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 (TcPO); 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 TcPO <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 TcPO <10 mm Hg. None of these methods performed before surgery was able to predict outcome in the revascularized patients.

Disparities Between International Guidelines (AHA/ESC/ESVS/ESVM/SVS) Concerning Lower Extremity Arterial Disease: Consensus of the French Society of Vascular Medicine (SFMV) and the French Society for Vascular and Endovascular Surgery (SCVE)

“…In contrast, a systolic toe pressure <30 mm Hg or a TcPO 2 <30 mm Hg tripled the risk of major amputation at 1 year. 216 These data confirm the poor reliability of ankle pressure in this population including many patients with diabetes and/or renal insufficiency. 46 The ESVM recently advocated a strategy comprising the measurement of ankle pressure in a nonspecialized facility as a preliminary test but defining toe pressure as the key parameter to be evaluated in any patient suspected of CLI but manifesting a normal or high ankle pressure.…”

Global vascular guidelines on the management of chronic limb-threatening ischemia

“…It should be present for >2 weeks and be associated with one or more abnormal hemodynamic parameters. These parameters include an ankle-brachial index (ABI) <0.4 (using higher of the dorsalis pedis [DP] and posterior tibial [PT] arteries), absolute highest AP <50 mm Hg, absolute TP <30 mm Hg, 169 Tissue loss related to CLTI includes gangrene of any part of the foot or nonhealing ulceration present for at least 2 weeks. It should be accompanied by objective evidence of significant PAD (eg, WIfI ischemia grade $1).…”

Applicability of Transcutaneous Oxygen Tension Measurement in the Assessment of Chronic Limb-Threatening Ischemia

“…Moreover, the usefulness of the ankle systolic pressure, imbedded in the WIfI classification, to predict the risk of major amputation in CLTI is currently under debate. 67 Especially in patients with CLTI with concomitant diabetes mellitus or chronic renal failure, TcPO 2 seems more reliable in comparison to current macrovascular diagnostics. 68 Furthermore, other factors in method of TcPO 2 use should be addressed to provide an adequate risk stratification scheme for TcPO 2 , such as positioning of the patient (supine vs sitting) and additional oxygen inhalation, both methods have proven to increase the predictive value of wound healing prognosis.…”