Effect of long-term enalapril therapy on neurohormones in patients with left ventricular dysfunction

The aim of this study was to compare the long-term effects of treatment with enalapril or placebo on plasma neurohormones in patients with left ventricular (LV) dysfunction. Elevated neurohormonal levels are associated with increased mortality in patients with congestive heart failure. Multiple studies have shown that angiotensin-converting enzyme inhibitors decrease mortality and morbidity in these patients. In Studies of Left Ventricular Dysfunction (SOLVD), enalapril significantly reduced mortality in patients with symptomatic LV dysfunction (treatment trial). In contrast, in patients with asymptomatic LV dysfunction (prevention trial), there was no significant reduction in mortality with enalapril therapy. The effect of enalapril was examined in 333 prevention trial and 129 treatment trial patients. Plasma norepinephrine (NE) and plasma renin activity were measured in these patients at baseline, and at 4 and 12 months of follow-up. In a subset of these patients, atrial natriuretic peptide (ANP) and arginine vasopressin were also measured. Analysis of covariance models were used to determine the effect of enalapril on each neurohormone. Participants in the treatment trial had significantly higher neurohormonal levels when compared with those in the prevention trial or normal control subjects. In the treatment trial, patients taking enalapril had a greater decrease in plasma NE levels than patients taking placebo (p < 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)