Aspirin renography in the diagnosis of renovascular hypertension: A comparative study with captopril renography

Captopril renography is used for the non-invasive diagnosis of renovascular hypertension, but suffers from the drawbacks of lower sensitivity and fals e-positive tests due to a fall in blood pressure. Aspirin renography has be en proposed as a useful test for evaluation of unilateral renal artery sten oses of moderate degree. We studied the clinical usefulness of aspirin reno graphy in 12 patients with a clinical suspicion of renovascular hypertensio n and compared it with captopril renography using Tc-99(m)-DTPA. The test w as considered positive if there were changes in the time-activity curve acc ording to the criteria specified by the American Society of Hypertension Wo rking Group. Four patients with discordant results between captopril and as pirin underwent intra-arterial digital substraction angiography. In two pat ients, the renal arteries were normal; captopril was false-positive in both these patients. Bilateral stenosis was noted in the third patient, with ca ptopril being false-negative on the right side with moderate stenosis, wher eas aspirin was true-positive. There was unilateral stenosis in the fourth patient; captopril was false-positive on the contralateral side. Our result s suggest that aspirin renography is superior to captopril renography in th e assessment of patients with a suspicion of both unilateral and bilateral renovascular hypertension. (C) 2000 Lippincott Williams & Wilkins).