Surgical and Pharmacological Treatment of Peripheral Artery Disease
Peripheral Matters | Marc P. Bonaca, MD, FACC, and Mark A. Creager, MD, FACC
Peripheral artery disease (PAD) is a common condition and the prevalence is increasing worldwide. A Peripheral Artery Disease Compendium recently published in Circulation Research included papers examining knowledge surrounding PAD including the treatment of the condition.
In a review of the pharmacological treatment of PAD, Marc P. Bonaca, MD, FACC, and Mark A. Creager, MD, FACC, examine the therapies for systemic vascular protection to reduce major adverse cardiovascular events (MACE) as well as therapies to reduce limb mortality.
Patients with PAD are at a higher risk of myocardial infarction, stroke, and death. Optimal treatment includes both lifestyle changes such as smoking cessation and exercise as well as medical therapy. Smoking cessation is the most important modifiable risk factor for patients with PAD, with 5-year survival shown to be twice as high in those who quit. Reduced blood flow to the leg can lead to limb morbidity in PAD. Exercise in the most effective noninvasive intervention to improve claudication symptoms. The authors wrote that exercise should be recommended to all PAD patients who do not have contraindications.
Pharmacological therapy for patients includes both lipid lowering and antihypertensive therapies. Statins have been shown to effectively reduce adverse cardiac events in PAD patients and ACC/American Heart Association guidelines recommend high-intensity statins in PAD patients 75 years of age or older. Ongoing trials will help to determine the benefits of nonstatin lipid-lowering therapies in PAD. The target blood pressure for PAD patients is the standard ≤140/90 mm Hg. Data suggest that angiotensin-converting enzyme inhibitors (ACE-I) offer the most benefit, and that beta-blockers can safely be used in patients with an indication such as coronary artery disease.
According to the authors, the use of antiplatelet therapy for prevention in PAD is complex. There is a need to balance the benefit in ischemic risk reduction with the risk of bleeding complications. PAD patients should receive antiplatelet monotherapy such as aspirin or clopidogrel. Warfarin is not indicated unless another indication is present. Pharmacological treatments are greatly underutilized in PAD, with data suggesting that as few as 19-27% of eligible patients receiving statins ACE-I/angiotensin-receptor blockers and antiplatelet therapy.
The second review, written by Shant M. Vartanian, MD, and Michael S. Conte, MD, examined surgical interventions for PAD. Revascularization of the limb plays a central role in the management of symptomatic PAD. The physiological state of the patient and the status of the limb primarily determine the appropriateness and urgency of intervention. Over the last 20 years, there has been an ongoing evolution of revascularizations options. In their review, the authors summarize the principles of surgical revascularization, patient selection and expected outcomes, while highlighting areas in need of further research and technological advancement.
Clinical presentation of PAD is broad and can be classified into three categories: asymptomatic disease, intermittent claudication (IC) and critical limb ischemia (CLI). Symptoms of IC occur only during physical activity, while CLI is a clinical syndrome of chronic, advanced limb ischemia manifested as rest pain, nonhealing ulcerations and necrosis. The fate of the patient and limb is dissimilar in these two conditions.
Patients with symptomatic PAD who are deemed suitable candidates for revascularization should undergo imaging to define the anatomic pattern of occlusive disease. Aortoiliac disease is particularly well suited for endovascular interventions given the excellent durability in larger caliber vessels and the attendant risks of open aortic reconstruction. However, some situations call for open revascularization, such as a concomitant aortic aneurysm, prior failed interventions, or a significant burden of disease. For femoropopliteal disease, technical success for initial treatment can almost always be accomplished with endovascular techniques; however, consideration should be given to the known specific factors that limit durability. The choice of revascularization is even more complicated in tibioperoneal disease, as most patients with CLI have significant comorbidities that translate into shorter life expectancy, and endoluminal interventions in tibioperoneal vessels have poor long-term durability.
Surgical revascularization concepts include endarterectomy, surgical bypass and hybrid approaches. As endovascular interventions evolve, vascular surgeons are increasingly using hybrid approaches—a combination of catheter-based and open techniques to achieve limb revascularization with less invasiveness. Strategies for surgical revascularization of PAD are based on the clinical presentation and the anatomic pattern of occlusive disease. There are three anatomic levels of disease: aortoiliac (inflow), femoropopliteal, and tibiopedal (both outflow).
The authors concluded that the emergence of percutaneous techniques for treating symptomatic PAD has expanded the treatment options but has not changed the fundamental principles of revascularization or the indications for intervention. Instead, the focus is on patient selection. Patient-specific factors are critical in selecting the most efficacious and durable outcome, with particular importance placed on comorbid conditions, estimated life expectancy, functional status, pattern of disease, and availability of conduit.Reference
- Bonaca MP, Creager MA. Circ Res. 2015;116:1579-98.
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