1031-32 Felodipine Versus Enalapril in Heart Failure: Results on Peak Oxygen Consumption, Holter Recordings Hemodynamics, Neurohormones, and Quality of Life

Felodipine (FEL) is a vasoselective dihydropyridine calcium antagonist that has shown promising results in smaller congestive heart failure (CHF) studies. Angiotensin converting enzyme inhibitors (ACEI) are the cornerstone of CHF therapy, but many patients can not be treated with these drugs because of side effects or contraindications. We compared the effects of FEL. 10mg b.Ld., and enalapril (ENA), 10mg b.Ld., in a double blind, parallel study in 50 patients with CHF. At baseline and after 16 weeks treatment cardiopulmonary exercise test, neurohormone sampling, Holter recording and quality of life questionaires were assessed.PatientsFifty patients with CHF, NYHA class II–III, mean age 64±7 yr., mean LVEF of 26±9%, mean peak oxygen consumption of 14.8±3.5ml/min/kg. mean norepinephrine 683±470pg/ml and mean plasma renin activity of 0.9±0.8ng/ml/hr were randomized, after a 2 week placebo period, to FEL and ENA.ResultsExercise duration was increased 63 sec and peak oxygen consumption 0.7ml/kg/min after FEL, and 60 sec and 1.4ml/kg/min after ENA (P=NS). Rate pressure product (RPP) at peak exercise was significantly lowered by Fel (p<0.005). Plasma norepinephrine decreased after both Fel and ENA by 46 and 150pg/ml respectively, whereas plasma renin increased by 0.7 and 4.1ng/ml/hr respectively (both P=NS). FEL patients significantly better results on quality of life score. Holter recordings revealed no proarhytmias with either drug. Side effects were minor with both drugs.DiscussionThe vasoselective calcium antagonist FEL demonstrated equal efficacy in exercise parameters, and was somewhat superior in quality of life parameters, if compared to ENA. The massive vasodilation induced by FEL, as demonstrated by the RPP was not accompanied by an activation of the neurohormonal system, so often observed with other vasodilating agents.ConclusionFEL can be seriously considered as an alternative treatment for ACEI in CHF patients. A direct comparison between FEL and ACEI in CHF, with special emphasis on long term efficacy and mortality seems of interest