Comparison of Ankle Pressure,Systolic Toe Pressure,and Transcutaneous Oxygen Pressure to Predict Major Amputation After 1 Year in the COPART Cohort

Abstract

The hemodynamic definition of critical limb ischemia (CLI) has evolved over time but remains controversial. We compared the prediction of major amputation by 3 hemodynamic methods. Patients were selected from the Cohorte des Patients ARTériopathes cohort of patients hospitalized for peripheral arterial disease. Patients with CLI were enrolled according to the Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease II definition and followed up for at least 1 year. We compared the major amputation rate according to initial ankle pressure (AP), systolic toe pressure (STP), and forefoot transcutaneous oxygen pressure (TcPO₂); 556 patients were included and divided into surgical (264) and medical (292) groups. The AP failed to identify 42% of patients with CLI. After 1 year, 27% of medical and 17% of surgical patients had undergone major amputation. The TP <30 mm Hg predicted major amputation in the whole sample and in the medical group (odds ratio [OR] 3.5 [1.7-7.1] and OR 5 [2-12.4], respectively), but AP did not. The TcPO₂ <10 mm Hg also predicted major amputation (OR 2.3 [1.5-3.5] and OR 3.8 [2.1-6.8]). The best predictive thresholds to predict major amputation were STP <30 mm Hg and TcPO₂ <10 mm Hg. None of these methods performed before surgery was able to predict outcome in the revascularized patients.