|Year : 2020 | Volume
| Issue : 4 | Page : 181-186
Efficacy of percutaneous renal revascularization in resistant hypertension patients
Bhushan Bari1, Deepak Sadashiv Phalgune2, Suhas Hardas1
1 Department of Cardiology, Poona Hospital and Research Centre, Pune, Maharashtra, India
2 Department of Research, Poona Hospital and Research Centre, Pune, Maharashtra, India
|Date of Submission||14-Jun-2020|
|Date of Decision||15-Jul-2020|
|Date of Acceptance||29-Jul-2020|
|Date of Web Publication||21-Jan-2021|
Dr. Deepak Sadashiv Phalgune
18/27, Bharat Kunj-1, Erandawane, Pune 411 038, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: Renovascular hypertension is one of the most common potentially curable types of secondary hypertension. Medical therapy alone does not inhibit the progressive loss of renal function. The aim of the present study was to evaluate the efficacy of percutaneous renal revascularization in resistant hypertension patients. Methods: Forty-two patients aged ≥ 45 years with resistant hypertension having renal artery stenosis (>50% luminal narrowing assessed by quantitative renal angiography) undergoing percutaneous transluminal renal angioplasty (PTRA) were included in the study. The primary outcome measures were a response of blood pressure (BP) and the requirement of the number of hypertensive drugs, whereas the secondary outcome measure was to study the correlation of renal vein renin levels (RVRLs) with postrenal angioplasty BP response. Chi-square/Fisher's exact test and unpaired t-test were used to compare qualitative and quantitative variables, respectively. A paired t-test was used for intragroup comparison. Results: The mean systolic BP at 6-month follow-up (159.5 mmHg) was significantly less as compared to baseline (181.3 mmHg) (P = 0.0001). The mean diastolic BP at 6-month follow-up (94.4 mmHg) was significantly less as compared to baseline (106.5 mmHg) (P = 0.0001). The mean number of antihypertensive drugs used at the baseline and 6-month follow-up was 3.4 and 1.8, respectively, which was statistically significant (P = 0.001). There was no significant correlation of RVRL with postrenal angioplasty BP response. Conclusions: In patients with resistant hypertension, PTRA improved BP control and reduced the requirement of antihypertensive drugs.
Keywords: Antihypertensive drugs, percutaneous transluminal renal angioplasty, renal vein renin levels, resistant hypertension
|How to cite this article:|
Bari B, Phalgune DS, Hardas S. Efficacy of percutaneous renal revascularization in resistant hypertension patients. J Indian coll cardiol 2020;10:181-6
|How to cite this URL:|
Bari B, Phalgune DS, Hardas S. Efficacy of percutaneous renal revascularization in resistant hypertension patients. J Indian coll cardiol [serial online] 2020 [cited 2022 Dec 7];10:181-6. Available from: https://www.joicc.org/text.asp?2020/10/4/181/307615
| Introduction|| |
Renovascular hypertension is one of the most common potentially curable types of secondary hypertension. Untreated cases of renovascular disease invariably progress to worsening of renal function, high cardiovascular (CV) morbidity, and mortality., Medical therapy alone does not inhibit the progressive loss of renal function.,, Once the renal artery is stenosed more than 70%, revascularization is definitely required. Renal revascularization performed in such cases not only prevents or reverses renal failure but also results in satisfactory blood pressure (BP) control and significantly improved survival.,
The renin–angiotensin–aldosterone system (RAAS) plays an important role. Furthermore, there is increasing evidence that activation of the RAAS at tissue level plays a pathophysiological role in cardiac and vascular hypertrophy, glomerular sclerosis, and atherosclerosis., For more than 30 years, there has been much interest and controversy over the use of measurement of plasma renin activity (PRA) as a biomarker for the prediction of future CV events. The earliest report of Brunner et al. in a small study of patients with essential hypertension appeared to demonstrate that patients with low levels of PRA had a significantly lower incidence of myocardial infarction and stroke during 10 years of observation. Following early reports, a number of observational studies in unselected individuals and in different patient groups have provided conflicting evidence as to whether measurements of PRA do or do not reliably and reproducibly predict future CV events.,,,
More recently, in the context of clinical trials in patients with coronary heart disease (CHD) and in patients with heart failure, there have been reports that PRA levels predict CV and all-cause mortality.,, In addition, there are now reports that PRA may be a predictor of renal outcomes in patients with CHD.
The renal vein renin sampling procedure has been one of the main diagnostic tests for renovascular hypertension. It has been argued that although the diagnostic value is good, the prognostic value of the test varies widely between centers., A decrease in renal pressure distal to the stenosis and its subsequent release of renin is the fundamental trigger of renovascular hypertension. Measurement of the trans-stenotic pressure gradient with pressure wires provides the most accurate means of hemodynamic assessment. Yet, what constitutes a significant pressure gradient remains largely unknown.
In recent years, radionuclide renal scintigraphy has been shown to be a useful screening test for renovascular hypertension. Renal scans are performed both before and after the administration of an angiotensin-converting enzyme inhibitor (ACEI) such as captopril. The changes in renal function have been observed following ACEI in renal scans performed with technetium 99m (99mTc) diethylenetriaminepentaacetic acid, 99mTc dimercaptosuccinic acid, and iodine-131 or iodine-123-hippurate (HIP).
It has been a practice in many cath labs by most operators to do angioplasty of critically stenosed renal artery detected on routine coronary angiography, especially in patients with hypertension. However, the recent Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) trial reported that there was not enough evidence of clinical benefit from revascularization in patients having atherosclerotic renovascular disease.
Therefore, in view of this controversy, there is a clear need for the development of more definitive criteria and choosing the right patient for renal artery stenting. Until now, no single trial has looked at renal vein renin level (RVRL) glomerular filtration rate (GFR) by renogram and gradient across the stenotic segment. The aim of the present study was to evaluate the efficacy of percutaneous renal revascularization in resistant hypertension patients.
| Methods|| |
This prospective observational study was conducted in 42 patients aged ≥45 years with resistant hypertension having renal artery stenosis (>50% luminal narrowing assessed by quantitative renal angiography) undergoing percutaneous transluminal renal angioplasty (PTRA) in the Department of Cardiology, Poona Hospital and Research Centre, Pune, from August 2015 to July 2016. Permission was obtained from the ethics committee and the scientific advisory committee of the institution. Patients with chronic kidney disease (creatinine clearance <30 mL/h), those with known chronic inflammatory diseases, those on dialysis, or those with decompensated/severe heart failure were excluded from the study.
Based on a previously published study, setting an alpha error at 0.05 and power at 80%, a sample size of 30 was calculated by the formula. We included 42 patients for better validation of results. Written informed consent was obtained from all the patients after explaining the risks and benefits of the procedure. Patients who were taking ACEI/angiotensin receptor blockers were asked to stop the medicines 7 days before the study.
Each patient was subjected to detailed clinical history and clinical examination and investigated as per the pretested study pro forma. Renogram was performed for evaluation of atherosclerotic renal artery disease, calculation of RVRL, and pressure gradient measurement. Blood urea and serum creatinine were measured at the baseline, at 1-month, and at 6-month follow-up.
BP measurement was taken on an outpatient basis with a calibrated sphygmomanometer as per the routine protocol. The patient was advised to take antihypertensive medications as prescribed and not to smoke or drink tea/coffee 1 h before and was advised to take rest for at least 15 min before documenting the BP. Three BP readings were taken in the supine position, and the lowest of the three readings was noted. In the present study, resistant hypertension was defined as, in spite of the simultaneous use of three antihypertensive agents of different classes, one of which was a diuretic, BP remained the above goal. Patients whose BP was controlled with four or more medications were considered to have resistant hypertension.
Creatinine clearance was estimated from plasma creatinine concentration with the use of the Cockcroft–Gault formula and was standardized to a body surface area of 1.73 m2. Pre-PTRA and follow-up total GFR were determined for each patient with the use of the same technique: inulin renal clearance, chromium-labeled ethylenediamine tetra-acetic acid (Cr-EDTA) renal clearance, or plasma 51Cr-EDTA. Tests were carried out after the patient fasted overnight and remained supine during the clearance periods, resuming the standing position only to void.
Renal vein renin release was stimulated by a single oral dose of 1 mg/kg captopril administered 1 h before renal vein sampling. Plasma active renin was measured by the immune-radiometric assay, using a commercially available kit (ERIA, Diagnostics Pasteur, Marnes-la-Coquette, France). We have considered the captopril-stimulated renal vein renin ratio ≥1.5 as a positive lateralization index. RVRL was measured before PTRA. The normal value of renal vein renin was considered as 2.8 ng/mL of plasma.
All PTRAs were performed by the same physician. After angioplasty, the balloon catheter was withdrawn with the guidewire left across the lesion until a repeat aortogram was performed to confirm satisfactory angioplasty. When obstructive parietal damage or a recoil phenomenon was observed and repeated, slow, long-lasting (3–4 min) pressure inflations were performed, and if necessary, a Wallstent endoprosthesis was inserted. At the end of the procedure, renal angiography was repeated and the technical outcome was assessed from this immediate postprocedural angiography. We have not prescribed antiplatelet aggregation therapy to patients after PTRA. The primary outcome measures were the response of BP and the requirement of the number of hypertensive drugs, whereas the secondary outcome measure was to study the correlation of RVRL with postrenal angioplasty BP response.
Data collected were entered in Excel 2007, and analysis of data was done using the Statistical Package for the Social Sciences for Windows, Version 20.0. IBM Corporation, Armonk, NY, USA. The data on categorical variables are shown as n (% of cases) and the data on continuous variables are presented as mean and standard deviation (SD). The comparison of categorical and quantitative variables was tested using Chi-square/Fisher's exact test and unpaired t-test, respectively. Intragroup comparison of means of continuous variables was done using paired t-test. The underlying normality assumption was tested before subjecting the study variables to the t-test. The confidence limit for significance was fixed at a 95% level with P < 0.05.
| Results|| |
In the present study, 42 patients with age more than 45 years with resistant hypertension having renal artery stenosis undergoing PTRA were included. Nineteen (45.2%) were males, whereas 23 (54.8%) were females. Twelve (28.6%), 17 (40.5%), 10 (23.8%), and 3 (7.1%) patients were in the age group of 46–55, 56–65, 66–75, and >75 years, respectively. The mean age of the patients was 60.2 years. The mean systolic blood pressure (SBP) in all the patients at the baseline and 6-month follow-up was 181.3 mmHg and 159.5 mmHg, respectively, which was statistically significant (P = 0.0001). The mean diastolic blood pressure (DBP) in all the patients at baseline and 6-month follow-up was 106.5 mmHg and 94.4 mmHg, respectively, which was statistically significant (P = 0.0001).
As evident from [Table 1], there is no statistically significant difference between mean age, age groups, gender, history of diabetes mellitus, history of flash pulmonary edema, SBP (the baseline and 6-month follow-up), DBP (the baseline and 6-month follow-up), mean serum creatinine, GFR (the baseline and 6-month follow-up), and a systolic gradient across the stenotic segment in patients whose renin levels were normal and whose renin levels were elevated.
The mean SBP was significantly lower at 6-month follow-up as compared to baseline SBP in both groups of patients whose RVRL was normal and whose RVRL was elevated [Table 2]. The mean DBP was significantly lower at 6-month follow-up as compared to baseline DBP in both groups of patients whose RVRL was normal and whose RVRL was elevated [Table 3]. The mean GFR was significantly higher as compared to baseline GFR in patients whose RVRL was elevated, whereas there was no significant difference in mean GFR in patients whose RVRL was normal [Table 4].
|Table 2: Mean systolic blood pressure at baseline and after 6-month follow-up|
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|Table 3: Mean diastolic blood pressure at baseline and after 6-month follow-up|
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|Table 4: Mean glomerular filtration rate at baseline and after 6-month follow-up|
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At the baseline, 36 (85.7%) and 6 (14.3%) patients were on three and four antihypertensive drugs, respectively. The mean number of antihypertensive drugs used in all the patients at the baseline and 6-month follow-up was 3.4 and 1.8 which was statistically significant (P = 0.001). There was no statistical difference in the number of antihypertensive drugs used at the baseline and 6-month follow-up in patients whose RVRL was normal and in those whose RVRL was increased [Table 5]. However, it can be seen from [Table 5] that 7/42 (16.7%) and 35/42 (83.3%) patients required only one and two hypertensive drugs, respectively, 6 months after PTRA.
| Discussion|| |
The present study was conducted to evaluate the efficacy of percutaneous renal revascularization in resistant hypertension patients. In the present study, 45.2% were males. Adel et al. and Gonçalves et al. reported 66.7% and 56.5% of the male patients, respectively, of resistant hypertension in their studies.
In the present study, mean SBP and DBP at 6-month follow-up were significantly less as compared to baseline SBP and DBP. Gonçalves et al. reported SBP 176.9 (±30.3) and 134.8 (±28.1) before and after, respectively, and DBP 98.0 (±16.6) and 83.1 (±8.5) before and after, respectively, which was statistically significant (P < 0.001). Corriere et al. reported that there was a statistically significant decrease in mean SBP (161.3 ± 25.2 vs. 148.5 ± 25.2 postintervention, P < 0.0001) and DBP (78.6 ± 13.3 vs. 72.5 ± 13.5 postintervention, P < 0.0001). Adel et al. reported SBP 189 ± 27 and 178 ± 27 before stenting and after stenting, respectively, and DBP 113.5 ± 24.2 and 97.2 ± 16.2 before stenting and after stenting, respectively. The above findings are comparable to our study.
Plouin et al. carried out a prospective randomized multicenter trial in France to compare changes in BP levels of groups of individuals undergoing drug therapy (control group) and angioplasty plus drug therapy (angioplasty group) within a period of 6 months. BP level measurements between randomization and the end of follow-up did not differ significantly between the groups. Six patients in the angioplasty group and none in the control group were off antihypertensive medications at the time of follow-up. The number of doses of antihypertensive drugs in the angioplasty group was also lower than in the control group. Webster et al. performed a prospective randomized multicenter study in the United Kingdom to evaluate the effects of renal artery angioplasty versus drug therapy on BP control. One hundred and thirty-five patients with hypertension and atherosclerotic renal artery stenosis (ARAS) were selected and 55 were randomized. BP values dropped consistently in all the groups. Patients with bilateral ARAS did not have statistically significant different BP levels versus patients on drug therapy 6 months into follow-up. However, the last set of tests revealed that patients with bilateral stenosis submitted to angioplasty had statistically significant lower SBP levels. A randomized trial by van Jaarsveld et al. was carried in 26 centers in The Netherlands. One hundred and six patients with renal artery stenosis were selected (unilateral or bilateral stenosis greater than 50%) to undergo balloon angioplasty without stenting (56 patients) or receive drug therapy alone (50 patients). The primary endpoint was SBP and DBP in the 3rd and 12th months after randomization. SBP and DBP levels in the 3rd and 12th months were not significantly different between the groups.
ASTRAL was designed to determine reliably whether revascularization together with medical therapy improves renal function and other outcomes, as compared with medical therapy alone, in patients with ARAS. Between 2000 and 2007, 806 patients from 57 hospitals (53 in the UK, 3 in Australia, and 1 in New Zealand) were randomized and assessed prospectively. Three hundred and seventeen patients submitted to renal angioplasty versus 379 offered drug therapy alone. SBP levels dropped in both the groups, with no statistically significant differences between them. The study confirmed that revascularization by angioplasty offered indiscriminately to patients with ARAS is not beneficial.
Cardiovascular Outcomes in Renal Atherosclerotic Lesions was a randomized multicenter trial sponsored by the National Heart, Lung, and Blood Institute enrolled 947 patients with ARAS. The authors reported that SBP declined in the stent group (by 16.6 ± 21.2 mmHg). A modest but consistent difference between the groups was observed in SBP (P = 0.03) in favor of the procedure group, although without clinical benefit.
In our study, the mean GFR at baseline and 6-month follow-up was 85.9 and 88.2, respectively (P = 0.085). The mean GFR was significantly higher as compared to baseline GFR in patients whose renin levels were elevated, whereas there was no significant difference in mean GFR in patients whose renin levels were normal. Balk et al. reported that 8%–51% of the patients who underwent renal artery revascularization were categorized as having improved renal function, and up to 31% had worsened renal function; therefore, the improvement in renal function by renal artery revascularization has been controversial. Corriere et al. reported that there was a statistically significant increase in mean estimated glomerular filtration rate from 46.8 ± 17.3 to 50.2 ± 19.7 (P = 0.0114).
In the present study, the mean number of antihypertensive drugs used at the baseline and 6-month follow-up was 3.4 and 1.8 which was statistically significant (P = 0.001). Gonçalves et al. reported a decrease in drugs before 3.1 ± 1.28 and after 2.3 ± 1.1 which was statistically significant (P < 0.0001). Corriere et al. reported that there was a statistically significant decrease in the mean number of antihypertensive drugs (3.3 ± 1.2 vs. 3.1 ± 1.3 postintervention, P = 0.009). Cooper et al. reported that at the baseline, participants were taking a mean of 2.1 ± 1.6 antihypertensive medications. At the end of the study, the number of medications increased in the stent group 3.3 ± 1.5.
This was a single-center study conducted on a small number of patients and follow-up for only 6 months. Patients could be enrolled in the trial with renal artery stenosis of 50% or more, and there is debate about the severity of stenosis that is necessary to justify intervention. Randomized controlled studies with more sample size and longer follow-up are needed to extrapolate the results to a larger population. Selective renal vein sampling is an invasive and technically challenging procedure.
| Conclusions|| |
PTRA offered to patients with resistant hypertension was accompanied by improvements in BP control. The requirement of antihypertensive drugs was significantly reduced after the procedure. The mean SBP and mean DBP were significantly lower at 6-month follow-up as compared to baseline in both the groups of patients whose RVRL was normal and whose RVRL was elevated There was no statistically significant difference in the number of antihypertensive drugs used at the baseline and 6-month follow-up in patients whose RVRL was normal and in those whose RVRL was increased.
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| References|| |
Bozić B, Borković Z, Bartolin Z, Savić I, Persec Z, Galesić K. Renovascular hypertension-diagnosis and treatment. Acta Med Croatica 2005;59:329-35.
Gray BH. Intervention for renal artery stenosis: Endovascular and surgical roles. J Hypertens Suppl 2005;23:S23-9.
Garovic V, Textor SC. Renovascular hypertension: Current concepts. Semin Nephrol 2005;25:261-71.
Covit AB. Medical treatment of renal artery stenosis: Is it effective and appropriate? J Hypertens Suppl 2005;23:S15-22.
Textor SC. Ischemic nephropathy: Where are we now? J Am Soc Nephrol 2004;15:1974-82.
Guerrero M, Syed A, Khosla S. Survival following renal artery stent revascularization: Four-year follow-up. J Invasive Cardiol 2004;16:368-71.
Ferrario CM. Role of angiotensin II in cardiovascular disease therapeutic implications of more than a century of research. J Renin Angiotensin Aldosterone Syst 2006;7:3-14.
Unger T. The role of the renin-angiotensin system in the development of cardiovascular disease. Am J Cardiol 2002;89 Suppl: 3A-10A.
Kwoh C, Shannon MB, Miner JH, Shaw A. Pathogenesis of nonimmune glomerulopathies. Annu Rev Pathol 2006;1:349-74.
Brunner HR, Laragh JH, Baer L, Newton MA, Goodwin FT, Krakoff LR, et al
. Essential hypertension: Renin and aldosterone, heart attack and stroke. N Engl J Med 1972;286:441-9.
Alderman MH, Madhavan S, Ooi WL, Cohen H, Sealey JE, Laragh JH. Association of the renin-sodium profile with the risk of myocardial infarction in patients with hypertension. N Engl J Med 1991;324:1098-104.
Meade TW, Cooper JA, Peart WS. Plasma renin activity and ischemic heart disease. N Engl J Med 1993;329:616-9.
Parikh NI, Gona P, Larson MG, Wang TJ, Newton-Cheh C, Levy D, et al
. Plasma renin and risk of cardiovascular disease and mortality: The Framingham Heart Study. Eur Heart J 2007;28:2644-52.
Meade T. Review: Plasma renin and the incidence of cardiovascular disease. J Renin Angiotensin Aldosterone Syst 2010;11:91-8.
Muhlestein JB, May HT, Bair TL, Prescott MF, Horne BD, White R, et al
. Relation of elevated plasma renin activity at baseline to cardiac events in patients with angiographically proven coronary artery disease. Am J Cardiol 2010;106:764-9.
Masson S, Solomon S, Angelici L, Latini R, Anand IS, Prescott M, et al
. Elevated plasma renin activity predicts adverse outcome in chronic heart failure, independently of pharmacologic therapy: Data from the Valsartan Heart Failure Trial (Val-HeFT). J Card Fail 2010;16:964-70.
Verma S, Gupta M, Holmes DT, Xu L, Teoh H, Gupta S, et al
. Plasma renin activity predicts cardiovascular mortality in the Heart Outcomes Prevention Evaluation (HOPE) study. Eur Heart J 2011;32:2135-42.
Muhlestein J. Elevated Plasma Renin Activity (PRA) is Associated with Adverse Renal Outcomes in Patients with Coronary Artery disease. Vancouver, BC, Canada: Paper presented at The World Congress of Nephrology; 2011.
Mann SJ, Pickering TG. Detection of renovascular hypertension. State of the art: 1992. Ann Intern Med 1992;117:845-53.
Pickering TG, Sos TA, Vaughan ED Jr, Laragh JH. Differing patterns of renal vein renin secretion in patients with renovascular hypertension, and their role in predicting the response to angioplasty. Nephron 1986;44 Suppl 1:8-11.
Colyer WR Jr., Cooper CJ, Burket MW, Thomas WJ. Utility of a 0.014” pressure-sensing guidewire to assess renal artery translesional systolic pressure gradients. Catheter Cardiovasc Interv 2003;59:372-7.
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron 1976;16:31-41.
ASTRAL Investigators, Wheatley K, Ives N, Gray R, Kalra PA, Moss JG, et al
. Revascularization versus medical therapy for renal-artery stenosis. N Engl J Med 2009;361:1953-62.
Adel SM, Syeidian SM, Najafi M, Mohammad N. Clinical efficacy of percutaneous renal revascularization with stent placement in hypertension among patients with atherosclerotic renovascular diseases. J Cardiovasc Dis Res 2011;2:36-43.
] [Full text]
Charan J, Biswas T. How to calculate sample size for different study designs in medical research? Indian J Psychol Med 2013;35:121-6.
] [Full text]
Berglund F. Renal clearances of inulin, polyfructosan-S and a polyethylene glycol (PEG 1,000) in the rat. Acta Physiol Scand 1965;64:238-44.
Garnett ES, Parsons V, Veall N. Measurement of glomerular filtration-rate in man using a 51Cr-edetic-acid complex. Lancet 1967;1:818-9.
Bröchner-Mortensen J. A simple method for the determination of glomerular filtration rate. Scand J Clin Lab Invest 1972;30:271-4.
Fitz A. Renal venous renin determinations in the diagnosis of surgically correctable hypertension. Circulation 1967;36:942-50.
Gonçalves JA, Amorim JE, Neto MM, Ribeiro AB, Lima VC. Clinical efficacy of percutaneous renal revascularization with stent placement in atherosclerotic renovascular disease, Arq Bras Cardiol 2007;88:76-80.
Corriere MA, Pearce JD, Edwards MS, Stafford JM, Hansen KJ. Endovascular management of atherosclerotic renovascular disease: Early results following primary intervention. J Vasc Surg 2008;48:580-7.
Plouin PF, Chatellier G, Darné B, Raynaud A. Blood pressure outcome of angioplasty in atherosclerotic renal artery stenosis: A randomized trial. Essai Multicentrique Medicaments vs Angioplastie (EMMA) Study Group. Hypertension 1998;31:823-9.
Webster J, Marshall F, Abdalla M, Dominiczak A, Edwards R, Isles CG, et al
. Randomised comparison of percutaneous angioplasty vs continued medical therapy for hypertensive patients with atheromatous renal artery stenosis. Scottish and Newcastle Renal Artery Stenosis Collaborative Group. J Hum Hypertens 1998;12:329-35.
van Jaarsveld BC, Krijnen P, Pieterman H, Derkx FH, Deinum J, Postma CT, et al
. The effect of balloon angioplasty on hypertension in atherosclerotic renal-artery stenosis. Dutch Renal Artery Stenosis Intervention Cooperative Study Group. N Engl J Med 2000;342:1007-14.
Cooper CJ, Murphy TP, Cutlip DE, Jamerson K, Henrich W, Reid DM, et al
. Stenting and medical therapy for atherosclerotic renal-artery stenosis. N Engl J Med 2014;370:13-22.
Balk E, Raman G, Chung M, Stanley IP, Tatsioni A. Alonso P, et al
. Effectiveness of management strategies for renal artery stenosis: A systematic review. Ann Intern Med 2006;145:901-12.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]