Search

Background: Patients with peripheral artery disease (PAD) are at heightened risk of acute limb ischemia (ALI), a thrombotic event associated with amputation, disability, and mortality. Previous lower extremity revascularization (LER) is associated with increased ALI risk in chronic PAD. However, the pattern of risk, clinical correlates, and outcomes after ALI early after LER are not well-studied, and effective therapies to reduce ALI post-LER are lacking. Methods: The VOYAGER PAD trial (Vascular Outcomes Study of ASA [Acetylsalicylic Acid] Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for PAD; rNCT02504216) randomized patients with PAD undergoing LER to rivaroxaban 2.5 mg twice daily or placebo on a background of low-dose aspirin. The primary outcome was a composite of ALI, major amputation of vascular cause, myocardial infarction, ischemic stroke, or cardiovascular death. ALI was prospectively ascertained and adjudicated by a blinded committee. The cumulative incidence of ALI was calculated using Kaplan-Meier estimates, and Cox proportional hazards models were used to generate hazard ratios and associated CIs. Analyses were performed as intention-to-treat. Results: Among 6564 patients followed for a median of 2.3 years, 382 (5.8%) had a total of 508 ALI events. In placebo patients, the 3-year cumulative incidence of ALI was 7.8%. After multivariable modeling, previous LER, baseline ankle-brachial index P =0.0001), with benefit starting early (HR, 0.45 [95% CI, 0.24–0.85]; P =0.0068 at 30 days). Benefit was present for severe ALI (associated with death, amputation, or prolonged hospitalization and intensive care unit stay, HR, 0.58 [95% CI, 0.40–0.83]; P =0.003) and regardless of LER type (surgical versus endovascular revascularization, P interaction=0.42) or clopidogrel use ( P interaction=0.59). Conclusions: After LER for symptomatic PAD, ALI is frequent, particularly early after LER, and is associated with poor prognosis. Low-dose rivaroxaban plus aspirin reduces ALI after LER, including ALI events associated with the most severe outcomes. The benefit of rivaroxaban for ALI appears early, continues over time, and is consistent regardless of revascularization approach or clopidogrel use.

Background: The VOYAGER PAD trial (Vascular Outcomes Study of ASA Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for Peripheral Artery Disease) demonstrated superiority of rivaroxaban plus aspirin versus aspirin to reduce major cardiac and ischemic limb events after lower extremity revascularization. Clopidogrel is commonly used as a short-term adjunct to aspirin after endovascular revascularization. Whether clopidogrel modifies the efficacy and safety of rivaroxaban has not been described. Methods: VOYAGER PAD was a phase 3, international, double-blind, placebo-controlled trial in patients with symptomatic PAD undergoing lower extremity revascularization randomized to rivaroxaban 2.5 mg twice daily plus 100 mg aspirin daily or rivaroxaban placebo plus aspirin. The primary efficacy outcome was a composite of acute limb ischemia, major amputation of a vascular cause, myocardial infarction, ischemic stroke, or cardiovascular death. The principal safety end point was TIMI (Thrombolysis in Myocardial Infarction) major bleeding, with International Society on Thrombosis and Haemostasis major bleeding a secondary safety outcome. Clopidogrel use was allowed at the discretion of the investigator for up to 6 months after the qualifying revascularization. Results: Of the randomized patients, 3313 (50.6%) received clopidogrel for a median duration of 29.0 days. Over 3 years, the hazard ratio for the primary outcome of rivaroxaban versus placebo was 0.85 (95% CI, 0.71–1.01) with clopidogrel and 0.86 (95% CI, 0.73–1.01) without clopidogrel without statistical heterogeneity ( P for interaction=0.92). Rivaroxaban resulted in an early apparent reduction in acute limb ischemia within 30 days (hazard ratio, 0.45 [95% CI, 0.14–1.46] with clopidogrel; hazard ratio, 0.48 [95% CI, 0.22–1.01] without clopidogrel; P for interaction=0.93). Compared with aspirin, rivaroxaban increased TIMI major bleeding similarly regardless of clopidogrel use ( P for interaction=0.71). With clopidogrel use >30 days, rivaroxaban was associated with more International Society on Thrombosis and Haemostasis major bleeding within 365 days (hazard ratio, 3.20 [95% CI, 1.44–7.13]) compared with shorter durations of clopidogrel ( P for trend=0.06). Conclusions: In the VOYAGER PAD trial, rivaroxaban plus aspirin reduced the risk of adverse cardiovascular and limb events with an early benefit for acute limb ischemia regardless of clopidogrel use. The safety of rivaroxaban was consistent regardless of clopidogrel use but with a trend for more International Society on Thrombosis and Haemostasis major bleeding with clopidogrel use >30 days than with a shorter duration. These data support the addition of rivaroxaban to aspirin after lower extremity revascularization regardless of concomitant clopidogrel, with a short course (≤30 days) associated with less bleeding. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02504216.

Introduction: Chronic kidney disease (CKD) is common among patients undergoing lower extremity revascularization (LER) for peripheral artery disease (PAD) and identifies a population at high risk for adverse outcomes. The VOYAGER PAD trial demonstrated the efficacy of rivaroxaban in PAD patients after LER on a composite of cardiovascular (CV) and limb ischemic events (HR 0.85 vs placebo, 95% CI 0.76-0.96; p=0.009); this analysis examines the prespecified subgroup of patients with CKD. Methods: VOYAGER PAD (NCT02504216) was a double-blind, placebo-controlled trial which randomized PAD patients with recent LER to rivaroxaban 2.5 mg twice daily or placebo on a background of aspirin 100 mg daily. The primary endpoint was a composite of acute limb ischemia, major amputation for vascular cause, myocardial infarction, ischemic stroke or CV death. The primary safety endpoint was TIMI major bleeding. Analysis of the intention-to-treat population utilized Kaplan Meier estimates and Cox proportional-hazards models. Results: Among 6319 VOYAGER patients with baseline estimated glomerular filtration rate (eGFR), 21% were 2 . During 28-month (median) follow up, patients with CKD had a higher rate of major CV and limb events: placebo group 10.0 events/100 patient-years (95% CI 8.5, 11.8) for eGFR Conclusions: Rivaroxaban reduced major CV and limb events in patients with PAD undergoing LER, including those with CKD, a particularly high-risk population.

Background: Prior studies suggest that atherosclerotic vascular disease may be associated with risk of venous thromboembolism (VTE), though the relationship remains uncertain and has not been well-studied in peripheral artery disease (PAD) after lower extremity revascularization (LER). Hypothesis: We hypothesized that patients with PAD undergoing LER are at risk for VTE and that this risk may be reduced by low-dose rivaroxaban plus aspirin versus aspirin alone. Methods: VOYAGER PAD randomized 6,564 PAD patients undergoing LER to rivaroxaban 2.5 mg twice daily or placebo on a background of aspirin 100 mg daily. Clopidogrel was allowed for up to 6 months. Patients could not be enrolled if they had an indication for therapeutic anticoagulation, including secondary prevention of VTE. Symptomatic VTE was a prespecified secondary endpoint. Results: Over a median of 28 months, there were 66 patients with VTE. In patients randomized to placebo, risk for VTE accrued steadily after randomization at a rate of ~0.5% per year resulting in a 3-year rate of 1.66%. Compared with placebo, rivaroxaban reduced the risk of VTE by 39% (HR 0.61, 95% CI 0.37-1.00, p=0.047), with benefit apparent early and sustained over time (Figure). The efficacy of rivaroxaban was not modified by use of clopidogrel at randomization (without clopidogrel HR 0.55, 95% CI 0.29, 1.07; with clopidogrel HR 0.69, 95% CI 0.32, 1.48; p-interaction = 0.67). Conclusions: PAD is associated with continuous and linearly increasing risk for VTE after LER. A strategy of low-dose rivaroxaban plus aspirin versus aspirin alone reduced this risk by 39% with benefits apparent early and continued over time. The addition of clopidogrel does not modify this benefit. VTE, along with arterial thrombotic events, is part of the adverse thrombotic risk profile in PAD patients, and low-dose rivaroxaban plus aspirin provides protection against venous and arterial thrombosis.

Peripheral artery disease affects >200 million people worldwide and is associated with significant limb and cardiovascular morbidity and mortality. Limb revascularization is recommended to improve function and quality of life for symptomatic patients with peripheral artery disease with intermittent claudication who have not responded to medical treatment. For patients with critical limb ischemia, the goals of revascularization are to relieve pain, help wound healing, and prevent limb loss. The baseline risk of cardiovascular and limb-related events demonstrated among patients with stable peripheral artery disease is elevated after revascularization and related to atherothrombosis and restenosis. Both of these processes involve platelet activation and the coagulation cascade, forming the basis for the use of antiplatelet and anticoagulant therapies to optimize procedural success and reduce postprocedural cardiovascular risk. Unfortunately, few high-quality, randomized data to support use of these therapies after peripheral artery disease revascularization exist, and much of the rationale for the use of antiplatelet agents after endovascular peripheral revascularization is extrapolated from percutaneous coronary intervention literature. Consequently, guideline recommendations for antithrombotic therapy after lower limb revascularization are inconsistent and not always evidence-based. In this context, the purpose of this structured review is to assess the available randomized data for antithrombotic therapy after peripheral arterial revascularization, with a focus on clinical trial design issues that may affect interpretation of study results, and highlight areas that require further investigation.

Objective— The objective of this study was to investigate the effects of lowering plasma triglycerides (TGs) on endothelial function and gain insight into the role played by free fatty acids (FFAs) in hypertriglyceridemia-associated vascular dysfunction. Methods and Results— Eleven hypertriglyceridemic subjects without coronary artery disease, diabetes, elevated low-density lipoprotein cholesterol, tobacco use, or hypertension were studied using a randomized, double-blinded, crossover design (fenofibrate and placebo, 14 days). After each regimen, forearm blood flow was assessed by plethysmography in response to arterial acetylcholine, nitroprusside, and verapamil infusion. Hourly plasma TGs, FFA, glucose, and insulin were measured during a 24-hour feeding cycle to characterize the metabolic environment. Changes in plasma FFA after intravenous heparin were used to estimate typical FFA accumulation in the luminal endothelial microenvironment. Fenofibrate lowered plasma TG ( P P P P P P P P P =0.054) and post-heparin ( P =0.028) FFA. Conclusions— Vascular smooth muscle function significantly improves after lowering plasma TG without changes in confounding lipoproteins or insulin resistance. The data raise additional questions regarding the role of FFA in hypertriglyceridemia-associated vascular dysfunction.

A predominance of small LDL particles (subclass phenotype B), as determined by gradient-gel electrophoresis is found among patients with myocardial infarction. Despite physical differences in phenotype A and B particles, differences in lipid composition of particles in these phenotypes have yet to be reported in an unselected population of males and females. The present study used lipid/apoB ratios to analyze the amount of lipid per LDL particle, isolated by density-gradient ultracentrifugation, in 70 healthy subjects. Relative to apoB, the LDL particles from phenotype B subjects were found to contain less free cholesterol (0.391±0.05 versus 0.465±0.05; mean±SD; P P P P =NS) despite higher plasma triglyceride levels in the phenotype B subjects. LDL size and buoyancy were positively correlated with particle free cholesterol, phospholipid, and cholesteryl ester but not with particle triglyceride. These data suggest that the physical properties of LDL from subjects with phenotype A and B reflect their lipid composition. The compositional differences between LDL particles of the two phenotypes may provide new insight into the increased risk of myocardial infarction in subjects with small, dense LDL.