Elevated Neutrophil to Lymphocyte Ratio is Associated with Worse Outcomes after Carotid Endarterectomy in Asymptomatic Patients

Association between platelet lymphocyte ratio and neutrophil lymphocyte ratio and clinical outcomes following carotid endarterectomy

Background

Approximately 30% of stroke cases result from carotid disease. Although several risk factors for complications after carotid endarterectomy have been identified, the existence of a biomarker that can estimate postoperative risk in these patients has not yet been proven.

Objectives

This study aimed to investigate correlations between the platelet-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) and postoperative clinical outcomes in patients undergoing carotid endarterectomy.

Methods

A retrospective study was conducted, including 374 patients who underwent carotid endarterectomy between 2002 and 2019 due to moderate to high extracranial internal carotid artery stenosis. Their platelet-lymphocyte ratio and neutrophil-lymphocyte ratios were obtained from the same blood samples.

Results

There was a statistically significant correlation between the PLR and the occurrence of restenosis (p < 0.01) and acute myocardial infarction (AMI) after endarterectomy (p = 0.03). Additionally, there was a statistically significant correlation between the PLR and the combined outcomes stroke and/or AMI and/or death (p = 0.03) and stroke and/or AMI and/or death and/or restenosis (p < 0.01). However, there were no significant correlations between NLR and these outcomes (p = 0.05, p = 0.16).

Conclusions

The platelet-lymphocyte ratio proved to be a useful test for predicting occurrence of strokes, acute myocardial infarctions, and deaths during the postoperative period after carotid endarterectomy. It was also associated with the risk of postoperative restenosis.

Vascular surgery patients with elevated neutrophil-to-lymphocyte ratios have downregulated neutrophil complement RNA expression

Elevated neutrophil-to-lymphocyte ratio (NLR) in patients who undergo elective vascular surgery (EVS) have increased mortality independent of perioperative surgical outcome. To understand why high NLR is associated with higher mortality, we investigated neutrophil and lymphocyte transcriptome expression in patients undergoing EVS. Blood samples were collected from patients undergoing EVS and healthy donors for NLR calculation. RNA samples were isolated from patients' neutrophils and lymphocytes and divided into NLR_Low (<3) and NLR_High (≥3) groups (n = 6 each). Paired samples with the highest RNA integrity number (mean = 9.8 ± 0.4) were sequenced and analyzed for differential expression. Normalized data were inputted for downstream analysis using iPathwayGuide (AdvaitaBio) and gene set enrichment analysis using GenePattern and MSigDB (Broad Institute). There was no clinical difference between the patient groups with regard to clinical diagnosis, age, sex, history of hypertension, lipid abnormalities, diabetes mellitus, smoking, or statin use. The mean NLR was 4.37 ± 0.27 SEM in the NLR_High and 1.88 ± 0.16 for the NLR_Low groups. Significantly differentially expressed gene sets identified in the RNA sequence data were enriched highly (P = 1E-24) in the humoral immunity and complement systems. Neutrophils from NLR_High patients downregulated complement genes (C1QA, C1QB, C1QC, C1S, C2, CR2, C3AR1, C3, C8G, and C9 and complement regulatory genes CD59, SERPING1, C4BPA, CFH, and CFI). Downregulation of gene expressions of humoral immunity and complement within the neutrophils are associated with elevated NLR. It remains to be determined whether and how these changes contribute to increased late mortality previously observed in patients undergoing EVS.

Increased Serum Systemic Immune-Inflammation Index is Independently Associated With Severity of Carotid Artery Stenosis

Stroke is a significant contributor to morbidity and mortality. The present study investigated how the systemic immune inflammation index (SII) could be used to predict the likelihood of developing carotid artery stenosis (CAS), which can be seen using carotid artery angiography (CAAG). This study comprised 418 individuals who underwent CAAG for CAS. SII was calculated by multiplying the platelet count by the neutrophil/lymphocyte ratio (NLR). The patients were divided into two groups: non-critical and critical CAS (stenosis below %70 and above ≥70%, respectively). Compared with the non-critical CAS, the critical CAS group had greater high sensitivity C-reactive protein levels (4.5 [3.1-5.7] vs 3.9 [2-5] [mg/L], P < .001), NLR (4.1 [2.9-7.5] vs 2.9 [1.8-3.7], P < .001), platelet/lymphocyte ratio (233 [110-297] vs 119 [96-197], P < .001), and SII (860 [608-2455] vs 604 [458-740], P < .001). Receiver Operating Characteristic Curve analysis demonstrated the best cutoff value of 672.3 for SII to predict the critical CAS with 71.2% sensitivity and 60.1% specificity. According to our study, an increase in SII is an independent predictor of the severity of CAS in patients undergoing CAAG.

Assessment and Correction of the Cardiac Complications Risk in Non-cardiac Operations – What's New?

Cardiovascular complications after non-cardiac surgery are the leading cause of 30-day mortality. The need for surgical interventions is approximately 5,000 procedures per 100,000 population, according to experts, the risks of non-cardiac surgical interventions are markedly higher in the elderly. It should be borne in mind that the aging of the population and the increased possibilities of medicine inevitably lead to an increase in surgical interventions in older people. Recent years have been characterized by the appearance of national and international guidelines with various algorithms for assessing and correcting cardiac risk, as well as publications on the validation of these algorithms. The purpose of this review was to provide new information about the assessment and correction of the risk of cardiac complications in non-cardiac operations. Despite the proposed new risk assessment scales, the RCRI scale remains the most commonly used, although for certain categories of patients (with oncopathology, in older age groups) the possibility of using specific questionnaires has been shown. In assessing the functional state, it is proposed to use not only a subjective assessment, but also the DASI questionnaire, 6-minute walking test and cardiopulmonary exercise test). At the next stage, it is proposed to evaluate biomarkers, primarily BNP or NT-proBNP, with a normal level – surgery, with an increased level – either an additional examination by a cardiologist or perioperative troponin screening. Currently, the prevailing opinion is that there is no need to examine patients to detect hidden lesions of the coronary arteries (non-invasive tests, coronary angiography), since this leads to excessive examination of patients, delaying the implementation of non-cardiac surgery. The extent to which this approach has an advantage over the previously used one remains to be studied.

Carotid Plaque Features and Inflammatory Biomarkers as Predictors of Restenosis and Mortality Following Carotid Endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) is the first-line surgical intervention for cases of severe carotid stenoses. Unfortunately, the restenosis rate is high after CEA. This study aims to demonstrate the predictive role of carotid plaque features and 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)) in carotid restenosis and mortality at 12 months following CEA.

METHODS

The present study was designed as an observational, analytical, retrospective cohort study and included all patients over 18 years of age with a minimum of 70% carotid stenosis and surgical indications for CEA admitted to the Vascular Surgery Clinic, Emergency County Hospital of Targu Mures, Romania between 2018 and 2021.

RESULTS

According to our results, the high pre-operative values of inflammatory biomarkers-MLR (OR: 10.37 and OR: 6.11; p < 0.001), NLR (OR: 34.22 and OR: 37.62; p < 0.001), PLR (OR: 12.02 and OR: 16.06; p < 0.001), SII (OR: 18.11 and OR: 31.70; p < 0.001), SIRI (OR: 16.64 and OR: 9.89; p < 0.001), and AISI (OR: 16.80 and OR: 8.24; p < 0.001)-are strong independent factors predicting the risk of 12-month restenosis and mortality following CEA. Moreover, unstable plaque (OR: 2.83, p < 0.001 and OR: 2.40, p = 0.04) and MI (OR: 3.16, p < 0.001 and OR: 2.83, p = 0.005) were independent predictors of all outcomes. Furthermore, AH (OR: 2.30; p = 0.006), AF (OR: 1.74; p = 0.02), tobacco (OR: 2.25; p < 0.001), obesity (OR: 1.90; p = 0.02), and thrombotic plaques (OR: 2.77; p < 0.001) were all independent predictors of restenosis, but not for mortality in all patients. In contrast, antiplatelet (OR: 0.46; p = 0.004), statin (OR: 0.59; p = 0.04), and ezetimibe (OR:0.45; p = 0.03) therapy were protective factors against restenosis, but not for mortality.

CONCLUSIONS

Our data revealed that higher preoperative inflammatory biomarker values highly predict 12-month restenosis and mortality following CEA. Furthermore, age above 70, unstable plaque, cardiovascular disease, and dyslipidemia were risk factors for all outcomes. Additionally, AH, AF, smoking, and obesity were all independent predictors of restenosis but not of mortality in all patients. Antiplatelet and statin medication, on the other hand, were protective against restenosis but not against mortality.

Neutrophil-to-Lymphocyte Ratio as a Predictive Tool for Post-Operative Outcomes in Patients Undergoing Open Lower Extremity Revascularization Procedures

INTRODUCTION

Elevated neutrophil-to-lymphocyte ratio (NLR), a marker of systemic inflammation, has been shown to correlate with worse outcomes in patients undergoing vascular surgery. Limited data exists on the association of NLR and outcomes in patients undergoing lower extremity vascular surgery. We sought to investigate whether preoperative NLR correlates with outcomes in patients undergoing open lower extremity revascularization procedures.

METHODS

We conducted a retrospective analysis of a prospectively maintained database of patients who underwent open lower extremity revascularization procedures from January 2011 to January 2017 (N=535). Preoperative NLR was calculated within six months of surgery. Primary outcomes were major adverse limb event (MALE) or death. The maximally-ranked statistic method was used to determine the NLR cut-off point. Kaplan-Meier analyses of death and MALE and NLR were used to compare the groups by NLR cut-off point. We conducted a multivariate analysis of the association between NLR and mortality using Cox proportional hazard models, including confounding variables such as age, smoking status, and diabetes. P-values <0.05 were considered statistically significant.

RESULTS

254 patients undergoing surgery from January 2011 to January 2013 were analyzed. The median NLR was 3.6 [IQR 2.5 - 6.7]. The analysis showed a negative correlation between elevated NLR and mortality (P<0.001), but not MALE (P=0.8). Controlling for multiple comorbidities including gender, age, smoking, BMI, diabetes, hyperlipidemia, hypertension, and infection, the NLR cut-off point was a significant independent predictor of mortality (P<0.0001), but not MALE (P=0.551). Elevated NLR was also correlated with statistically and clinically significant longer hospital stays (6.5 [IQR 3.0 - 12.8] days vs. 4.0 [IQR 2.0 - 8.0] days, P=0.027).

CONCLUSION

This study suggests that NLR is an independent predictor of mortality and hospital length of stay in patients undergoing open lower extremity revascularizations. Going forward, we plan to expand this study to include more patients and to compare NLR to other risk assessment tools.