An Update on Diagnosing & Treating PAD

Peripheral arterial disease (PAD) is a common and dangerous condition that affects millions of Americans, especially those with a history of diabetes or smoking. Despite efforts to increase awareness in the medical community, the disease remains largely underdiagnosed. For many patients, PAD is asymptomatic and may not lead to recognizable symptoms. In turn, a diagnosis may be delayed. If left untreated, PAD has been shown in published research to be predictive of heart attack, stroke, leg amputations, and death.

In 2005, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA), along with collaborating societies, released guidelines for the management of PAD. In 2011, the ACCF/AHA updated these guidelines to reflect new data in the diagnosis and treatment of the condition. “The 2011 guideline includes new information for diagnosing PAD, smoking cessation, the use of antiplatelet therapy, and interventions for treating severely ischemic limbs and abdominal aortic aneurysms (AAAs),” says Thom W. Rooke, MD, FACC, who chaired the committee that developed the 2011 guidelines. “The update can assist primary care clinicians, cardiologists, pulmonologists, interventional radiologists, vascular surgeons, and vascular medicine specialists in improving patient care.”

Diagnosing Peripheral Arterial Disease

The 2011 ACCF/AHA guideline includes a recommendation to lower the age at which anklebrachial index (ABI) diagnostic testing should be performed in the practice setting. “Previously, the recommendation was for patients aged 70 or older to receive an ABI,” says Dr. Rooke. “That threshold has been lowered to age 65 or older based on mounting evidence demonstrating that people in this age range have a 20% chance of having either symptomatic or asymptomatic PAD.” Furthermore, ABI diagnostic testing is now recommended for patients aged 50 and older if they have a history of diabetes or smoking because they are considered at especially high risk for PAD.

Smoking Cessation Strongly Recommended by Guidelines

Recommendations for physicians to help people with PAD quit smoking are strengthened in the 2011 ACCF/AHA guideline update (Table 1). Doctors are now recommended to consistently ask current and former smokers about tobacco use at each visit. In addition, physicians should be proactive about offering support through counseling, pharmacologic therapies, and formal smoking cessation programs. “In addition to other health benefits, getting patients to quit smoking can have a significant impact on outcomes in PAD,” says Dr. Rooke. “Smoking cessation can lower risks of disease-related comorbidities, including heart attack, stroke, and lower limb amputation.”

Other Important Guideline Recommendations

In addition to changes in diagnosing PAD and increasing smoking cessation efforts, the 2011 guideline update broadens the indications for using antiplatelet therapies and antithrombotic drugs (Table 2). “The use of therapies that prevent clotting is important when treating patients with PAD,” Dr. Rooke says. Several new Class IIa and IIb recommendations were made in the update, while other recommendations from the 2005 guidelines were modified to reflect new evidence that has emerged in recent years.

Leg artery angioplasty is indicated as a first-line treatment for certain individuals with severe PAD who may require amputation. Balloon angioplasty, however, is not an ideal treatment for all patients with PAD. The guidelines now recommend angioplasty as the initial procedure to improve distal blood flow for patients with limb-threatening lower extremity ischemia and an estimated life expectancy of 2 years or less. Bypass surgery is recommended for these patients if they have an estimated life expectancy of more than 2 years.

New recommendations were also added for managing AAAs. Open or endovascular repair of infrarenal AAAs and common iliac aneurysms is now indicated in patients who are good surgical candidates. Open aneurysm repair can be used in good surgical candidates who cannot comply with the periodic long-term surveillance that is required after endovascular repair. However, it is unknown whether or not patients with infrarenal aortic aneurysms who are at high surgical or anesthetic risk will benefit from endovascular repair.

Looking Forward to Reduce Undetected PAD

When PAD is undetected and poorly managed, it is among the most costly cardiovascular diseases. “We still have a long way to go in order to improve the management of PAD,” says Dr. Rooke. “The 2011 ACCF/AHA guideline update can serve as a roadmap to the most appropriate practices and interventions based on evidence-based science, but opportunities remain to further our knowledge and efforts for prevention and earlier, life-saving interventions. Until more data emerge, promoting use of these guidelines in hospitals and healthcare systems may reduce the burden of PAD and improve clinical outcomes associated with the disease.”