ABI (ABPI) Measurement
Non-invasive assessment of arterial blood flow in the legs – particularly important in chronic wounds.
What is the ABI?
The Ankle-Brachial Index (ABI), also known as the Ankle-Brachial Pressure Index (ABPI), compares the systolic blood pressure at the ankle with the systolic blood pressure at the upper arm. It provides an objective indication of how well the legs and feet are supplied with arterial blood. [1, 2, 3]
The ABI is a simple, non-invasive assessment used to detect peripheral arterial disease (PAD). Reduced arterial blood flow can significantly impair wound healing. The ABI is therefore particularly important in chronic wounds, ulcers and diabetic foot ulcers. [2, 3, 4]
The ABI helps determine whether the tissue in the foot is receiving an adequate supply of arterial blood.
How is the ABI measured?
The measurement is performed while the patient is resting in the supine position. Blood pressure cuffs are placed on the upper arms and ankles. The systolic blood pressure values are then measured. [1, 2]
The ABI is calculated from the ratio of the systolic ankle pressure to the systolic upper-arm pressure:
ABI = systolic ankle arterial pressure / systolic upper-arm pressure
With automated measurement, the MESI mTABLET ABI performs the measurement and calculates the values. The system uses oscillometric plethysmography and automatically displays the measurement results. [1, 2]
What do the ABI values mean?
- ABI ≤ 0.90: indicates clinically relevant peripheral arterial disease. [3]
- ABI 0.91–0.99: borderline; PAD cannot be reliably excluded. [2, 3]
- ABI 1.00–1.40: generally considered within the normal range. [2, 5]
- ABI > 1.40: may indicate arteries that are severely stiffened or cannot be compressed sufficiently. The ABI may therefore not be reliable. [2, 5]
What does an ABI > 1.40 mean?
A very high ABI does not automatically mean that arterial blood flow is particularly good. In severely stiffened arteries, for example in possible medial arterial calcification (Mönckeberg sclerosis), the cuff may not be able to compress the artery sufficiently. This can result in an artificially high measured value. [2, 5]
An ABI above 1.40 therefore does not by itself prove medial arterial calcification. Rather, it indicates that the ABI may not be reliably interpretable. In this situation, further vascular assessment should be performed. [2, 3, 5]
ABI measurement at WundPal
In patients with chronic or poorly healing wounds, ABI measurement can be an important part of wound and vascular assessment. The result is always considered together with the wound, symptoms, risk factors and other clinical findings. [3, 4]
ABI measurement is an assessment of arterial vascular status and does not replace comprehensive vascular diagnostics. If the result is abnormal or cannot be interpreted reliably, WundPal recommends further medical or vascular assessment. [3, 5]
Scientific sources
[1]
MESI.
Ankle-Brachial Index – Measurement with the
MESI mTABLET ABI.
Manufacturer information on measurement methods,
application and result display.
MESI – Ankle-Brachial Index
[2] MESI. Successful management of peripheral arterial disease (PAD). MESI PAD e-book, data status April 2024.
[3]
AWMF.
S3 Guideline: Diagnosis, Treatment and Follow-up
of Peripheral Arterial Disease.
AWMF Registry No. 065-003,
2024.
AWMF – S3 Guideline on Peripheral Arterial Disease
[4] AWMF. S2k Guideline: Diagnosis and Treatment of Venous Leg Ulcers. AWMF Registry No. 037-009, 2024.
[5]
Gornik HL et al.
2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS
Guideline for the Management of Lower Extremity
Peripheral Artery Disease.
Circulation, 2024.
2024 ACC/AHA Guideline – Lower Extremity PAD