Abstract
BACKGROUND: Although systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI) have garnered attention as novel inflammatory response markers in various clinical contexts, their application in patients with ST-segment elevation myocardial infarction (STEMI) following percutaneous coronary intervention (PCI) remains unclear. This study aims to fill this gap by investigating and validating the relationships between SII, SIRI, and the risks for all-cause mortality and major adverse cardiovascular events (MACEs) in this specific patient population. METHODS: 1222 participants diagnosed with STEMI and who underwent urgent PCI were included in the study. Cox proportional hazards regression analyses were employed to analyze the association between log(10) SII, SIRI, and the occurrence of all-cause mortality and MACEs. Receiver operating characteristic (ROC) curves were used to compare the predictive values of log(10) SII and SIRI for all-cause mortality and MACEs. Restricted cubic spline (RCS) curves were performed to explore the non-linear relationships between log(10) SII, SIRI and all-cause mortality, MACEs. Additionally, subgroup analyses were conducted to further investigate the distribution characteristics of log(10) SII and SIRI across different participant groups. RESULTS: After a 1-year follow-up, 106 experienced all-cause mortality, and 163 experienced MACEs. Higher levels of log(10) SII and SIRI were independent risk factors for all-cause mortality (log(10) SII: hazard ratio [HR] = 8.994, 95% confidence interval [CI] 1.265-63.948, p = 0.028; SIRI: HR = 3.671, 95% CI 1.004-13.425, p = 0.049) after adjusting for covariates. The area under the curve (AUC) for log(10) SII and SIRI combined with other variables was 0.781. Meanwhile, higher levels of log(10) SII and SIRI were also independent risk factors for MACEs (log(10) SII: HR = 6.465, 95% CI 1.356-30.821, p = 0.019; SIRI: HR = 4.739, 95% CI 1.778-12.632, p = 0.002) after adjusting for covariates. The AUC for log(10) SII and SIRI combined with other variables was 0.694. The restricted cubic spline (RCS) curves indicated non-linear relationships between SIRI not log(10) SII and all-cause mortality, MACEs. CONCLUSIONS: Log(10) SII and SIRI are positively associated with the occurrence of all-cause mortality and MACEs, with this correlation being more significant in the higher-level log(10) SII and SIRI groups.