Association Between Systemic ImmuneInflammation Index and Long-Term Mortality in Patients with Critical Limb-Threatening Ischemia Undergoing Endovascular Therapy Below the Knee

Abstract

Introduction: Endovascular interventions have been increasingly used for the treatment of patients suffering from below-the-knee (BTK) ischemic lesions. Yet, there is a paucity of data regarding long-term adverse events in patients with critical limb ischemia (CLI) undergoing endovascular revascularization for BTK lesions. Recently introduced systemic immune-inflammation index (SII) is a reliable indicator of poor outcomes in various cardiovascular conditions. Herein, we aimed to investigate the prognostic role of the SII on mortality in patients with CLI undergoing endovascular revascularization for BTK lesions. Patients and Methods: The records of 112 patients with symptomatic CLI undergoing endovascular revascularization for BTK lesions between January 2015 and December 2019 were analyzed. Patients were divided into groups with low and high SII values based on an SII cut-off value derived from a ROC analysis. For each group, procedural details and follow-up outcomes were analyzed. Results: The mean follow-up time was 40.3 ± 19.9 months. According to our data, patients with high SII values had higher rates of mortality compared to patients with low SII values (65.2% vs 30.3%, p< 0.001). To determine the SII cut-off value for predicting mortality, the ROC curve was drawn, and the best cut-off value was determined as 966 by using the Youden index, (AUC= 0.658, 95% CI= 0.556-0.760, p= 0.004). Cox multivariate regression analysis also identified the SII score as an independent predictor of mortality. Conclusion: SII is an independent predictor of mortality, especially among patients with CLI who underwent endovascular revascularization for BTK lesions.