Serum-free thyroxine and thyrotropin concentrations in euthyroid patients with decompensated congestive heart failure

We realized a prospective study of 106 consecutive patients hospitalized in an Internal Medicine Service with decompensated CHF. Between the 95 patients with normal serum-free thyroxine and thyrotropin concentrations, patients older than 70 years had a significant higher serum free thyroxine concentration (13.1±2.6 vs. 10.1±1.5 pmol/l, p=0.006) and a lower, but not significant, serum thyrotropin concentration (1.3±1.2 vs. 1.7±1.1 mU/l, p=0.11). No correlation was found between the functional class, the echocardiographic ejection fraction or the in-hospital stay and the serum free thyroxine and thyrotropin concentrations. The sex, the presence of systolic dysfunction, diastolic dysfunction, atrial fibrillation or comorbidity did not determine significant differences in the serum-free thyroxine and thyrotropin concentrations.