Evaluation of the prevalence and prognosis of the association between subclinical hypothyroidism and heart failure in hospitalized elderly patients

Abstract

Subclinical hypothyroidism (SCH) presents as raised TSH with normal free T4. It may be associated with long-term cardiovascular complications, such as heart failure (HF), although this relationship remains uncertain. This study aims to better understand the association between SCH and HF, focusing on prevalence and prognosis in hospitalized elderly patients. This is a retrospective, cross-sectional observational study conducted with patients aged ≥ 60 years hospitalized with HF in a cardiology reference hospital. TSH levels and additional tests were assessed in 241 elderly patients who met the study's inclusion and exclusion criteria. The mean age of the participants was 70.59 years, with the majority being male and of mixed ethnicity. SCH was present in 15.8% of the participants, and in-hospital mortality occurred in 9.5%. Although the mean left ventricular ejection fraction (LVEF) was lower in the SCH group, the difference between the groups was not statistically significant. Notably, 18.4% of patients with SCH died during hospitalization, compared to 7.9% in the control group; however, this difference was also not statistically significant. Therefore, in elderly patients hospitalized for heart failure, the presence of HSC did not result in worse laboratory and imaging test outcomes, nor in more severe clinical outcomes.