Association Of Free Thyroxine/Free Triiodothyronine With Postoperative In-stent Restenosis In Patients With Acute Coronary Syndrome

ObjectiveTo investigate the correlation between free thyroxine/free triiodothyronine(FT4/FT3)and in-stent restenosis(ISR)in patients with acute coronary syndrome(ACS)who received percutaneous coronary intervention(PCI).To investigate whether there are differences in the relationship between FT4/FT3 and ISR at different levels of low density lipoprotein cholesterol(LDL-C).To provide some clinical reference for improving the prognosis of patients with ACS.MethodsThis study retrospectively selected 255 patients with ACS who received PCI at the Chest Pain Center of the First Hospital of Jiaxing from January 1,2018 to July 1,2021 and had a coronary angiogram at 6-1 8 months after the procedure.Patients were divided into ISR group(n=48)and non-ISR group(n=207)according to whether the stenosis was greater than 50%at the stent or within 5mm of the stent edge when they received the second coronary angiography.Part Ⅰ:Univariate analysis was performed to assess baseline characteristics and preliminarily screen influence factors.Multicollinearity was assessed by linear regression and the co-linear variables were removed by stepwise regression method.Multifactor logistic regression analysis was performed to establish different models to assess the relationship between FT4/FT3 and postoperative ISR;Area Under Curve(AUC)was performed to evaluate the predictive value of FT4/FT3 and the optimal cut-off value of FT4/FT3 was calculated;The trend analysis of the predictive effect of FT4/FT3 was conducted using logistic regression based on different models;The quantitative-effect relationship between FT4/FT3 and ISR was evaluated using generalized additive model(GAM)and smoothed curve fitting based on model 3 fully adjusted for variables;The consistency of the predictive value of FT4/FT3 and the interaction were assessed based on different subgroups.Part Ⅱ:The population in this study was divided into LDL-C≥2.98mmol/L and LDL-C<2.98mmol/L group according to LDL-C levels.Based on the optimal cut-off value of FT4/FT3,the enrolled patients were divided into FT4/FT3≥3.355 and FT4/FT3<3.355 group.Spearman correlation analysis was conducted to assess the correlation between different lipid components and FT4/FT3;Multifactorial logistic regression was performed to establish different models to assess the correlation between FT4/FT3 and ISR at different LDL-C levels,and the interaction between FT4/FT3 and ISR at different LDL-C levels was examined;The quantitative-effect relationship was explored by generalized additive model and smoothed curve fitting based on model 3 fully adjusted for variables.ResultsPart Ⅰ:Of the 255 patients,the mean age was 61.8 years and the male accounted for 85.5%.ISR occurred in 48 patients,with an overall incidence of 18.8%.The multifactorial logistic regression model fully adjusted for variables showed FT4/FT3(OR=8.482,95%CI:3.747 to 19.198,P<0.001)was an independent risk factor for postoperative ISR;The area under the curve of FT4/FT3 was 0.743(95%CI:0.667 to 0.819,P<0.001),and when the cut-off value was taken as 3.355,the sensitivity of the diagnosis was 7 9.2%and the specificity was 61.8%;Trend analysis showed that compared with FT4/FT3<2.86,the ORs of ISR were 1.274(P=0.723),2.926(P=0.072)and 13.960(P<0.001)respectively with each increase in levels of FT4/FT3 in model 3 fully adjusted for variables,which indicating a significant trend of correlation(P for trend<0.001);The smoothed curve based on the generalized additive model showed an approximately linear correlation between FT4/FT3 and ISR while the value of likelihood ratio test was 0.110 with no significant threshold or saturation effect;The predictive value of FT4/FT3 was consistent across subgroups and no significant interaction items were found(P for interaction>0.05).Part Ⅱ:Spearman correlation analysis showed no significant correlation between FT4/FT3 and different lipid components;In model 3 fully adjusted for variables,for each additional unit of FT4/FT3 in the group of LDL-C<2.98mmol/L,the risk of postoperative ISR increased by 3.291 times(OR=4.291,95%CI:1.139 to 16.175,P=0.031)and for each additional unit of FT4/FT3 in the group of LDL-C≥2.98mmol/L,the risk of postoperative ISR increased more significantly(OR=21.919,95%CI:5.755 to 83.478,P<0.001);In the group of LDL-C<2.98 mmol/L,the risk of postoperative ISR increased by 4.3 13 times in the group of FT4/FT3≥3.355 compared to FT4/FT3<3.355(OR=5.313,95%CI:1.247 to 22.627,P=0.024)after FT4/FT3 was converted to a dichotomous variable;In the group of LDL-C≥2.98 mmol/L,the risk of postoperative ISR was similarly increased in the FT4/FT3≥3.355 group(OR=13.928,95%CI:4.032 to 48.110,P<0.001)and there was no significant interaction between LDL-C and FT4/FT3(P for interaction=0.082);Smoothed curve fitting showed a positive association between FT4/FT3 and postoperative ISR at different LDL-C levels.ConclusionPart Ⅰ:The levels of FT4/FT3 are approximately linearly correlated with the risk of postoperative ISR with good predictive value,and shows good agreement across subgroups with nonsignificant interaction.This indicator facilitates the assessment and prevention of patients at high risk of ISR in contemporary PCI practice.Part Ⅱ:The correlation between FT4/FT3 and postoperative ISR is independent of baseline LDL-C levels.The role of FT4/FT3 in the preventive management of ISR should be emphasized regardless of LDL-C levels.