Recombinant Growth Hormone Therapy in Patients With Ischemic Cardiomyopathy

Abstract

Background —We studied the effects of recombinant growth hormone (rhGH) on exercise capacity and cardiac function in patients with ischemic cardiomyopathy. Methods and Results —Seven patients (aged 55±9 years) with mild to moderate congestive heart failure (ejection fraction 31±4%) who were on standard therapy were included. The patients were studied at baseline, after 3 months of rhGH treatment, and 3 months after rhGH discontinuation. Cardiac function was assessed by exercise capacity, right heart catheterization at rest and after submaximal exercise, MRI, echocardiography, and Holter monitoring. When administered at a dose of 2 IU/d, rhGH doubled the serum concentration of insulin-like growth factor-I. rhGH improved clinical symptoms and exercise capacity significantly (New York Heart Association class 2.4±0.5 initially versus 1.4±0.5 at 3 months [mean±SD], P <0.05; V̇ o 2 max 13.6±3.8 versus 17.4±5.4 mL · kg −1 · min −1 , P <0.05). Additionally, pulmonary capillary wedge pressures at rest and after submaximal exercise were reduced significantly. Cardiac output increased, particularly at rest (5.0±1.1 versus 5.8±1.3 L/min; P <0.05). Posterior wall thickness was increased (1.08±0.1 versus 1.24±0.3 cm; P <0.05), and the end-diastolic and end-systolic volume indexes decreased significantly after rhGH treatment. There was no significant increase in left ventricular ejection fraction. The improvements were partially reversed 3 months after rhGH discontinuation. Conclusions —The administration of rhGH for 3 months in patients with ischemic cardiomyopathy results in significant improvement in hemodynamics and clinical function. The attenuation of left ventricular remodeling persisted 3 months after discontinuation of treatment.