Captopril Renal Scintigraphy Research Articles

Clinical Value of the Combination Detection of Captopril Renal Scintigraphy and Plasma Renin Activity in the Diagnosis of Renal Hypertension.

This study aimed to investigate the clinical value of the combination detection of captopril renal scintigraphy (CRS) and plasma renin activity (PRA) in the diagnosis of renal hypertension (RHR). Retrospective analysis was conducted on the clinical data of 163 patients with suspected RHR admitted to our hospital from March 2019 to March 2021, and all patients underwent blood pressure, CRS and digital subtraction angiography (DSA). The patients were divided into the positive group (n = 100) and the negative group (n = 63) in accordance with the results of DSA examination. PRA, angiotensin II and aldosterone levels of the two groups were detected and compared. The receiver operating characteristic curve was used to analyse the CRS, PRA and combined diagnostic performance. The uptake ratio value after captopril intervention in the positive group was 36.71% ± 8.79%, which was significantly lower than that in the negative group (56.79% ± 10.09%, p < 0.05). The serum PRA level of the positive group was 4.70 ± 1.67 ng/mLꞏh, which was distinctly higher than that of the negative group (2.12 ± 1.03 ng/mLꞏh, p < 0.05). The sensitivity and Youden index under the combination detection (area under the curve (AUC) = 0.956, p < 0.001) were all higher than those under single detection. The combined detection of PRA and CRS can provide considerable evidence for the early diagnosis and treatment of RHR, which has a certain clinical value.

Value of non-contrast-enhanced MR angiography combined with captopril renal scintigraphy in the diagnosis of renovascular hypertension

Objective To evaluate the clinical value of non-contrast-enhanced MR angiography (NCE-MRA) combined with captopril renal scintigraphy (CRS) in the diagnosis of renovascular hypertension (RVH). Methods A total of 52 patients (33 males, 19 females; age: (54.5±16.3) years) with highly suspected RVH between January 2018 and October 2018 from Henan Provincial People′s Hospital were retrospectively analyzed. The examination data of NCE-MRA, basic renal dynamic imaging, CRS and digital subtraction angiography (DSA) were collected and reviewed. The renal artery stenosis (RAS) rate≥70% was the criterion for RVH diagnosed by DSA, which was considered as the gold standard. The diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of NCE-MRA, CRS and NCE-MRA+ CRS were determined. The consistency between NCE-MRA and DSA was analyzed by Kappa test. The differences of diagnostic efficiencies between CRS and NCE-MRA + CRS were compared by χ2 test or Fisher exact test. Results There was a high consistency between NCE-MRA and DSA in the diagnosis of RVH (Kappa=0.81, 95% CI: 0.62-0.96; P<0.01). The diagnostic sensitivity, specificity, accuracy, PPV and NPV of NCE-MRA were 88.89%(24/27), 92.00%(23/25), 90.38%(47/52), 92.31%(24/26), and 88.46%(23/26) respectively, those of CRS were 81.48%(22/27), 72.00%(18/25), 76.92%(40/52), 75.86%(22/29) and 78.26%(18/23) respectively, and those of NCE-MRA+ CRS were 74.07%(20/27), 100%(25/25), 86.54%(45/52), 100%(20/20) and 78.12%(25/32) respectively. Compared with CRS, the specificity (P=0.01) and PPV (P=0.03) of NCE-MRA+ CRS in the diagnosis of RVH were increased. Conclusion NCE-MRA and CRS are effective in the diagnosis of RVH, and the combination of two methods can significantly improve the diagnostic specificity and PPV than CRS alone. Key words: Hypertension, renovascular; Radionuclide imaging; Captopril; Technetium Tc 99m pentetate; Magnetic resonance imaging

Value of the Filtration Fraction Assessed by Dynamic 99mTc-Diethylenetriaminepentaacetic Acid Renal Scintigraphy After Angiotensin-Converting Enzyme Inhibition for the Diagnosis of Renovascular Hypertension.

This study aimed to determine the diagnostic value of the relative filtration fraction (RFF) assessed by dynamic 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) renal scintigraphy after angiotensin-converting enzyme (ACE) inhibition for renovascular hypertension (RVHT) diagnosis. 99mTc-DTPA captopril renal scintigraphy performed in adolescents or adults (≥ 10years) with suspected RVHT was retrospectively reviewed. The RFF of the affected kidney was qualitatively assessed as the relative glomerular filtration rate during the 2 to 3-min period compared with the relative perfusion during the first 60s (qualitative RFF) and scored from 1 (definitely same) to 5 (definitely decreased). The quantitative RFF of the affected kidney was obtained by dividing the percentage of glomerular filtration rate by the percentage of renal perfusion. Overall, 173 patients (high probability, n = 15; and low probability, n = 158) were included based on conventional captopril renal scintigraphic criteria. An abnormal qualitative RFF was observed in 12 patients with high probability, and the diagnostic sensitivity was 80.0% (95% CI, 51.9-95.7). The RFF was normal in 152 patients with low probability, and the diagnostic specificity was 96.2% (95% CI, 91.9-98.6). The RFF was lower in patients with high probability than in those with low probability (0.79 ± 0.15 vs. 1.02 ± 0.11, P < 0.0001). The RFF assessed by dynamic 99mTc-DTPA renal scintigraphy after ACE inhibition can detect patients with high probability for RVHT. The RFF after ACE inhibition might be a useful diagnostic criterion especially when baseline scintigraphy is not available for evaluating ACE inhibition-induced changes.

Renal artery stenting for atherosclerotic renal artery stenosis identified in patients with coronary artery disease: Does captopril renal scintigraphy predict outcomes?

The authors evaluated the effectiveness of percutaneous renal revascularization (PRR) with stenting for the treatment of atherosclerotic renal artery stenosis (ARAS) in patients with coronary artery disease and the usefulness of captopril renal scintigraphy for predicting clinical outcomes after PRR. Sixty-four consecutive patients, referred for evaluation of suspected ARAS, after coronary angiography, underwent baseline captopril renal scintigraphy followed by renal angiography. Forty-four patients (68.7%) were diagnosed with a significant ARAS≥ 60% and were treated with PRR plus medical therapy. Twenty-four months after PRR, 86.4% and 73.3% of patients showed a hypertension and renal benefit, respectively. Captopril renal scintigraphy positivity had moderate sensitivity and high specificity in predicting a hypertension and renal benefit. In patients with ARAS≥ 70%, the sensitivity and specificity were 100% for both a hypertension and renal benefit.PRR for ARAS conferred a substantial benefit in patients with a high coronary artery disease burden. Captopril renal scintigraphy was highly accurate in predicting clinical outcomes.

The role of a captopril renal scintigraphy in examination of children with hypertension: A case report

Introduction. Secondary hypertension is a relatively common form of hypertension in childhood with renovascular hypertension being responsible for 5%?10% of all arterial hypertensions in children. An early diagnosis of renovascular hypertension is important when considering an appropriate treatment of hypertension that may prevent or slow further progression of kidney damage. To validate the usefulness of a captopril renal scintigraphy in hypertensive children, we report a case of a 16-year-old female patient with a history of hypertension as a result of fibromuscular dysplasia. Case report. The patient was asymptomatic with elevated blood pressure revealed by a routine physical examination. Laboratory tests showed the increased levels of plasma renin activity with the normal levels of aldosteron. The renal ultrasound was normal. The Doppler of the renal arteries showed no significant differences of resistive index. A renal captopril scintigraphy was performed, including two day study protocol, the baseline study followed by another captopril study several days later. The scintigraphy showed the abnormal baseline and captopril renogram curve of the right kidney with significant cortical retention of radiotracer after angiotensin-converting enzyme inhibition. Following the captopril scintigraphy a renovasography was obtained confirming the presence of a 2 mm long circular narrowing of the right renal artery. It was immediately treated resulting in a significant expansion of the lumen. Conclusion. The captopril renal scintigraphy allows non-invasive functional testing in a selected group of hypertensive children, which can either confirm or rule out the existence of hemodynamically significant renal artery stenosis.

Captopril Renal Scintigraphy in Screening and Diagnosis of Renal Artery Stenosis - A Prospective Study

The present study was carried out to assess the role of Tc99m-DTPA captopril renal scintigraphy in screening and diagnosing of patients with renal artery stenosis. Materials and Methods: A total of 26 hypertensive patients with a clinical suspicion of RAS underwent baseline and captopril scintigraphy using 259-370 MBq (7-10mCi) of Tc99m-DTPA. The captopril scintigraphy was done after oral dose of 50mg of captopril with in three baseline study. DSA was done in all patients irrespective of scintigraphy results due to high clinical suspicion of RAS. Results: Of 26 patients, 18 had renal artery stenosis (10 unilateral, 8 bilateral), making a total of 26 involved RA on DSA. Of these 26 involved RA, 16 were stenosis&gt; 60%, 2 were stenosed&lt; 60% while 8 were completely occluded. Of the sixteen RA with stenosis &gt; 60%, only 12 were detected by captopril scintigraphy (Sensitivity-75%). Eight kidneys with complete occlusion, 6 were non-functioning and 2 were poorly functioning (&lt;20%) on scintigraphy. Among 27 normal RA, (25 normal and two &lt;60% stenosis) only 19 were negative on scintigraphy (specificity-70%). Two kidneys with less than 60% stenosis were positive on scintigraphy. The overall accuracy of captopril DTPA scintiography was found to be 72.1% with PPV and NVP of 66.7% and 82.6% respectively. Two patients with accessory RA were not picked up on captopril scintigraphy. Conclusion: Tc99m-DTPA captopril scintigraphy has average sensitivity and specificity. The effectiveness of captopril scintigraphy in diagnosis of completely occuluded RA, accessory RAS and RAS in poorly functioning kidney is poor, therefore this test cannot be considered as screening test for RVH. Nepalese Journal of Radiology; Vol. 2; Issue 2; July-Dec. 2012; 28-35 DOI: http://dx.doi.org/10.3126/njr.v2i2.7682

Glomerular Filtration Rate Measured by 51Cr-EDTA Clearance: Evaluation of Captopril-Induced Changes in Hypertensive Patients with and without Renal Artery Stenosis

INTRODUCTION:Renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using 51Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis.METHODS:This prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis (51Cr-EDTA) and 99mTc-DMSA scintigraphy were performed before and after captopril administration in all patients.RESULTS:The mean baseline glomerular filtration rate was 48.6±21.8 ml/kg/1.73 m2 in the group wuth renal artery stenosis, which was significantly lower than the GFR of 65.1±28.7 ml/kg/1.73m2 in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6±14.8 ml/ kg/1.73m2, p=0.001) and an insignificant change in the group without RAS (to 62.2±23.6 ml/kg/1.73m2, p=0.68). Scintigraphy with technetium-99m dimercapto-succinic acid (DMSA) did not show significant differences in differential renal function from baseline to post-captopril images in either group.CONCLUSIONS:Captopril induced a decrease in the GFR that could be quantitatively measured with 51Cr-EDTA. The reduction is more pronounced in hypertensive patients with RAS.

Captopril-enhanced renal scintigraphy in the diagnosis of pediatric hypertension

Hypertension in childhood is no longer a rare condition mainly secondary to renal, or renovascular diseases, as a growing proportion of children are obese and hypertensive, with the phenotype of metabolic syndrome. Thus, we need to reconsider our practice in the examination of the hypertensive child and redefine the place of non-invasive methods for screening of renovascular hypertension, and specifically, to evaluate the value of captopril-enhanced renal scintigraphy at the two ends of the palette: the obese child with hypertension and the severely hypertensive prepubertal child. Renal artery stenosis in children is mainly due to fibromuscular dysplasia and stenoses associated with syndromes involving single or multiple smaller branch vessels. This explains the low specificity and sensitivity of the color-Doppler ultrasound method and captopril renal scintigraphy. Even the more sophisticated computed tomography (CT) and magnetic resonance imaging (MRI) angiographic techniques are, at present, not sensitive enough to exclude stenoses of the small branches definitely. Thus, children in whom there is a strong suggestion of renovascular hypertension should undergo angiography with a view to endovascular treatment, as non-invasive imaging has no significant benefit and might lead to a delay in treatment. In the cases when the probability of renovascular disease is moderate a basic assessment of renal function and structure is sufficient. In the neonate, catheter-associated thromboembolic disease is among the most common causes hypertension. It should be controlled medically until the patient is old enough to undergo angiography and angioplasty successfully. Thus, in this age group, there is a place for functional imaging with renal sonography and angiotensin-converting enzyme inhibitor (ACEI) renography to detect hemodynamically significant renovascular disease, with the limitations mentioned above. However, the rapid technical evolution of non-invasive methods requires periodic re-consideration of the actual standpoints.

Renovascular Hypertension and Double Renal Arterial Supply Diagnosed by Tc-99m MAG3 Captopril Renography

Renovascular hypertension is the most frequent secondary cause of hypertension (0.5–2%). Captopril renal scintigraphy is safe, noninvasive, and effective in the detection of renovascular hypertension. Positive captopril renography may suggest a cure of hypertension and improvement in renal function with successful renal revascularization. The authors report the case of successful detection of renovascular hypertension by captopril renal scintigraphy in a patient with 2 hilar renal arteries. Revascularization of the stenosed hilar artery was obtained by transluminal angioplasty and stent placement, leading to rapid control of the hypertension.

Analysis of Recent Papers in Hypertension

Analysis of Recent Papers in Hypertension

Ischemic renal disease in Kuwait.

Ischemic renal disease (IRD) is a frequent cause of end-stage renal disease. Its prevalence is mainly known from autopsy or retrospective arteriographic studies. This prospective study was conducted in 115 subjects selected from 732 patients with advanced chronic renal failure (CRF). Only patients with clinical features suggestive of IRD were selected for this study. In addition to detailed clinical and laboratory evaluation, captopril renal scintigraphy was performed in selected cases. All subjects underwent renal arteriography and all were followed up for 18.4 +/- 11.4 months. Renovascular disease was seen in 15 patients and significant bilateral renal artery disease leading to IRD was observed in 13 (11.3%). Hence the prevalence of IRD in the advanced CRF patients was 1.7%. The majority of patients with IRD (8 [61%]) were above 46 years of age and there were more men than women (10:3). Atherosclerotic renovascular disease was the most common (10 [77%]), even though arthritis (1 [7.6%]), and fibromuscular dysplasia (2 [15.3%]) were also observed. Serum creatinine at time of presentation was significantly higher in patients with IRD (784 +/- 292, p = 0.043) compared to those who did not have IRD (359 +/- 126). Corrective procedures were performed in 5 patients. After treatment the improvement in serum creatinine in patients with IRD at 3 and 6 months (166 +/- 32 and 173 +/- 47, respectively) was significantly different (p < or = 0.05) compared to those who were not treated (610 +/- 194 and 645 +/- 220, respectively). Hyperlipidemia, coronary artery disease and peripheral vascular disease were more prevalent in patients who had IRD compared to those with renal failure. The incidence of diabetes mellitus were similar in both groups. This study denotes a lower prevalence of IRD in the advanced CRF population; they had more severe renal failure at presentation but specific corrective treatment delayed progression of renal disease significantly.

Tc-99m-DTPA captopril renography in the detection of renovascular hypertension due to renal polar artery stenosis

A 24-year-old man whose clinical features were suggestive of renovascular hypertension was referred for captopril renal scintigraphy. Captopril renal scintigraphy was positive for renovascular hypertension only when the left kidney was analyzed in 2 separate regions. Angiography confirmed severe stenosis (90%) in the upper branch of the left renal artery.

Current Perspectives on the Role of Captopril Imaging in the Diagnosis of Renovascular Disease

-As the population ages, renal artery stenosis has been increasingly detected among patients with refractory hypertension and/or renal dysfunction. There is a need for a safe, simple, reliable, cost-effective method for detecting clinically significant renal artery stenoses in patients who will benefit from revascularization. The asymmetric renal response to angiotensin converting enzyme inhibition in the setting of renal artery stenosis is the basis for several diagnostic techniques that screen patients with suspected renal artery stenoses to determine functional significance. Captopril renal scintigraphy is the most widely applied, however, ACE inhibition in conjunction with ultrasound and magnetic resonance are the focus of the most recent research. This review focuses primarily on the physiologic basis, indications, techniques and utility of captopril renal scintigraphy. Newer captopril imaging methods are introduced and consideration given to practical issues such as cost and risk/benefit analysis.

Current Perspectives on the Role of Captopril Imaging in the Diagnosis of Renovascular Disease

As the population ages, renal artery stenosis has been increasingly detected among patients with refractory hypertension and/or renal dysfunction. There is a need for a safe, simple, reliable, cost-effective method for detecting clinically significant renal artery stenoses in patients who will benefit from revascularization. The asymmetric renal response to angiotensin converting enzyme inhibition in the setting of renal artery stenosis is the basis for several diagnostic techniques that screen patients with suspected renal artery stenoses to determine functional significance. Captopril renal scintigraphy is the most widely applied, however, ACE inhibition in conjunction with ultrasound and magnetic resonance are the focus of the most recent research. This review focuses primarily on the physiologic basis, indications, techniques and utility of captopril renal scintigraphy. Newer captopril imaging methods are introduced and consideration given to practical issues such as cost and risk/benefit analysis.

Renal Artery Stenosis Complicating Polycystic Kidney Disease

Polycystic kidney disease (PCKD) commonly causes hypertension and leads to chronic renal insufficiency. Correctable renal artery stensosis can coexist with PCKD and contribute to both hypertension and progressive decline in renal function but is often overlooked. To illustrate the diagnostic and therapeutic implications of this unusual combination of pathology, the authors present the case of a 59-year-old woman with severe PCKD who presented with recurrent bouts of malignant hypertension, flash pulmonary edema, and accelerated decline of renal function over a 3-month period. In the course of normal findings from cardiac catheterization, aortography demonstrated severe right renal artery stenosis. Captopril renal scintigraphy confirmed the viability of both kidneys and the physiologic significance of the right renal artery stenosis even in the setting of chronic renal insufficiency. Right renal artery revascularization was achieved by using a hepatorenal bypass with reversed greater saphenous vein. The patient had an immediate improvement in renal function and blood pressure control as evidenced by a decline in creatinine and a reduction of medication requirements, respectively. In 15 months' follow-up, this therapeutic result has been maintained and she has not experienced any further bouts of pulmonary edema. This unusual case emphasizes the need to pursue correctable pathology of the renal arteries despite the presence of chronic renal insufficiency unrelated to vascular occlusive disease in order to preserve renal function and stabilize hypertension. Patients with multiple etiologies of renal dysfunction represent diagnostic and therapeutic challenges that are not insurmountable but require diligence in pursuing repairable lesions when their clinical course deviates from that expected from the uncorrectable pathology.

Diagnosis of renal artery stenosis and renovascular hypertension

Renovascular hypertension resulting from renal artery stenosis is a potentially curable form of secondary hypertension. Although uncommon in the general hypertensive population, the prevalence of renovascular hypertension rises in selected groups of hypertensive patients. Because of the possibility of cure, screening measures for renal artery stenosis are warranted in hypertensive patients with clinical features suggestive of renovascular disease. For a long time, angiography has been considered the ‘gold standard’ in screening for arterial stenosis. However, it is invasive and associated with inherent morbidity. Thus, less invasive screening measures with high diagnostic sensitivity and specificity are currently being sought. Magnetic resonance angiography and captopril renal scintigraphy are safer alternatives to angiography, but are expensive and not widely available. Duplex ultrasound is more widely available and provides both anatomic and functional assessment of renal artery stenosis; however, sensitivity and specificity vary considerably among different laboratories. Echo-enhanced duplex ultrasound using the galactose-based agent Levovist® produces higher quality images of the renal artery than conventional color Doppler, while significantly reducing mean examination time and improving diagnostic confidence. In addition, Levovist does not compromise the safety of duplex ultrasound. Other advances in Doppler imaging techniques that may improve ultrasound sensitivity and specificity in detection of renal artery stenosis are power Doppler, echo-enhanced harmonic spectral Doppler imaging, and echo-enhanced harmonic power Doppler imaging.

Symmetrical bilateral induced abnormalities in captopril renal scintigraphy

Symmetrical bilateral induced abnormalities in captopril renal scintigraphy

A review of captopril renal scintigraphy and its effect on patient management.

Renal artery stenosis is an important and potentially curable cause of hypertension. Captopril renography is now recognized to have a high sensitivity and specificity in its diagnosis. Ultimately, however, the result is of little benefit if it does not lead to a change in patient management. To assess how patient management was changed following the result of a captopril renogram, we reviewed the notes of 95 patients who had undergone this test over a 5 year period to identify renal artery stenosis. Of these patients, significant renal artery stenosis was suggested in 16 (17%), of whom only 9 (56%) underwent a change in management (7 proceeding to angiography with or without angioplasty, 2 having alterations in medication). In the 67 patients who had a negative renogram, 16 (24%) had an alteration in management (13 angiography, 3 altered drug treatment). Finally, of the 12 patients who had a non-diagnostic renogram, 7 (60%) had a management change (3 angiography, 4 altered drug therapy). Our results suggest that, despite evidence from the literature that captopril renography is both sensitive and specific for renal artery stenosis, clinicians still rely on other factors when determining who has significant stenosis and, therefore, who should proceed to a further investigation or have a change in medication. Ultimately, this reduces the clinical value of the test at present.

Renovascular Hypertension due to Takayasu's Arteritis Demonstrated by Tc-99m Ethylenedicysteine Captopril Scintigraphy

A 34-year-old woman with severe hypertension underwent Tc-99m ethylenedicycteine (Tc-99m EC) captopril renal scintigraphy. There was bilateral parenchymal retention of the tracer suggesting renal artery stenosis. Angiography confirmed bilateral renal artery stenosis and also demonstrated contour irregularities of the abdominal aorta, and stenosis in mesenteric and subclavian arteries with increased collateral circulation consistent with Takayasu's arteritis. In light of this case of renal artery stenosis, it was concluded that Tc-99m EC can be used successfully as a potential renal agent in the diagnosis of renal involvement in patients with Takayasu's arteritis.

Role of captopril renography in the diagnosis of renovascular hypertension

Eighty-six hypertensive patients with clinical suspicion of renovascular hypertension (RVH) were evaluated by captopril renal scintigraphy (CRS) and intra-arterial digital subtraction angiography (IADSA) to determine the usefulness of CRS in the diagnosis of RVH and to predict the outcome of revascularization procedures. Technetium 99m-diethylenetriaminepentaacetic acid (DTPA) renal scintigraphy was performed on 2 consecutive days before and after captopril administration. Captopril renal scintigraphy was considered positive if there were changes in the time activity curve according to the criteria specified by the American Society of Hypertension working group. Captopril renal scintigraphy data were compared with presence or absence of anatomic renal artery stenosis (RAS). Of 86 hypertensive patients investigated, 45 had RAS. Aortoarteritis was the cause of RAS in 40 (89%) patients. Revescularization was done in 25 patients, and response to revascularization was compared with that of captopril renography. Compared with IADSA, CRS showed a sensitivity of 82.8% and a specificity of 98.2%. Fourteen patients had bilateral RAS on IADSA. In these patients, CRS was suggestive of bilateral disease in seven patients, unilateral in four, and negative in three. Comparison of CRS with the results of revascularization showed a sensitivity and specificity in detecting curable RAS (RVH) of 95% and 100%, respectively (positive predictive value, 100%; negative predictive value, 85%). In conclusion, we found CRS to be useful in the diagnosis of RVH due to aortoarteritis.