Lower Levels of Triiodothyronine Are Associated with Poor Hemodynamic Profile and All-Cause Mortality in Heart Failure

Background: We aimed to assess the association of triiodothyronine (T3) hormone with invasive hemodynamic parameters and all-cause mortality in heart failure with reduced ejection fraction (HFrEF). Results: About 483 HFrEF patients were enrolled. Patients with the lowest T3 tertile had advanced New York Heart Association (NYHA) classes, had higher uric acid, brain natriuretic peptide. T3 level had a positive correlation with cardiac index (CI) and a negative correlation with pulmonary vascular resistance and pulmonary capillary wedge pressure. Adjusted with NYHA III–IV classes, uric acid, aspartate aminotransferase and CI, T3 level was found to be an independent predictor of all-cause mortality. In Kaplan–Meier analysis, the lowest T3 tertile had the lowest survival function. Conclusion: Free T3 is positively correlated with CI and negatively correlated with pulmonary vascular resistance and pulmonary capillary wedge pressure in patients with HFrEF. Lower levels of T3 seems to be a poor prognostic factor in this particular patient population.