Treating leg pain from peripheral artery disease – identifying durable solutions

In people with peripheral artery disease (PAD), arteries that have become narrowed by fatty deposits or calcium buildup cannot distribute enough blood to the legs or arms to meet demand. In its more severe forms, PAD, a common condition affecting some 8.5 million Americans, causes pain with walking, a condition known as claudication.

Claudication and PAD are often successfully treated through lifestyle modifications. Quitting smoking and increasing exercise, as well as some medications, can relieve symptoms by improving circulation.

Meanwhile, the use of more invasive procedures to treat claudication, such as balloon angioplasty and stenting, has increased rapidly in the last decade, even though the durability and effectiveness of these treatments, and which patients are more likely to benefit from them, are largely unknown.

“There’s a big concern about whether we’re over-treating this disease – and we don’t really know if that’s true because no one has studied the durability of these interventions long-term,” Nicholas Osborne, M.D., M.S., an assistant professor of vascular surgery in the U-M Medical School, and a vascular surgeon with Michigan Medicine, explains.

Under one of the first career development awards from the American Heart Association, Osborne will attempt to answer some of these open questions about these so-called endovascular interventions, including what factors may guide physicians in choosing among the different treatment options for patients experiencing claudication.

Although many have suggested that monetary incentives have driven the proliferation of endovascular interventions, the true motivations and provider perceptions of the effectiveness of these treatments are unclear.

Part of the challenge in evaluating the long-range risks and benefits of these procedures is a lack of long-term data to answer these questions. Following surgical patients over time through a registry would be prohibitively expensive, as well as difficult to track individuals over multiple years or decades.

Administrative data available through Medicare or other sources, meanwhile, do not capture the level of detail needed to understand these issues. And existing clinical trial data frequently exclude the populations most commonly treated for claudication, who generally are older, have a higher incidence of diabetes, more often smoke, and have more severe disease.

Osborne’s project will create a novel longitudinal database of patients diagnosed with claudication from Veterans Health Administration (VHA) records using natural language processing tools (which is a way of extracting relevant clinical information from data that may not have a standard format, like providers’ notes and dictations). The database will be used to examine the long-term effectiveness of endovascular treatment by comparing outcomes to those of patients who underwent medical therapy only.

The project will also examine provider perceptions of the effectiveness of endovascular interventions and motivators of claudication treatment choices within a statewide multi-specialty collaborative, the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2). BMC2 member hospitals and providers across the state work together to share best practices and data to improve the quality of care in focused areas.

“The goal of this work is to develop a better understanding about these treatments that will better equip patients and providers to make decisions about managing this condition,” Osborne says. “Long term, we hope this will lead to the development of programs to improve the care of patients with claudication, reduce unnecessary procedures, improve communication, and set clear expectations for care.”