Single-dose captopril test and captopril renal scintigraphy in the evaluation of renovascular hypertension

Abstract

The effectiveness of single-dose captopril test (CP-T) and captopril renal scintigraphy with 99mTc-DTPA (CP-RG) in the diagnosis of renovascular hypertension (RVH) was evaluated in 27 patients with (Group I, 16 patients) or without (Group II, 11 patients) renal vascular disease. Group I consisted of RVH in 8 patients (bilateral in 3, unilateral in 5), arteriovenous malformation in 3, renal artery aneurysm in 4, including 2 with essential hypertension, and asymptomatic renal artery stenosis in 1. Group II consisted of 6 hypertensive patients (2 with essential hypertension and 4 with renal hypertension) and 5 normotensive patients. Sensitivity of CP-T and CP-RG in the diagnosis of RVH was 29% (2/7) and 86% (6/7), respectively, indicating the latter was more sensitive than the former. In 3 patients with bilateral RVH, positive response in CP-RG was observed only in the unilateral kidney. Specificity of CP-T and CP-RG was 86% (6/7) and 100% (5/5), respectively in Group I, 100% (8/8) and 83% (5/6), respectively in 16 hypertensive patients. CP-T and CP-RG before and after the treatment of RVH were evaluated in 4 patients. The change of positive response in CP-T and CP-RG into negative after percutaneous transluminal renal angioplasty (PTA) or surgery were found in 3, all followed by a fall in blood pressure, which was not observed in the other patient with positive response after PTA.(ABSTRACT TRUNCATED AT 250 WORDS)