ABI of 0.95: Borderline Cardiovascular Risk Requiring Further Evaluation
An ankle-brachial index of 0.95 falls in the "borderline" range (0.91-1.00) and indicates increased cardiovascular risk that warrants further evaluation, even though it does not meet the diagnostic threshold for peripheral arterial disease (PAD). 1
Clinical Interpretation
Not Diagnostic of PAD
- An ABI <0.90 is required to confirm the diagnosis of lower-extremity PAD 1
- Your value of 0.95 is above this threshold, so PAD cannot be diagnosed based on this resting ABI alone
- Normal ABI values range from 0.90 to 1.40 2
Borderline Cardiovascular Risk Category
Subjects with an ABI between 0.91 and 1.00 are considered "borderline" in terms of cardiovascular risk, and further evaluation is appropriate 1. This is a Class IIa recommendation with Level of Evidence A from the American Heart Association.
This borderline zone exists because:
- The 95% confidence interval for ABI measurement reproducibility is approximately ±0.10 1
- Values close to the 0.90 threshold require careful interpretation
- These patients may have early atherosclerotic disease not yet meeting diagnostic criteria
Recommended Next Steps
If Symptomatic (Leg Pain, Claudication)
Proceed with post-exercise ABI or other noninvasive tests, which may include imaging 1. This is a Class I recommendation with Level of Evidence A.
Specific criteria for abnormal exercise testing:
- Post-exercise ankle pressure decrease >30 mm Hg, OR
- Post-exercise ABI decrease >20% 1
If Asymptomatic
The ABI can provide incremental cardiovascular risk information beyond standard risk scores 1. Consider:
- Comprehensive cardiovascular risk assessment
- Evaluation for other atherosclerotic disease manifestations
- Optimization of cardiovascular risk factors (smoking cessation, blood pressure control, lipid management, diabetes control)
Important Caveats
Measurement Reproducibility
Given that your ABI of 0.95 is within 0.10 of the diagnostic threshold (0.90), reproducibility becomes crucial 1. Consider:
- Repeating the measurement to confirm the value
- Ensuring proper technique was used (patient supine, appropriate cuff size, correct Doppler angle of 45-60°)
- Verifying the higher brachial pressure was used as the denominator
Both Legs Matter
The lower ABI of both legs should be used for cardiovascular risk assessment, as PAD may be unilateral or asymmetric 1. If only one leg was measured, measure the other leg to avoid missing significant disease.
Cardiovascular Risk Implications
Even without PAD diagnosis, an ABI in the borderline range suggests:
- Possible early systemic atherosclerosis
- Increased risk for cardiovascular events compared to normal ABI (1.11-1.40)
- Need for aggressive cardiovascular risk factor modification
What NOT to Do
- Do not dismiss this value as "normal" - it requires action
- Do not wait for symptoms to develop before further evaluation if cardiovascular risk factors are present
- Do not assume a single measurement is definitive when close to threshold values
The key message: 0.95 is not PAD, but it's not reassuring either - it demands further evaluation and cardiovascular risk optimization.