Systemic Inflammatory Biomarkers and Chest CT Findings as Predictors of Acute Limb Ischemia Risk, Intensive Care Unit Admission, and Mortality in COVID-19 Patients

Abstract

Background: Numerous tools, including inflammatory biomarkers and lung injury severity scores, have been evaluated as predictors of thromboembolic events and the requirement for intensive therapy in COVID-19 patients. This study aims to verify the predictive role of inflammatory biomarkers [monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), systemic inflammatory index (SII), Systemic Inflammation Response Index (SIRI), and Aggregate Index of Systemic Inflammation (AISI)] and the CT Severity Score in acute limb ischemia (ALI) risk, intensive unit care (ICU) admission, and mortality in COVID-19 patients.; Methods: The present study was designed as an observational, analytical, retrospective cohort study and included all patients older than 18 years of age with a diagnosis of COVID-19 infection, confirmed through real time-polymerase chain reaction (RT-PCR), and admitted to the County Emergency Clinical Hospital of Targu-Mureș, Romania, and Modular Intensive Care Unit of UMFST “George Emil Palade” of Targu Mures, Romania between January 2020 and December 2021. Results: Non-Survivors and “ALI” patients were associated with higher incidence of cardiovascular disease [atrial fibrillation (AF) p = 0.0006 and p = 0.0001; peripheral arterial disease (PAD) p = 0.006 and p < 0.0001], and higher pulmonary parenchyma involvement (p < 0.0001). Multivariate analysis showed a high baseline value for MLR, NLR, PLR, SII, SIRI, AISI, and the CT Severity Score independent predictor of adverse outcomes for all recruited patients (all p < 0.0001). Moreover, the presence of AF and PAD was an independent predictor of ALI risk and mortality. Conclusions: According to our findings, higher MLR, NLR, PLR, SII, SIRI, AISI, and CT Severity Score values at admission strongly predict ALI risk, ICU admission, and mortality. Moreover, patients with AF and PAD had highly predicted ALI risk and mortality but no ICU admission.

Keywords: AISI; COVID-19; MLR; NLR; PLR; SII; SIRI; acute limb ischemia.

Figure 1

ROC curve analysis concerning the ALI risk (A) MLR (AUC: 0.829; p < 0.0001), (B) NLR (AUC: 0.856; p < 0.0001), (C) SII (AUC: 0.858; p < 0.0001), (D) SIRI (AUC: 0.785; p < 0.0001), (E) AISI (AUC: 0.765; p < 0.0001), and (F) TSS (AUC: 0.759; p < 0.0001).

Figure 2

ROC curve analysis concerning ICU admission (A) MLR (AUC: 0.829; p < 0.0001), (B) NLR (AUC: 0.856; p < 0.0001), (C) SII (AUC: 0.858; p < 0.0001), (D) SIRI (AUC: 0.785; p < 0.0001), (E) AISI (AUC: 0.765; p < 0.0001), and (F) TSS (AUC: 0.759; p < 0.0001).

Figure 3

ROC curve analysis concerning the mortality (A) MLR (AUC: 0.829; p < 0.0001), (B) NLR (AUC: 0.856; p < 0.0001), (C) SII (AUC: 0.858; p < 0.0001), (D) SIRI (AUC: 0.785; p < 0.0001), (E) AISI (AUC: 0.765; p < 0.0001), and (F) TSS (AUC: 0.759; p < 0.0001).

Figure 4

ROC curve analysis for the CT Severity Score (A) concerning the ALI risk (AUC: 0.725; p < 0.0001), (B) concerning the ICU admission (AUC: 0.733; p < 0.0001), and (C) concerning the mortality rate (AUC: 0.816; p < 0.0001).