A Randomized, Controlled Trial of L-arginine and Spironolactone in Dialysis-dependant End Stage Renal Disease

We hypothesize that that abnormalities in aldosterone and nitric oxide (NO) homeostasis contribute to the progression of microvascular disease and myocardial fibrosis in ESRD and that agents designed to restore normal aldosterone and NO homeostasis will improve microvascular and diastolic cardiac function in the heart of individuals with dialysis dependent ESRD. We will test 2 specific agents: The mineralocorticoid receptor blocker spironolactone; and L-arginine, an agent which improves NO bioavailability. Two specific aims will be addressed using a prospective, double-blinded, 2x2 factorial trial in dialysis dependent patients with ESRD. Subjects will be randomized to placebo, spironolactone plus placebo, L-arginine plus placebo, or combination spironolactone and L-arginine therapy. Diastolic cardiac function will be assessed using tissue Doppler index (TDI) determined mitral annular velocities (E') on LV echocardiography, and microvascular supply will be assessed using CFR-the ratio of hyperemic to resting myocardial blood flow-measured by positron emission tomography (PET) scans at baseline, 2 weeks and after 9 months of randomized therapy.

This randomized trial of spironolactone and L-arginine will provide important data about the contributions of aldosterone and NO to the pathogenesis of cardiovascular disease in ESRD, will demonstrate the therapeutic potential of L-arginine and spironolactone as as targeted cardiovascular therapies for use in ESRD, and will provide important insights into the underlying pathophysiology of cardiovascular disease in ESRD. The results generated will provide the data needed to design large-scale trials testing whether spironolactone or L-arginine can improve mortality or cardiovascular outcomes in ESRD.