Racial Heterogeneity in Treatment Effects in Peripheral Artery Disease

Improving symptoms, functions, and quality-of-life (ie, health status) is one of the important goals in treatment of patients with peripheral artery disease (PAD).1 However, it is unknown whether health status responses differ by race (black versus white) with alternative PAD treatment modalities. Such differences may exist given the disproportionate burden of PAD in minority populations, and rapid disease progression as compared with white,2 as well as differences in psychosocial and economic factors and possibly differences in exercise level, which is known to improve outcomes in patients with PAD.3,4 Understanding whether black and white respond differently to treatments can help us better support targeted therapy to improve quality of care. This is relevant because until now, supervised exercise (SE) programs for PAD were not available in the United States, and recently, the Centers for Medicare and Medicaid Services agreed to reimburse for SE therapy.5 If there is heterogeneity in response to SE, knowing this difference is important to provide patient-centered care and to get maximum treatment benefit for each unique patient population. The CLEVER trial (Claudication: Exercise Versus Endoluminal Revascularization) randomized patients with claudication from aortoiliac disease to SE, stent therapy (ST), or optimal medical care (OMC). Short-term results indicated superior treadmill walking performance (ie, peak walking time and claudication onset time) with SE than either ST or OMC. Conversely, benefit in PAD-specific health status (Peripheral Artery Questionnaire [PAQ] summary score)6 was more favorable for ST than either SE or OMC.3 Similarly, general quality-of-life benefit as assessed with Short Form-12 Physical Component Summary (SF-12 PCS)7 was similar for ST and SE when compared with OMC.3 Long-term results, however, showed similar and sustained benefits for both ST and SE over OMC in treadmill walking performance, but PAQ summary score was more favorable …