Association of the Derived Neutrophil-Lymphocyte Ratio With Critical Limb Ischemia

A systematic review of the neutrophil to lymphocyte and platelet to lymphocyte ratios in patients with lower extremity arterial disease

Lower extremity arterial disease (LEAD) is caused by atherosclerotic plaque in the arterial supply to the lower limbs. The neutrophil to lymphocyte and platelet to lymphocyte ratios (NLR, PLR) are established markers of systemic inflammation which are related to inferior outcomes in multiple clinical conditions, though remain poorly described in patients with LEAD. This review was carried out in accordance with PRISMA guidelines. The MEDLINE database was interrogated for relevant studies. Primary outcome was the prognostic effect of NLR and PLR on clinical outcomes following treatment, and secondary outcomes were the prognostic effect of NLR and PLR on disease severity and technical success following revascularisation. There were 34 studies included in the final review reporting outcomes on a total of 19870 patients. NLR was investigated in 21 studies, PLR was investigated in two studies, and both NLR & PLR were investigated in 11 studies. Relating to increased levels of systemic inflammation, 20 studies (100%) reported inferior clinical outcomes, 13 (92.9%) studies reported increased disease severity, and seven (87.5%) studies reported inferior technical results from revascularisation. The studies included in this review support the role of elevated NLR and PLR as key components influencing the clinical outcomes, severity, and success of treatment in patients with LEAD. The use of these easily accessible, cost effective and routinely available markers is supported by the present review.

The Role of Neutrophils in Lower Limb Peripheral Artery Disease: State of the Art and Future Perspectives

In recent years, increasing attention has been paid to the role of neutrophils in cardiovascular (CV) disease (CVD) with evidence supporting their role in the initiation, progression, and rupture of atherosclerotic plaque. Although these cells have long been considered as terminally differentiated cells with a relatively limited spectrum of action, recent research has revealed intriguing novel cellular functions, including neutrophil extracellular trap (NET) generation and inflammasome activation, which have been linked to several human diseases, including CVD. While most research to date has focused on the role of neutrophils in coronary artery and cerebrovascular diseases, much less information is available on lower limb peripheral artery disease (PAD). PAD is a widespread condition associated with great morbidity and mortality, though physician and patient awareness of the disease remains low. To date, several studies have produced some evidence on the role of certain biomarkers of neutrophil activation in this clinical setting. However, the etiopathogenetic role of neutrophils, and in particular of some of the newly discovered mechanisms, has yet to be fully elucidated. In the future, complementary assessment of neutrophil activity should improve CV risk stratification and provide personalized treatments to patients with PAD. This review aims to summarize the basic principles and recent advances in the understanding of neutrophil biology, current knowledge about the role of neutrophils in atherosclerosis, as well as available evidence on their role of PAD.

Neutrophil-to-Lymphocyte Ratio and Systemic Inflammation Index as Predictors of Poor Outcome in Patients with Critical Limb Ischemia Treated with Remote Endarterectomy

Introduction: Severe ischemia occurring in the lower limbs represents the advanced stage of peripheral artery disease (PAD). Atherosclerosis and inflammatory markers have been intensively studied to identify prognostic tools with a role in the evolution of patients with PAD. The aim of this study is to demonstrate the predictive value of systemic inflammatory markers such as the neutrophil-to-lymphocyte ratio (NLR) and the systemic inflammation index (SII) in the prognosis of patients diagnosed with critical leg ischemia (CLI) undergoing infrainguinal surgical revascularization with remote endarterectomy.

Materials and methods: This retrospective study included all patients admitted to the Vascular Surgery Clinic of the County Emergency Clinical Hospital of Târgu Mureș, Romania between January 2018 and December 2021, who had critical limb ischemia Leriche-Fontaine stage III and were treated with endarterectomy. Patients were divided into two groups based on the presence or absence of patency in the lower limbs at 12 months.

Results: There was a higher baseline value of neutrophil count (p <0.0001), platelet count (p = 0.006), NLR and SII value (p <0.0001), as well as a lower value of lymphocyte count (p = 0.001) in the group without patency at 12 months. The ROC curve analysis showed that the NLR and SII were associated with the risk of major amputation and primary patency failure at 12 months, while multivariate analysis has shown that arterial hypertension (OR 3.63, p = 0.04), history of myocardial infarction (OR 2.93, p = 0.009), diabetes mellitus (OR 2.20; p = 0.04) and smoking (OR 3.48, p <0.0001) were also predictors of primary patency failure.

Conclusions: The results of this study demonstrated the predictive role of NLR and SII regarding poor outcomes among patients with CLI Leriche-Fontaine stage III undergoing infrainguinal surgical revascularization with remote endarterectomy.

Neutrophil-lymphocyte ratio as a link between complex pedal ulcers and poor clinical results after infrainguinal surgical revascularization

BACKGROUND

Our aim was to evaluate the influence of preoperative neutrophil-lymphocyte ratio (NLR) on patency and clinical results after infrainguinal surgical revascularization for chronic limb ischemia.

METHODS

Retrospective analysis of 150 infrainguinal autologous bypasses performed to infragenicular popliteal artery or tibial vessels in 140 (93%) patients with chronic limb-threatening ischemia (CLTI) and in 10 (7%) with disabling claudication. NLR was calculated using blood samples obtained 24 hours preoperatively. The cohort was stratified into 2 groups according to interquartile ranges of NLR: "ELEVATED-NLR" (Quartile 4 N.=37) and "LOW-NLR" (Quartile 1-2-3 N.=113). Reperfused ulcers were described using the WIfI classification. Patency, freedom from MALE and amputation-free survival at 24 months were calculated using the Kaplan-Meier method. Univariate comparisons between NLR groups were performed using the Log-Rank test. Statistical differences on univariate analysis were adjusted in a multivariate model (Cox regression).

RESULTS

NLR values were similar between CLTI and claudication. Ischemic ulcers were more frequent, (83.4% vs. 59.3% P<0.01), more severe (W2-3: 37.8% vs. 22.1% P=0.01) and pedal infection was deeper (fI 2-3: 40.5% vs. 18.6% P=0.003) in "ELEVATED-NLR" group. Severe ischemia (I3) was similar between groups. High NLR values were independent predictors of patency loss (HR: 1.77 CI95% [1.01-3.10] P=0.04), MALE (HR: 2.04 CI95% [1.03-4.04] P=0.04) and worse amputation-free survival (HR:2.10 CI95% [1.06-4.14] P=0.03) rates at 24 months.

CONCLUSIONS

High preoperative NLR values are associated with severe and deep infected ulcers and predicts primary patency loss, higher major adverse limb events and worse amputation-free survival rates on long-term follow-up after infrainguinal surgical revascularization.

Critical limb ischemia patients clinically improving with medical treatment have lower neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios

OBJECTIVES

Inflammation is a component in the pathogenesis of critical limb ischemia. We aimed to assess how inflammation affects response to treatment in patients treated for critical limb ischemia using neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocytes ratios (PLR) as markers of inflammation.

METHODS

Patients in a single tertiary cardiovascular center with critical limb ischemia unsuitable for surgical or interventional revascularization were retrospectively identified. Data were collected on medical history for risk factors, previous surgical or endovascular revascularization, and outcome. A standard regimen of low molecular weight heparin, aspirin, statins, iloprost infusions, and a standard pain medication protocol were applied to each patient per hospital protocol. Patients with improvement in ischemic pain and healed ulcers made up the responders group and cases with no worsening pain or ulcer size or progression to minor or major amputations made up the non-responders group. Responders and Non-responders were compared for risk factors including pretreatment NLR and PLR.

RESULTS

268 included patients who were not candidates for surgical or endovascular revascularization were identified. Responders had significantly lower pretreatment NLR (4.48 vs 8.47, p < 0.001) and PLR (162.19 vs 225.43, p = 0.001) values. After controlling for associated risk factors NLR ≥ 4.63 (p < 0.001) and PLR ≥ 151.24 (p = 0.016) were independently associated with no response to treatment.

CONCLUSIONS

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocytes ratio are markers of inflammation that are reduced in patients improving with medical treatment suggesting a decreased state of inflammation before treatment in responding patients.

Assessment of Inflammatory Status Based on Total Blood Count and Its Relationship to Cardiovascular Diseases

Background: Inflammation seems to be the most important trigger for atherosclerosis. Lower extremity artery disease (LEAD) and hypertension (HTN) are the most important atherosclerotic diseases. Total blood count-derived neutrophil-lymphocyte ratio (NLR) and red cell distribution width (RDW) have been proposed as inflammatory biomarkers in cardiovascular diseases. The aim of this study was to assess the correlation with LEAD and HTN.

Material and methods: In total, 134 subjects were included in the study, divided into 2 groups as follows: group 1 – patients with LEAD and HTN; group 2 – subjects with HTN, without LEAD. Complete blood count (CBC) and lipid profile were determined. To assess peripheral artery disease, the ankle-brachial index (ABI) was measured with a handheld Doppler device (BiDop ES100V3 Hadeco®). We compared the inflammatory status between the groups with the use of white blood cell count (WBC), red cell distribution (RDW), and neutrophil-lymphocyte ratio (NLR).

Results: In group 1, there was a significant negative correlation between the ABI and RDW (p = 0.04, r2 = –0.24, 95% CI: 0.4647–0.0013), as well as between the ABI and NLR (p = 0.001, r2 = –0.38, 95% CI: 0.5801–0.1592). In group 2, there was a positive correlation between NLR and total serum cholesterol levels (p = 0.003, 95% CI: 0.1274–0.5472, r2 = 0.12), as well as between NLR and triglyceride levels (p = 0.002, 95% CI: 0.1387–0.5552, r2 = 0.13).

Conclusion: NLR and RDW could represent first-line investigations in patients with cardiovascular disease due their cost efficiency. They can also play a role in triaging patients with atherosclerotic disease, monitoring treatment response and prognosis of the disease.

Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio Predict Severity and Prognosis of Lower Limb Arteriosclerosis Obliterans

BACKGROUND

The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are 2 markers of inflammation, which are associated with worse cardiovascular disease outcomes. Here, we aimed to determine the association between these ratios and disease severity and evaluate predictive validity of the NLR and PLR in lower limb arteriosclerosis obliterans (ASO).

METHODS

We evaluated 211 patients with a diagnosis of ASO from January 2016 to December 2018 at Shanghai Jiaotong University Renji Hospital. The NLR and PLR were accessed from routinely drawn peripheral venous blood at the ward of vascular surgery during hospitalization. The association between the NLR and PLR with baseline characteristics, disease severity, and one-year outcomes were determined, respectively.

RESULTS

Both the NLR and PLR showed significant values on predicting disease severity. A higher NLR (P = 0.001) and PLR (P < 0.001) were associated with lower ankle-brachial index and worse clinical presentation. Both the NLR and PLR are positively correlated with one-year readmission rate (P < 0.001, P = 0.001, respectively). Both the NLR and PLR also positively correlated with the tissue loss rate and one-year mortality (P = 0.007, P = 0.034, respectively).

CONCLUSIONS

The NLR and PLR show a positive association with the severity of lower extremity peripheral artery disease, both higher ratios correlate with poor prognosis, especially, the risk of one-year readmission. A higher NLR also correlates with one-year mortality.

Relationship Between Postoperative Neutrophil-Lymphocyte Ratio and 6-Month Primary Patency of Percutaneous Transluminal Angioplasty in Femoropopliteal disease With Drug-Coated and Uncoated Balloons

We investigated the relationship of postoperative neutrophil-lymphocyte ratio (NLR) with 6-month primary patency of percutaneous transluminal angioplasty (PTA) in femoropopliteal disease using drug-coated balloon (DCB) or uncoated balloon (UCB). This retrospective study included 106 patients who received DCB (n = 44) or UCB (n = 62). The postoperative NLR was lower in the DCB group than that in the UCB group (2.60 vs 3.23; P = .004), and 6-month primary patency rate was significantly higher in DCB group than that in the UCB group (77.3% vs 53.2%; P = .011). Multivariate logistic analysis showed that the postoperative NLR was an independent predictor of 6-month primary patency after PTA in patients with femoropopliteal disease (odds ratio: 1.589, 95% confidence interval: 1.078-2.343; P = .019). The cutoff value of postoperative NLR was 3.05 for prediction of 6-month primary patency, with a sensitivity of 64.1% and specificity of 65.7%. The 6-month primary patency rate in the NLR ≤3.05 group was higher than that in the NLR >3.05 group (75.9% vs 47.9%; P = .003). In conclusion, DCB may improve early primary patency by inhibiting inflammation. A higher postoperative NLR was associated with early restenosis.

Effects of arterial blood on the venous blood vessel wall and differences in percentages of lymphocytes and neutrophils between arterial and venous blood

Vascular sclerosis mostly occurs in arteries and is mainly related to anatomic structure and hemodynamics of artery. This study aimed to investigate effects of arterial blood on vein wall and explore differences of composition between arterial and venous blood.Ultrasound was used to examine the distal venous structure of arteriovenous fistula in uremia patients. Immunohistochemistry was used to study the pathology of the distal vein. Twelve patients were divided into control group and trial group. Patients received an arteriovenous fistula within 1 month in control group. Patients had undergone this surgery ≥2 years before in the trial group. Blood samples were collected from the aortic, arterial, and venous vessels of 51 patients who had taken coronary angiography and analyzed with blood routine rest, biochemical, and immunological measures to compare the differences of blood composition between artery and vein. This study was registered with the China Clinical Trial Center website under registration number ChiCTR-OOC-16008085.In the trial group, the vascular wall of distal veins of fistula were thickened and hardened. No significant differences of blood composition were found between the aortic and radial arterial blood. However, the differences in the percentages of lymphocytes and neutrophils between arterial and venous blood were significant (Pa = .0095, Pb = .01).Under smooth hemodynamic conditions, arterial blood caused hardening of the venous wall. Arterial and venous blood differed in the percentage of lymphocyte and neutrophils. This may contribute to the vascular sclerosis that is observed in arteries more often than veins.

The role of inflammation in cardiovascular diseases: the predictive value of neutrophil-lymphocyte ratio as a marker in peripheral arterial disease

Peripheral arterial disease (PAD) is an important manifestation of atherosclerosis, with increasing prevalence worldwide. A growing body of evidence shows that the systemic inflammatory response is closely related to the development, progression, and prognosis of atherosclerosis. In the last decade, several studies have suggested the role of measured inflammatory biomarkers as predictors of severity and prognosis in PAD in an effort to stratify the risk of these patients, to improve treatment selection, and to predict the results after interventions. A simple inflammatory marker, more available than any other, is the neutrophil-lymphocyte ratio (NLR), which can be easily obtained in clinical practice, based on the absolute count of neutrophils and lymphocytes from the differential leukocytes count. Many researchers evaluated vigorously the NLR as a potential prognostic biomarker predicting pathological and survival outcomes in patients with atherosclerosis. In this work, we aim to present the role of NLR as a prognostic marker in patients with PAD through a thorough review of the literature.