Table 6

PARC Functional/Clinical Outcome Definitions for Patients With Intermittent Claudication and Critical Limb Ischemia

Intermittent ClaudicationRef. #
Walking/functional capacity definitionsPeak walking time(s)Claudication onset time(s)6-min walk test (feet/min)
Assessed using a graded treadmill protocol that records the longest time of exercise limited by maximally tolerated claudication pain.Assessed using a graded treadmill protocol that records the time during exercise at the onset of claudication pain. Defines a clinically relevant endpoint, and may be responsive to treatment effect.Assessed on an unobstructed course of 50 or 100 feet. Measures the maximal distance walked after 6 min, regardless of whether or not the patient stops to rest (rest periods are acceptable).(1,9,15)
Quality of life (recommended assessment tools)Walking Impairment QuestionnairePeripheral Artery Questionnaire(30,31)
A validated disease-specific assessment of patient-reported outcomes that quantifies the patient’s ability to walk a defined distance, speed, and stairs.A disease-specific health status questionnaire that quantifies the patient’s physical limitations, symptoms, social function, treatment satisfaction, and quality of life.
Clinical assessmentsChange in symptom classificationClinical failure(9,32)
Report the change in symptom classification on the basis of PARC classificationNeed for major repeat revascularization (repeat endovascular intervention, thrombolysis, open bypass, open revision of existing bypass) or lower extremity amputation.
Critical Limb Ischemia
Amputation definitionsLower extremity amputationMajor amputationMinor amputation(8,9,32,33)
Any procedure that results in the removal of bone and tissue from the lower extremity.Any procedure that results in an amputation at the level of the ankle or above;
  • Below knee amputation—amputation affecting the tibia at any point below the knee and above the ankle;

  • Above knee amputation—amputation above the knee, affecting the femur at any level.

Any procedure that results in an amputation below the ankle, including the foot or toe(s).
Clinical assessmentMajor adverse limb eventsWound healingIschemic pain relief(7,8,24)
Above-ankle amputation of the index limb or major repeat revascularization (new bypass graft, jump/interposition graft revision, or thrombectomy/thrombolysis).Complete epithelialization of an ischemic wound of target limb persistent for at least 14 days.Improvement in (or relief of) pain of target limb for at least 2 weeks using visual analogue scale.

Abbreviations as in Tables 2 and 5.