Systemic Inflammatory Response Index Is a More Promising Prognostic Index Than Systemic Immune Inflammation Index in Critically Ill Heart Failure Patients: A Retrospective Cohort Analysis of the MIMIC-IV Database.

Aim: The incidence of heart failure (HF) remains high throughout the world, posing a serious threat to human health, with inflammation being a pivotal factor in the entire pathophysiologic process. Systemic inflammatory response index (SIRI) and systemic immune inflammation index (SII) are novel indicators for poor prognosis of HF. This paper aimed to ascertain the connection between SIRI and mortality in critically ill HF patients and to compare the prognostic value with SII.

Methods: All data on HF patients were sourced from MIMIC-IV. Cox proportional hazards analysis, restricted cubic spline, and Kaplan-Meier survival analysis were utilized to determine the link between SIRI or SII and in-hospital mortality. Receiver operating characteristic curve, area under the curve (AUC), and Youden index were employed to compare the prognostic value of SIRI and SII. Subgroup analysis was conducted to confirm the predictive capability of SIRI on mortality. Propensity score matching was utilized to reveal the connection between SIRI and secondary outcomes.

Results: 754 patients were included and 45 patients (6.0%) died. There was a positive link between SIRI and in-hospital mortality in both unadjusted (p < 0.001) and adjusted models (p < 0.001 and p = 0.001, respectively), outperforming SII in all models (p > 0.05 in all models). SIRI had a higher AUC and Youden index than SII, indicating better prognostic power. In addition, hospital stay was shorter in the low SIRI group (p = 0.034).

Conclusion: SIRI predicts in-hospital mortality in critically ill HF patients, and the prognostic power is superior to SII.