Inaugural CERTAIN Study Results Published in JAMA Surgery

Wednesday, August 17, 2016

Revascularization better for peripheral arterial disease


Results of the PAD Study found that patients with intermittent claudication, a form of peripheral arterial disease, who had circulation-restoring procedures called revascularization had better quality of life and fewer symptoms a year later than patients who underwent medical management. The inaugural study of the CERTAIN Collaborative and the CERTAIN network, published today in JAMA Surgery, compared two ways to treat intermittent claudication by evaluating outcomes that are important to patients. 

CERTAIN researcher Emily Beth Devine, UW associate professor of pharmacy, and her 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?

"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 Dr. Devine. "Our findings provide the best community-based evidence available to date. The results suggest that those with moderate cases of intermittent claudication may also benefit from surgery or stent placement."

Peripheral arterial disease affects 8 million Americans. In this condition, plaque builds up in the arteries and limits the flow of oxygen. The peripheral arterial disease study looked 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 it is not clear which treatment option is best.

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 study showed that intermittent claudication patients who had revascularization procedures experienced significantly higher function, better quality of life, and fewer symptoms. Comparative effectiveness research is designed to inform healthcare decisions by providing evidence on the effectiveness, benefits, and harms of different treatment options.

The authors of the study wrote that 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 study was conducted through an Agency for Healthcare Research and Quality grant award. David R. Flum, associate chief medical officer for UW Medicine, UW professor of surgery, and director of the Surgical Outcomes Research Center (SORCE), conceived of the project and collaborated with a multidisciplinary team called the Comparative Effectiveness Research Translation Network (CERTAIN) Collaborative. Devine, a member of the UW School of Pharmacy Pharmaceutical Outcomes Research and Policy Program, was the lead comparative effectiveness research methods investigator.

This study is the first of several that build on research for the Surgical Care and Outcomes Assessment Program (SCOAP), a statewide quality improvement registry which Dr. Flum launched in 2005 by enlisting over 91 percent of hospitals across the state of Washington. The data gathered in the registry identifies 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 diseases through the lens of patient-centered care. The intermittent claudication paper published this week 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.