Variability in Coagulation Profiles in Patients with Chronic Kidney Disease and Peripheral Artery Disease

BACKGROUND

Chronic Kidney Disease (CKD) has been associated with a prothrombotic state. CKD affects hemostasis through altered platelet function and coagulation factors. Traditional tests provide limited insight into these changes. We used Thromboelastography (TEG) to evaluate coagulation profiles in CKD and non-CKD patients, comparing parameters based on glomerular filtration rate (GFR) to better understand clotting dynamics. The aim of the study was to evaluate coagulation profiles in patients across GFR categories using Thromboelastography (TEG), which enables comprehensive assessment of clot formation dynamics.

METHODS

We prospectively evaluated patients with peripheral artery disease undergoing revascularization (December 2020-2023). Patients were stratified by GFR into 3 groups: >60 mL/min, 30-59 mL/min, and <30 mL/min. Pre-surgical blood samples were analyzed using TEG parameters, including Maximum Amplitude (MA), Citrated Functional Fibrinogen (CFF), and Functional Fibrinogen Levels (FLEV). Statistical analysis employed Kruskal-Wallis tests.

RESULTS

Among 254 patients (182 with GFR >60, 56 with GFR 30-59, and 16 with GFR <30), those with declining kidney function showed progressively higher values in CRT MA (62.80 vs. 65.85 vs. 67.85 mm, P = 0.0021), CK MA (61.10 vs. 64.00 vs. 66.70 mm, P = 0.0063), CFF MA (21.40 vs. 24.10 vs. 33.70 mm, P = 0.0017), and CFF FLEV (390.5 vs. 487.2 vs. 556.6 mg/dL, P = 0.0029). This pattern persisted in patients on mono antiplatelet therapy (MAPT). Patients receiving MAPT showed consistently higher coagulation marker levels compared to those on dual antiplatelet therapy (DAPT), particularly in severe renal impairment (GFR <30).

CONCLUSION

Patients with decreased kidney function demonstrated relative hypercoagulability compared to those with normal kidney function, as evidenced by elevated fibrinogen levels and stronger blood clots. While DAPT was associated with lower coagulation marker levels compared to MAPT, platelet reactivity remained similar across GFR categories. However, these laboratory findings did not translate into increased clinical events, with no significant differences in bleeding episodes (P = 0.436) or arterial thrombotic events (P = 0.095) across GFR categories.

Rivaroxaban plus aspirin after lower-extremity revascularization

INTRODUCTION

Patients undergoing revascularization of the lower extremities have unacceptably high rates of major adverse cardiac and limb events despite the routine use of antiplatelet therapy. Optimization of antithrombotic therapy provides an opportunity to reduce this risk. Recent large, randomized trials have demonstrated substantial benefit from the combination of low-dose rivaroxaban and aspirin compared with aspirin alone. Despite this new evidence, uptake remains limited.

AREAS COVERED

This review will outline the drug profile of rivaroxaban, summarize the key efficacy and safety data for the combination of low-dose rivaroxaban and aspirin following lower extremity revascularization, and examine barriers to therapy uptake.

EXPERT OPINION

Combination of low-dose rivaroxaban and aspirin is the only antithrombotic regimen that has been shown to reduce both cardiac and limb events following peripheral revascularization while maintaining an acceptable bleeding profile. Single and dual antiplatelet therapy have limited randomized evidence for this indication, but are commonly used. An important contributor is the failure of major societal guidelines to incorporate this new evidence. Moving forward, there is an urgent need to update these guidelines. Further evaluation of the efficacy and safety of dual antiplatelet therapy will help to inform optimal antithrombotic therapy after lower extremity revascularization.

Epidemiology of Peripheral Artery Disease: Narrative Review

Past decades have witnessed a major epidemiologic transition with a considerable increase in the disease burden associated with atherosclerotic cardiovascular diseases (CVDs), with low-income and middle-income countries (LMICs) experiencing substantial increase in CVDs. As the global population is aging and peripheral artery disease (PAD) is strongly age-related, it is estimated to become increasingly prevalent in the future. PAD shares risk factors with coronary and cerebrovascular risk factors, particularly diabetes mellitus and smoking, and is associated with significant CVD morbidity and mortality. Despite advances in therapeutic modalities, 236 million people were estimated to be suffering from PAD worldwide in 2015, and numbers have been rising since. The prevalence of asymptomatic PAD has remained high; PAD prevalence seems higher among women and is related to ethnicity. Although several epidemiological studies have been published on PAD during the past decades, data from LMICs are scarce. Besides providing up-to-date epidemiological data retrieved from the literature and the Global Burden of Disease (GBD) study database, this narrative review also intends to draw attention to the substantial disease burden of PAD manifesting in more Years of Life Lost (YLL), age-adjusted mortality and amputation rates, with a special focus on some European countries and especially Hungary, i.e., the country with the highest amputation rate in Europe.

Medical Therapy Following Urgent/Emergent Revascularization in Peripheral Artery Disease Patients (Canadian Acute Limb Ischemia Registry [CANALISE I])

Background

Following severe limb ischemia requiring urgent/emergent revascularization, peripheral arterial disease patients suffer a high risk of recurrent atherothrombosis.

Methods

Patients discharged from Hamilton General Hospital (Hamilton, Ontario) between April 2016 and September 2017 following severe limb ischemia requiring urgent/emergent revascularization were identified via the Local Health Integration Network CorHealth database, with supplemental information from chart review.

Results

A total of 158 patients admitted for urgent/emergent revascularization were identified (148 alive at discharge). Among patients without a pre-existing indication for anticoagulation, 38.8% (n = 47) were discharged on single-antiplatelet therapy, 27.3% (n = 33) on dual-antiplatelet therapy, 19.8% (n = 24) on anticoagulants plus antiplatelet therapy, 6.6% (n = 8) on anticoagulants alone, and 2.6% (n = 3) on unknown therapy. Patients who received angioplasty with stenting were more likely be discharged on dual-antiplatelet therapy (hazard ratio [HR]: 7.14; 95% confidence interval [CI]: 2.87-17.76; P < 0.01); patients who received an embolectomy/thrombectomy were more likely be discharged on an anticoagulant alone (HR: 2.61; 95% CI: 1.00-6.81; P = 0.049); and patients who received peripheral bypass grafting were more likely be discharged on single-antiplatelet therapy (HR: 2.28; 95% CI: 1.11-4.69; P = 0.024). Neither statins (60.8% vs 56.3%; P = 0.23) nor renin–angiotensin–aldosterone system inhibitors (48.7% vs 50.6%; P = 0.58) were prescribed at higher rates at discharge, compared with the rate at admission.

Conclusions

Substantial heterogeneity exists in antithrombotic prescription following urgent/emergent revascularization. No intensification of non-antithrombotic vascular protective medications occurred during hospitalization. Clinical trials and health system interventions to optimize medical therapy in peripheral arterial disease patients are urgently needed.

Efficacy and Safety of Rivaroxaban Therapy for Patients With Peripheral Artery Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

We performed a systematic review and meta-analysis to evaluate the efficacy and safety of rivaroxaban in patients with PAD for the first time.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library database for randomized controlled trials (RCTs) conducted for PAD.

RESULTS

Three trials which contained 14873 patients were included for final meta-analysis. The results showed patients with rivaroxaban was associated with reduction in primary efficacy outcome (RR 0.83; 95% CI 0.76 to 0.90; p < 0.001). The RR was 0.85 (0.71 to 1.01) for patients with rivaroxaban alone and 0.81 (0.74 to 0.89) for those with rivaroxaban plus aspirin (p for heterogeneity between groups = 0.65). Patients with rivaroxaban showed a lower rate of acute limb ischemia (0.56; 0.47 to 0.66; p < 0.001). There was a trend toward a reduction in the rate of major amputation for vascular causes in the rivaroxaban arm (0.81; 0.63 to 1.03; p = 0.08). Compared with control, rivaroxaban therapy did not reduce the risks of myocardial infarction (0.87, 0.73 to 1.04, p = 0.12), ischemic stroke (0.85, CI 0.68 to 1.06, p = 0.15), death from cardiovascular causes (0.99, 0.85 to 1.15, p = 0.91) or death from any cause (1.00, 0.90 to 1.12, p = 0.98). Rivaroxaban therapy was associated with a 1.57-fold higher major bleeding rate as compared with those with aspirin or warfarin alone.

CONCLUSIONS

Overall, the risks of the primary efficacy outcomes or adverse limb events were significantly lower with rivaroxaban than with aspirin or warfarin alone in patients with PAD. It also points out the significant major bleeding that occur because of such therapies.

Prevention and Management of Urgent/Emergent Limb Ischemia

PURPOSE OF REVIEW

Patients who require urgent or emergent peripheral revascularization represent one of the highest risk subgroups of PAD patients. They suffer unacceptably high complication rates including recurrent ALI, vascular amputation, and death. In this article, we examine (1) the burden of cardiovascular complications according to PAD severity, (2) discuss medical optimization to improve vascular outcomes in symptomatic LE-PAD patients, and (3) review the evidence for management of patients following urgent/emergent limb ischemia.

RECENT FINDINGS

The VOYAGER trial recently demonstrated that rivaroxaban 2.5 mg BID + ASA daily significantly reduces major adverse cardiac and limb events in patients following lower extremity revascularization. A recent Canadian survey also demonstrated that significant heterogeneity exists in antithrombotic prescribing practices following urgent/emergent revascularization. COMPASS and VOYAGER have demonstrated the efficacy of aspirin 81 mg daily and rivaroxaban 2.5 mg twice daily at reducing MACE and MALE events in stable PAD patients and those undergoing elective revascularization. Patients who require urgent or emergent peripheral revascularization remain the highest thrombotic risk subgroup of PAD patients, in whom there is insufficient evidence to guide antithrombotic therapy. Despite clear evidence that multi-modal medical therapy (including statins, antihypertensive agents and smoking cessation) benefits patients with atherosclerosis, their use remains unacceptably low in PAD, and greater efforts are needed to understand and address patient, health provider, and system issues that prevent their optimal implementation in practice.

Reducing residual thrombotic risk in patients with peripheral artery disease: impact of the COMPASS trial

Patients with peripheral artery disease (PAD) are at a high risk not only for the classical cardiovascular (CV) outcomes (major adverse cardiovascular events; MACE) but also for vascular limb events (major adverse limb events; MALE). Therefore, a comprehensive approach for these patients should include both goals. However, the traditional antithrombotic approach with only antiplatelet agents (single or dual antiplatelet therapy) does not sufficiently reduce the risk of recurrent thrombotic events. Importantly, the underlying cause of atherosclerosis in patients with PAD implies both platelet activation and the initiation and promotion of coagulation cascade, in which Factor Xa plays a key role. Therefore, to reduce residual vascular risk, it is necessary to address both targets. In the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial that included patients with stable atherosclerotic vascular disease, the rivaroxaban plus aspirin strategy (versus aspirin) markedly reduced the risk of both CV and limb outcomes, and related complications, with a good safety profile. In fact, the net clinical benefit outcome composed of MACE; MALE, including major amputation, and fatal or critical organ bleeding was significantly reduced by 28% with the COMPASS strategy, (hazard ratio: 0.72; 95% confidence interval: 0.59-0.87). Therefore, the rivaroxaban plus aspirin approach provides comprehensive protection and should be considered for most patients with PAD at high risk of such events.

Rivaroxaban and Aspirin in Peripheral Vascular Disease: a Review of Implementation Strategies and Management of Common Clinical Scenarios

PURPOSE OF REVIEW

Peripheral artery disease (PAD) affects an estimated 200 million people worldwide and is associated with significant cardiovascular morbidity and mortality. Cardiovascular risk is further increased among individuals with polyvascular disease, where either cerebrovascular or coronary artery disease is present in addition to PAD. In this review, we present common clinical scenarios encountered when managing patients with PAD and provide an evidence-based approach to prescribing optimal antithrombotics in this population.

RECENT FINDINGS

The COMPASS trial recently demonstrated that rivaroxaban 2.5 mg BID + ASA daily significantly reduces major adverse cardiac and limb events in patients with PAD. Despite these advances, morbidity following MALE events remains high. With widespread approval by federal health regulators, the COMPASS regimen should be strongly considered in PAD patients who do not have a high bleeding risk. Implementing the COMPASS regimen in patients with PAD, along with other vascular risk reduction strategies, will have a substantial impact on reducing atherothromboembolic risk in patients with established vascular disease.