EXPRESS: Association of Systemic Immune-inflammation Index and Systemic Inflammation Response Index with All-cause Mortality in the Critically Ill Population with Coronary Heart Disease and Heart Failure - A Study Based on the MIMIC-IV Database.

Abstract

Background: This study aimed to investigate the associations of the systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) with all-cause mortality (ACM) in critically ill patients with coronary heart disease (CHD) and heart failure (HF).

Methods: Data from critically ill patients with CHD and HF were extracted from the MIMIC-IV database. Cox proportional hazards models were used to examine the associations of SII and SIRI with ACM. Restricted cubic spline (RCS) models were applied to assess potential nonlinear relationships between SII, SIRI, and ACM. The area under the receiver operating characteristic (ROC) curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were calculated to evaluate the incremental predictive value of adding SII and SIRI to the Sequential Organ Failure Assessment (SOFA) score.

Results: A total of 1,865 participants were included. Cox proportional hazards models showed that patients in the third quartile (Q3) and fourth quartile (Q4) of SII had significantly higher risks of 30-day ACM. RCS analyses demonstrated nonlinear associations between SII, SIRI, and ACM. The ROC analysis showed that the AUCs of SII and SIRI were 0.651 and 0.685, respectively, indicating moderate discriminatory ability for adverse outcomes. In addition, incorporating SII and SIRI into the SOFA score improved the predictive accuracy of the model.

Conclusions: SII and SIRI were associated with adverse prognosis in critically ill patients with CHD complicated by HF and may have potential prognostic value.