Renal artery stenosis: evaluation of Doppler US after inhibition of angiotensin-converting enzyme with captopril.
OBJECTIVE
To evaluate the modifications of Doppler ultrasound waveform morphology after inhibition of angiotensin-converting enzyme with captopril to increase the sensitivity of Doppler sonography in detecting renal artery stenosis.


METHODS
Sixty-two renal arteries were studied in 31 hypertensive patients who underwent Doppler scanning before and 1 hour after administration of captopril prior to undergoing angiography. Pattern recognition criteria were applied to classify the Doppler waveforms as having a normal or pulsus tardus configuration. Doppler scanning results were compared with those of arteriography.


RESULTS
On the basis of recognition of the pulsus tardus, precaptopril Doppler scanning showed 13 (68%) of 19 significant renal artery stenoses found at angiography (95% confidence interval, 0.43, 0.85), whereas 19 (100%) of 19 stenoses were detected with postcaptopril Doppler scanning (95% confidence interval, 0.85, 1.0).


CONCLUSIONS
Captopril significantly (95% confidence intervals) increases Doppler scanning sensitivity in detecting renal artery stenoses by inducing or enhancing the pulsus tardus distal to a significant renal artery stenosis.
René
P C
PC
Department of Radiology, Hôpital Notre-Dame, Montreal, Quebec, Canada.
Oliva
V L
VL
Bui
B T
BT
Froment
D
D
Harel
C
C
Nicolet
V
V
Courteau
M
M
Carignan
L
L
D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D001027:Aortography; D002216:Captopril; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D006978:Hypertension, Renovascular / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated; D011446:Prospective Studies; D011674:Pulse; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000187:drug effects; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance / Q000187:drug effects
D002216:Captopril