A Thyroid Hormone Analog to Fight Heart Failure: Phase II Trial (DITPA)

Intervention: After enrollment, patients receive a clinical assessment, echocardiogram and laboratory studies. Then, each patient receives treatment with one of two doses of 3,5-diiodothyropropionic acid (DITPA) or placebo for six months. Primary hypothesis: DITPA will improve cardiovascular function and clinical status in patients with moderately severe heart failure and be similar to placebo on safety measures. Secondary hypothesis: Primary Outcomes: 1. Composite endpoint composed of cardiovascular mortality/morbidity, change in NYHA class and change in global assessment, and 2. safety. Study Abstract: Congestive heart failure (CHF) affects 4-5 million Americans, and its prevalence is predicted to increase over the next few decades. Thyroid hormone has unique actions which make it a novel and potentially useful agent for treatment of CHF. Due to possible adverse effects of thyroid hormone, there is interest in developing analogs with fewer undesirable side effects. DITPA has been shown to improve diastolic function in both animal models and a recently completed double-blind placebo controlled trial in 19 humans. The goal of the proposed Phase II study is to define the dose of DITPA needed to achieve hemodynamic improvement in patients with CHF. This study is a prerequisite for a larger Phase III trial which would determine whether mortality is improved with DITPA. To better define the appropriate doses, prior to the Phase II study we will conduct an initial pharmacokinetic study.