Recombinant growth hormone therapy in patients with ischemic cardiomyopathy - Effects on hemodynamics, left ventricular function, and cardiopulmonaryexercise capacity

Background-We studied the effects of recombinant growth hormone (rhGH) on e xercise capacity and cardiac function in patients with ischemic cardiomyopa thy. Methods and Results-Seven patients (aged 55+/-9 years) with mild to moderat e congestive heart failure (ejection fraction 31+/-4%) who were on standard therapy were included. The patients were studied at baseline, after 3 mont hs of rhGH treatment, and 3 months after rhGH discontinuation. Cardiac func tion was assessed by exercise capacity, right heart catheterization at rest and after submaximal exercise, MRI, echocardiography, and Holter monitorin g. When administered at a dose of 2 IU/d, rhGH doubled the serum concentrat ion of insulin-like growth factor-I. rhGH improved clinical symptoms and ex ercise capacity significantly (New York Heart Association class 2.4+/-0.5 i nitially versus 1.4+/-0.5 at 3 months [mean+/-SD], P<0.05; (V) over dot 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 in creased (1.08+/-0.1 versus 1.24+/-0.3 cm; P<0.05), and the end-diastolic an d end-systolic volume indexes decreased significantly after rhGH treatment. There was no significant increase in left ventricular ejection fraction. T he improvements were partially reversed 3 months after rhGH discontinuation . Conclusions-The administration of rhGH for 3 months in patients with ischem ic cardiomyopathy results in significant improvement in hemodynamics and cl inical function. The attenuation of left ventricular remodeling persisted 3 months after discontinuation of treatment.