The correlation between the systemic immune-inflammatory index and the risk of major adverse cardiovascular events after transcatheter aortic valve replacement: a retrospective cohort study.

AIMS: This study aimed to explore the association between the systemic immune-inflammatory index (SII) and major adverse cardiovascular events (MACE) after transcatheter aortic valve replacement (TAVR). METHODS: This retrospective cohort study included 138 patients who underwent TAVR surgery. SII was defined as an exposure variable, and MACE, including the occurrence of one or more of the following: all-cause death, cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke, was defined as an outcome variable. Univariate and multivariate Cox regression analyses, subgroup analyses, receiver operating characteristic curve (ROC) and restricted cubic spline plot (RCS) were used to explore the association between SII and MACE. RESULTS: During the median follow-up period of 12.5 months, 22 patients experienced MACE (15.94%). Compared with those without MACE, patients in the MACE group had higher levels of SII (P < 0.05). In multivariate Cox regression analysis, after adjusting for potential confounders, higher levels of SII were still statistically associated with a higher hazard of MACE. Each 1-standard deviation increase in SII was associated with a 29.7% higher hazard of MACE (hazard ratio [HR] = 1.297, 95% confidence interval [CI]: 1.054-1.597, P = 0.014). The subgroup analyses based on the Model 3 indicated that SII remained associated with MACE in most subgroups (P < 0.05). The ROC curve analysis indicated that SII showed a modest discriminatory ability for MACE (AUC = 0.697, 95% CI: 0.578-0.815, P = 0.004). The RCS analysis indicated a positive linear association between SII and MACE (P-nonlinear > 0.05). CONCLUSION: In patients undergoing TAVR, a higher level of SII was associated with a higher risk of MACE. However, these findings still require further validation in larger, multicenter prospective clinical trials.