Beneficial effects of long-term triiodothyronine (T3) infusion in patients with advanced heart failure and low T3 syndrome

In patients with advanced congestive heart failure a reduction of circulating T3 levels is frequently associated with poor ventricular function and is a strong predictor of poor short-term outcome. In a group (n=6) of advanced heart failure patients (3 males and 3 females, age 64 +/-8 yrs, mean:!:SEM) with low T3 syndrome (total T3 < 60 ng/dl), and under stable conventional treatment, we administered substitutive doses of T3 by long-term i.v. infusion (20 mug/day/m(2) b.s. for 96 hours). Hemodynamic assessment was performed by Swan-Ganz.. T3 infusion was followed by a progressive reduction in systemic vascular resistance (p <0.03), an increase in cardiac output (p <0.01), ejection fraction (p <0.04), and urinary output (p <0.02). Our preliminary results indicate that treatment with substitutive doses of T3 may represent a promising therapeutic strategy to improve cardiovascular function during evolution of congestive heart failure.