Related Experiment Videos
Ability of ankle-brachial index to detect lower-extremity atherosclerotic disease progression
R B McLafferty1, G L Moneta, L M Taylor
1Department of Surgery, Oregon Health Sciences University, Portland, USA.
Insights
The ankle-brachial index (ABI) is not sensitive for detecting lower-extremity arterial occlusive disease (LEAOD) progression. Imaging studies are more accurate for evaluating LEAOD progression in atherosclerosis research.
Area of Science:
- Vascular Surgery
- Cardiovascular Research
- Medical Imaging
Background:
- Accurate assessment of lower-extremity arterial occlusive disease (LEAOD) progression is crucial for natural history studies and evaluating atherosclerosis therapies.
- Existing methods for monitoring LEAOD progression require validation for clinical utility.
Purpose of the Study:
- To evaluate the correlation between changes in the ankle-brachial index (ABI) and LEAOD progression.
- To determine the diagnostic accuracy of ABI compared to imaging studies for LEAOD progression.
Main Methods:
- Retrospective analysis of 193 extremities in 114 patients undergoing lower-extremity revascularization.
- Comparison of baseline arteriography/duplex scans with follow-up imaging to assess LEAOD progression in native arteries.
- ABI measurements were taken postoperatively and at follow-up; progression defined as a decrease of ≥0.15.
Main Results:
- Arteriography or duplex scanning revealed LEAOD progression in 37.3% of extremities over a mean follow-up of 3.3 years.
- The ABI demonstrated a sensitivity of 41% and specificity of 84% for detecting LEAOD progression compared to imaging.
- Accuracy of ABI in identifying progression was 68%, with a negative predictive value of 71%.
Conclusions:
- The ankle-brachial index (ABI) is relatively insensitive for identifying the progression of lower-extremity arterial occlusive disease (LEAOD).
- Imaging studies (arteriography or duplex scanning) are recommended over ABI for accurate evaluation of LEAOD progression in atherosclerosis research.
Background:
Accurate determination of progression of lower-extremity arterial occlusive disease (LEAOD) is required for natural history studies and evaluation of therapies for atherosclerosis.
Objective:
To determine if changes in the ankle-brachial index (ABI) correlated with progression of LEAOD as determined by arteriography or duplex scanning.
Design:
In patients with prior suprainguinal or infrainguinal lower-extremity revascularization, progression of LEAOD in native arteries was determined by comparing a preoperative (baseline) arteriogram with late follow-up arteriography or duplex scanning. Superficial femoral and popliteal arteries were graded as having less than 50% stenosis, 50% to 99% stenosis, or as being occluded. Tibial arteries were graded as continuously patent or occluded. Operated and nonoperated extremities were included in the study. The baseline ABI was performed postoperatively and repeated at follow-up arteriography or duplex scanning. Progression of LEAOD by the ABI was defined as a decrease in the ABI of 0.15 or greater. Progression of LEAOD by imaging studies was defined as an increase in 1 category of stenosis. Extremities with suprasystolic pressures were excluded.
Setting:
Tertiary vascular surgical service. EXTREMITIES AND PATIENTS: One hundred ninety-three extremities were studied in 114 patients during a mean follow-up of 3.3 years.
Results:
Seventy-two lower extremities (37.3%) showed progression of atherosclerosis by late follow-up arteriography or duplex scanning. Using the imaging studies as the criterion standard, the ABI had 102 true negatives, 29 true positives, 42 false negatives, and 20 false positives (sensitivity, 41%; specificity, 84%; positive predictive value, 59%; negative predictive value, 71%; and accuracy, 68%) for determining the progression of LEAOD.
Conclusions:
The ABI is relatively insensitive in identifying the progression of LEAOD as demonstrated by the use of imaging studies. In studies of natural history or therapy for atherosclerosis, imaging studies should be used in preference to the ABI to evaluate the progression of LEAOD accurately.