Implications of Hemostasis Disorders in Patients with Critical Limb Ischemia-An In-Depth Comparison of Selected Factors

Prognostic impact of atrial fibrillation on the outcomes of peripheral artery disease according to preoperative symptoms for endovascular revascularization

Peripheral artery disease (PAD) and atrial fibrillation (AF) are associated with major cardiovascular and cerebrovascular events (MACCE). However, outcomes stratified according to the preoperative symptoms of PAD in patients with AF have not been sufficiently investigated. This was a retrospective study of prospectively collected data pertaining to 2237 patients (1179 patients with intermittent claudication [IC] and 1058 patients with critical limb-threatening ischemia [CLTI]) who underwent endovascular therapy at 34 hospitals between August 2014 and August 2016. AF was present in 91 (7.7%) patients with IC and 150 (14.2%) patients with CLTI. In the CLTI group, patients with AF had a higher event rate of MACCE and all-cause death than those without AF (1-year rates of freedom from MACCE: 0.66 and 0.81 in patients with and without AF, respectively, p < 0.001). In contrast, in the IC group, there was no statistically significant difference in the rates of MACCE between patients with and without AF. In the Cox multivariate analysis, AF was a significant predictor of MACCE in patients with CLTI but not in patients with IC, even after adjusting for covariates. The impact of AF on the outcome of patients with PAD was greater in those with CLTI. Further studies are needed to clarify the possible mechanisms underlying these differences.

The Role of the Coagulation System in Peripheral Arterial Disease: Interactions with the Arterial Wall and Its Vascular Microenvironment and Implications for Rational Therapies

Peripheral artery disease (PAD) is a clinical manifestation of atherosclerotic disease with a large-scale impact on the economy and global health. Despite the role played by platelets in the process of atherogenesis being well recognized, evidence has been increasing on the contribution of the coagulation system to the atherosclerosis formation and PAD development, with important repercussions for the therapeutic approach. Histopathological analysis and some clinical studies conducted on atherosclerotic plaques testify to the existence of different types of plaques. Likely, the role of coagulation in each specific type of plaque can be an important determinant in the histopathological composition of atherosclerosis and in its future stability. In this review, we analyze the molecular contribution of inflammation and the coagulation system on PAD pathogenesis, focusing on molecular similarities and differences between atherogenesis in PAD and coronary artery disease (CAD) and discussing the possible implications for current therapeutic strategies and future perspectives accounting for molecular inflammatory and coagulation targets. Understanding the role of cross-talking between coagulation and inflammation in atherosclerosis genesis and progression could help in choosing the right patients for future dual pathway inhibition strategies, where an antiplatelet agent is combined with an anticoagulant, whose role, despite pathophysiological premises and trials' results, is still under debate.

Inflammatory and Prothrombotic Biomarkers, DNA Polymorphisms, MicroRNAs and Personalized Medicine for Patients with Peripheral Arterial Disease

Classical risk factors play a major role in the initiation and development of atherosclerosis. However, the estimation of risk for cardiovascular events based only on risk factors is often insufficient. Efforts have been made to identify biomarkers that indicate ongoing atherosclerosis. Among important circulating biomarkers associated with peripheral arterial disease (PAD) are inflammatory markers which are determined by the expression of different genes and epigenetic processes. Among these proinflammatory molecules, interleukin-6, C-reactive protein, several adhesion molecules, CD40 ligand, osteoprotegerin and others are associated with the presence and progression of PAD. Additionally, several circulating prothrombotic markers have a predictive value in PAD. Genetic polymorphisms significantly, albeit moderately, affect risk factors for PAD via altered lipoprotein metabolism, diabetes, arterial hypertension, smoking, inflammation and thrombosis. However, most of the risk variants for PAD are located in noncoding regions of the genome and their influence on gene expression remains to be explored. MicroRNAs (miRNAs) are single-stranded, noncoding RNAs that modulate gene expression at the post-transcriptional level. Patterns of miRNA expression, to some extent, vary in different atherosclerotic cardiovascular diseases. miRNAs appear to be useful in the detection of PAD and the prediction of progression and revascularization outcomes. In conclusion, taking into account one’s predisposition to PAD, i.e., DNA polymorphisms and miRNAs, together with circulating inflammatory and coagulation markers, holds promise for more accurate prediction models and personalized therapeutic options.

Circulating Biomarkers in Lower Extremity Artery Disease

Lower extremity artery disease (LEAD), a chronic condition with disturbed lower extremity circulation due to narrowing of the arteries, is predominantly caused by atherosclerosis and is associated with the presence of cardiovascular risk factors and an increased risk of cardiovascular events. LEAD is prevalent among older individuals and predicted to rise with the ageing population. In progressive disease, the patient experiences symptoms of ischaemia when walking and, in advanced critical limb-threatening ischaemia, even at rest. However, LEAD is asymptomatic in most patients, delaying diagnosis and treatment. In this setting, circulating biomarkers may facilitate earlier diagnosis in selected individuals. This review provides a broad overview of the circulating biomarkers investigated to date in relation to LEAD and discusses their usefulness in clinical practice.

Possible indicators of amputation and insufficient perfusion after heat press injury: A retrospective study

INTRODUCTION

Amputation outcome after heat press injury is associated with insufficient perfusion. We aimed to determine other risk factors for heat press injury and mechanisms of insufficient perfusion associated with amputation.

METHODS

We retrospectively classified 120 inpatients into the emergency and clinic groups, with arrival time before and after 48 h of injury, respectively. We performed propensity score-match to identify significant variables and combine them with those previously identified. Patients with or without amputation were categorized in different subgroups according to arrival time and perfusion with receiver-operator-characteristic (ROC) curves.

RESULTS

In the emergently insufficient perfusion subgroup, red blood cell distribution width of standard deviation (RDW-SD) was statistically different between patients without and with amputation (cutoff = 43 fL; specificity = 0.909). In the urgent group, neutrophil-lymphocyte-ratio (NLR) and relative lymphocyte count (L%) showed no association with perfusion, but was associated with amputation (NLR cutoff value = 3.12; sensitivity = 0.846). Differential leukocytes and related ratios (both groups), D-dimer (emergency group), and creatine kinase (CK) (clinic group) were also associated with insufficient perfusion.

CONCLUSION

The study showed some correlations. Inflammation variables, D-dimer, and CK were associated with amputation and perfusion after heat press injury. Several factors were associated with amputation, including RDW-SD increase in insufficiently perfused patients within 48 h of injury, and NLR increase and L% decrease in patients after 48 h post-injury.

Antithrombotic Therapy in Patients with Peripheral Artery Disease: A Focused Review on Oral Anticoagulation

Peripheral artery disease (PAD) is a major cause of morbidity and mortality but it is usually underdiagnosed and undertreated. Patients with PAD present dysregulated procoagulant, anticoagulant, and fibrinolytic pathways leading to arterial and venous thrombosis. The risk of several ischemic-related complications could be mitigated with appropriate antithrombotic therapy, which plays a central role in all types of PAD. For years, antiplatelets have been indicated in patients with symptomatic PAD or those who have undergone revascularization. Unfortunately, a non-negligible proportion of patients with PAD will suffer from adverse events during the follow-up, even despite proper medical therapies for the prevention of PAD complications. Thus, there is room for improving clinical outcomes in these patients. Given the implication of both, primary and secondary hemostasis in arterial thrombosis and the pathophysiology of PAD, the combination of antiplatelets and anticoagulants has emerged as a potential antithrombotic alternative to antiplatelets alone. In this narrative review article, we have highlighted the most recent evidence about antithrombotic therapy in PAD patients, with a special focus on oral anticoagulation. Certainly, COMPASS and VOYAGER PAD trials have shown promising results. Thus, rivaroxaban in combination with aspirin seem to reduce cardiovascular outcomes with a similar bleeding risk compared to aspirin alone. Nevertheless, results from real-world studies are needed to confirm these observations, and other trials will provide novel evidence about the safety and efficacy of emerging anticoagulant agents.

Tissue-type plasminogen activator and plasminogen activator inhibitor type 1 in patients with symptomatic lower extremity artery disease

BACKGROUND

Lower extremity artery disease (LEAD) involves progressive arterial narrowing manifested by intermittent claudication (IC). LEAD entails endothelial dysfunction and fibrinolytic disorders. In the current study, we analyze the selected parameters of the fibrinolytic system in the blood of patients with symptomatic LEAD depending on clinical parameters.

METHODS

The test group was comprised of 80 patients with diagnosis of LEAD based on Ankle-Brachial Index (ABI) test (27 female/53 male) with an average age of 63.5±9 years. The control group included 30 healthy, non-smoking volunteers (10 female/20 male), with the median age of 56±6 years. The research material - venous blood - was sampled to determine the concentrations of tissue-type plasminogen activator (t-PA Ag), plasminogen activator inhibitor type 1 (PAI-1 Ag), D-dimer, fibrinogen, and platelet count (PLT).

RESULTS

We found elevated concentrations of t-PA Ag, PAI-1 Ag, D-dimer, and fibrinogen in the plasma of subjects with symptomatic LEAD. Various stages of the Fontaine classification demonstrated a gradual, statistically significant increase in the concentrations of fibrinogen and PLT count as the disease progressed. More so, in the subgroup of LEAD patients aged ≥65 years, we observed significantly higher levels of D-dimer than in the group of younger subjects. In addition to that, the LEAD group demonstrated negative correlations of IC distance, fibrinogen concentrations, and PLT count, negative correlations of ABI at rest and concentrations of D-dimer and PLT count, as well as positive correlations between age and D-dimer levels.

CONCLUSIONS

High t-PA Ag concentrations in LEAD patients suggest damage to the endothelium which comprises the main source of this factor. With high PAI-1 Ag levels, inactive fibrinolytic t-PA-PAI-1 complexes are formed. Increasing fibrinogen concentrations at the subsequent stages in accordance with the Fontaine classification, indicate increasing inflammation. Moreover, heightened values of D-dimer reflect an increased secondary fibrinolysis activation as patients get older and impaired extremity vascularization, manifested by the decreasing ABI, progresses.