhibitors of angiotensin converting enzyme in cardiovascular disease, especially in populations with epidemiologically low renin profile. For ex- ample, a poor antihy-pertensive efficacy of en- alapril monotherapy has been reported both in North American [6] and African [7,8] black pa- tients with essential hypertension. Compensatory neurohumoral mechanisms in heart failure and concurrent diuretic therapy may, however, in con- cert, cause activation of the Renin-angiotensin-al- dosterone system [9] and render Africans more responsive to inhibition of the converting enzyme. 0167~5273/90/$03.50 0 1990 Elsevier Science Publishers B.V. (Biomedical Division)