Elsevier

The American Journal of Cardiology

Volume 139, 15 January 2021, Pages 57-63
The American Journal of Cardiology

Relation Between Thyroid Function and Mortality in Patients With Chronic Heart Failure

https://doi.org/10.1016/j.amjcard.2020.10.034Get rights and content

Highlights

  • •

    Subclinical thyroid dysfunction is very common in patients with chronic heart failure (∼10%).

  • •

    There is a U-shaped relation between Thyroid-Stimulating Hormone and mortality.

  • •

    Subclinical hypothyroidism is associated with worse outcome in univariable analysis, but the association disappears after adjustment for age and natriuretic peptide level.

  • •

    There is a weak but significant association between increasing Thyroid-Stimulating Hormone and outcome in patients with heart failure with normal ejection fraction.

Thyroid dysfunction is common in patients with chronic heart failure (CHF), but there is conflicting evidence regarding its prognostic significance. We investigated the relation between thyroid function and prognosis in a large, well characterized cohort of ambulatory patients with CHF. Heart failure was defined as signs and symptoms of the disease and either left ventricular systolic dysfunction (LVSD) mild or worse (heart failure with reduced ejection fraction [HFrEF]), or no LVSD and raised amino-terminal pro-B-type natriuretic peptide (NT-proBNP) levels (>125 ng/L; heart failure with normal ejection fraction [HFnEF]). Euthyroid state was defined as a thyroid-stimulating hormone (TSH) level between 0.35 and 4.70 mIU/l, hypothyroidism as TSH >4.70 mIU/l, and hyperthyroidism as TSH <0.35 mIU/l. 2997 patients had HFrEF and 1995 patients had HFnEF. 4491 (90%) patients were euthyroid, 312 (6%) were hypothyroid, and 189 (4%) were hyperthyroid. In univariable analysis, both hypothyroid patients (hazard ratio [HR] 1.25, 95% confidence interval [CI] 1.08 to 1.45) and hyperthyroid patients (HR 1.21, 95% CI 1.01 to 1.46) had a greater risk of death compared with euthyroid patients. There was a U-shaped relation between TSH and outcome. Increasing TSH was a predictor of mortality in univariable analysis (HR 1.02, 95% CI 1.01 to 1.03), but the association disappeared in multivariable analysis. The three strongest predictors of adverse outcome were increasing age, increasing NT-proBNP, and higher NYHA class. In conclusion, although thyroid dysfunction is associated with worse survival in patients with CHF, it is not an independent predictor of mortality.

Section snippets

Methods

This study was a retrospective analysis of patients included in the HullLifeLab registry. Between March 2000 and March 2018, we enrolled 6,782 consecutive patients, referred by both primary and secondary care physicians, to a community heart failure clinic serving a local population of ∼600,000 people. Some patients had no prior diagnosis of heart failure and were treatment naive, therefore requiring initiation of guideline-recommended therapy; many others had a pre-existing diagnosis of HF and

Results

The flow of patients through the study is shown in Figure 1.

The distribution of TSH was positively skewed (Figure 2). Most patients were euthyroid; 6.3% (n = 312) were hypothyroid, of whom only 12 had overt hypothyroidism. A much smaller proportion of patients had hyperthyroidism, with only 0.9% having overt hyperthyroidism. Baseline characteristics of patients by thyroid status are shown in Table 1. Patients with thyroid dysfunction were more likely to be female, had lower systolic and

Discussion

We have shown that although thyroid dysfunction is related to outcome in patients with chronic heart failure, the association disappears when adjustment is made for established prognostic variables such as age, NT-proBNP, and NYHA class. The strength of our study is that we have investigated a large, unselected cohort of consecutive patients for the vast majority of whom we also had available NT-proBNP levels. Ours is the first study to examine the prognostic significance of thyroid dysfunction

Author Contribution

NAS: Conceptualization, Methodology, Formal analysis, data curation, writing – original draft, writing – review & editing, Visualization. JJC: Methodology, Writing – review & editing. OIB: Methodology, Writing – review & editing, Visualization. SK: Data curation. ASR: Methodology, Formal analysis, Writing – review & editing. JGCF: Writing – Review & Editing, Supervision. ALC: Conceptualization, Methodology, Validation, Formal analysis, Writing – Review & Editing, Supervision, Project

Acknowledgments

None.

References (25)

  • L Chaker et al.

    Subclinical hypothyroidism and the risk of stroke events and fatal stroke: an individual participant data analysis

    J Clin Endocrinol Metab

    (2015)
  • T-H Collet et al.

    Subclinical hyperthyroidism and the risk of coronary heart disease and mortality

    Arch Intern Med

    (2012)

    • Cited by (4)

    Conflicts of Interest: None.

    Funding: NAS was supported by a grant from The Academy of Medical Sciences and the Wellcome Trust.

    View full text
    © 2020 Elsevier Inc. All rights reserved.