The effects of lisinopril on serum catecholamine concentrations both at rest and on exercise in patients with congestive cardiac failure. A double blind, placebo controlled, parallel group study.

Patients with congestive cardiac failure have elevated sympathetic activity at rest which contributes to the pathophysiology of this syndrome. In addition, the sympathetic response to exercise in these patients is abnormal. Sympathetic activity is accurately reflected by serum noradrenaline levels. In a double-blind, placebo-controlled, parallel group study, 16 patients of New York Heart Association (NYHA) functional class II, stabilised on optimum doses of diuretics were randomised into two equal groups, to receive either low-dose Lisinopril, an orally active angiotensin converting enzyme (ACE) inhibitor, or matching placebo, over a 12 week period. At the end of the 12 week treatment phase, there was no significant change in noradrenaline levels at rest (p = 0.33) mid exercise (p = 0.17), or peak exercise (p = 0.69), in the lisinopril group. Both lisinopril and placebo groups improved subjectively as assessed by change in NYHA grade, (p < 0.01 for placebo and p < 0.001 for those given lisinopril). Exercise duration improved significantly in the lisinopril group (p = 0.0296), but not in the placebo group after treatment. Low dose lisinopril is of use in congestive cardiac failure even in the absence of measurable changes in sympathetic tone.