Antithrombotic therapy in peripheral artery disease: A review of the EUCLID trial results and current ongoing trials

The vascular complications of diabetes: a review of their management, pathogenesis, and prevention

INTRODUCTION

This review highlights the pathogenesis of both microvascular and macrovascular complications of diabetes and how these mechanisms influence both the management and preventative strategies of these complications. The cumulative data shown in this review suggest hyperglycemic and blood pressure control remain central to this intricate process.

AREAS COVERED

We reviewed the literature including retrospective, prospective trials as well as meta-analysis, and post hoc analysis of randomized trials on microvascular andmacrovascular complications.

EXPERT OPINION

Further research is needed to explore the ideal intervention targets and preventative strategies needed to prevent macrovascular complications. Furthermore, as the data for trials looking at microvascular complications lengthen more long-term data will further elucidate the role that the duration of diabetes has on these complications. Additionally, trials looking to maximize hyperglycemic control with multiple agents in diabetes, such as metformin, SGL2isand GLP-1 receptor agonists are currently in process, which will have implications for rates of microvascular as well as macrovascular complications.

Incidence and Factors Associated With Major Amputation in Patients With Peripheral Artery Disease

Background:

Peripheral artery disease (PAD) is associated with increased risk of mortality, cardiovascular morbidity, and major amputation. Data on major amputation from a large randomized trial that included a substantial cohort of patients without critical limb ischemia (CLI) have not been described. The objective was to describe the incidence and types of amputations in the EUCLID trial (Examining Use of Ticagrelor in Peripheral Artery Disease) population, subcategorize amputations in the CLI versus no CLI cohorts, and describe the events surrounding major amputation.

Methods and Results:

Postrandomization major amputation was analyzed in the EUCLID trial. Patients were stratified by baseline CLI status. The occurrence of major amputation was ascertained and defined as the highest level. Perioperative events surrounding major amputation were obtained including acute limb ischemia, revascularization, and all-cause mortality. All variables were assessed for significance in univariable and multivariable models. The rate of major amputation during the course of the trial was 1.6% overall, 8.4% in the CLI at baseline group, and 1.2% in the no CLI at baseline group. The annualized rate of major amputation was 0.6% in PAD overall, 3.9% in the CLI at baseline group, and 0.5% in the no CLI at baseline group. Several factors were associated with increased risk of major amputation, including history of amputation, the presence of diabetes mellitus, baseline Rutherford category 4 to 6, and an ankle-brachial index <0.8. Factors associated with a lower risk for major amputation included prior statin use. The 30-day mortality rate after major amputation was 6.5% overall, 5.6% in the CLI at baseline group, and 6.8% in the no CLI at baseline group. The annual mortality rate following major amputation was 22.8% in the CLI at baseline group and 16.0% in the no CLI at baseline group.

Conclusions:

The risk factors for major amputation in EUCLID patients are similar to previous large registries’ reports except for diabetes mellitus in patients with CLI. The mortality following major amputation is lower in the EUCLID trial compared with registry data.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01732822.

Ticagrelor-based antiplatelet regimens in patients with atherosclerotic artery disease-A meta-analysis of randomized clinical trials

BACKGROUND

Randomized trials did not consistently support superiority of ticagrelor, as monotherapy or in combination with aspirin, in terms of efficacy or safety, in patients with atherosclerotic artery disease.

METHODS

Medline, EMBASE, the Cochrane Central Register of Controlled Trials, and scientific session abstracts were searched for trials of patients with coronary or peripheral artery disease (with >1,000 participants and a follow-up ≥3 months) randomly assigned to ticagrelor-based or conventional antiplatelet therapies. Trial-level hazard ratios (HRs) were pooled using a fixed- or random-effect model (in case of significant heterogeneity) with the inverse variance weighting. The primary outcome was all-cause mortality. Other outcomes were myocardial infarction (MI), stroke, and major bleeding.

RESULTS

Overall 77,489 patients received either ticagrelor-based (n = 38,721) or conventional antiplatelet regimens (n = 38,768) in 6 trials. The primary outcome occurred in 4.5% of patients treated with experimental therapy and 4.9% of patients treated with control therapy (HR = 0.91, 95% CI 0.81-1.01; P = .07). Overall, patients treated with ticagrelor-based versus conventional antiplatelet regimens showed no significant difference in terms of all-cause death, MI, stroke, or major bleeding after 20 months. However, in trials of patients with coronary artery disease as primary diagnosis, the risk for all-cause death (HR = 0.84 [0.77-0.91], P < .001) and MI (HR = 0.87 [0.80-0.94], P = .007) was significantly reduced by experimental therapy.

CONCLUSIONS

In patients with atherosclerotic artery disease, the benefit of ticagrelor-based therapies was confined to patients treated for coronary artery disease. The drug significantly reduced the risk for all-cause death and MI without excess risk of bleeding in these patients. In consideration of limitations of subgroup analyses, these results need further validation.

Antiplatelet therapy for peripheral artery disease

Atherosclerotic cardiovascular (CV) disease represents one of leading cause of mortality and morbidity in Western countries. An increased risk of CV events was identified in patients with peripheral arterial diseases (PADs), which include all arterial diseases, other than coronary arteries and the aorta. In particular, lower extremity artery disease (LEAD) and/or carotid artery disease present growing incidence in general population and a consequent increase in mortality and morbidity. Medical treatment, including antiplatelet therapy, is a cornerstone in management of these patients, even when they are treated with endovascular or surgical procedures. Despite their clinical relevance, data on optimal antiplatelet treatment in this clinical setting are lacking and often derived from clinical trials on coronary artery disease and by subgroups analysis. The purpose of this review is to examine the available data from registries, randomized trials and meta-analysis on antiplatelet treatment in patients with LEAD and carotid stenosis with the aim to provide evidence to support clinical decision making.

Antithrombotic therapy in peripheral artery disease: A review of the EUCLID trial results and current ongoing trials

In addition to risk-factor modification, antithrombotic therapy is the hallmark of management to reduce cardiovascular ischemic events in patients with peripheral artery disease (PAD). Currently, the guidelines recommend long-term antiplatelet therapy with aspirin or clopidogrel in this patient population to reduce myocardial infarction, stroke, and vascular death. Past outcomes studies have shown some benefit of ticagrelor, another antiplatelet agent, as compared with clopidogrel in patients with coronary disease and concomitant PAD. However, most recently, the Examining Use of Ticagrelor in Peripheral Artery Disease (EUCLID) trial has shown no additional benefit of ticagrelor over clopidogrel. In this trial, a minority of patients had concomitant coronary artery disease, making it unique to previous studies. The EUCLID trial's evidence of neutrality between clopidogrel and ticagrelor sheds light into the complexity of studying the PAD population and the continued need to meticulously design trials to investigate the optimal therapies. The topics that will be discussed in this review include the role of antiplatelet therapy in the management of patients with PAD, a review of the EUCLID trial results and the important factors to be considered in interpreting the surprising results, and promising recent ongoing clinical trials assessing therapies in the treatment of patients with PAD.