Pingitore A, et al. - In 37 patients with acute myocardial infarction (AMI) and low T3 syndrome (LT3S), researchers assessed the safety as well as the impact of thyroid hormone replacement therapy on infarct size, left ventricular (LV) volumes and function. In addition to standardized treatment, patients were randomly treated or untreated with liothyronine (T3) therapy (maximum dosage 15 mcg/m2/die) (T3-treated group, n = 19; untreated group, n = 18). A significant increase in fT3 was seen in T3-treated patients at discharge and 1-month. No signs or symptoms of hyperthyroidism or arrhythmias were found in these subjects. Both groups had a significant reduction in wall motion score index (WMSI) at follow-up, with the T3-treated group vs the untreated group having a significantly higher difference value (discharge/follow-up). Additionally, the T3-treated group had significantly increased stroke volume at follow-up. In this pilot study, safety as well as the efficacy of T3 replacement therapy in improving regional dysfunction in patients with STEMI/LT3S was established for the first time ever.