Simplified captopril renography in diagnosis and treatment of renal artery stenosis.

Abstract

To improve the diagnosis and forecast the response to surgery or renal angioplasty in patients with hypertension and renal artery stenosis, we employed a simplified captopril renography protocol in conjunction with renal arteriography in 94 clinically selected patients. Fifty hypertensive patients (group 1) with a high clinical likelihood of renovascular hypertension were evaluated using a simplified captopril renography protocol and renal angiography on the arterial side. Criteria for normal captopril renal scintigrams were established based on this original cohort and validated in an additional 44 clinically comparable patients (group 2). Renal revascularization or nephrectomy was performed in 39 patients, and success of the procedure was determined in the 34 patients for whom 3-month follow-up was available. In the 94 patients, 44 (47%) had renal artery stenosis. Simplified captopril renography was 91% sensitive and 94% specific in identifying or excluding renal artery stenosis in the combined group, with no difference in the diagnostic utility between groups 1 and 2, or in those with renal insufficiency (n=38) or those with bilateral disease (n=17). Scintigraphic abnormalities induced by captopril were strongly associated with cure or improvement in blood pressure control following revascularization or nephrectomy (15 of 18), while the lack of captoprilinduced changes was associated with failure of such intervention (13 of 16) (/?=0.0004). We conclude that simplified captopril renography is highly sensitive and specific in the diagnosis of renal artery stenosis in a clinically selected high-risk population and that the test accurately predicts the success or failure of therapeutic intervention. {Hypertension 1991; 18:289-298)

Diagnostic usefulness of renal scanning after angiotensin converting enzyme inhibitors.

“…This group reports the hippuran renogram after captopril to be highly predictive of the blood pressure response to angioplasty or reconstructive surgery, with a sensitivity of 96% and a specificity of 95%. These excellent results exceed any so far published with DTPA, including those of Setaro et al 5 Additionally, in the majority of their patients, only one hippuran scan (after ACEI) was required. A second scan was undertaken without ACEI only in those subjects whose hippuran scan after ACEI was abnormal and who had azotemia.…”

“…This suggestion has been extensively evaluated using both markers for GFR ("Tc-diethylenetriamine pentaacetic acid [DTPA]) and renal plasma flow (RPF) (hippuran). In the current issue of Hypertension, Setaro et al 5 report the experience of the Yale Vascular Center in the use of a test based on renal scanning with "Tc-DTPA (renal scintigraphy) in 94 patients.…”

ACC/AHA 2005 Practice Guidelines for the Management of Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic)

“…The accuracy of captopril renography in identifying patients with renovascular disease has been variable, with reported sensitivities of approximately 85% (range 45% to 94%) and specificities of approximately 93% (range 81% to 100%) (674)(675)(676)(677)(678)(679)(680)(681)(682)(683)(684)(685).…”

Atherosclerotic Vascular Disease Conference

“…Unfortunately, the predictive value for measures of plasma renin activity to identify atherosclerotic renal artery stenosis is low because these measures may be influenced by medications or other medical conditions and because hypertension is generally not renin dependent. Although the sensitivity and specificity of captopril renal scintigraphy are both Ͼ90%, 61,62 it is heavily influenced by renal parenchymal disorders and obstructive uropathy and is therefore not a practical screening test. When there is a high index of clinical suspicion, an imaging study should be used to confirm the diagnosis of renal artery stenosis.…”