Comparative Effectiveness of Management Strategies for Renal Artery Stenosis: An Updated Systematic Review

Assessment of renal insufficiency in patients with renal artery stenosis by multiparametric magnetic resonance imaging

OBJECTIVES

To evaluate the function of kidneys with renal artery stenosis using multiparametric magnetic resonance imaging, assess the diagnostic efficacy of multiparametric magnetic resonance imaging for single kidney dysfunction.

MATERIALS AND METHODS

Renal multiparametric magnetic resonance imaging was performed on 62 patients with RAS using the Philips Ingenia CX 3.0 T MRI machine. The scanning sequences included arterial spin labeling, phase contrast MRI, diffusion weighted imaging, T1 mapping, and blood oxygen level-dependent MRI. All patients underwent radionuclide renal dynamic imaging, and the glomerular filtration rate (GFR) was calculated to determine renal function. Individual kidneys from renal artery stenosis patients were classified into normal (GFR ≥ 30) and reduced (GFR < 30) groups and the ability of the uni- and multi-variate logistic regression model to predict the group was determined.

RESULTS

MR parameters demonstrated considerable diagnostic efficacy for single kidney dysfunction, with AUC range of 0.597- 0.864. The strongest predictor was mean renal artery blood flow. The sensitivity and specificity were 0.93 and 0.69AUC was 0.864. The strongest predictors of the renal microstructure were cortical apparent diffusion coeffecient and T1 value, with ROC AUCs of 0.756 and 0.741, sensitivities of 0.875 and 0.689, and specificities of 0.537 and 0.731. Multiparametric MRI combined with the values of cortical renal blood flow and cortical T1 exhibited the highest diagnostic efficacy, with an AUC of 0.92, and sensitivity of 0.919, and specificity of 0.743.

CONCLUSION

Multiparametric magnetic resonance imaging can effectively detect the single renal dysfunction of kidneys with renal artery stenosis, which holds promise for the diagnosis and prognosis of patients with renal artery stenosis.

Combination of medical therapy and percutaneous transluminal renal angioplasty versus medical therapy alone for patients with atherosclerotic renal artery stenosis: systematic review and meta-analysis

We investigated whether the combination of medical therapy plus percutaneous transluminal renal angioplasty (PTRA) provides superior clinical outcomes compared to those afforded by medical therapy alone in patients with hypertension due to atherosclerotic renal artery stenosis (ARAS) by conducting a systematic review and meta-analysis of the relevant randomized controlled trials (RCTs). The evaluated outcomes included: (1) cardiovascular disease (CVD)-related mortality, (2) the incidence of CVD events, (3) changes in blood pressure (BP), (4) suppression of renal function decline, (5) changes in the number of antihypertensive drugs used, and (6) serious adverse events. Nine RCTs involving 2275 patients were analyzed, revealing that the combination therapy significantly reduced the number of antihypertensive drugs compared to medical therapy alone (mean difference: -0.42, 95% confidence interval: -0.71 to -0.12). However, there were no significant differences between the combination therapy and medical therapy alone in CVD mortality, the incidence of CVD events, BP changes, suppression of renal function decline, or serious adverse events. The included studies demonstrated a low-to-moderate risk of bias, with performance and detection bias being the most prominent concerns. Together our findings demonstrate that compared to medical therapy alone, the combination of medical therapy + PTRA reduced the number of antihypertensive drugs used but did not improve adverse CVD or renal outcomes. The quality of the included RCTs represents a potential limitation of this analysis.

A preliminary study of renal function for renal artery stenosis using multiparametric magnetic resonance imaging

OBJECTIVE

To comprehensively evaluate the renal structure and function of patients with renal artery stenosis (RAS) using multiparametric magnetic resonance imaging (MRI), and analyze the correlation between magnetic resonance (MR) parameters and renal function.

MATERIALS AND METHODS

Renal multiparametric MRI was conducted on 62 patients with RAS utilizing a Philips Ingenia CX 3.0 T MRI system. The scanning protocols encompassed arterial spin labeling, phase contrast MRI, diffusion weighted imaging, T1 mapping, and blood oxygen level-dependent MRI. All patients underwent radionuclide renal dynamic imaging to calculate the glomerular filtration rate (GFR) for assessing renal function.

RESULTS

Most MR parameters were correlated with GFR: renal parenchymal volume (R = 0.603), whole kidney renal blood flow (RBF) (R = 0.192), renal cortical RBF (R = 0.294), renal artery mean velocity (R = 0.593), stroke volume (R = 0.599), mean flux (R = 0.629), renal cortical apparent diffusion coefficient (ADC) (R = 0.466), medullary ADC (R = 0.332), cortical T1 value (R = - 0.206), corticomedullary T1 difference (R = 0.204), cortical T2* value (R = 0.448), and medullary T2* value (R = 0.272). The best prediction model for GFR using multiparametric MRI was obtained, including renal PV, whole kidney RBF, cortical RBF, mean velocity, mean flux, and CMD T1.

CONCLUSION

Multiparametric MRI is a novel noninvasive examination method that can effectively and comprehensively assess the renal structure and function of RAS.

Hypertension

Resistant and uncontrolled hypertension are common presentations to the nephrology clinic. Many of these patients benefit from evaluation for secondary hypertension in order to optimize antihypertensive therapy and reduce the risks of target organ damage from uncontrolled hypertension. The purpose of this review is to present several cases of difficult-to-control and/or secondary hypertension and to identify optimal approaches to evaluating and managing hypertension in these high-risk patients.

Vascular Closure Devices For Axillary Artery Access: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the technical success and complication rates of vascular closure devices (VCDs) in the axillary artery.

MATERIALS AND METHODS

MEDLINE and Embase were searched independently by two reviewers to identify observational studies from inception through October 2021. The following outcomes were meta-analyzed: technical success, hematoma, dissection, pseudoaneurysm, infection, and local neurological complications. Complications were also graded as mild, moderate, and severe. A logistic regression evaluating the influence of sheath size for the outcome of technical success rate was performed using individual patient-level data.

RESULTS

Of 1496 unique records, 20 observational studies were included, totaling 915 unique arterial access sites. Pooled estimates were as follows: technical success 84.8% (95% confidence interval [CI]: 78%-89.7%, I2=60.4%), hematoma 7.9% (95% CI: 5.8%-10.6%, I2=0%), dissection 3.1% (95% CI: 1.3%-7.3%, I2=0%), pseudoaneurysm 2.7% (95% CI: 1.3%-5.7%, I2=0%), infection <1% (95% CI: 0%-5.7%, I2=20.5%), and local neurological complications 2.7% (95% CI: 1.7%-4.4%, I2=0%). There was a significant negative association between sheath size and technical success rate (odds ratio [OR]: 0.87 per 1 French (Fr) increase in sheath size, 95% CI: 0.80-0.94, p=0.0005). Larger sheath sizes were associated with a greater number of access-site complications (adjusted odds ratio [aOR]: 1.21 per 1 Fr increase sheath size, 95% CI: 1.04-1.40, p=0.013).

CONCLUSIONS

Off-label use of VCDs in the axillary artery provides an 85% successful closure rate and variable complication rate, depending on the primary procedure and sheath size. Larger sheaths were associated with a lower technical success and greater rate of access-related complications.

CLINICAL IMPACT

Safe arterial access is the foundation for arterial intervention. While the common femoral artery is a well established access site, alternative arterial access sites capable of larger sheath sizes are needed in the modern endovascular era. This article provides the largest synthesis to date on the use of vascular closure devices for percutaneous axillary artery access in endovascular intervention. It should serve clinicians with added confidence around this approach in terms of providing a reference for technical success and complications. Clinically, this data is relevant for patient consent purposes as well as for practice quality improvement in setting safety standards for this access site.

Managing hypertension in older people: current concepts

Hypertension management in older people is challenging due to pathophysiological changes brought about by ageing, associated comorbidities, frailty and polypharmacy and often has a poor evidence base. This article gives an overview of these factors and related available evidence with particular attention to clinical issues and consensus guidance.

Long-term outcomes of percutaneous transluminal renal artery intervention: a retrospective study at a single center

BACKGROUND

The indications, benefits, and outcomes of percutaneous transluminal renal artery intervention (PTRI) remain controversial. The study purpose was to evaluate the long-term outcomes of PTRI in clinical practice.

METHODS

A retrospective review of 217 subjects (254 renal arteries; mean age, 59.8 years) who underwent PTRI based on medical database.

RESULTS

The most common cause of renal artery stenosis was atherosclerosis in 217 (85.4%), followed by Takayasu arteritis (TA) in 23 (9.1%), fibromuscular dysplasia in five (2.0%) and others in nine (3.5%). Mean follow-up duration was 5.7 ± 3.7 years. The first restenosis rate was 7.5% (n = 19; highest in TA: n = 9, 47.4%) and second restenosis occurred in six arteries (five TAs, one fibromuscular dysplasia). Follow-up blood pressure improved from 142.0/83.5 to 122.8/73.5 mmHg (P < 0.001). There was no change within 5 years' follow-up in estimated glomerular filtration rate (P = 0.44), whereas TA changed from 69.8 ± 20.5 to 84.2 ± 17.9 mL/min/1.73 m² (P = 0.008). Progressive renal dysfunction was related to diabetes mellitus, chronic kidney disease, and peripheral artery obstructive disease on multivariate analysis with hazard ratios (95% confidence intervals) of 2.24 (1.21-4.17), 2.54 (1.33-4.84), and 3.93 (1.97-7.82), respectively.

CONCLUSIONS

PTRI was associated with a blood pressure reduction. Despite a higher rate of restenosis, patients with TA showed significant improvement in estimated glomerular filtration rate. Diabetes mellitus, chronic kidney disease, and peripheral artery obstructive disease were related with progressive renal dysfunction after PTRI.

Therapy for Renal Artery Stenosis: A Call for Change

CLINICAL IMPACT

We present a brief case description of a patient who benefitted from stenting in ARAS and provide a comprehensive review of ARAS; its prevalence, pathophysiology, clinical manifestations, diagnosis and treatment. We review the evidence for and against stenting in ARAS as well as consensus guidelines for stenting. Our review is valuable as we argue that stenting in ARAS is underutilized and the randomized control data for stenting in those patients who may benefit most is lacking. Our review will provide an important perspective for clinicians faced with decisions of how to treat ARAS.

Safety and Biodistribution of an Autologous Bone Marrow-Derived Mononuclear Cell Infusion into Renal Arteries in Patients with Focal Segmental Glomerulosclerosis: A Phase 1 Study

Patients with focal segmental glomerulosclerosis (FSGS) who are refractory to drug treatment may present progressive loss of kidney function, leading to chronic kidney disease stage 5 under dialysis treatment. The safety of systemic administration of bone marrow-derived mononuclear cells (BMDMCs) has been shown in different preclinical models of kidney diseases. However, to date, no study has evaluated the safety and biodistribution of BMDMCs after infusion in renal arteries in patients with FSGS. We used a prospective, non-randomized, single-center longitudinal design to investigate this approach. Five patients with refractory FSGS and an estimated glomerular filtration rate (eGFR) between 20 and 40 ml/min/1.73 m2 underwent bone marrow aspiration and received an arterial infusion of autologous BMDMCs (5 × 107) for each kidney. In addition, BMDMCs labeled with technetium-99m (99mTc-BMDMCs) were used to assess the biodistribution by scintigraphy. All patients completed the 270-day follow-up protocol with no serious adverse events. A transient increase in creatinine was observed after the cell therapy, with improvement on day 30. 99mTc-BMDMCs were detected in both kidneys and counts were higher after 2 hr compared with 24 hr. The arterial infusion of BMDMCs in both kidneys of patients with FSGS was considered safe with stable eGFR at the end of follow-up. This trial is registered with NCT02693366.

Severe acute kidney injury in a patient with renal artery stenosis of a single-functioning kidney: A case report of rapid normalisation of the renal function after percutaneous transluminal angioplasty with stent placement

Revascularisation of renal arterial stenosis in acute settings, such as uncontrolled arterial hypertension, flash pulmonary oedema and/or acute renal failure, has shown controversial results in observational and prospective studies. Current guidelines do not recommend revascularisation in the occurrence of renal failure as revascularisation and best medical treatment have shown similar long-term outcomes on renal function. We describe a case of acute degradation of the renal function (with oligo-anuria and a peak creatinine of 462 µmol/L) after the re-introduction of an angiotensin-II receptor blocker (irbesartan) in a 66-year-old Caucasian diabetic male patient with bilateral renal stenosis and a right-sided single-functioning kidney, with a rapid improvement of the renal function which normalized 5 days after percutaneous angioplasty and stenting of the right renal artery.

Endovascular treatments of atherosclerotic renovascular disease: a narrative review and literature search

In recent years, endovascular treatments have become more common in patients with renal artery stenosis and aneurysm. Although the treatment algorithms are not universally accepted, endovascular therapy can be readily utilized for the appropriate indications in the context of surgical treatment for renovascular diseases. The most important factor to consider is that the correct indication is applied for such treatment. Although the applied procedures are believed to have minimal risk, any complications that occur may result in major problems. Moreover, the pathology that is being treated (e.g., hypertension, high serum creatinine concentration, or low glomerular filtration rate) must be well defined. As stent and balloon technologies continue to be developed, more positive results are expected in the coming years. In the present study, we reviewed the endovascular treatment algorithms for atherosclerotic renovascular disease and performed a narrative review of the current literature.

The Use of Vascular Closure Devices for Brachial Artery Access: A Systematic Review and Meta-Analysis

PURPOSE

To estimate the rates of technical success and adverse events of vascular closure devices (VCDs) in the brachial artery and compare the rates of adverse events with manual compression.

MATERIALS AND METHODS

MEDLINE and Embase were searched for observational studies examining VCDs in the brachial artery. Meta-analyses were performed using random effects for the following outcomes: (a) technical success, (b) hematoma at the access site, (c) pseudoaneurysm, (d) local neurological adverse events, and (e) total number of adverse events. A pairwise meta-analysis compared VCD with manual compression for the outcomes of hematoma and the total number of adverse events.

RESULTS

Of 1,761 eligible records, 16 studies including 510 access sites were included. Primary procedures performed were peripheral arterial disease interventions, percutaneous coronary intervention, and endovascular thrombectomy for ischemic stroke. The technical success rate was 93% (95% CI, 87%-96%; I² = 47%). Data on the following adverse events were obtained via meta-analysis: (a) hematoma, 9% (5%-15%; I² = 54%); (b) stenosis or occlusion at access site, 3% (1%-14%; I² = 51%); (c) infection, 0% (0%-5%; I² = 0%); (d) pseudoaneurysm, 4% (1%-13%; I² = 61%); (e) local neurological adverse events, 5% (2%-13%; I² = 54%); and (f) total number of adverse events, 15% (10%-22%; I² = 51%). Angio-Seal success rate was 96% (93%-98%; I² = 0%), whereas the ExoSeal success rate was 93% (69%-99%; I² = 61%). When comparing VCD and manual compression, there was no difference in hematoma formation (relative risk, 0.75; 95% CI, 0.35-1.63; I² = 0%; P = .47) or the total number of adverse events (relative risk, 0.75; 95% CI, 0.35-1.58; I² = 76%; P = .45).

CONCLUSIONS

Despite being off-label, studies suggest that VCDs in the brachial artery have a high technical success rate. There was no significant difference in adverse events between VCDs and manual compression in the brachial artery.

Revascularization for Renovascular Disease: A Scientific Statement From the American Heart Association

Renovascular disease is a major causal factor for secondary hypertension and renal ischemic disease. However, several prospective, randomized trials for atherosclerotic disease failed to demonstrate that renal revascularization is more effective than medical therapy for most patients. These results have greatly reduced the generalized diagnostic workup and use of renal revascularization. Most guidelines and review articles emphasize the limited average improvement and fail to identify those clinical populations that do benefit from revascularization. On the basis of the clinical experience of hypertension centers, specialists have continued selective revascularization, albeit without a summary statement by a major, multidisciplinary, national organization that identifies specific populations that may benefit. In this scientific statement for health care professionals and the public-at-large, we review the strengths and weaknesses of randomized trials in revascularization and highlight (1) when referral for consideration of diagnostic workup and therapy may be warranted, (2) the evidence/rationale for these selective scenarios, (3) interventional and surgical techniques for effective revascularization, and (4) areas of research with unmet need.

The Maintained Glycemic Target Goal and Renal Function Are Associated with Cardiovascular and Renal Outcomes in Diabetic Patients Following Stent-Supported Angioplasty for Renovascular Atherosclerotic Disease

Patients with type 2 diabetes mellitus (T2DM) constitute a large proportion of patients with atherosclerotic renal artery stenosis (ARAS). However, the mechanism of impaired renal function and hypertension in this subset of patients is multifactorial. We aimed to investigate whether, in diabetic patients, renal function (RF), systolic (SBP) and diastolic blood pressure (DBP) values following stent-supported angioplasty (PTA) for ARAS have an impact on cardiovascular and renal outcomes. Methods: The study group included 93 patients with T2DM and resistant hypertension who underwent PTA for ARAS. The pre- and post-procedure (6 to 12, and 24 months) values of SBP, DBP, eGFR and glycaemia were obtained. The prospective follow-up of median 44 months was performed for combined outcome: major cardiac and cerebral events (MACCE) and progression to renal replacement therapy (RRT). Results: MACCE-RRT occurred in 46 (49.5%) patients, with higher incidence in patients with higher values of SBP (147.8 ± 25.8 vs. 136.7 ± 15.8 mmHg, p = 0.006), DBP (80.8 ± 13.3 vs. 74.4 ± 12.3 mmHg, p = 0.009), chronic kidney disease in stages 3B to 5 (p = 0.029) and those who have not obtained target glycemic goals compared to well-maintained T2DM (p = 0.007) at 24-months. On multivariate Cox analysis, well-maintained T2DM targets [Hazard Ratio (HR):0.27; 95% Confidence Interval (CI):0.13−0.57; p < 0.001], eGFR below 45 mL/min/m2 (HR: 2.20; 95%CI: 1.20−4.04; p = 0.011), previous stroke (HR:2.52; 95%CI:1.19−5.34; p = 0.015) retained their associations with MACCE-RRT, while BP values were not associated with the outcome. Conclusions: The post-procedural RF, maintained glycemic target goal and previous stroke are vital for the outcome in patients undergoing PTA for renovascular disease in diabetic patients.

Renal Artery Stenting in Consecutive High-Risk Patients With Atherosclerotic Renovascular Disease: A Prospective 2-Center Cohort Study

Background

The aim of this study was to prospectively evaluate the effects of renal artery stenting in consecutive patients with severe atherosclerotic renal artery stenosis and high‐risk clinical presentations as defined in a national protocol developed in 2015.

Methods and Results

Since the protocol was initiated, 102 patients have been referred for revascularization according to the following high‐risk criteria: severe renal artery stenosis (≥70%) with true resistant hypertension, rapidly declining kidney function, or recurrent heart failure/sudden pulmonary edema. At baseline, the mean 24‐hour ambulatory systolic blood pressure was 166.2 mm Hg (95% CI, 162.0–170.4), the defined daily dose of antihypertensive medication was 6.5 (95% CI, 5.8–7.3), and the estimated glomerular filtration rate was 41.1 mL/min per 1.73m² (95% CI, 36.6–45.6). In 96 patients with available 3‐month follow‐up data, mean 24‐hour ambulatory systolic blood pressure decreased by 19.6 mm Hg (95% CI, 15.4–23.8; P<0.001), the defined daily dose of antihypertensive medication was reduced by 52% (95% CI, 41%–62%; P<0.001), and estimated glomerular filtration rate increased by 7.8 mL/min per 1.73m² (95% CI, 4.5–11.1; P<0.001). All changes persisted after 24 month follow‐up. Among 17 patients with a history of hospitalization for acute decompensated heart failure, 14 patients had no new episodes after successful revascularization.

Conclusions

In this prospective cohort study, we observed a reduction in blood pressure and antihypertensive medication, an increase in estimated glomerular filtration rate, and a decrease in new hospital admissions attributable to heart failure/sudden pulmonary edema after renal artery stenting.

Registration

URL: https://clinicaltrials.gov. Identifier: NCT02770066.

Impact of Percutaneous Transluminal Renal Angioplasty on Autonomic Nervous System and Natriuresis in Hypertensive Patients With Renal Artery Stenosis

Background

We investigated the early postoperative effect of percutaneous transluminal renal angioplasty on ambulatory blood pressure (BP) and the circadian characteristics of natriuresis and autonomic nerve activity.

Methods and Results

A total of 64 patients with hypertension with hemodynamically significant renal artery stenosis (mean age, 60.0±21.0 years; 31.3% fibromuscular dysplasia) who underwent angioplasty were included, and circadian characteristics of natriuresis as well as heart rate variability indices, including 24‐hour BP, low‐frequency and high‐frequency (HF) components, and the percentage of differences between adjacent normal R‐R intervals >50 ms were evaluated using an oscillometric device, TM‐2425, both at baseline and 3 days after angioplasty. In both the fibromuscular dysplasia and atherosclerotic stenosis groups, 24‐hour systolic BP (fibromuscular dysplasia, −19±14; atherosclerotic renal artery stenosis, −11±9 mm Hg), percentage of differences between adjacent normal R‐R intervals >50 ms, HF, brain natriuretic peptide, and nighttime urinary sodium excretion decreased (all P<0.01), and heart rate increased (both P<0.05) after angioplasty. In both groups, revascularization increased the night/day ratios of percentage of differences between adjacent normal R‐R intervals >50 ms (both P<0.01) and HF, and decreased those of low frequency/HF (all P<0.05) and nighttime urinary sodium excretion (fibromuscular dysplasia, 1.17±0.15 to 0.78±0.09; atherosclerotic renal artery stenosis, 1.37±0.10 to 0.99±0.06, both P<0.01). Multiple logistic regression analysis indicated that a 1‐SD increase in baseline low frequency/HF was associated with at least a 15% decrease in 24‐hour systolic BP after angioplasty (odds ratio, 2.30 [95% CI, 1.03–5.67]; P<0.05).

Conclusions

Successful revascularization results in a significant BP decrease in the early postoperative period. Intrarenal perfusion might be a key modulator of the circadian patterns of autonomic nerve activity and natriuresis, and pretreatment heart rate variability evaluation seems to be important for treatment success.

Numerical simulation in the abdominal aorta and the visceral arteries with or without stenosis based on 2D PCMRI

It is important to obtain accurate boundary conditions (BCs) in hemodynamic simulations. This article aimed to improve the accuracy of BCs in computational fluid dynamics (CFD) simulation and analyze the differences in hemodynamics between healthy volunteers and patients with visceral arterial stenosis (VAS). The geometric models of seven cases were reconstructed using the magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA) imaging data. The physiological flow waveforms obtained from 2D Phase Contrast Magnetic Resonance Imaging (PCMRI) were imposed on the aortic inlet and the visceral arteries' outlets. The individualized RCR values of the three-element Windkessel model were imposed on the aortic outlet. CFD simulations were run in the open-source software: svSolver. Two specific time points were selected to compare the hemodynamics of healthy volunteers and patients with VAS. The results suggested that blood in the stenotic visceral arteries flowed at high speed throughout the cardiac cycle. The low pressure is distributed at stenotic lesions. The wall shear stress (WSS) reached 4 Pa near stenotic locations. The low time average wall shear stress (TAWSS), high oscillatory shear index (OSI), and high relative residence time (RRT) concentrated in the abdominal aorta. Besides, the ratios of the areas with low TAWSS, high OSI, and high RRT to the computational domain were higher in patients with VAS than which in the healthy volunteers. The individualized BCs were used for hemodynamic simulations and results suggest that patients with stenosis have a higher risk of blood retention and atherosclerosis formation in the abdominal aorta.

Prediction of Split Renal Function Improvement After Renal Artery Stenting by Blood Oxygen Level–Dependent Magnetic Resonance Imaging

Background

The discrepancy between the high technical success rate and the relatively low clinical response rate of renal artery stenting (RAS) raises the importance to identify atherosclerotic renal artery stenosis (ARAS) patients who are most likely to benefit from RAS. This study aimed to investigate the feasibility and accuracy of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) in predicting split renal function (SRF) improvement after RAS in patients with ARAS.

Methods

Thirty patients with severe ARAS who were treated with RAS were enrolled. Baseline cortical and medullary R2* values of each kidney were measured by BOLD-MRI, and each patient’s SRF was evaluated by nuclear renal dynamic imaging at baseline and 1-month follow-up.

Results

In total, 35 severe stenotic renal arteries of the 30 patients were analyzed. At 1-month follow-up, 34 kidneys (97.1%) of severe ARAS had acquired SRF. SRF improved in 12 kidneys of 10 patients. The cortical R2* and medullary R2* values in the SRF improvement kidneys were higher than those in the non-improvement kidneys (P ≤ 0.001). The area under the curve of medullary R2* was 0.879 (95% confidence interval [CI] 0.736–1.000). A medullary R2* value ≥29.1 s^–1 was noted to provide good sensitivity (0.833, 95% CI 0.552–0.970) and specificity (0.864, 95% CI 0.667–0.953) in predicting SRF improvement. Medullary R2* value was the only independent predictor of SRF improvement in multivariable analysis (P = 0.034, OR 3.017, 95%CI 1.089–8.358).

Conclusion

This study showed that a BOLD-MRI medullary R2* value ≥29.1 s^–1 was an excellent predictor of SRF improvement in patients with severe ARAS who underwent renal artery stenting.

Living donor kidney transplant following nephrectomy for renal artery stenosis with arterial reconstruction and viability assessment using ex vivo normothermic perfusion

Ex vivo normothermic perfusion (EVNP) is increasingly recognised as a viability tool to increase organ utilisation in deceased donor transplantation. We report the use of EVNP to assess graft perfusion quality following indication nephrectomy and back-bench arterial reconstruction in a case of renal artery stenosis, unamenable to endovascular treatment. Once explanted, it was not possible to effectively cold perfuse the graft through the main renal artery or collaterals. An arterial reconstruction was performed with patch angioplasty using the largest collateral creating a single common stem. EVNP was used to assess organ perfusion and, therefore, viability. Excellent global perfusion was evident alongside urine production, demonstrating that the arterial reconstruction was satisfactory. A patient with end-stage renal disease was consented with particular attention to the uncertainty of the underlying donor disease process and long-term outcome of the reconstruction. Primary function was achieved and recipient estimated glomerular filtration rate (eGFR) remains stable at 58 mL/min/1.73 m² at 6 months.

Cell-based regenerative medicine for renovascular disease

Renal artery stenosis (RAS) elicits the development of hypertension and post-stenotic kidney damage, which may become irresponsive to restoration of arterial patency. Rather than mere losses of blood flow or oxygen supply, irreversible intrarenal microvascular rarefaction, tubular injury, and interstitial fibrosis are now attributed to intrinsic pathways activated within the kidney, focusing attention on the kidney parenchyma as a therapeutic target. Several regenerative approaches involving the delivery of reparative cells or products have achieved kidney repair in experimental models of RAS and the delivery of mesenchymal stem/stromal cells (MSCs) has already been translated to human subjects with RAS with promising results. The ongoing development of innovative approaches in kidney disease awaits application, validation, and acceptance as routine clinical treatment to avert kidney damage in RAS.

Progressive abdominal pain in a 63-year-old man

50%-60% of patients with chronic mesenteric ischemia suffer from concomitant cardiovascular disease. We therefore suggest an extensive diagnostic screening to detect coronary artery and peripheral arterial disease in these patients.

Renal interventions in the management of hypertension

PURPOSE OF REVIEW

In the present comprehensive review, we describe the pathophysiology, indications, and evidence for both renal artery stenting and renal artery denervation. We also discuss the procedural techniques, risks, benefits, and future directions of renal intervention in the management of hypertension (HTN).

RECENT FINDINGS

Hemodynamic confirmation of lesion severity in severe renal artery stenosis is a resting or hyperemic translesional systolic gradient >20, resting or hyperemic mean translesional gradient >10 and/or renal fractional flow reserve <0.8 are considered severe. Knowing that correct stent size was used is the best predictor of restenosis, intravascular ultrasound is effective and well tolerated for stent sizing. The main categories of renal denervation: radiofrequency ablation, ultrasound, chemical ablation, and brachytherapy have shown impressive outcomes in treating resistant HTN.

SUMMARY

Over the past decade, several studies have shown the safety and benefit of catheter-based renal interventions in managing HTN. Renal artery stenting and renal artery denervation are the leading alternative invasive treatment employed in managing HTN.

Renal artery stenosis

Renal artery stenosis is the most common secondary cause of hypertension and predominantly caused by atherosclerosis. In suspected patients, a non-invasive diagnosis with ultrasound is preferred. Asymptomatic, incidentally found RAS does not require revascularization. In symptomatic patients requiring revascularization, renal artery stenting is the preferred therapy. Selecting appropriate patients for revascularization requires careful consideration of lesion severity and is optimized with a multidisciplinary team. All patients with atherosclerotic RAS should be treated with guideline-directed medical therapy, including hypertension control, diabetes control, statins, antiplatelet therapy, smoking cessation and encouraging activity.

Color-coded summation images in the evaluation of renal artery stenosis before and after percutaneous transluminal angioplasty

BACKGROUND

Endovascular therapy is the gold standard in patients with hemodynamic relevant renal artery stenosis (RAS) resistant to medical therapy. The severity grading of the stenosis as well as the result assessment after endovascular approach is predominantly based on visible estimations of the anatomic appearance. We aim to investigate the application of color-coded DSA parameters to gain hemodynamic information during endovascular renal artery interventions and for the assessment of the procedures´ technical success.

METHODS

We retrospectively evaluated 32 patients who underwent endovascular renal artery revascularization and applied color-coded summation imaging on selected monochromatic DSA images. The differences in time to peak (dTTP) of contrast enhancement in predefined anatomical measuring points were analyzed. Furthermore, differences in systolic blood pressure values (SBP) and serum creatinine were obtained. The value of underlying diabetes mellitus as a predictor for clinical outcome was assessed. Correlation analysis between the patients´ gender as well as the presence of diabetes mellitus and dTTP was performed.

RESULTS

Endovascular revascularization resulted in statistically significant improvement in 4/7 regions of interest. Highly significant improvement of perfusion in terms of shortened TTP values could be found at the segmental artery level and in the intrastenotical segment (p < 0.001), significant improvement prestenotical and in the apical renal parenchyma (p < 0.05). In the other anatomic regions, differences revealed not to be significant. Differences between SBP and serum creatinine levels before and after the procedure were significant (p = 0.004 and 0.0004). Patients´ gender as well as the presence of diabetes mellitus did not reveal to be predictors for the clinical success of the procedure. Furthermore, diabetes and gender did not show relevant correlation with dTTP in the parenchymal measuring points.

CONCLUSIONS

The supplementary use of color-coding DSA and the data gained from parametric images may provide helpful information in the evaluation of the procedures´ technical success. The segmental artery might be a particularly suitable vascular territory for analyzing differences in blood flow characteristics. Further studies with larger cohorts are needed to further confirm the diagnostic value of this technique.

[Treatment of renal artery stenosis in the year 2021]

Severe arteriosclerotic stenosis of the renal artery with at least 60-70% narrowing of the lumen can lead to various diseases: in the case of unilateral stenosis it can lead to renovascular hypertension, in the case of bilateral narrowing (or in a stenotic solitary kidney) also to an often progressive renal insufficiency (ischemic kidney disease) and/or to acute pulmonary edema (pulmonary flash edema). Renal artery stenosis may be treated by revascularization using either percutaneous (balloon angioplasty with or without stenting) or less commonly open surgical procedures, both with excellent primary patency rates of over 90%; however, randomized trials of catheter-based interventions have failed to demonstrate a longer term benefit with respect to blood pressure control and renal function as well as improved overall survival over optimal medicinal management alone. Due to improved clinical outcomes interventional revascularization is justified in cases with critical stenoses and clinical sequelae, such as pulmonary flash edema and progressive renal failure. Careful patient selection is essential to maximize a potential clinical benefit.

Use of percutaneous transluminal renal angioplasty in atherosclerotic renal artery stenosis: a systematic review and meta-analysis

OBJECTIVE

For patients with atherosclerotic renal artery stenosis (ARAS), the role of percutaneous transluminal renal angioplasty (PTRA) remains inconclusive. This study aimed to comparatively evaluate the benefits of best medical therapy (BMT) plus PTRA and BMT alone in treating ARAS.

METHODS

We performed a systematic review and meta-analysis, and searched for all randomized, controlled trials that reported patients with ARAS. The effectiveness and safety in the BMT plus PTRA and BMT alone groups were estimated, taking into account hypertension, stroke, renal events, cardiac events, and mortality.

RESULTS

Nine randomized, controlled trials involving 2309 patients were included. In the BMT plus PTRA group, the incidence of refractory hypertension was significantly lower compared with that in the BMT alone group (odds ratio 0.09; 95% confidence interval 0.01, 0.70). However, there were no significant differences in the rates of stroke, renal events, cardiac events, cardiac mortality, and all-cause mortality between the two groups.

CONCLUSIONS

PTRA plus BMT improves blood pressure in patients with ARAS, but there is insufficient evidence for this therapy in improving stroke, renal events, cardiac events, and cardiac and all-cause mortality.

How should we define appropriate patients for percutaneous transluminal renal angioplasty treatment?

Renovascular hypertension (RVH) is one of the most common causes of secondary hypertension and can result in resistant hypertension. RVH is associated with an increased risk for progressive decline in renal function, cardiac destabilization syndromes including "flash" pulmonary edema, recurrent congestive heart failure, and cerebrocardiovascular disease. The most common cause of renal artery stenosis (RAS) is atherosclerotic lesions, followed by fibromuscular dysplasia. The endovascular technique of percutaneous transluminal renal angioplasty (PTRA) with or without stenting is one of the standard treatments for RAS. Randomized controlled trials comparing medical therapy with PTRA to medical therapy alone have failed to show a benefit of PTRA; however, the subjects of these randomized clinical trials were limited to atherosclerotic RAS patients, and patients with the most severe RAS, who would be more likely to benefit from PTRA, might not have been enrolled in these trials. This review compares international guidelines related to PTRA, reevaluates the effects of PTRA treatment on blood pressure and renal and cardiac function, discusses strategies for the management of RVH patients, and identifies factors that may predict which patients are most likely to benefit from PTRA.

When and How Should We Revascularize Patients With Atherosclerotic Renal Artery Stenosis?

Atherosclerotic renal artery stenosis is the leading cause of secondary hypertension and may lead to resistant (refractory) hypertension, progressive decline in renal function, and cardiac destabilization syndromes (pulmonary edema, recurrent heart failure, or acute coronary syndromes) despite guideline-directed medical therapy. Although randomized controlled trials comparing medical therapy with medical therapy and renal artery stenting have failed to show a benefit for renal artery stenting, according to comparative effectiveness reviews by the Agency for Healthcare Research and Quality, the trials may not have enrolled patients with the most severe atherosclerotic renal artery stenosis, who would be more likely to benefit from renal stenting. Because of limitations of conventional angiography, it is critical that the hemodynamic severity of moderately severe (50% to 70%) atherosclerotic renal artery stenosis lesions be confirmed on hemodynamic measurement. The authors review techniques to optimize patient selection, to minimize procedural complications, and to facilitate durable patency of renal stenting. The authors also review the current American College of Cardiology and American Heart Association guidelines and the Society for Cardiovascular Angiography and Interventions appropriate use criteria as they relate to renal stenting.

Selection of Patients for Angioplasty for Treatment of Atherosclerotic Renovascular Disease: Predicting Responsive Patients

Atherosclerotic renal artery stenosis (ARAS) can cause secondary hypertension, progressive decline in renal function, and cardiac complications. Recent randomized controlled trials including the Cardiovascular Outcomes in Renal Atherosclerotic Lesions study have not reported the benefit of renal artery stenting compared with medical therapy alone to improve renal function or reduce cardiovascular and renal events in the enrolled patients with ARAS. However, observational evidence indicating the benefits of angioplasty in the selected high-risk patients with ARAS has been increasing. Thus, the timely correction of stenosis through angioplasty may have a beneficial effect in selected patients. However, optimal patient selection for angioplasty has been debated and can be challenging at times. Clinicians must identify the responsive patients who would benefit from angioplasty through risk stratification and the prediction of outcomes. Efforts have been made for the determination of predictors that can identify the subgroups of patients who would benefit from angioplasty. Lower age, more severe stenosis, preserved renal perfusion, and absence of diabetes or generalized atherosclerosis have been reported as the predictors for the improvement of hypertension after angioplasty. Global renal ischemia, rapidly declining renal function over 6-12 months, progressive shrinkage of the affected kidney, lower resistive index, and lower levels of albuminuria have been reported as predictors of improved or preserved renal function after angioplasty. This review discusses the identification of ARAS patients who will potentially respond well to angioplasty.

Renal artery stenosis presenting as preeclampsia

Background

Renal artery stenosis is a notorious cause of secondary hypertension which classically presents as chronic refractory hypertension, recurrent flash pulmonary edema or renal insufficiency after initiation of an angiotensin converting enzyme inhibitor. Rarely, there have been reported cases of pregnant patients presenting with new onset or superimposed preeclampsia secondary to renovascular hypertension. In this subset of patients, renovascular hypertension carries significantly higher risks including obstetric, fetal and medical emergencies and death. Prompt treatment is required. However, the teratogenic risks of radiological investigations and antihypertensive medications limit diagnostic and management options thus posing quite a dilemma.

Case presentation

A 38-year-old female, at 33 weeks of gestation, was hospitalized for preeclampsia with severe features. A viable neonate had been expeditiously delivered yet the patient’s post-partum blood pressures remained severely elevated despite multi-class anti-hypertensive therapy. Renal artery dopplers revealed greater than 60% stenosis of the proximal left renal artery and at least 60% stenosis of the right renal artery. Renal angiography showed 50% stenosis of the left proximal renal artery for which balloon angioplasty and stenting was performed. The right renal artery demonstrated less than 50% stenosis with an insignificant hemodynamic gradient, thus was not stented. Following revascularization, the patient’s blood pressure improved within 48 h, on dual oral antihypertensive therapy.

Conclusions

Preeclampsia that is refractory to multi-drug antihypertensive therapy should raise suspicion for renal artery stenosis. Suspected patients can be screened safely with Doppler ultrasonography which can be then followed by angiography. Even if renal artery stenosis does not seem severe, early renal revascularization may be considered in patients with severe preeclampsia who do not respond to antihypertensive management.

Renal and Mesenteric Artery Intervention

Atherosclerotic renal artery stenosis is the most common cause of secondary hypertension and may cause progressive renal disease and cardiac destabilization syndromes. Guideline-directed medical therapy is advised in all patients. Patients with refractory symptoms and hemodynamically significant stenoses are more likely to benefit from renal artery stent placement. Chronic mesenteric ischemia (CMI) is an infrequent and difficult to diagnose illness. Due to robust collateralization, clinical symptoms from mesenteric artery stenosis or occlusion is uncommon. Atherosclerosis is the most common etiology of CMI. Current evidence suggests that, compared with open surgical repair, endovascular therapy is the most cost-effective choice for CMI.

Blood pressure decreases after revascularization in atherosclerotic renal artery disease: A cohort study based on a multidisciplinary meeting

Background

In atherosclerotic renal artery disease, the benefit of revascularization is controversial. A clinical decision-making process based on a multidisciplinary meeting was formalized in the Lyon university hospital.

Objectives

To investigate whether this decisional process ensured a clinical benefit to patients assigned to renal revascularization.

Methods

Single-centre retrospective cohort study, including patients diagnosed from April 2013 to February 2015 with an atherosclerotic renal artery disease with a peak systolic velocity >180cm/s. For each patient, the decision taken in multidisciplinary meeting (medical treatment or revacularization) was compared to the one guided by international guidelines. Blood pressure values, number of antihypertensive medications, presence of an uncontrolled or resistant hypertension, and glomerular filtration rate at one-year follow-up were compared to baseline values. Safety data were collected.

Results

Forty-nine patients were included: 26 (53%) were assigned to a medical treatment and 23 (47%) to a renal revascularization. Therapeutic decision was in accordance with the 2013 American Health Association guidelines and with the 2017 European Society of Cardiology guidelines for 78% and 22% of patients who underwent revascularization, respectively. Patients assigned to revascularization presented a significant decrease in systolic blood pressure (-23±34mmHg, p = 0.007), diastolic blood pressure (-12±18mmHg, p = 0.007), number of antihypertensive medications (-1.00±1.03, p = 0.001), and number of uncontrolled or resistant hypertension (p = 0.022 and 0.031) at one-year follow-up. Those parameters were not modified among patients assigned to medical treatment alone. There was no grade 3 adverse event.

Conclusion

Based on a multidisciplinary selection of revascularization indications, patients on whom a renal revascularization was performed exhibited a significant improvement of blood pressure control parameters with no severe adverse events.

A randomized unblinded trial to compare effects of intensive versus conventional lipid-lowering therapy in patients undergoing renal artery stenting

BACKGROUND

Although current guidelines recommend the use of statins for severe atherosclerotic renal artery stenosis (ARAS), the renal protection of intensive lipid-lowering therapy in patients with ARAS who underwent stent placement remains uncertain. The aim of this study was to compare the renal-protective effect of intensive lipid lowering with that of conventional lipid lowering in patients with ARAS undergoing stent placement.

METHODS

A total 150 patients with severe ARAS undergoing stent placement were randomly (1:1) assigned to receive intensive lipid lowering [target low-density lipoprotein cholesterol (LDL-C) <70mg/dL] or conventional lipid lowering (target LDL-C ≥70mg/dL, <128mg/dL). All patients received rosuvastatin. We adjusted LDL-C to the goal within two months after renal stenting and maintained stability. The primary endpoint was the change in estimated glomerular filtration rate (eGFR) at 12 months.

RESULTS

During the study period, LDL-C was lower in the patients with intensive lipid lowering than with conventional lipid lowering (at 12 months 58.0±11.6 vs 85.1±15.5mg/dL, p<0.001). At 12-month follow-up, eGFR (91.8±30.2 vs 78.5±19.5)mL/min·1.73m², p=0.002) and the increase in eGFR compared to baseline [14.8(IQR, 4.1, 26.7) vs -0.4(IQR, -9.5, 8.0)mL/min·1.73m², p<0.001] were higher in the patients with intensive lipid lowering than with conventional lipid lowering. Urinary albumin-creatinine ratio [42.2(IQR, 20.0, 60.9) vs 60.8(IQR, 26.8, 121.6)mg/g, p=0.032] was lower and the decrease in urinary albumin-creatinine ratio compared to baseline [27.4(IQR, 3.0, 53.8) vs -3.1(IQR, -17.3, 30.9)mg/g, p=0.001] was higher in the patients with intensive lipid lowering than with conventional lipid lowering. The restenosis rate (3.1% vs 3.4%, p=0.711) and major clinical events (6.8% vs 11.0%, p=0.37) were similar between the two groups.

CONCLUSIONS

In patients with severe ARAS undergoing stent placement, intensive lipid lowering showed significant benefits in renal protection over conventional lipid-lowering therapy.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

[Renal, vascular and urological variations and abnormalities in living kidney donor candidates]

INTRODUCTION

The aim of this study was to determine the prevalence of anatomic variations (renal, vascular and urological) and acquired renal pathologies in living kidney donor candidates (LKDC).

METHODS

This is a retrospective study of all LKDC referred to our center between April 2003 and September 2014. Of the 491 LKDC, 189 were initially excluded for medical reasons (n=140) or others reasons (n=49), without undergoing a radiological assessment. In total, 302 had a radiological assessment (angio-CT or MRI) in anticipation of the donation and 226/302 (73.5%) could donate a kidney.

RESULTS

One or more anatomical variations and/or acquired abnormalities were observed in 178/302 (58.9%) of the LKDC. The most frequent were arterial variations or abnormalities (multiple arteries, fibrodysplasia, aneurysms, stenosis≥70%) which where observed in 39.3% of the LKDC, followed by the venous abnormalities (27.8%). Kidney stones were observed in 5.6% of the LKDC and the urinary abnormalities (duplication/ureteral bifidity) were found in 3% of the LKDC. No malignant tumour was diagnosed, while 4 benign tumours (1.3%) were identified, and one of them required additional investigations.

CONCLUSION

We found a high prevalence of anatomical variations and acquired abnormalities in a population of LKDC. However, these findings resulted in the exclusion of only 4% of the candidates, because they did not contraindicate the donation or, in most of cases, the contralateral kidney could be used.

LEVEL OF EVIDENCE

3.

Is there still a role for renal artery stenting in the management of renovascular hypertension - A single-center experience and where do we stand?

BACKGROUND

Renal artery (RA) stenosis has been implicated in the pathophysiological mechanism for resistant hypertension. Despite the increasingly diagnosed frequency of hemodynamically significant lesions, the value of RA revascularization remains controversial. Our group had previously demonstrated significant blood pressure (BP) reduction in a retrospective cohort of appropriately selected patients undergoing RA stenting up to 18-months of follow-up. We herein present long-term clinical outcomes data 5-years post revascularization on 26 subjects who continued follow-up at our institution.

METHODS

Retrospective analysis was performed on subjects who underwent RA stenting at our institution for hemodynamically significant (≥70%) RA stenosis and systolic hypertension on ≥3 antihypertensive agents. Clinical outcome data for systolic blood pressure (SBP), diastolic blood pressure (DBP), creatinine level and number of antihypertensive drugs was assessed prior to and then later at 6-12 months and 3-5 years post RA stenting.

RESULTS

Mean age was 69 ± 9 years; 27% (7/26) were male. Median follow-up was 5.1 years. Blood pressure reduction was sustained at long-term follow-up (135/70 ± 18/11 mmHg) compared to initial reduction noted at 6-months (136/69 ± 16/8 mmHg; p ≤0.01 for both) and from baseline (162/80 ± 24/18 mmHg; p ≤0.001 for both). The number of antihypertensive agents also decreased from 4.1 ± 1.0 to 2.7 ± 2.1 (p = 0.002) at 6-months and was sustained at long-term follow-up, 3.4 ± 1.2 (p = 0.03) with no difference in renal function between short- and long-term follow-up compared to baseline.

CONCLUSIONS

This study shows sustained benefit of RA stenting in BP reduction in an appropriately selected cohort with significant stenosis ≥70% and uncontrolled hypertension on multiple medications on long-term follow-up.

Current Concepts in the Treatment of Renovascular Hypertension

Renovascular disease (RVD) remains a major cause of secondary and treatment-resistant hypertension. Most cases are related either to fibromuscular or atherosclerotic lesions, but a variety of other causes including arterial dissection, stent occlusion, and embolic disease can produce the same syndrome. Recent studies emphasize the kidney's tolerance to moderate flow reduction during antihypertensive drug therapy and the relative safety of medical therapy to control blood pressure. Several prospective trials in moderate RVD fail to identify major benefits from endovascular revascularization for moderate atherosclerotic disease. However, high-risk and progressive renovascular syndromes are recognized to be relatively refractory to medical therapy only and respond better to combining renal revascularization with ongoing medical therapy. Clinicians caring for complex hypertension should be familiar with pathogenic pathways, imaging techniques, and a rational approach to managing renovascular hypertension in the current era.

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.

[How to develop Choosing Wisely recommendations for internal medicine]

"Choosing Wisely" is an initiative of the German Society of Internal Medicine with the aim to provide recommendations for diagnostic and therapeutic procedures that are of clear medical and scientifically proven benefit, but are rather underused in daily practice. As such, these positive recommendations are indicative of an undersupply. On the other hand, the German Society of Internal Medicine also developed "negative recommendations", pointing out diagnostic and therapeutic procedures that are frequently used but for which there is little or no scientific evidence. They indicate oversupply. So far, the various internal medicine societies have each developed five positive and five negative recommendations, and there are more to come.