Preprocedural Systemic Immune-Inflammation Index as a marker of risk for major adverse cardiac events and stroke after transcatheter aortic valve implantation

Abstract Background The Systemic Immune-Inflammation Index (SII), calculated as neutrophils × platelets / lymphocytes, reflects the interplay between systemic inflammation and immune status. Its prognostic relevance in patients undergoing transcatheter aortic valve implantation (TAVI) remains poorly understood. Aim To evaluate the prognostic significance of preprocedural SII in patients undergoing TAVI. Methods This retrospective cohort study included 1822 patients undergoing TAVI for severe aortic stenosis between 2014 and 2023 at two TAVI centers in Germany. Patients were divided into derivation and validation cohorts. Preprocedural SII was calculated from differential blood counts. In the derivation cohort, patients were stratified into tertiles based on preprocedural SII. Using receiver operating characteristics (ROC) analysis an optimized cut-off value for the validation cohort was identified to stratify patients into high- and low-risk groups. A generalized linear model (GLM) was used to identify clinical predictors of SII. Results In the derivation cohort, multivariate analysis showed that SII was independently associated with both major adverse cardiovascular events (MACE) (hazard ration HR: 1.0001 1.00001; 1.00002, p = 0.020) and stroke (HR: 1.0003 1.00002; 1.00004, p 1204) showed an increased risk for one-year all-cause mortality (HR: 2.19 1.59; 3.02, p < 0.001). Conclusion Higher preprocedural SII was independently associated with increase rates of MACE and stroke at one-year following TAVI. A SII cut-off of 1204 effectively stratifies patients into high- and low-risk groups and may provide additional value for preprocedural risk stratification. Graphical Abstract