Objective To investigate the relationship of serum levels of 5-methoxytryptophan(5-MTP)and histone deacetylase 3(HDAC3)with myocardial fibrosis in elderly patients with acute myocardial infarction(AMI).Methods A prospective study was conducted on 261 elderly AMI patients(observation group)admitted in our hospital from January 2021 to March 2024.Ano-ther 60 matched individuals who took physical examination in our hospital during same period served as control group.The AMI patients were further divided into myocardial fibrosis subgroup(104 cases)and non-myocardial fibrosis subgroup(157 cases)according to cardiac magnetic reso-nance imaging.The baseline data were collected for all participants,and late gadolinium enhance-ment(LGE)was used to evaluate myocardial fibrosis.The correlation of serum 5-MTP and HDAC3 levels and LGE score was analyzed.Univariate and multivariate logistic regression analy-ses were employed to identify the factors affecting myocardial fibrosis in elderly AMI patients.ROC curve was applied to evaluate the diagnostic performance of serum 5-MTP and HDAC3 lev-els for myocardial fibrosis.Results The observation group had significantly lower serum 5-MTP level and higher HDAC3 level than the control group(P＜0.01).Pearson correlation analysis showed that serum 5-MTP(r=-0.891,P=0.000)was negatively,and HDAC3 was positively correlated with LGE score(r=0.732,P=0.000).The serum 5-MTP level was significantly lower,and the HDAC3 level was obviously higher in the myocardial fibrosis subgroup than the non-myo-cardial fibrosis group(P＜0.01).Logistic regression analysis indicated that 5-MTP(OR=0.522,95％CI:0.361-0.754,P=0.001)and HDAC3(OR=2.024,95％CI:1.354-3.025,P=0.001)were predictors for myocardial fibrosis in elderly AMI patients.ROC curve analysis revealed that when the cutoff value of 5-MTP was 14.45 ng/L,the sensitivity and specificity were 83.65％and 78.98％,respectively,and the AUC value was 0.755(95％CI:0.618-0.892);when the cutoff value of HDAC3 was 150.40 μg/L,the sensitivity and specificity were 77.88％and 75.16％,respectively,and the AUC value was 0.809(95％CI:0.685-0.932);further regression analysis showed that the sensitivity and specificity were 95.17％and 96.82％,respectively,and the AUC value was 0.994(95％CI:0.977-1.000).Conclusion Serum 5-MTP and HDAC3 are abnormally expressed in elderly AMI patients,and they can be used to evaluate the occurrence and develop-ment of myocardial fibrosis.

Objective To investigate the relationship of serum levels of 5-methoxytryptophan(5-MTP)and histone deacetylase 3(HDAC3)with myocardial fibrosis in elderly patients with acute myocardial infarction(AMI).Methods A prospective study was conducted on 261 elderly AMI patients(observation group)admitted in our hospital from January 2021 to March 2024.Ano-ther 60 matched individuals who took physical examination in our hospital during same period served as control group.The AMI patients were further divided into myocardial fibrosis subgroup(104 cases)and non-myocardial fibrosis subgroup(157 cases)according to cardiac magnetic reso-nance imaging.The baseline data were collected for all participants,and late gadolinium enhance-ment(LGE)was used to evaluate myocardial fibrosis.The correlation of serum 5-MTP and HDAC3 levels and LGE score was analyzed.Univariate and multivariate logistic regression analy-ses were employed to identify the factors affecting myocardial fibrosis in elderly AMI patients.ROC curve was applied to evaluate the diagnostic performance of serum 5-MTP and HDAC3 lev-els for myocardial fibrosis.Results The observation group had significantly lower serum 5-MTP level and higher HDAC3 level than the control group(P＜0.01).Pearson correlation analysis showed that serum 5-MTP(r=-0.891,P=0.000)was negatively,and HDAC3 was positively correlated with LGE score(r=0.732,P=0.000).The serum 5-MTP level was significantly lower,and the HDAC3 level was obviously higher in the myocardial fibrosis subgroup than the non-myo-cardial fibrosis group(P＜0.01).Logistic regression analysis indicated that 5-MTP(OR=0.522,95％CI:0.361-0.754,P=0.001)and HDAC3(OR=2.024,95％CI:1.354-3.025,P=0.001)were predictors for myocardial fibrosis in elderly AMI patients.ROC curve analysis revealed that when the cutoff value of 5-MTP was 14.45 ng/L,the sensitivity and specificity were 83.65％and 78.98％,respectively,and the AUC value was 0.755(95％CI:0.618-0.892);when the cutoff value of HDAC3 was 150.40 μg/L,the sensitivity and specificity were 77.88％and 75.16％,respectively,and the AUC value was 0.809(95％CI:0.685-0.932);further regression analysis showed that the sensitivity and specificity were 95.17％and 96.82％,respectively,and the AUC value was 0.994(95％CI:0.977-1.000).Conclusion Serum 5-MTP and HDAC3 are abnormally expressed in elderly AMI patients,and they can be used to evaluate the occurrence and develop-ment of myocardial fibrosis.