Abstract 182 Poster Session III, Monday, 5/3 (poster 130)

Studies have suggested growth hormone (GH) therapy as a treatment of dilated cardiomyopathy. To evaluate cardiac effects of GH we examined cardiac status serially by echo before (7.5 yrs after anthracycline), during (yearly for 3 yrs), and after (yearly for 4 yrs) GH in 34 Children's Hosp anthracycline-treated long-term survivors of childhood cancer who received GH replacement from 1988 to 1991, with follow-up to 1998. The control population consisted of 104 anthracycline-treated long-term survivors of childhood cancer who did not receive GH therapy. Left ventricular (LV) contractility was significantly more depressed in GH-deficient pts than in the control group, was unaffected by GH, and progressively deteriorated during the study (stress-velocity index: -1.08 SD before GH and -1.88 SD after GH, p=.001). Decreased LV wall thickness, resulting in increased LV afterload and depressed LV fractional shortening, typical of late pediatric anthracycline cardiotoxicity was noted in both groups. Three years of GH therapy significantly increased the treated children's LV wall thickness (-1.38 SD before GH and -1.09 SD after 3 yrs on GH, p=0.03), but this effect was lost shortly after stopping GH (1.50 SD 1 yr after GH) and worsened with follow-up (-1.96 SD 4 yrs after GH). LV peak wall stress, a mediator of hypertrophy, became less elevated during the GH therapy interval in the treated children relative to the controls, but remained elevated relative to normal. GH appeared to increase height, heart rate, blood pressure, preload, and LV mass, and decrease LV dilation. After stopping GH, the trend was for LV mass and wall thickness to decrease and LV dimension to increase. In conclusion, GH replacement did not affect the course of progressive LV dysfunction but did increase LV wall thickness slightly, an effect lost after discontinuation of GH.