Objective To investigate the expression of TXNIP and NLRP3 in atherosclerotic plaque of coronary artery and their relationship with secondary lesion of plaque and sudden death of coronary heart dis-ease.Methods A total of 105 cases of cardiac coronary samples extracted from autopsy anatomy and related data in the Forensic Judicial Appraisal Center of Guizhou Medical University from January 2019 to March 2022 were analyzed retrospectively.They were divided into the non-lesion group (n=20) and plaque group (n=85) according to whether or not having harden plaque in coronary artery.Then the plaque group was divided into the non-coronary heart disease sudden death group (n=25),coronary heart disease sudden death without sec-ondary lesion group (n=30) and coronary heart disease sudden death complicating secondary lesion group (n=30).The hematoxylin-eosin (HE) dyed section was prepared.The IPP6.0 image analysis software was used to measure the thickness of coronary intima and lesion,the thickness of fibrous cap,the thickness of nec-rotic lesion and the degree of lumen stenosis.Immunohistochemical method,Western blot and real-time fluo-rescent quantitative reverse transcription-PCR (qRT-PCR) were used to detect the distribution characteristics and expression levels of TXNIP and NLRP3 in coronary arteries.Results Compared with the non-lesion group,the thickness of the intima,lesion,fibrous cap and necrosis lesion in the other three groups was thicker,the stenosis degree of lumen was higher,and the differences were statistically significant (P<0.05).Com-pared with the coronary heart sudden death without secondary lesion group,the thickness of the intima,lesion and necrose lesion in the coronary heart disease sudden death complicating secondary lesion group was thic-ker,the necrosis degree of lumen was higher,and the differences were statistically significant (P<0.05).The TXNIP and NLRP3 proteins expressions were not seen in the coronary arterial wall of the no-lesion group.The strong positive expression rates of TXNIP and NLRP3 in the non-coronary sudden death group were 40.0% and 36.0%,the weak positive expression rates were 32.0% and 36.0%,and the weaker positive ex-pression rates were 28.0% and 28.0%.The strong positive expression rates in the coronary heart disease sud-den death without secondary lesion group were 50.0% and 43.3%,the stronger positive expression rates were 33.3% and 36.7%,and the weak positive expression rates were 16.7% and 20.0%;the strong positive ex-pression rates in the coronary heart disease sudden death complicating secondary lesion group were 73.3% and 76.7%,the stronger positive expression rates were 26.7% and 23.3%.The coronary artery TXNIP and NLRP protein and mRNA levels in the coronary heart disease sudden death complicating secondary lesion group were higher than those in the other three groups with statistical difference (P<0.05).TXNIP in coro-nary arterial plaque was positively correlated with the absorbance value of NLRP3 expression absorbance val-ue,protein and mRNA expression level (P<0.05).The TXNIP and NLRP3 expression levels were positively correlated with the intima and lesion thickness,and negatively correlated with the fibrous cap thickness (P<0.05).The necrosis lesion area of coronary artery was positively correlated with the TXNIP and NLRP3 (P<0.05).Conclu-sion TXNIP and NLRP3 could serve as the diagnostic indicators of coronary heart disease sudden death.