Prognostic implications of thyroid hormone alterations in acute coronary syndrome-A systematic review

Free triiodothyronine to free thyroxine ratio as a marker of poor prognosis in euthyroid patients with acute coronary syndrome and diabetes after percutaneous coronary intervention

Objectives

In recent years, the free triiodothyronine/free thyroxine (FT3/FT4) ratio, a new comprehensive index for evaluating thyroid function, which could reflect thyroid function more stably and truly than serum thyroid hormone level, has been demonstrated to correlate with the risks of diabetes and cardiovascular disease in euthyroid adults. However, the correlation between thyroid hormone sensitivity and long-term prognosis in euthyroid patients with acute coronary syndrome (ACS) and diabetes after percutaneous coronary intervention (PCI) remains unclear.

Methods

A total of 1,786 euthyroid patients with ACS who successfully underwent PCI at Beijing Anzhen Hospital from August 2021 to April 2022 were included in our study, which was divided into three groups according to tertiles of thyroid hormone sensitivity index. Cox regression, Kaplan-Meier, and receiver operating characteristic analyses were applied to analyze the associations between the FT3/FT4 ratio with ACS and diabetes after PCI.

Results

Our analysis indicated that a lower level of FT3/FT4 ratio in euthyroid patients with acute coronary syndrome (ACS) and diabetes after PCI showed significantly higher incidences of major adverse cardiac and cerebrovascular events (MACCE) when compared with a higher level of FT3/FT4 ratio. After adjusting for other covariates, patients with a lower level of FT3/FT4 ratio were negatively associated with the risk of MACCE than those with a higher level of FT3/FT4 ratio (adjusted OR =1.61, 95% CI 1.05-2.47, P = 0.028). In subgroup analyses, individuals were stratified by age, sex, BMI, ACS type, hypertension, and dyslipidemia, showing that there were no significant interactions between the FT3/FT4 ratio and all subgroups for MACCE. In addition, the FT3/FT4 ratio performed better on ROC analyses for cardiac death prediction [area under the curve (AUC), 0.738].

Conclusion

A reduced level of FT3/FT4 ratio was a potential marker of poor prognosis in euthyroid patients with ACS and diabetes after PCI.

A Cross-Sectional Study of Acute Coronary Syndrome and Thyroid Profile: Dissecting the Relationship to Improve Patient Care

INTRODUCTION

Thyroid-releasing hormones are pivotal in regulating cardiovascular (CVS) function and maintaining its hemodynamics and homeostasis. Even a minor alteration in thyroid function has an enormous implication on CVS morbidity and mortality. Moreover, hypothyroidism was found to be a potential menace for coronary artery disease (CAD). The objective of this study was to determine the role of thyroid-releasing hormones in patients suffering from acute coronary syndrome (ACS).

METHODOLOGY

Among a cohort of 100 patients suffering with ACS, a complete history and clinical information followed by physical examination and electrocardiography were recorded. Blood samples were also collected to record the blood sugar levels i.e., fasting blood sugar (FBS), postprandial blood sugar (PPBS), and thyroid profile, including free thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and reverse triiodothyronine (rT3). The data was analyzed using SPSS version 26 software (IBM Corp., Armonk, NY, USA).

RESULT

The study identified alterations in the thyroid hormone levels in 27% of patients suffering from ACS. The prevalence of euthyroid sick syndrome was found to be 59.3%, while subclinical hypothyroidism and subclinical hyperthyroidism were reported among 18.5% and 14.8% of patients respectively. There was no significant difference found between males and females. The study illustrated a greater occurrence of aberrant thyroid hormone profiles among those aged 40-60 years. The ST-elevated myocardial infarction (STEMI) group had a statistically significant higher prevalence of an aberrant thyroid hormone profile compared to the non-ST-elevated myocardial infarction (NSTEMI) and unstable angina (UA) groups (p=0.02). A total of nine patients died with ACS and all of those had statistically significant low fT3 and TSH values while higher rT3 values (p<0.05).

CONCLUSION

An atypical thyroid status has been found to elevate the likelihood of developing CAD and experiencing CVS mortality. This condition can impact ventricular function and serum cholesterol levels as well as heart rate and rhythm. Therefore, understanding this relationship could potentially lead to improved treatment strategies for individuals with ACS which will further prevent major CVS complications.

THE RELATIONSHIP BETWEEN TSH LEVELS, THYROID AUTOANTIBODIES AND ATHEROGENIC INDEX OF PLASMA, AST TO PLATELET RATIO INDEX SCORE, AND FIBROSIS 4 INDEX IN PATIENTS WITH HYPOTHYROIDISM

Context

Thyroid hormones have metabolic effects such as relationship between hypothyroidism and atherosclerosis.

Objective

Evaluate the effects of hypothyroidism on Non-Alcoholic Fatty Liver Disease and atherosclerosis by using AIP, APRI score, FIB-4 indices.

Material and Methods

1370 patients with hypothyroidism who applied to the Endocrinology and Metabolism outpatient clinic between 01.01.2017-30.12.2021 were included the study. Pregnants, patients with a history of thyroid carcinoma, cardiovascular and liver diseases were excluded. TSH, fT4, Anti TPO, Anti TG, thrombocyte, ALT, AST, HDL, Triglyceride values of the cases were analyzed and atherogenic index of plasma (AIP), AST to Platelet Ratio Index (APRI) and Fibrosis-4 (FIB-4) indices were calculated.

Results

1170 (85.4%) of the cases were female.The age of those who had high risk of AIP was found to be higher than those with low and moderate risk (p=0.001; p=0.003; p<0.01). The ages of those who had low-risk FIB-4 Index were found to be lower than those with moderate risk and high risk (p=0.001; p=0.001; p<0.01). A positive relationship was detected between APRI and FIB-4 (r=0.681; p=0.001; p<0.01).AIP increased as TSH increased in hypothyroid patients. No significant correlations were detected between TSH, APRI, and the FIB-4 Index. No significant differences were detected between AIP, APRI, FIB-4, and thyroid autoantibodies.

Conclusion

In hypothyroid patients, the AIP index increased with age and the increase in TSH. A strong relationship was detected between AIP and TSH . For this reason, we think that keeping TSH within the normal range with regular follow-ups and treatment in patients with hypothyroidism will reduce the risk of atherosclerosis.