Effects of levothyroxine in subclinical hypothyroidism and heart failure with reduced ejection fraction: An open-label randomized trial

Abstract

We report a randomized, multicenter, open-label trial (ClinicalTrials.gov: NCT03096613) to investigate the clinical benefits of levothyroxine (L-T4) administration in subclinical hypothyroidism (SCH) patients with heart failure with reduced ejection fraction (HFrEF). Overall, 117 patients were enrolled and received L-T4 plus standard HFrEF treatment (experimental group, N= 57) or standard HFrEF therapy alone (control group, N= 60). The change of 6-min walk test distance in the experimental group was significantly higher than that in the control group at 24weeks (70.08± 85.76m vs. 27.73± 82.00 m, mean difference [95% confidence interval (CI)] 46.90 [12.90, 80.90], p<0.001). Improvements in New York Heart Association (NYHA) classification (p= 0.033) and thyroid function were significant. Adverse event incidence was similar between groups (risk ratio [95% CI]: 0.942 1.053 (0.424, 2.616); p= 0.628). L-T4 addition to HFrEF treatment improved activity tolerance, NYHA class, and thyroid function within 6months, suggesting its potential for combined therapy in HFrEF patients with SCH. Future double-blind, placebo-controlled trials should be performed to confirm these results.