Takayasu arteritis can be diagnosed using a classification tree approach.
|
top level |
second level |
third level |
diagnosis |
|
bruit over subclavian artery or aorta |
age of onset <= 40 years |
|
TA |
|
|
age of onset > 40 years |
decreased brachial pulse |
TA |
|
|
|
normal brachial pulse |
non-TA |
|
no bruits over subclavian artery or aorta |
decreased brachial pulse |
blood pressure difference > 10 mm Hg |
TA |
|
|
|
blood pressure difference <= 10 mm Hg |
non-TA |
|
|
normal brachial pulse |
|
non-TA |
Surrogate criteria:
(1) If information on bruits is not available, then an abnormal arteriogram may be used as the initial branch point.
(2) If both information on bruits and results of an arteriogram are not available, then the blood pressure difference > 10 mm Hg may be used at the initial level.
(3) If the blood pressure difference is not known, then arteriogram results can be used at the third level.
|
Criteria |
Comment |
|
age of disease onset <= 40 years |
|
|
claudication of extremities |
development and worsening of fatigue and discomfort in muscles of one or more extremities while in use, especially the upper extremities |
|
decreased brachial artery pulse |
decreased pulsation in one or both brachial arteries |
|
blood pressure difference > 10 mm Hg |
difference of > 10 mm Hg in systolic blood pressure between arms |
|
bruit over subclavian artery or aorta |
bruit audible on auscultation over one or both subclavian arteries or abdominal aorta |
|
arteriographic abnormalities |
narrowing, aneurysms or occlusion of the entire aorta, its primary branches, or large arteries in the proximal upper or lower extremities, not due to arteriosclerosis, fibromuscular dysplasia or similar causes; changes usually focal or segmental |
|
Patient Subsets |
Findings |
|
TA patients |
subclavian or aortic bruit; age <= 40 years |
|
|
subclavian or aortic bruit; age > 40 years; decreased brachial pulse |
|
|
no subclavian or aortic bruit; decreased brachial pulse; blood pressure difference > 10 mm Hg |
|
non-TA patients |
subclavian or aortic bruit; age > 40 years; normal brachial pulse |
|
|
no subclavian or aortic bruit; decreased brachial pulse; blood pressure difference <= 10 mm Hg |
|
|
no subclavian or aortic bruit; normal brachial pulse |
Performance:
• The sensitivity of classification tree 92.1%, specificity 97%
Specialty: Immunology/Rheumatology
