Abstract 10993: Prognostic Value of Low T 3 Syndrome in Patients with Acute Decompensated Heart Failure in Osaka Prefectural Acute Heart Failure Registry (OPAR)

Abstract

Backgrounds: It is widely recognized that thyroid dysfunction is a potential cause of heart failure (HF). In HF, one of the alterations of thyroid functions is referred to as low T 3 syndrome marked by a reduction in serum free triiodothyronine (T 3 ) with normal levels of thyroid-stimulating hormone (TSH). However, there is little information available about the association between low T 3 syndrome and future cardiac events in patients with acute decompensated heart failure (ADHF), relating to left ventricular ejection fraction (LVEF). Methods and Results: We studied 565 patients admitted for ADHF with survival discharge in our prospective cohort study. Laboratory data including free T 3 , thyroxine and TSH were obtained at discharge. Among the patients with euthyroid (0.35 μU/mL <TSH <4.94 μU/mL, n=438), there was 62 patients who were diagnoses as low T 3 syndrome (free T 3 ≦1.68 pg/mL). The primary end point of this study was all-cause death (ACD). During a mean follow up period of 2.9±1.4 years, 121 patients died. Study subjects were stratified into two LVEF subgroup as follows; 239 patients had LVEF<50% (HFrEF), and 199 patients had LVEF≧50% (HFpEF). While 68 HFrEF parients died, 53 HFpEF patients died. Kaplan-Meier curve analysis revealed that patients with the low free T 3 group had the greater risk of ACD than those with the normal free T 3 group in both LVEF subgroup (log-rank p=0.0233 in HFrEF and p=0.0265 in HFpEF). Multivariate Cox analysis showed that free T 3 was significantly associated with ACD after multivariable adjustment for major confounders, such as age, sex, systolic blood pressure and plasma brain natriuretic peptide level in both LVEF subgroup (p=0.0039 in HFrEF, p=0.0487 in HFpEF). Conclusion: Low T 3 syndrome was significantly associated with poor outcome in ADHF patients with both HFrEF and HFpEF.