The correlation between FT4/FT3 ratio and the degree of coronary artery calcification and stenosis in patients with normal thyroid function

Jiang Peng; Zhang Yidan; Yin Qiuguo; Qin Xintong; Guo Ping; Jiang Youxu; Jian Liguo

doi:10.3969/j.issn.1674-4055.2025.01.14

Abstract：Objective To investigate the correlation between the free thyroxine/free triiodothyronine(FT4/FT3)ratio and the degree of coronary artery calcification and stenosis in patients with normal thyroid function.Methods From November 2021 to November 2022,126 patients with coronary heart disease confirmed by coronary angiography(Coronary angiography,CAG)and intravascular ultrasound(Intravascular ultrasound,IVUS)were retrospectively selected from the cardiovascular Department of the Second Affiliated Hospital of Zhengzhou University.According to the calcification index(P33=0.0836,P66=0.3517),the two groups were divided into non-calcification and mild calcification group(calcification index<0.0836,n=50)and moderate-severe calcification group(calcification index>0.0836,n=76).The patients were divided into mild to moderate stenosis group(stenosis rate<76.7196,n=84)and severe stenosis group(stenosis rate>76.7196,n=42)according to the vascular stenosis rate(P33=72.4301,P66=76.7196).The baseline data,examination results,and imaging data of the two groups were compared,respectively.The risk factors for coronary artery calcification and stenosis were analyzed by stepwise logistic regression.The predictive value of FT4/FT3 alone and combined with other independent risk factors for coronary artery calcification and stenosis was analyzed by receiver operating characteristic curve(ROC curve).Results The ratio of FT4/FT3 in no-calcification to mild calcification group was lower than that in moderate-severe calcification group,and the ratio of FT4/FT3 in mild-moderate stenosis group was lower than that in severe stenosis group,the difference was statistically significant(P<0.05).Multivariate logistic regression analysis showed that FT4/FT3 was an independent risk factor for coronary artery calcification(OR=1.954,95％CI:1.095～3.488,P=0.023).FT4/FT3 was an independent risk factor for coronary artery stenosis(OR=3.944,95％CI:2.195～7.087,P<0.001).ROC curve analysis results:The area under ROC curve(AUC)of FT4/FT3 alone and combined with other independent risk factors for predicting moderate-severe coronary artery calcification were 0.710(95％CI:0.617～0.803)and 0.815(95％CI:0.742～0.888),respectively.The AUC for severe stenosis was 0.773(95％CI:0.690～0.857)and 0.829(95％CI:0.757～0.901),respectively.Conclusion FT4/FT3 is correlated with the degree of coronary artery calcification and stenosis in CHD patients with normal thyroid function,and is an independent risk factor for coronary artery calcification and stenosis in CHD patients with normal thyroid function.FT4/FT3 has certain predictive value for coronary artery calcification and stenosis,and the combined traditional independent risk factors have higher predictive value.