BACKGROUND: Captopril renal scanning (CRS) is commonly recommended as a noninvasive method for detecting renal artery stenosis (RAS), based on performance characteristics determined in research settings. Scant data are available, however, regarding the utility of CRS in clinical practice. METHODS: We evaluated the performance characteristics (sensitivity, specificity, and predictive values) of CRS in a consecutive series of 90 patients who underwent both CRS and renal arteriography within a 6-month period (January 1, 1991, through December 31, 1995) at a university hospital. RESULTS: Among 86 eligible patients (and 169 kidneys), the prevalence of RAS was 43%. The sensitivity of CRS was 74% (95% confidence interval [CI], 62%-83%); the specificity was 59% (95% CI, 49%-69%); the positive predictive value was 58% (95% CI, 47%-68%); and the negative predictive value was 75% (95% CI, 64%-84%). Also, there was evidence of spectrum bias, because the sensitivity and specificity (as well as the positive and negative predictive values) were different for groups with and without vascular disease. CONCLUSIONS: The results of CRS were substantially worse in a clinical practice setting than previously reported in research settings, despite a similar prevalence of RAS. Captopril renal scanning should not be used as an initial screening test for diagnosing RAS, even among patients with high clinical likelihood of disease.
BACKGROUND:Captopril renal scanning (CRS) is commonly recommended as a noninvasive method for detecting renal artery stenosis (RAS), based on performance characteristics determined in research settings. Scant data are available, however, regarding the utility of CRS in clinical practice. METHODS: We evaluated the performance characteristics (sensitivity, specificity, and predictive values) of CRS in a consecutive series of 90 patients who underwent both CRS and renal arteriography within a 6-month period (January 1, 1991, through December 31, 1995) at a university hospital. RESULTS: Among 86 eligible patients (and 169 kidneys), the prevalence of RAS was 43%. The sensitivity of CRS was 74% (95% confidence interval [CI], 62%-83%); the specificity was 59% (95% CI, 49%-69%); the positive predictive value was 58% (95% CI, 47%-68%); and the negative predictive value was 75% (95% CI, 64%-84%). Also, there was evidence of spectrum bias, because the sensitivity and specificity (as well as the positive and negative predictive values) were different for groups with and without vascular disease. CONCLUSIONS: The results of CRS were substantially worse in a clinical practice setting than previously reported in research settings, despite a similar prevalence of RAS. Captopril renal scanning should not be used as an initial screening test for diagnosing RAS, even among patients with high clinical likelihood of disease.
Authors: Timothy P Murphy; Christopher J Cooper; Karol M Pencina; Ralph D'Agostino; Joseph Massaro; Donald E Cutlip; Kenneth Jamerson; Alan H Matsumoto; William Henrich; Joseph I Shapiro; Katherine R Tuttle; David J Cohen; Michael Steffes; Qi Gao; D Christopher Metzger; William B Abernethy; Stephen C Textor; John Briguglio; Alan T Hirsch; Sheldon Tobe; Lance D Dworkin Journal: Hypertension Date: 2016-09-19 Impact factor: 10.190