Dual vs single antiplatelet therapy in patients with lower extremity peripheral artery disease – A meta-analysis

Pharmacotherapy and revascularization strategies of peripheral artery disease

The global epidemiological transition of atherosclerotic vascular diseases is witnessing a rapid redistribution of its burden, shifting from high-income to low- and middle-income countries. With a wide clinical spectrum, spanning from intermittent claudication to more complex critical limb threatening ischemia, nonhealing ulcers, gangrene as well as acute limb ischemia, peripheral artery disease is often faced with the challenges of under-diagnosis and under-treatment despite its high prevalence. The management of peripheral arterial disease in patients with multiple comorbidities presents a formidable challenge and remains a pressing global health concern. In this review, we aim to provide an in-depth overview of the pathophysiology of peripheral artery disease and explore evidence-based management strategies encompassing pharmacological, lifestyle, interventional, and surgical approaches. By addressing these challenges, the review contributes to a better understanding of the evolving landscape of peripheral artery disease, offering insights into effective and holistic management strategies.

Optimizing platelet inhibition in peripheral artery disease: A comparison of mono-antiplatelet therapy and dual-antiplatelet therapy using thromboelastography

BACKGROUND

Antiplatelet therapy is used to prevent thrombosis in patients with peripheral artery disease (PAD) following revascularization. However, the current standard of care for these patients remains at the physician's discretion, varying from mono-antiplatelet therapy (MAPT) to dual-antiplatelet therapy (DAPT). Viscoelastic assays such as Thromboelastography with Platelet Mapping (TEG-PM) provide insight into individual coagulation profiles and measure real-time platelet function. This prospective, observational study looks at the differences in platelet function for patients on MAPT versus DAPT using TEG-PM.

METHODS

Patients with PAD undergoing revascularization were prospectively evaluated between December 2020 and June 2023. TEG-PM analysis compared platelet function for patients prescribed MAPT (aspirin or clopidogrel) at the initial encounter and DAPT (aspirin and clopidogrel) at the next visit. Platelet function measured in percent inhibition was evaluated at these visits, and within-group t-tests were performed.

RESULTS

Of the 195 patients enrolled, 486 samples were analyzed by TEG-PM. Sixty-four patients met the study criteria. At the initial visit, 52 patients had been prescribed aspirin, and 12 patients had been prescribed clopidogrel. For patients initially prescribed aspirin MAPT, an increase of 96.8%in the mean ADP platelet inhibition was exhibited when transitioning to DAPT [22.0% vs. 43.3%, p < .01], as well as an increase of 34.6%in the mean AA platelet inhibition when transitioning to DAPT [60.9% vs. 82.0%, p < .01]. For patients prescribed initial clopidogrel MAPT, an increase of 100% in AA platelet inhibition was exhibited on DAPT compared to the MAPT state [42.3% vs. 84.6%, p < .01].

CONCLUSIONS

Patients on DAPT showed a significant increase in platelet inhibition when compared to initial aspirin MAPT. A significant difference in AA %platelet inhibition was shown for patients on DAPT when compared to initial clopidogrel MAPT. The results show that patients may benefit from DAPT post-revascularization. Personalizing antiplatelet therapy with objective viscoelastic testing to confirm adequate treatment may be the next step in optimizing patient outcomes to reduce thrombosis in PAD patients.

Medical Management of Cardiovascular Disease

We offer an overview of lipid lowering, antiplatelet, antihypertensive, and glucose-lowering therapies for vascular surgeons and their respective medical teams. Further reviews should offer additional guidance on smoking cessation, exercise therapy, and nutritional optimization.

Risk of bleeding after percutaneous coronary intervention and its impact on further adverse events in clinical trial participants with comorbid peripheral arterial disease

BACKGROUND

Both patients with obstructive coronary artery disease (CAD) and patients with peripheral arterial disease (PADs) have an increased bleeding risk. Information is scarce on bleeding in CAD patients, treated with percutaneous coronary intervention (PCI), who have comorbid PADs. We assessed whether PCI patients with PADs have a higher bleeding risk than PCI patients without PADs. Furthermore, in PCI patients with PADs we evaluated the extent by which bleeding increased the risk of further adverse events.

METHODS

Three-year pooled patient-level data of two randomized PCI trials (BIO-RESORT, BIONYX) with drug-eluting stents were analyzed to assess mortality and the composite endpoint major adverse cardiac events (MACE: all-cause mortality, any myocardial infarction, emergent coronary artery bypass surgery, or target lesion revascularization).

RESULTS

Among 5989 all-comer patients, followed for 3 years, bleeding occurred in 7.7% (34/440) with comorbid PADs and 5.0% (279/5549) without PADs (HR: 1.59, 95%CI: 1.11-2.23, p = 0.010). Of all PADs patients, those with a bleeding had significantly higher rates of all-cause mortality (HR: 4.70, 95%CI: 2.37-9.33, p < 0.001) and MACE (HR: 2.39, 95%CI: 1.23-4.31, p = 0.003). Furthermore, PADs patients with a bleeding were older (74.4 ± 6.9 vs. 67.4 ± 9.5, p < 0.001). After correction for age and other potential confounders, bleeding remained independently associated with all-cause mortality (adj.HR: 2.97, 95%CI: 1.37-6.43, p = 0.006) while the relation of bleeding with MACE became borderline non-significant (adj.HR: 1.85, 95%CI: 0.97-3.55, p = 0.06).

CONCLUSION

PCI patients with PADs had a higher bleeding risk than PCI patients without PADs. In PADs patients, bleeding was associated with all-cause mortality, even after adjustment for potential confounders.

Anticoagulation and Antiplatelet Agents in Peripheral Arterial Interventions

Effective revascularization of peripheral artery disease relies on periprocedural pharmacological regulation of the clotting cascade. Patient-specific factors such as cardiovascular risk factors, contraindications, and individual psychosocial factors must be considered when initiating post revascularization management. Management with anticoagulant and antiplatelet agents is discussed to guide the interventionalist on which therapy may be appropriate for their patient. While exact treatment may be institution and provider dependent, the interventionist must be familiar with the available classes of medications and how they can be prescribed in the postprocedural setting to improve cardiovascular outcomes.

Mono or Dual Antiplatelet Therapy for Treating Patients with Peripheral Artery Disease after Lower Extremity Revascularization: A Systematic Review and Meta-Analysis

The efficacy of dual antiplatelet therapy (DAPT) for patients with peripheral artery disease (PAD) after lower-limb intervention remains controversial. Currently, the prescription of DAPT after an intervention is not fully recommended in guidelines due to limited evidence. This study compares and analyzes the prognosis for symptomatic PAD patients receiving DAPT versus monotherapy after lower-limb revascularization. Up to November 2021, PubMed/MEDLINE, Embase, and Cochrane databases were searched to identify studies reporting the efficacy, duration, and bleeding complications when either DAPT or monotherapy were used to treat PAD patients after revascularization. Three randomized controlled trials and seven nonrandomized controlled trials were included in our study. In total, 74,651 patients made up these ten studies. DAPT in PAD patients after intervention was associated with lower rates of all-cause mortality (HR = 0.86; 95% CI, 0.79−0.94; p < 0.01), major adverse limb events (HR = 0.60; 95% CI, 0.47−0.78; p < 0.01), and major amputation (HR = 0.78; 95% CI, 0.64−0.96) when follow-up was for more than 1-year. DAPT was not associated with major bleeding events when compared with monotherapy (OR = 1.22; 95% CI, 0.69−2.18; p = 0.50) but was associated with a higher rate of minor bleeding as a complication (OR = 2.54; 95% CI, 1.59−4.08; p < 0.01). More prospective randomized studies are needed to provide further solid evidence regarding the important issue of prescribing DAPT.

Artificial-Intelligence-Assisted Discovery of Genetic Factors for Precision Medicine of Antiplatelet Therapy in Diabetic Peripheral Artery Disease

An increased risk of cardiovascular events was identified in patients with peripheral artery disease (PAD). Clopidogrel is one of the most widely used antiplatelet medications. However, there are heterogeneous outcomes when clopidogrel is used to prevent cardiovascular events in PAD patients. Here, we use an artificial intelligence (AI)-assisted methodology to identify genetic factors potentially involved in the clopidogrel-resistant mechanism, which is currently unclear. Several discoveries can be pinpointed. Firstly, a high proportion (>50%) of clopidogrel resistance was found among diabetic PAD patients in Taiwan. Interestingly, our result suggests that platelet function test-guided antiplatelet therapy appears to reduce the post-interventional occurrence of major adverse cerebrovascular and cardiac events in diabetic PAD patients. Secondly, AI-assisted genome-wide association study of a single-nucleotide polymorphism (SNP) database identified a SNP signature composed of 20 SNPs, which are mapped into 9 protein-coding genes (SLC37A2, IQSEC1, WASHC3, PSD3, BTBD7, GLIS3, PRDM11, LRBA1, and CNR1). Finally, analysis of the protein connectivity map revealed that LRBA, GLIS3, BTBD7, IQSEC1, and PSD3 appear to form a protein interaction network. Intriguingly, the genetic factors seem to pinpoint a pathway related to endocytosis and recycling of P2Y12 receptor, which is the drug target of clopidogrel. Our findings reveal that a combination of AI-assisted discovery of SNP signatures and clinical parameters has the potential to develop an ethnic-specific precision medicine for antiplatelet therapy in diabetic PAD patients.

Efficacy and Safety of Antiplatelet Therapies in Symptomatic Peripheral Artery Disease: A Systematic Review and Network Meta-Analysis

BACKGROUND

Clopidogrel monotherapy is guideline-recommended in symptomatic peripheral artery disease (PAD). The advent of new antithrombotic strategies prompts an updated analysis of available evidence on antiplatelet therapy for PAD.

METHODS

We searched MEDLINE, Embase and CENTRAL through January 2019 for randomised controlled trials and observational studies comparing antiplatelet therapies as monotherapy, dual therapy, or combination with anticoagulants. Efficacy (major adverse cardiovascular events, acute or chronic limb ischaemia, vascular amputation, peripheral revascularisation) and safety (all-cause mortality and overall bleeding) outcomes were evaluated via Bayesian network meta-analyses.

RESULTS

We analysed 26 randomised controlled trials. Clopidogrel (hazard ratio, HR, 0.78; 95% credible interval [CrI] 0.65-0.93) and ticagrelor (HR 0.80; 95% CrI 0.65-0.98) significantly reduced major adverse cardiovascular events risk compared with aspirin. No significant difference was observed for dual antiplatelet therapy with clopidogrel and aspirin. Vorapaxar significantly reduced limb ischaemia and revascularisation compared with placebo, while dual antiplatelet therapy with clopidogrel and aspirin showed a trend for reduced risk of amputation compared with aspirin (risk ratio 0.68; 95% CrI 0.43-1.04). For all-cause mortality, picotamide, vorapaxar, dipyridamole with aspirin, and ticlopidine showed a significantly lower risk of all-cause mortality vs aspirin. Clopidogrel and ticagrelor showed similar overall bleeding risk vs aspirin, while dual antiplatelet therapy with clopidogrel and aspirin significantly increased bleeding risk.

CONCLUSION

This updated network meta-analysis confirms that clopidogrel significantly decreases the risk of major adverse cardiovascular events compared with aspirin, without increasing bleeding risk. Clopidogrel should remain a mainstay of PAD treatment, at least in patients at higher bleeding risk.

Effects of dual antiplatelet therapy on graft patency after lower extremity bypass

OBJECTIVE

Current guidelines recommend single-agent antiplatelet therapy for patients with symptomatic peripheral artery disease and consideration of dual antiplatelet therapy (DAPT) after surgical revascularization. The objective of this study was both to explore prescribing patterns of single antiplatelet therapy vs DAPT after lower extremity bypass surgery and to investigate the effects of antiplatelet therapy on bypass graft patency.

METHODS

A retrospective analysis of prospectively collected nonemergent infrainguinal lower extremity bypass operations entered in the national Vascular Quality Initiative (2003-2018) with captured long-term follow-up was performed. Patients discharged on aspirin monotherapy or DAPT were identified. Linear regression investigated temporal trends in antiplatelet use. Multivariable Cox regression investigated predictors of primary, primary assisted, and secondary patency.

RESULTS

Of the 13,020 patients investigated, 52.2% were discharged on aspirin monotherapy and 47.8% on DAPT. The proportion of patients discharged on DAPT increased from 10.6% in 2003 to 60.6% in 2018 (P < .001). The DAPT cohort was younger, had higher rates of medical (hypertension, diabetes, congestive heart failure, chronic obstructive pulmonary disease) and atherosclerotic (coronary artery disease, prior coronary artery bypass graft or percutaneous coronary intervention, prior lower extremity intervention) comorbidities, and had higher risk bypass procedures (more distal targets, prior inflow bypass procedure, prosthetic conduit use). Multivariable Cox regression analysis did not show any difference between the DAPT and aspirin cohorts in primary patency (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.88-1.10; P = .78), primary assisted patency (HR, 0.93; 95% CI, 0.80-1.07; P = .30), or secondary patency (HR, 0.88; 95% CI, 0.74-1.06; P = .18). On subgroup analysis based on bypass conduit, DAPT was found to have a protective effect on patency only in the prosthetic bypass cohort (primary patency: HR, 0.81 [95% CI, 0.66-1.00; P = .05]; primary assisted patency: HR, 0.74 [95% CI, 0.58-0.94; P = .01]; and secondary patency: HR, 0.60 [95% CI, 0.44-0.82; P < .001]). No patency differences were observed on adjusted subgroup analysis for the other bypass conduits.

CONCLUSIONS

A significant and increasing proportion of patients are discharged on DAPT after lower extremity bypass revascularization. These patients represent a higher risk cohort with more medical comorbidities and higher risk bypass features. After controlling for these differences, DAPT therapy had no beneficial effect on overall bypass graft patency or major adverse limb events. However, on subgroup analysis, DAPT was associated with improved bypass graft patency in patients receiving prosthetic bypass conduits. Further study is warranted to investigate optimal duration of DAPT therapy and its possible bleeding complications in prosthetic bypass patients.

Ticagrelor in the prevention of coronary and non-coronary atherothrombotic events: A comprehensive meta-analysis of 10 randomized trials

BACKGROUND AND AIMS

More potent antithrombotic strategies have significantly reduced the rate of recurrent ischemic events in cardiovascular disease. Ticagrelor, in particular, has significantly improved the outcome in patients with acute coronary syndromes, offering potential benefits also in terms of survival. In addition, more recent data have suggested that the advantages of ticagrelor could be extended also to non-coronary atherothrombotic disease, although with contrasting results, especially for mortality reduction. The aim of the present meta-analysis was to investigate the safety and effectiveness of a newer antiplatelet strategy with ticagrelor as compared to traditional antiplatelet regimens in patients with coronary or non-coronary atherothrombotic disease.

METHODS

Literature and main scientific session abstracts were searched for studies comparing a ticagrelor-based antiplatelet regimen vs. different antiplatelet agents in the secondary prevention of cardiac, cerebral or vascular atherothrombotic events. The primary efficacy endpoint was mortality, primary safety endpoint was the occurrence of major bleedings. Secondary endpoints were myocardial infarction and stroke.

RESULTS

We included 10 randomized clinical trials, for a total population of 73,121 patients, 54.9% randomized to ticagrelor. At a mean follow-up of 13.4 ± 12.6 months, a newer antiplatelet strategy based on ticagrelor was associated with a significant reduction in mortality as compared to a traditional therapy (OR[95%CI] = 0.92[0.86,0.99], p=0.02; phet = 0.14), however, such benefits were more evident in patients with coronary artery disease, while not in non-coronary trials, with a significant interaction between patients' setting and the prognostic impact of ticagrelor (p int = 0.03). A similar result was achieved for cardiovascular mortality, recurrent myocardial infarction, while for the risk of stroke, the largest advantages were observed in patients with a previous cerebrovascular accident. Major bleeding events were increased in ticagrelor treated patients (OR [95%CI] = 1.11 [1.02, 1.20], p=0.01; phet = 0.0003), although not affecting overall mortality, as confirmed by meta-regression analysis.

CONCLUSIONS

Based on the current meta-analysis, a newer antiplatelet strategy based on ticagrelor is associated with a significant reduction in mortality and recurrent cardiovascular events, as compared to a traditional treatment, among patients treated for coronary disease but not among those with non-coronary atherothrombotic disease. However, ticagrelor therapy was associated with a significant increase in major bleeding complications.

Anti-platelet and anti-coagulant therapy in peripheral arterial disease prior to surgical intervention

OBJECTIVE

Peripheral artery disease is a major clinical co-morbidity that can significantly affect quality of life, especially in the presence of diabetes mellitus and older age. The focus of this literature review is on medical management, through anti-platelet and anti-coagulation, of peripheral artery disease prior to undergoing surgical or endovascular management.

METHOD

Extensive electronic literature search performed in four major databases (PubMed, SCOPUD, Embase and Ovid) to identify the published randomized and non-randomized studies that compared and discussed the management of peripheral artery disease with different anti-thrombotic agents.

RESULTS

A total of 17 studies were identified to meet the inclusion criteria of this review. Among them, 4 were systematic review and meta-analyses, 1 was observational study and 12 were randomized controlled trials. The reported outcomes in each study are summarized and reported separately within this review.

CONCLUSION

Peripheral artery disease is a complex and multifactorial clinical condition. The use of dual anti-platelets, such as aspirin and clopidogrel, are the key in preventing major cardiovascular events as well as stroke and death. Utilization of anti-coagulation such as direct oral anti-coagulants' as additional parameters for the prevention of disease progression, is paramount. Eventually, the choice of either dual-antiplatelet therapy or combined anti-coagulation with anti-platelets should be carefully considered, particularly following the most recent published debatable studies.

Disease-specific characteristics of vascular cell adhesion molecule-1 levels in patients with peripheral artery disease

Peripheral arterial disease (PAD) is one of the most common manifestations of systemic atherosclerosis. The prevalence of unrecognized PAD is high, leading to a lack of opportunity to detect subjects at a high risk for cardiovascular events. Inflammatory processes play an important role in the disease initiation as well as in the disease progression. Vascular cell adhesion molecule 1 (VCAM-1), a biomarker of endothelial dysfunction, appears to be an important mediator in inflammatory processes. Therefore, we hypothesized that in patients with PAD, circulating VCAM-1 might be elevated due to its function in mediating adhesion of immune cells to the vascular endothelium in the process of endothelial dysfunction and inflammation, and, therefore, applicable as a diagnostic biomarker. A total of 126 non-consecutive patients were enrolled in this study, of whom 51 patients had typical clinical manifestations of PAD and as controls 75 patients with no history of PAD or cardiovascular disease. All serum samples were obtained either during hospitalization or during out-patient visits and analyzed for VCAM-1 by the ELISA. Compared with controls, median levels of VCAM-1 were significantly elevated in patients suffering from PAD (953 vs. 1352 pg/ml; p < 0.001). Furthermore, VCAM-1 appeared to be highly discriminative for the detection of PAD (AUC = 0.76; CI 0.67-0.83). We could not observe dynamics related to increasing disease stages according to Rutherford classes in patients with apparent PAD. VCAM-1 was shown to be a potential discriminator and biomarker for the severity of systemic atherosclerosis. In a logistic regression analysis, VCAM-1 was robustly associated with the diagnosis of PAD, even after correction for clinically relevant cofounders (namely age, arterial hypertension, diabetes and LDL levels). Thusly, VCAM-1 might serve as a biomarker for PAD screening and detection.