PURPOSE: To determine whether an angiotensin-converting enzyme (ACE) inhibitor, 
enalapril, prevents cardiac function deterioration (defined using maximal 
cardiac index [MCI] on exercise testing or increase in left ventricular 
end-systolic wall stress [LVESWS]) in long-term survivors of pediatric cancer.
PATIENTS AND METHODS: This was a randomized, double-blind, controlled clinical 
trial comparing enalapril to placebo in 135 long-term survivors of pediatric 
cancer who had at least one cardiac abnormality identified at any time after 
anthracycline exposure.
RESULTS: There was no difference in the rate of change in MCI per year between 
enalapril and placebo groups (0.30 v 0.18 L/min/m(2); P =.55). However, during 
the first year of treatment, the rate of change in LVESWS was greater in the 
enalapril group than in the placebo group (-8.59 v 1.85 g/cm(2); P =.033) and 
this difference was maintained over the study period, resulting in a 9% 
reduction in estimated LVESWS by year 5 in the enalapril group. Six of seven 
patients removed from random assignment to treatment because of cardiac 
deterioration were initially treated with placebo (P =.11), and one has died as 
a result of heart failure. Side effects from enalapril included dizziness or 
hypotension (22% v 3% in the placebo group; P =.0003) and fatigue (10% v 0%; P 
=.013).
CONCLUSION: Enalapril treatment did not influence exercise performance, but did 
reduce LVESWS in the first year; this reduction was maintained over the study 
period. Any theoretical benefits of LVESWS reduction in this 
anthracycline-exposed population must be weighed against potential side effects 
from ACE inhibitors when making treatment decisions.