Table 3.

Potential Characteristics of Trials Assessing PAD Symptoms (Not Cardiovascular Morbidity/Mortality)

	Intermittent Claudication		Critical Limb Ischemia
	Medical Therapies	Revascularization Therapies	Medical Therapies	Revascularization Therapies
Patient selection	Intermittent claudication for >6 mo and ABI <0.9	Intermittent claudication for > 6 mo and ABI <0.9	Pain at rest or ulceration/gangrene of the foot or toes and Ankle pressure ≤50 –70 mm Hg or toe pressure ≤30 –50 mm Hg	Pain at rest or ulceration/gangrene of the foot or toes and Ankle pressure ≤50 –70 mm Hg or toe pressure ≤30 –50 mm Hg
Trial design	RCT double-blind	RCT with at least blinded end-point assessment	RCT double-blind	RCT with at least blinded end-point assessment
Duration	6 mo–1 y	1–2 y	6 mo–1 y	1–2 y
Primary efficacy end point	Peak walking time*	Peak walking time*	Major amputation±death, MI, CVA	Major amputation±death, MI, CVA
Secondary end points	Claudication onset time	Claudication onset time	Complete ulcer healing	Complete ulcer healing
	6-min walk	6-min walk	Pain relief	Pain relief
	Quality of life	Quality of life	Quality of life	Quality of life

ABI indicates ankle-brachial index; CVA, cerebrovascular accident; MI, myocardial infarction; PAD, peripheral artery disease; and RCT, randomized, controlled trial. Medical therapies include pharmacological or cell-based therapies; revascularization includes open surgical or percutaneous methods.

^*The 6-minute walking distance may be a more appropriate primary end point than peak walking time if the subject group is frail or if exercise therapy with a treadmill is in 1 arm of a trial and could lead to a learning/training effect.