摘要Background The association of systemic inflammatory response index(SIRI)with prognosis of coronary artery disease(CAD)patients has never been investigated in a large sample with long-term follow-up.This study aimed to explore the association of SIRI with all-cause and cause-specific mortality in a nationally representative sample of CAD patients from United States.Methods A total of 3386 participants with CAD from the National Health and Nutrition Examination Survey(NHANES)1999-2018 were included in this study.Cox proportional hazards model,restricted cubic spline(RCS),and receiver operating characteristic curve(ROC)were performed to investigate the association of SIRI with all-cause and cause-specific mortality.Piece-wise linear regression and sensitivity analyses were also performed.Results During a median follow-up of 7.7 years,1454 all-cause mortality occurred.After adjusting for confounding factors,higher lnSIRI was significantly associated with higher risk of all-cause(HR=1.16,95％CI:1.09-1.23)and CVD mortality(HR=1.17,95％CI:1.05-1.30)but not cancer mortality(HR=1.17,95％CI:0.99-1.38).The associations of SIRI with all-cause and CVD mortality were detected as J-shaped with threshold values of 1.05935 and 1.122946 for SIRI,respectively.ROC curves showed that lnSIRI had robust predictive effect both in short and long terms.Conclusions SIRI was independently associated with all-cause and CVD mortality,and the dose-response relationship was J-shaped.SIRI might serve as a valid predictor for all-cause and CVD mortality both in the short and long terms.