Performing TBI in Patients with Pedal Edema and Absent Pedal Pulses

Rationale for TBI in Patients with Pedal Edema and Absent Pulses

The American College of Cardiology recommends TBI as the diagnostic test when pedal pulses cannot be adequately assessed due to edema, as it provides a more reliable measure of distal perfusion than ankle-brachial index (ABI) in these circumstances 1, 2, 3, 4
Pedal edema can mask palpable pulses and interfere with accurate ABI measurement, making TBI a more reliable alternative for assessing peripheral arterial disease (PAD) in patients with edema 1, 2, 3, 4
TBI is specifically indicated when arterial calcification or edema makes standard ABI measurements unreliable, and is recommended by the American College of Cardiology/American Heart Association guidelines for patients with suspected PAD when standard assessments are compromised 1, 2, 3, 5

TBI should be performed with waveform analysis to provide additional diagnostic information beyond the numerical index, as recommended by the American College of Cardiology 2, 3
A TBI value ≤0.70 is considered abnormal and diagnostic of PAD, even when ABI cannot be reliably measured due to edema, according to the American College of Cardiology guidelines 2, 3, 4
When performing TBI in patients with edema, ensure proper positioning and careful placement of the toe cuff to minimize the effect of fluid accumulation on measurement accuracy, as suggested by the American College of Cardiology 5

In patients with pedal edema and absent pulses, consider supplementing TBI with transcutaneous oxygen pressure (TcPO2) and/or skin perfusion pressure (SPP) measurements for a more comprehensive assessment of tissue perfusion, as recommended by the American College of Cardiology 2, 3
For patients with suspected chronic limb-threatening ischemia (CLTI), TBI with waveforms should be combined with other perfusion assessments to determine the likelihood of wound healing and need for revascularization, according to the American College of Cardiology guidelines 2, 3, 4

If TBI confirms PAD (≤0.70), further anatomic assessment with duplex ultrasound, CTA, MRA, or invasive angiography may be indicated if revascularization is being considered, as recommended by the American College of Cardiology 1, 3
Patients with confirmed PAD should receive guideline-directed management including risk factor modification, antiplatelet therapy, and consideration for revascularization based on symptom severity, according to the American College of Cardiology guidelines 1, 3