Comparison of effects on peak oxygen consumption, quality of life, and neurohormones of felodipine and enalapril in patients with congestive heart failure

Angiotensin-converting enzyme (ACE) inhibition is currently the cornerstone of congestive heart failure (CHF) therapy, but these drugs are not tolerated in up to 20% of patients. For these patients, therapeutic alternatives with comparable efficacy are needed. Felodipine, a vasoselective dihydropyridine calcium antagonist with a slow onset of action and a long plasma half-life, may be such an agent. Therefore, the efficacy and safety or felodipine were examined and compared with enalpril using a double-blind design. We studied 46 patients with a left ventricular ejection fraction <0.40, peak oxygen consumption <20 ml-min⁻¹·kg⁻¹, and symptoms of CHF despite therapy with diuretics and digoxin. After 16 weeks of therapy, there were no statistically significant differences in peak oxygen consumption (felodipine +1.6, enalapril +2.5 ml·min⁻¹·kg⁻¹) and exercise tolerance (felodipine +61 seconds, enalapril +64 seconds). Quality-of-life parameters were affected slightly better by felodipine man by enalapril. Plasma norepinephrine decreased by 143 pg·ml⁻¹ with enalapril and by 12 pg·ml⁻¹ with felodipine (p > 0.20 between groups). Both drugs were generally well tolerated. These data suggest that felodipine and enalapril have comparable effects on exercise parameters in patients with CHF. Neurohumoral activation was not observed with either drug.