What are the diagnostic approaches and management strategies for peripheral artery disease and peripheral neuropathy?

From the Guidelines

Peripheral artery disease (PAD) and peripheral neuropathy require distinct diagnostic approaches and management strategies, with a focus on aggressive cardiovascular risk factor modification and tight glycemic control for diabetic patients, as recommended by the 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS guideline 1.

Diagnostic Approaches

For PAD diagnosis, clinicians should perform ankle-brachial index (ABI) testing, with values below 0.9 indicating disease, as stated in the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases 1. Additional diagnostics include duplex ultrasound, CT angiography, or MR angiography to assess arterial flow and identify stenosis.

• ABI testing is a non-invasive and cost-effective method for diagnosing PAD.
• Duplex ultrasound, CT angiography, or MR angiography can provide detailed images of the arterial flow and identify stenosis or occlusions.

Management Strategies

Management includes aggressive cardiovascular risk factor modification with antiplatelet therapy (aspirin 75-100mg daily or clopidogrel 75mg daily), statins (atorvastatin 40-80mg daily), smoking cessation, and blood pressure control, as recommended by the 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS guideline 1.

• Antiplatelet therapy can help reduce the risk of myocardial infarction and stroke.
• Statins can help lower LDL-C levels and reduce the risk of cardiovascular events.
• Smoking cessation is crucial for reducing the risk of PAD progression and cardiovascular events.
• Blood pressure control can help reduce the risk of cardiovascular events and slow the progression of PAD.

Exercise Therapy

Exercise therapy, particularly supervised walking programs for 30-45 minutes 3-5 times weekly, improves claudication symptoms, as stated in the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases 1.

• Supervised walking programs can help improve walking distance and reduce claudication symptoms.
• Regular exercise can also help improve overall cardiovascular health and reduce the risk of cardiovascular events.

Revascularization

Severe cases may require revascularization through endovascular procedures or bypass surgery, as recommended by the 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS guideline 1.

• Endovascular procedures, such as angioplasty and stenting, can help improve blood flow and reduce symptoms.
• Bypass surgery can help restore blood flow to the affected limb and reduce the risk of amputation.

Peripheral Neuropathy Management

For peripheral neuropathy, diagnosis begins with clinical assessment using monofilament testing, vibration perception, and nerve conduction studies, as stated in the 2016 IWGDF guidance on the diagnosis, prognosis, and management of peripheral artery disease in patients with foot ulcers in diabetes 1. Management depends on the underlying cause; diabetic neuropathy requires tight glycemic control (HbA1c <7%), while other forms may need specific treatments for their etiology.

• Tight glycemic control can help reduce the risk of neuropathy progression and improve symptoms.
• Pain management often includes gabapentin, pregabalin, duloxetine, or tricyclic antidepressants like amitriptyline.
• Regular foot examinations, proper footwear, and patient education on foot care can help prevent complications like ulceration or infection.

From the FDA Drug Label

The efficacy of the maximum recommended dose of pregabalin capsules for the management of neuropathic pain associated with diabetic peripheral neuropathy was established in three double-blind, placebo-controlled, multicenter studies The efficacy of duloxetine for the management of neuropathic pain associated with diabetic peripheral neuropathy in adults was established in 2 randomized, 12-week, double-blind, placebo-controlled, fixed-dose trials

The diagnostic approaches and management strategies for peripheral artery disease are not directly addressed in the provided drug labels. However, for peripheral neuropathy, the management strategies include the use of:

• Pregabalin capsules, which have been shown to statistically significantly improve the endpoint mean pain score and increase the proportion of patients with at least a 50% reduction in pain score from baseline 2
• Duloxetine, which has been established as effective in the management of neuropathic pain associated with diabetic peripheral neuropathy in adults, with treatment resulting in statistically significantly improved endpoint mean pain scores from baseline and increased proportion of patients with at least a 50% reduction in pain scores from baseline 3 Key points:
• Pregabalin and duloxetine are used for the management of neuropathic pain associated with diabetic peripheral neuropathy
• The efficacy of these medications has been established in multiple clinical trials
• The management of peripheral artery disease is not directly addressed in the provided drug labels

From the Research

Diagnostic Approaches for Peripheral Artery Disease (PAD) and Peripheral Neuropathy

• The ankle-brachial index (ABI) is a widely used diagnostic tool for PAD, but its accuracy can be limited in certain populations, such as those with diabetes or arterial calcification 4.
• The ABI is a simple, non-invasive test that measures the ratio of blood pressure in the ankles to blood pressure in the arms, but it may not be sufficient for diagnosing PAD in asymptomatic adults 5.
• Other diagnostic methods, such as toe pressure measurement, may be more accurate in certain cases, particularly when there is concomitant clinical peripheral neuropathy or high risk of arterial calcification 4.
• For peripheral neuropathy, electromyography (EMG) is an essential diagnostic tool, but its use should be justified based on diagnostic utility and cost 6.
• The Michigan Neuropathy Screening Instrument (MNSI) is a screening tool that can help identify patients with peripheral neuropathy, particularly those with diabetes or chronic limb-threatening ischemia (CLTI) 7.

Management Strategies for PAD and Peripheral Neuropathy

• Supervised exercise and physical therapy may be beneficial for patients with PAD, but the evidence is limited 5.
• Patients with PAD and peripheral neuropathy are at increased risk of amputation, revascularization, and death, and expanding neuropathy screening in vascular surgery clinic visits may help identify patients at higher risk 7.
• The US Preventive Services Task Force (USPSTF) concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for PAD with the ABI in asymptomatic adults 5.
• Well-designed cross-sectional studies are required to evaluate the accuracy of ABI in patients presenting with early symptoms of peripheral arterial disease in all healthcare settings 8.

Screening and Risk Assessment

• The ABI can be used to screen for PAD and cardiovascular disease risk, but its predictive ability needs to be more clearly defined, particularly in patients with diabetes or CLTI 7, 4.
• A significant proportion of patients presenting to vascular specialists for PAD have undiagnosed neuropathy, and screening for peripheral neuropathy may help identify patients at higher risk of adverse outcomes 7.