Related Experiment Videos
[Status of the captopril test in the diagnosis of hypertension]
S Degenhardt1, H Friedrich, G Wambach
1Medizinische Klinik II und Poliklinik Universität zu Köln.
Insights
Captopril testing effectively screens for unilateral renal artery stenosis in renovascular hypertension. While sensitive for unilateral cases, it shows lower sensitivity for bilateral disease.
Area of Science:
- Nephrology
- Cardiology
- Diagnostic Imaging
Context:
- Renovascular hypertension diagnosis remains challenging.
- Captopril testing is a debated screening tool.
- 113 hypertensive patients underwent evaluation for secondary hypertension.
Purpose:
- To assess the diagnostic utility of captopril testing for renovascular hypertension.
- Compare captopril testing with digital subtraction angiography (DSA) and renal scintigraphy.
- Evaluate sensitivity and specificity for unilateral and bilateral renal artery stenosis.
Summary:
- Captopril testing demonstrated 100% sensitivity for unilateral renal artery stenosis but 50% for bilateral.
- Intravenous DSA showed 79% overall sensitivity for renal artery stenosis (100% unilateral, 40% bilateral).
- Renal scintigraphy had lower sensitivity (50% unilateral, 43% bilateral) for detecting renal artery stenosis.
Impact:
- Captopril testing is valuable for detecting unilateral renal artery stenosis.
- Findings support captopril's role in screening for specific renovascular hypertension cases.
- Highlights limitations of captopril testing in bilateral renal artery stenosis detection.
Abstract:
The place of captopril (C) testing in the screening for renovascular hypertension is still controversial. Baseline and C-stimulated plasma renin concentrations (PRC) were measured in 113 hypertensives, who where referred for the exclusion of secondary hypertension. In addition intravenous digital subtraction angiography (DSA) and a renal scintigraphy were performed. When renal artery disease was revealed by DSA or renin was stimulated the renal arteries were visualized by direct arteriography (and treated by angioplasty if possible). 86 patients underwent each diagnostic test: 21% had renovascular hypertension. Unilateral renal artery stenosis (n = 10) was detected by the captopril test (cutoff values: baseline greater than 40 microU/ml, after C greater than 180 microU/ml, sensitivity 100%). Bilateral renal artery stenosis (n = 8) was missed when the disease was equally severe on either side (sensitivity 50%). The specificity of C testing was 82%, overall sensitivity (uni- and bilateral disease 78%, prevalence 21%, predictive value of the positive test 0.56, predictive value of the negative test 0.93). With i.v.-DSA the renal arteries were technically evaluable in 91% (82/92) of cases. The sensitivity for the detection of all renal artery stenoses was 79% (uni-lateral 100%, bilateral 40%, specificity 97%). The sensitivity of renal scintigraphy for the detection of unilateral renal artery stenoses was 50%, for the detection of bilateral renal artery stenoses 43%, specificity 81%. The present study demonstrates the usefulness of captopril for the detection of unilateral renal artery stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)