Thyroid supplementation in heart failure

This 5-year observational study shows that thyroid hormone supplementation increases major adverse cardiovascular events (MACE), cardiovascular death, and all-cause mortality in patients with heart failure. Indirectly, this is in accordance with the well-documented benefits of beta-adrenergic receptor blockade in persons with cardiac failure.

Clinically, in patients with concomitants hypothyroidism and heart failure, thyroid hormone supplementation should be started at a low dose, increased slowly, and aiming a higher TSH target than in general population.


Also see


Heart Failure


Retrospective cohort

December 2018

Context, Objective, Design

  • Hypothyroidism has detrimental effects on the cardiovascular system, but controversy remains concerning the benefits of levothyroxine (LT4) substitution in patients with heart failure (HF).

  • Examining the effects of LT4 in patients with HF.

  • Retrospective cohort study.



All Danish citizens aged ≥ 18 years diagnosed with HF between 1997-2012. LT4 treatment was identified from nationwide registers. Incidence rate ratios (IRR) were calculated using Poisson-regression models.



All-cause mortality, myocardial infarction (MI), cardiovascular death and major adverse cardiovascular events (MACE).



  • 224,670 patients were diagnosed with HF (mean age 70.7 years, 53% male).

  • 6,560 patients were treated with LT4 at baseline

  • 9,007 patients initiated LT4 during follow-up.

  • 209,103 patients did not receive LT4.

  • During a median follow-up of 4.8 years, 147,253 patients died.

  • Increased risk of the following was observed for treatment on-going at baseline and initiated during follow-up, respectively:

    • All-cause mortality (IRR 1.25, IRR 1.13 p<0.05)

    • Cardiovascular death (IRR 1.23, IRR 1.11, p<0.05)

    • MACE (IRR 1.26, IRR 1.05, p<0.05)

  • Increased risk of MI (IRR 1.32, p<0.05) was observed for ongoing treatment, reduced risk (IRR 0.87, p<0.05) was observed for incident treatment.



On-going and incident LT4 treatment in patients with HF was associated with an increased risk of all-cause mortality, cardiovascular death, and MACE. Increased risk of MI was observed for on-going treatment, reduced risk was observed for incident treatment.

Thyroid Heart