Ankle Brachial Index (ABI)
The Ankle Brachial Index (ABI) is a simple, non-invasive test that compares blood pressure in the ankle and arm to assess for peripheral artery disease (PAD). ABI is a critical screening tool for early detection of vascular disease and risk stratification. It is recommended for patients with leg pain, non-healing wounds, or risk factors such as diabetes, smoking, or advanced age.
ABI is the ratio of the blood pressure at the ankle to the blood pressure in the arm. A low ABI indicates reduced blood flow to the legs, which may be caused by arterial narrowing or blockage. This test is widely used for PAD screening and monitoring.
- Quick and painless
- Highly sensitive for detecting PAD
- Recommended for at-risk populations
- Leg pain with walking (claudication)
- Non-healing wounds or ulcers on the feet/legs
- History of diabetes, smoking, hypertension, or high cholesterol
- Age > 65, or > 50 with risk factors
- Abnormal pulses or cool, pale extremities
- Asymptomatic but at high risk for PAD
Blood pressure cuffs are placed on the arm and ankle. Systolic pressures are measured at both sites, and the ABI is calculated by dividing the ankle pressure by the arm pressure. The result helps determine the presence and severity of PAD. Automated systems like VasoGuard ensure accuracy and reproducibility.
- Standardized protocol for accuracy
- Automated measurement and calculation
- Results interpreted using established clinical guidelines
- Patient should rest supine for 10 minutes before measurement
- Room should be warm and quiet
- Remove shoes and socks
- Non-compressible arteries (ABI > 1.4) may occur in diabetes/elderly
- ABI may be falsely normal in severe aortoiliac disease
- Consider Toe-Brachial Index (TBI) if ABI is > 1.4
| ABI Value | Interpretation | Recommendation |
|---|---|---|
| > 1.4 | Calcified/Noncompressible Vessel | Consider TBI, refer to vascular specialist |
| 1.0 - 1.4 | Normal | None |
| 0.9 - 1.0 | Acceptable | Monitor |
| 0.8 - 0.9 | Some Arterial Disease | Treat risk factors |
| 0.5 - 0.8 | Moderate Disease | Refer to vascular specialist |
| < 0.5 | Severe Disease | Urgent referral |
ABI is invaluable for:
- Screening for peripheral artery disease (PAD)
- Assessing cardiovascular risk (low ABI is linked to higher risk of heart attack and stroke)
- Monitoring disease progression and response to therapy
- Guiding further diagnostic and therapeutic decisions
ABI is endorsed by major vascular and cardiovascular societies as a first-line test for PAD. Early detection can lead to interventions that prevent limb loss and improve quality of life.
ABI testing is reimbursable under CPT code 93922 (Limited bilateral noninvasive physiologic studies of upper or lower extremity arteries). Coverage is typically provided for patients with symptoms or risk factors for PAD. Proper documentation and adherence to clinical guidelines are essential for reimbursement.
- Check with payers for specific coverage criteria
- Include relevant symptoms, risk factors, and test findings in documentation
- Combine with segmental pressures or PVR for comprehensive assessment
VasoGuard automates ABI measurement with high-precision sensors and user-friendly software. The system guides clinicians through the process, calculates the ABI instantly, and provides clear, actionable results. Data can be exported for EMR integration or further analysis.
- Automated cuff inflation and measurement
- Instant ABI calculation and reporting
- Seamless workflow and data management