August 19, 2016

UW researchers find revascularization provides greater improvements for patients with peripheral arterial disease

Peripheral arterial disease can cause pain in the legs and make walking uncomfortable.

Peripheral arterial disease can cause pain in the legs and make walking uncomfortable.ThinkStock

Study published in JAMA Surgery compares effectiveness of two ways to treat intermittent claudication by evaluating outcomes that are important to patients

UW researchers found that patients with intermittent claudication, a form of peripheral arterial disease, who had procedures to restore circulation called revascularization had better quality of life and fewer symptoms a year later than patients who underwent medical management.

Emily Beth Devine, PhD, PharmD, MBA, of the University of Washington School of Pharmacy, and colleagues compared the effectiveness of two treatments for intermittent claudication: a medical management program consisting of walking exercise, medicines, and smoking cessation counseling; and revascularization by surgically unblocking clogged blood vessels or by implanting tiny wire mesh tubes called stents into the vessels that help keep arteries open. The study focused on outcomes that matter most to patients: for example, can they climb stairs and walk farther and faster with less pain, has their quality of life improved, and do they experience fewer symptoms?

Dr. Emily B. Devine compared the effectiveness of a medical program against a procedural intervention, focusing on outcomes of greatest importance to patients with Intermittent Claudication.

Dr. Emily B. Devine compared the effectiveness of a medical program against a procedural intervention, focusing on outcomes of greatest importance to patients with Intermittent Claudication.

“Revascularization procedures such as surgery or stents are normally reserved for the most severe symptoms, but we looked at whether these interventions may benefit patients with less severe cases of intermittent claudication,” said Devine. “Our findings provide the best community-based evidence available to date and suggest that those with moderate cases of intermittent claudication may also benefit from surgery or stent placement.”

Peripheral arterial disease (PAD) is a disease affecting 8 million Americans in which plaque builds up in the arteries and limits the flow of oxygen. The peripheral arterial disease study, published in JAMA Surgery, looked at intermittent claudication, which limits the ability to walk. Both medical interventions and revascularization interventions such as angioplasty, stents, and surgical bypass aim to increase walking comfort and distance, but there is inconclusive evidence of the comparative benefit of revascularization given the possible risk of limb loss.

The study was conducted at 15 clinics associated with 11 hospitals in Washington state. Participants were 21 years or older with newly diagnosed or established intermittent claudication. A total of 323 adults were enrolled, with 282 (87 percent) receiving the medical treatment program. At the start of the study, the average duration of disease was longer for participants who received the medical intervention program, while those who underwent revascularization reported more severe disease.

At 12 months, this comparative effectiveness research (CER) study showed that intermittent claudication patients who had revascularization procedures experienced significantly higher function, better quality of life, and fewer symptoms.

“Patients who were treated with surgery or stents reported improvements in walking distance, speed, stair climb, pain, health-related quality of life, and symptoms. These improvements exceeded those of patients who were treated with medicines, smoking cessation counseling and exercise. Results suggest that revascularization is a reasonable alternative to medical management for patients with moderate to severe intermittent claudication, providing important information to inform treatment strategies in the community,” the authors write. Comparative effectiveness research is designed to inform healthcare decisions by providing evidence on the effectiveness, benefits, and harms of different treatment options.

The study was conducted under the auspices of an AHRQ grant written by David R. Flum, MD, MPH, Associate Dean for Research, UW Department of Surgery and the Director of the Surgical Outcomes Research Center (SORCE). He conceived of the research project and collaborated with a multidisciplinary research team called the Comparative Effectiveness Research Translation Network (CERTAIN) Collaborative. Devine, a faculty member in the UW School of Pharmacy Pharmaceutical Outcomes Research and Policy Program (PORPP) was the lead CER methods investigator.

This study is the first of several to come that build on research for Flum’s statewide quality improvement registry, the Surgical Care & Outcomes Assessment Program (SCOAP), which he launched in 2005 by enlisting over 91% of hospitals across the state of Washington. The data gathered in the registry identify best practices to improve patient care.

CERTAIN is a statewide research infrastructure that leverages SCOAP data to study the comparative effectiveness of treatment strategies for a variety of disease states through the lens of patient-centered care. The intermittent claudication study published in JAMA Surgery is the inaugural study of the CERTAIN Collaborative and the CERTAIN network.

This project was supported by grant number R01HS020025 from the Agency for Healthcare Research and Quality. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality.

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The full study, “Effectiveness of a Medical vs Revascularization Intervention for Intermittent Leg Claudication Based on Patient-Reported Outcomes,” may be viewed online at JAMA Surgery.

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