Thyroid Dysfunction in Patients Admitted in Cardiac Care Unit: Prevalence, Characteristic and Hospitalization Outcomes

Introduction: Cardiovascular disease is one of the main causes of hospital admission and mortality, and thyroid dysfunction increases the risk of developing acute or exacerbation of chronic cardiac conditions. The aim of this study is to investigate the prevalence of thyroid hormone abnormality among patients in the cardiac care unit (CCU) patients and its relation to admission diagnosis, clinical, biochemical data, and hospital-related outcomes.

Methods: We conducted a retrospective cohort observational that included adult patients who were admitted to the CCU. We excluded those with known thyroid dysfunction and those who received amiodarone or IV contrast.

Results: A total of 374 patients with a mean age of 62.7+14.7 years old were included. Ischemic changes were observed in 70.6% of the patients based on the admission diagnosis. In comparison to the non-ischemic group, the ischemic group was more likely to be male (P=0.010), to be active/former smokers (P=0.011), to have diabetes (P=0.009), to have diastolic dysfunction (P=<0.001), to have undergone thrombolysis (P=<0.001), and to have been referred to a tertiary center (P=<0.001). Euthyroidism was observed in 57.8% of the patients based on the thyroid function test at admission. Compared to patients with thyroid dysfunction, those with Euthyroidism were more likely to be active/former smokers (P=0.002), to have lower heart rates (P=0.018), to not have chronic kidney disease (P=0.016), to not have heart failure (P=0.006), to have lower thyroid-stimulating hormone (TSH) levels (P=<0.001), and to have lower tricuspid regurgitation (P=0.042).

Conclusion: Thyroid dysfunction is common among patients admitted to the CCU. Non-significant positive correlations between TSH and hospitalization length, tertiary center referral, 30-day readmission, and in-hospital mortality when adjusting for potential confounders.