Objective To investigate the correlation of serum levels of basic fibroblast growth factor(bFGF)and soluble triggering receptor expressed on myeloid cells 1(sTLT-1)in patients with coronary heart disease with in-stent restenosis(ISR)after stent implantation.Methods From January 2020 to March 2022,450 patients with coronary heart disease who underwent stent implantation in our hospital were enrolled.They were divided into ISR group(41 cases)and non-ISR group(409 cases)based on the occurrence of ISR after 1-year follow-up.The general information,laboratory indicators,and serum bFGF and sTLT-1 levels were compared between the two groups.Pearson correlation was applied to analyze the correlation of serum bFGF and sTLT-1 levels with ISR in patients with coronary heart disease after stent implantation.Logistic regression was applied to analyze the influencing factors of ISR in patients with coronary heart disease after stent implantation.The receiver operating characteristic(ROC)curves were plotted to analyze the clinical value of serum bFGF and sTLT-1 levels in diagnosing ISR after stent implantation in patients with coronary heart disease.Results The degree of stenosis,number of implanted stents,preoperative Gensini score,and serum sTLT-1 and C-reactive protein(CRP)levels in the ISR group were significantly higher in ISR group than those of the non-ISR group,while the stent diameter,and serum bFGF and cystatin C(cysC)levels were significantly lower(P<0.05).Serum bFGF levels in gradeⅢpatients were significantly higher than those with grade Ⅳ(P<0.05),and serum sTLT-1 levels in grade Ⅲ patients were significantly lower(P<0.05).There was a negative correlation between serum bFGF and sTLT-1 levels in patients with ISR after stent implantation for coronary heart disease(r=-0.648,P<0.001).STLT-1 and CRP were risk factors for ISR in patients with coronary heart disease after stent implantation,while bFGF and CysC were protective factors(P<0.05).The area under the curve(AUC)of a combination measurement of serum bFGF and sTLT-1 levels in the diagnosis of ISR after stent implantation in coronary heart disease patients was 0.901,which was superior to a single measurement(Z combination-bFGF=3.086 and Z combination-sTLT-1=2.754;P=0.002 and P=0.030,respectively).The sensitivity and specificity of the combined diagnosis was 89.80%and 76.12%,respectively.Conclusion Coronary heart disease patients with ISR after stent implantation have decreased serum bFGF levels and increased serum sTLT-1 levels,both of which are influencing factors for ISR.A combination measurement of serum bFGF and sTLT-1 levels has a high efficacy on diagnosing ISR in coronary heart disease patients after stent implantation.