Antithrombotic Therapy and Major Adverse Limb Events in Peripheral Artery Disease

Long-Term Adverse Limb Events After Femoral Artery Endovascular Revascularization: The Boston FAROUT Study

Background

: Patient, lesion, and procedural characteristics may impact the long-term risks of adverse limb outcomes differently after successful endovascular revascularization for lower extremity peripheral artery disease. The study objective was to assess the relationships of patient, lesion, and procedural characteristics to the subsequent risk of major and minor adverse limb events over the decade after successful endovascular revascularization of the superficial femoral artery for chronic limb-threatening ischemia (CLTI) or lifestyle-limiting claudication.

Methods

A retrospective cohort of patients who underwent endovascular revascularization between 2003-2011 were followed for a median of 9.3 (IQR, 6.8-11.1) years. Hazard ratios (HR) and 95% CI from Cox proportional hazards models assessed the risk of major adverse limb events (MALE) (major amputation, bypass, or thrombolysis) or minor revascularization, MALE alone, and minor revascularization alone.

Results

There were 232 index limb revascularizations in 185 patients. Longer lesion length was associated with a higher risk of MALE or minor revascularization (HR, 2.09; 95% CI, 1.22-3.60) and minor revascularization alone (HR, 2.53; 95% CI, 1.39-4.61). Current smoking was linked with minor revascularization (HR, 3.83; 95% CI, 1.54-9.56). CLTI was associated with MALE or minor revascularization (HR, 1.89; 95% CI, 1.09-3.29), and MALE alone (HR, 7.43; 95% CI, 3.11-17.79). Black race/ethnicity (HR, 4.74; 95% CI, 1.51-14.9) and low-density lipoprotein >100 mg/dL (HR, 2.76; 95% CI, 1.20-6.35) were linked to MALE alone.

Conclusions

Factors related to MALE differed from those related to minor revascularization. Lesion length and smoking were linked to minor revascularization, whereas CLTI, Black race/ethnicity, and elevated low-density lipoprotein were linked to MALE.

Methods, design, and initial results of an angiographic core lab from VOYAGER-PAD

Background: Anatomy is critical in risk stratification and therapeutic decision making in coronary disease. The relationship between anatomy and outcomes is not well described in PAD. We sought to develop an angiographic core lab within the VOYAGER-PAD trial. The current report describes the methods of creating this core lab, its study population, and baseline anatomic variables. Methods: Patients undergoing lower-extremity revascularization for symptomatic PAD were randomized in VOYAGER-PAD. The median follow up was 2.25 years. Events were adjudicated by a blinded Clinical Endpoint Committee. Angiograms were collected from study participants; those with available angiograms formed this core lab cohort. Angiograms were scored for anatomic and flow characteristics by trained reviewers blinded to treatment. Ten percent of angiograms were evaluated independently by two reviewers; inter-rater agreement was assessed. Clinical characteristics and the treatment effect of rivaroxaban were compared between the core lab cohort and noncore lab participants. Anatomic data by segment were analyzed. Results: Of 6564 participants randomized in VOYAGER-PAD, catheter-based angiograms from 1666 patients were obtained for this core lab. Anatomic and flow characteristics were collected across 16 anatomic segments by 15 reviewers. Concordance between reviewers for anatomic and flow variables across segments was 90.5% (24,417/26,968). Clinical characteristics were similar between patients in the core lab and those not included. The effect of rivaroxaban on the primary efficacy and safety outcomes was also similar. Conclusions: The VOYAGER-PAD angiographic core lab provides an opportunity to correlate PAD anatomy with independently adjudicated outcomes and provide insights into therapy for PAD. (ClinicalTrials.gov Identifier: NCT02504216).

Contemporary Medical Management of Peripheral Artery Disease

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis. Modifiable risk factors including cigarette smoking, dyslipidemia, diabetes, poor diet quality, obesity, and physical inactivity, along with underlying genetic factors contribute to lower extremity atherosclerosis. Patients with PAD often have coexistent coronary or cerebrovascular disease, and increased likelihood of major adverse cardiovascular events, including myocardial infarction, stroke and cardiovascular death. Patients with PAD often have reduced walking capacity and are at risk of acute and chronic critical limb ischemia leading to major adverse limb events, such as peripheral revascularization or amputation. The presence of polyvascular disease identifies the highest risk patient group for major adverse cardiovascular events, and patients with prior critical limb ischemia, prior lower extremity revascularization, or amputation have a heightened risk of major adverse limb events. Medical therapies have demonstrated efficacy in reducing the risk of major adverse cardiovascular events and major adverse limb events, and improving function in patients with PAD by modulating key disease determining pathways including inflammation, vascular dysfunction, and metabolic disturbances. Treatment with guideline-recommended therapies, including smoking cessation, lipid lowering drugs, optimal glucose control, and antithrombotic medications lowers the incidence of major adverse cardiovascular events and major adverse limb events. Exercise training and cilostazol improve walking capacity. The heterogeneity of risk profile in patients with PAD supports a personalized approach, with consideration of treatment intensification in those at high risk of adverse events. This review highlights the medical therapies currently available to improve outcomes in patients with PAD.

Efficacy and safety of DOACs in patients with peripheral arterial disease: A systematic review and meta-analysis

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs) in patients with peripheral arterial disease are not completely understood. Therefore, we conducted a meta-analysis to explore the effects of DOACs in this population.

METHODS

We systematically searched the PubMed, Cochrane Library, and Web of Science till April 2020 for relevant randomized controlled trials and observational studies, with no linguistic restrictions. The efficacy outcomes were cardiovascular death, stroke, myocardial infraction, major adverse cardiovascular events (MACE), acute limb ischemia, amputation, and target lesion revascularization. The safety outcome was major bleeding events. Random effects risk ratios with 95% confidence intervals were calculated.

RESULTS

A total four randomized controlled trials were included in this meta-analysis. Among peripheral arterial disease patients, DOACs did not reduce the risk of cardiovascular death (RR = 1.02 95%CI 0.75-1.37, P = 0.92), stroke (RR = 0.73 95%CI 0.46-1.14, P = 0.16), myocardial infraction (RR = 0.85 95%CI 0.70-1.03, P = 0.10), MACE (RR = 0.73 95%CI 0.46-1.14, P = 0.16), or amputation (RR = 0.73 95%CI 0.46-1.14, P = 0.16) compared with control. However, DOACs were associated with reduction in acute limb ischemia (RR = 0.67 95%CI 0.55-0.80, P < 0.01) and target lesion revascularization (RR = 0.89 95%CI 0.81-0.99, P = 0.02) at the expense of major bleeding events (RR = 1.43 95%CI 1.16-1.77, P < 0.01) compared with control.

CONCLUSIONS

Based on current evidence, no significant difference in cardiovascular death, stroke, myocardial infraction, MACE, and amputation was found when DOACs were compared to antiplatelet monotherapy. The benefits of preventing target lesion revascularization and acute limb ischemia were balanced by amplified risk of major bleeding. Larger randomized controlled trials are needed to figure out the uncertainty around efficacy and safety of medications for peripheral arterial disease.

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.