Abstract
BACKGROUND: Acute coronary syndrome (ACS) is closely associated with inflammation status. The systemic inflammation score (SIS), which is calculated using the serum albumin level and lymphocyte-to-monocyte ratio (LMR), has emerged as a valuable biomarker for predicting the clinical outcomes of several diseases. Nonetheless, the value of SIS in predicting the long-term prognostic risk in patients with ACS undergoing percutaneous coronary intervention (PCI) remains unknown. We aimed to explore the associations of SIS with major adverse cardiovascular events (MACEs), all-cause mortality, and cardiovascular death. METHODS: This prospective cohort study consecutively enrolled 1582 patients with ACS who underwent PCI at the Department of Cardiology in the Affiliated Hospital of Chengde Medical University (Chengde, China) between January 2016 and December 2018. The primary endpoint was MACEs, including all-cause mortality, rehospitalization for heart failure, revascularization, recurrence of acute myocardial infarction, and restenosis/intrastent thrombosis. RESULTS: The Kaplan-Meier survival analysis revealed that a high SIS was correlated with MACEs and all-cause mortality and that increasing SIS was independently associated with the risks of MACEs and all-cause mortality by Cox regression. Landmark analysis provided evidence for the time window of predictive ability, which could guide clinical applications. A clear correlation between the increasing tendency of hazard ratio in patients with ACS undergoing PCI and the risks of MACEs or all-cause mortality was noted (p for trend <0.05). The sensitivity analysis with a competing risk model showed that high SIS level was correlated with the risks of cardiac death and rehospitalization. The mediation analysis revealed that the hemoglobin level exerted a mediating effect on the relationship between SIS and MACEs. CONCLUSION: The SIS exhibited a strong correlation with the risks of MACEs and all-cause mortality. Notably, the SIS was particularly effective in predicting the risk of cardiac death and likelihood of rehospitalization.