Studies Offer New Insights into Peripheral Arterial Disease

Targeted research designed to accelerate understanding of disease status

Peripheral Arterial Disease Monitoring Ankle Cuffs

Two recently published studies offer new insights into treatments for peripheral arterial disease (PAD), a condition with limited therapeutic options and poor outcomes. Duke interventional cardiologist Jennifer A. Rymer, MD, MBA, was lead author for both studies and one of several Duke specialists contributing to the analyses.

One study reviewed outcomes related to changes in symptom classification; the other examined the relationship between changes in health status instrument scores and cardiovascular and limb events. Both were based on data from a large-scale trial of more than 13,800 patients with PAD comparing the effectiveness of ticagrelor and clopidogrel.

The EUCLID (Examining Use of Ticagrelor in Symptomatic Peripheral Artery Disease) trial, which ended in 2016, did not demonstrate any significant differences in cardiovascular or acute limb events for patients who received ticagrelor versus clopidogrel. But the rich data available from the trial remains a valuable resource for cardiologists evaluating the characteristics and outcomes of patients with PAD.

“Cardiologists know a great deal about treating patients with coronary artery disease (CAD), but as a field, we are not as well-versed in treating patients with PAD. Unfortunately, PAD oftentimes goes unrecognized, and patients do not receive therapies, such as statins, to reduce risks,” says Rymer. The two studies were designed to examine additional ways to monitor progression of PAD, including changes in patient-reported outcomes and changes in symptom classification.

The study published in October in Circulation: Cardiovascular Interventions, an American Heart Association journal, determined that worsening symptom classification over 12 months was associated with an increased risk of all-cause death, amputation and a composite of cardiovascular death, myocardial infarction, or stroke. In addition to Rymer, Duke Health and Duke Clinical Research Institute contributors included Manesh R. Patel, MD, W. Schuyler Jones, MD, Frank Rockhold, PhD, ScM, Dennis Narcisse, MD, MS, and Hillary Mulder.

Using scores to predict clinical outcomes

Reviewing nearly 13,000 patients from the EUCLID trial, researchers examined changes in the Rutherford classification of PAD symptoms over 12 months. Patients with worsening symptom classification (Rutherford classification) over 12 months were more likely to have comorbidities, such as diabetes, and a prior history of cardiovascular disease. This decline was associated with an increased risk of mortality.

In the other study, published in September in The Journal of the American Heart Association, Rymer and colleagues measured patients’ performance using several well-known self-reported health status instruments, including the EuroQol 5-Dimension (EQ-5D), the Visual Analog Scale (VAS), and the Peripheral Artery Questionnaire. The EQ-5D is a generic health status instrument which includes five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is then ranked to describe the state of a patient’s health.

Improvement in the EQ-5D and the VAS over 12 months was associated with a reduced risk in subsequent major adverse cardiovascular or lower-extremity revascularization events.

In the future, clinicians may be able to use the scores on these instruments (and changes in scores) to predict clinical outcomes. “We are working to determine an effective way to measure future risk for these patients,” Rymer adds. “Can we develop a tool, a classification system, or clinical measurement that will improve our understanding of the status of a patient’s disease? These instruments may help us accomplish that.”