RENAL-ARTERY STENOSIS - EVALUATION OF DOPPLER US AFTER INHIBITION OF ANGIOTENSIN-CONVERTING ENZYME WITH CAPTOPRIL

PURPOSE: To evaluate the modifications of Doppler ultrasound waveform morphology after inhibition of angiotensin-converting enzyme with capt opril to increase the sensitivity of Doppler sonography in detecting r enal artery stenosis. MATERIALS AND METHODS: Sixty-two renal arteries were studied in 31 hypertensive patients who underwent Doppler scannin g before and 1 hour after administration of captopril prior to undergo ing angiography. Pattern recognition criteria were applied to classify the Doppler waveforms as having a normal or pulsus tardus configurati on. Doppler scanning results were compared with those of arteriography . RESULTS: On the basis of recognition of the pulsus tardus, precaptop ril Doppler scanning showed 13 (68%) of 19 significant renal artery st enoses found at angiography (95% confidence interval, 0.43, 0.85), whe reas 19 (100%) of 19 stenoses were detected with postcaptopril Doppler scanning (95% confidence interval, 0.85, 1.0). CONCLUSION: Captopril significantly (95% confidence intervals) increases Doppler scanning se nsitivity in detecting renal artery stenoses by inducing or enhancing the pulsus tardus distal to a significant renal artery stenosis.