Rapid decline in renal function reflects reversibility and predicts the outcome after angioplasty in renal artery stenosis

Outcomes after stenting of renal artery stenosis in patients with high-risk clinical features

BACKGROUND

In patients with renal artery stenosis, revascularization was seen as a mean to improve outcomes, but large studies failed to show significant benefit in general population. However, data on benefits of renal artery stenting in patients with high-risk features, such as rapidly declining renal function and cardiac destabilization syndromes, are limited, as they were excluded from trials. In this descriptive study, we aimed to evaluate short- and long-term outcomes in high-risk patients with renal artery stenosis, treated by angioplasty and stenting. We have retrospectively interrogated our local databases for renal artery percutaneous interventions; patients at high-risk (rapidly declining renal function; stable chronic renal failure and bilateral renal artery disease; severe hypertensive crisis) were selected for the current analysis.

RESULTS

Of 30 patients undergoing renal artery stenting, 18 patients were deemed "high-risk." On short term, good in-hospital control of hypertension and cardiac stabilization were obtained in all patients. Renal function improved significantly only in patients admitted with rapidly declining renal function, with significant creatinine level fall from median 3.98 mg/dL to 2.02 mg/dL, p = 0.023. However, for the whole group, creatinine change was non-significant (- 0.12 mg/dL, p = NS). On the long term, five patients (27.8%) ended-up on chronic hemodialysis and six patients died (33.3%) after a median of 20 months. No death occurred during the first year after the procedure.

CONCLUSIONS

Percutaneous procedures are feasible and safe in patients with high-risk renal artery stenosis, especially in those with rapidly declining renal function, probably saving some of them from the immediate need for renal replacement therapy, but long-term results are negatively influenced by the precarious general and cardio-vascular status of these patients and by the pre-existing significant renal parenchymal disease, non-related to the renal artery stenosis.

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.

Ultra-Low-Dose Contrast Using Transluminal Renal Angioplasty: The ULTRA Study

BACKGROUND

Although severe atherosclerotic renal artery stenosis (ARAS) is a predictor of future cardiovascular events, large trials have not shown the benefits of percutaneous transluminal renal angioplasty (PTRA). This study aimed to validate the safety and efficacy of PTRA using low-concentration digital subtraction angiography (LC-DSA) in patients with severe ARAS and advanced chronic kidney disease (CKD).

MATERIALS AND METHODS

This prospective study was conducted between August 2018 and October 2021. Eighteen patients with 20 lesions, CKD stage 3b or worse, and significant renal artery stenosis were included and underwent PTRA using ultra-low-dose contrast medium. The primary endpoint was a change in renal function based on serum creatinine (sCr) level.

RESULTS

The mean sCr level significantly improved from 3.34 ± 1.8 mg/dL pre-PTRA to 2.48 ± 1.19 mg/dL at 1 month post-PTRA (P = .02). The mean amount of contrast used was 8.3 ± 3.9 mL per vessel. More severe stenosis and rapid deterioration of renal function before treatment were associated with improved kidney function. No cardiovascular or renal complications such as stroke or contrast-induced nephropathy were observed during the 30-day period.

CONCLUSIONS

PTRA using an ultra-low-dose contrast medium is safe and provides acceptable results.

A new threshold for kidney asymmetry improves association with abnormal renal-aortic ratio for diagnosis of renal artery stenosis

BACKGROUND

Renal artery stenosis (RAS) reflects more widespread atherosclerosis deposition and is associated with high morbidity and mortality. According to the guidelines, a discrepancy in the size of the kidneys of over 15 mm found in an ultrasound should initiate the RAS diagnostic algorithm. This study aims to find the optimal threshold for renal asymmetry that better reflects the frequency of a significantly abnormal renal-aortic ratio (RAR), justifying further RAS diagnostic workup, than the currently used cut-off of 15 mm difference in renal diameters.

METHODS

The analysis included 1175 patients (mean age: 52 years, IQR: 38-66, men/women: 597/578) who underwent Doppler ultrasonography screening of renal arteries with recorded kidney size and RAR calculation. Ultrasound features of RAS were defined as a RAR greater than 3.5 or signs of renal artery occlusion. Receiver operating characteristic (ROC) curves were created and analyzed for absolute differences in kidney size and abnormal RAR. We calculated the area under the curve (AUC) and optimal cut-off values for sensitivity and specificity analysis.

RESULTS

The final analysis included 169 patients with a significant difference in renal dimension. RAS features were met in 61 patients. According to ROC curve analysis, the optimal index of renal asymmetry was 12 mm. The sensitivity and specificity for this method were 82.0% and 83.3%, respectively, and AUC was 86.3%.

CONCLUSION

Changing the definition of a significant difference in kidney size from 15 mm to 12 mm increases sensitivity and specificity for abnormal RAR and this finding may accelerate the diagnosis of RAS.

Case Report: Endovascular Treatment of Chronic Atherosclerotic Renal Artery Total Occlusions with Failed Medical Therapy

Background

Current guidelines generally no longer support revascularization for chronic renal artery occlusive diseases because results from randomized controlled trials favor medical therapy over angioplasty. However, increasing reports indicate that patients with renal artery occlusion (RAO) can benefit from revascularization under certain circumstances.

Case summary

Here, we present a patient with renal artery stenosis (RAS) who does not have refractory hypertension or fit any clinical trial inclusion criteria by far. Medical therapy failed to prevent the progression of RAS in this patient, leading to total occlusion of his right renal artery. This patient had progressive renal insufficiency but recovered renal function after endovascular treatment.

Conclusion

This case demonstrates that angioplasty can be beneficial in selected RAO patients, especially those with residual renal function and collateral perfusion.

Managing acute presentations of atheromatous renal artery stenosis

BACKGROUND

Atherosclerotic renovascular disease (ARVD) often follows an asymptomatic chronic course which may be undetected for many years. However, there are certain critical acute presentations associated with ARVD and these require a high index of suspicion for underlying high-grade RAS (renal artery stenosis) to improve patient outcomes. These acute presentations, which include decompensated heart failure syndromes, accelerated hypertension, rapidly declining renal function, and acute kidney injury (AKI), are usually associated with bilateral high-grade RAS (> 70% stenosis), or high-grade RAS in a solitary functioning kidney in which case the contralateral kidney is supplied by a vessel demonstrating renal artery occlusion (RAO). These presentations are typically underrepresented in large, randomized control trials which to date have been largely negative in terms of the conferred benefit of revascularization.

CASE PRESENTATION

Here we describe 9 individual patients with 3 classical presentations including accelerated phase hypertension, heart failure syndromes, AKI and a fourth category of patients who suffered recurrent presentations. We describe their response to renal revascularization. The predominant presentation was that consistent with ischaemic nephropathy all of whom had a positive outcome with revascularization.

CONCLUSION

A high index of suspicion is required for the diagnosis of RAS in these instances so that timely revascularization can be undertaken to restore or preserve renal function and reduce the incidence of hospital admissions for heart failure syndromes.

Atherosclerotic Renovascular Disease: A KDIGO (Kidney Disease: Improving Global Outcomes) Controversies Conference

The diagnosis and management of atherosclerotic renovascular disease (ARVD) is complex and controversial. Despite evidence from the ASTRAL (2009) and CORAL (2013) randomized controlled trials showing that percutaneous renal artery revascularization did not improve major outcomes compared with best medical therapy alone over 3-5 years, several areas of uncertainty remain. Medical therapy, including statin and antihypertensive medications, has evolved in recent years, and the use of renin-angiotensin-aldosterone system blockers is now considered the primary means to treat hypertension in the setting of ARVD. However, the criteria to identify kidneys with renal artery stenosis that have potentially salvageable function are evolving. There are also data suggesting that certain high-risk populations with specific clinical manifestations may benefit from revascularization. Here, we provide an overview of the epidemiology, diagnosis, and treatment of ARVD based on consensus recommendations from a panel of physician experts who attended the recent KDIGO (Kidney Disease: Improving Global Outcomes) Controversies Conference on central and peripheral arterial diseases in chronic kidney disease. Most focus is provided for contentious issues, and we also outline aspects of investigation and management of ARVD that require further research.

Salvage from hemodialysis via percutaneous transluminal renal artery stenting for a jeopardized solitary functioning kidney: A case report

Atherosclerotic renal artery stenosis (ARAS) causes resistant hypertension, progressively declining renal function, and cardiac destabilization syndromes, including heart failure. We report a patient who underwent successful percutaneous transluminal renal angioplasty (PTRA) for anuretic acute kidney injury (AKI) due to ARAS. This patient, admitted to our hospital with congestive heart failure, developed anuretic AKI and started hemodialysis 3 days after admission. Computed tomography and magnetic resonance angiograms showed total occlusion of the proximal right renal artery, with atrophy of the right kidney and severe stenosis of the proximal left renal artery. These findings suggested that only the left kidney was functioning. We performed PTRA of the left renal artery in which the culprit lesion causing the AKI appeared to be located. Using intravascular ultrasound, severe calcification in the ostium of the left renal artery and a necrotic core with plaque rupture in the culprit lesion were observed. Kidney function recovered immediately after revascularization, which permitted successful withdrawal of hemodialysis. There is no clear consensus regarding the indication for PTRA in patients with ARAS; however, our experience suggests that PTRA may be beneficial for patients with a jeopardized solitary functioning kidney. <Learning objective: There is no clear consensus regarding the indication for percutaneous transluminal renal angioplasty (PTRA) in patients with atherosclerotic renal artery stenosis. However, patients with a jeopardized solitary functioning kidney may benefit from PTRA, which should be considered as soon as possible before irreversible ischemic changes occur. It is important to recognize that PTRA may be indicated in select similar cases.>.

Renovascular Hypertension in Chronic Hemodialytic Patient

Background: Hypertension is a major contributor to the development of chronic kidney disease. Data in Indonesia, hypertension is still the most comorbid disease in CKD patients on dialysis (51%). Hypertension in CKD on dialysis patients is common and often uncontrolled.  Renovascular hypertension is the most common cause of secondary hypertension. Diagnosis and treatment of RAS is very important, because it can accelerate the achievement of blood pressure targets, reduce the risk and complications due to hypertension. Case Report: A 52-year-old woman with CKD has been undergoing hemodialysis for 2 years. Hypertension that was previously well controlled for 2 years required an increase in antihypertensive therapy from 2 to 4 drugs in recent months. On physical examination the blood pressure 180/90 mmHg, pulse 79 bpm, respiration 20/min, temperature 36.7oC. Conjunctiva looks anemic, cardiomegaly, lungs within normal limits, no ascites and edema in the extremities. On renal artery duplex ultrasound examination, right main renal artery acceleration time 147.65 ms, Peak Systolic Velocity (PSV) 31.9 cm/s. RI 0.69 and left main renal artery acceleration time 120.81 ms, PSV 16.9 cm/s, RI 0.61. There was 20-30% left renal artery stenosis, 80% right renal artery stenosis. A stent was placed on the right renal artery. The patient's condition after PTRA improved, but at the next follow-up, mean systole and diastole 170 mmHg and 80 mmHg, respectively. Patient received 4 antihypertensive therapy. Conclusion: Renal artery stenosis is a disease that consists of a broad spectrum of different entities with different pathophysiologies that require varied approaches to diagnose and treat. Current diagnostic tools include MRA, CTA and renal artery duplex ultrasonography. Patients with renal parenchymal disease are poorer candidates for revascularization.

Determinant role of renal artery stenting in recovery from acute worsening of atherosclerotic renal failure

Because previous randomized clinical trials have failed to show any benefits of renal artery stenting (RAS), clinicians have been confused regarding the optimal management of patients with atherosclerotic renal artery stenosis (ARAS). Here, we report a notable case with ARAS whose clinical course could help clinicians identify patients suitable for RAS. A 66-year-old woman with ARAS and some parameter abnormalities on renal duplex ultrasound was admitted to our hospital with severe hypertension (>250 mmHg). After the initiation of antihypertensive intravenous treatment, the patient manifested acute worsening of renal function over 6 days and required dialysis. Because renal failure continued to deteriorate over more than 4 weeks, we performed stenting to the severe ostial stenosis of the right renal artery. As a result, the patient achieved dramatic improvement in renal function and successful withdrawal from dialysis and has maintained stable control of blood pressure without additional events for more than 2 years since discharge. This case suggests that careful analysis of the patient's profile, such as history of rapidly deteriorating renal failure, presence of bilateral ARAS, or a solitary functional kidney, in addition to various parameters of renal duplex ultrasound, may help predict the efficacy of RAS in patients with ARAS.

<Learning objective: Because several randomized studies have reported negative results for renal artery stenting (RAS), an individual-based approach is required for the treatment of atherosclerotic renal artery stenosis (ARAS). To determine whether RAS could be effective in patients with ARAS, it is important to assess patient-specific characteristics such as progression of renal failure (e.g. acute worsening), presence of bilateral ARAS, or the existence of a solitary functional kidney, as well as parameters of related examinations such as the renal arterial resistive index.>

Short Term Prognosis of Renal Artery Stenosis Secondary to Acute Type B Aortic Dissection With TEVAR

Objective: To determine the effect of renal artery stenosis (RAS) resulting from acute type B aortic dissection (ATBAD) with thoracic endovascular aortic repair (TEVAR) on early prognosis in patients with ATBAD.

Methods: A total of 129 ATBAD patients in the National Acute Aortic Syndrome Database (AASCN) who underwent TEVAR between 2019 and 2020 were enrolled in our study. Patients were divided into two groups: the RAS group and the non-RAS group.

Results: There were 21 RAS patients (16.3%) and 108 non-RAS patients (83.7%) in our cohort. No patient in our cohort died during the 1-month follow-up. There was no significant difference in preoperative creatinine clearance rate (CCr) between the two groups (90.6 ± 46.1 μmol/L in the RAS group vs. 78.7 ± 39.2 μmol/L in the non-RAS group, P = 0.303) but the RAS group had a significantly lower estimated glomerular filtration rate (eGFR) than the non-RAS group (83.3 ± 25.0 vs. 101.9 ± 26.9 ml/min, respectively; P = 0.028).One month after TEVAR, CCr was significantly higher (99.0 ± 68.1 vs. 78.5 ± 25.8 ml/min, P = 0.043) and eGFR (81.7 ± 23.8 vs. 96.0 ± 20.0 ml/min, P = 0.017) was significantly lower in the RAS group than in the non-RAS group.

Conclusions: In ATBAD, RAS could result in acute kidney injury (AKI) in the early stage after TEVAR. The RAS group had a high incidence of hypertension. These results suggest that patients with RAS may need further treatment.

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.

Atherosclerotic-nephropathy: an updated narrative review

The increased prevalence of chronic kidney disease (CKD) in elderly patients recognizes, as main cause, the long-term exposure to atherosclerosis and hypertension. Chronic ischemic damage due to critical renal arterial stenosis induces oxidative stress and intra-renal inflammation, resulting in fibrosis and microvascular remodelling, that is the histological picture of atherosclerotic renal vascular disease (ARVD). The concomitant presence of a long history of hypertension may generate intimal thickening and luminal narrowing of renal arteries and arterioles, glomerulosclerosis, interstitial fibrosis and tubular atrophy, more typically expression of hypertensive nephropathy. These complex mechanisms contribute to the development of CKD and the progression to End Stage Kidney Disease. In elderly CKD patients, the distinction among these nephropathies may be problematic; therefore, ischemic and hypertensive nephropathies can be joined in a unique clinical syndrome defined as atherosclerotic nephropathy. The availability of novel diagnostic procedures, such as intra-vascular ultrasound and BOLD-MRI, in addition to traditional imaging, have opened new scenarios, because these tools allow to identify ischemic lesions responsive to renal revascularization. Indeed, although trials have deflated the role of renal revascularization on the renal outcomes, it should be still used to avoid dialysis initiation and/or to reduce blood pressure in selected elderly patients at high risk. Nonetheless, lifestyle modifications (smoking cessation, increased physical activity), statins and antiplatelet use, as well as cautious use of renin-angiotensin system inhibitors, remain the main therapeutic approach aimed at slowing the renal damage progression. Mesenchymal stem cells and Micro-RNA are promising target of anti-fibrotic therapy, which might provide potential benefit in ARVD patients, though safety and efficacy profile in humans is unknown too.

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.

Early Rapid Decline in Kidney Function in Medically Managed Patients With Atherosclerotic Renal Artery Stenosis

Background

Early rapid declines of kidney function may occur in patients with atherosclerotic renal artery stenosis with institution of medical therapy. The causes and consequences are not well understood.

Methods and Results

Patients enrolled in the medical therapy–only arm of the CORAL (Cardiovascular Outcomes With Renal Artery Lesions) study were assessed for a rapid decline (RD) in estimated glomerular filtration rate (eGFR), defined as a ≥30% decrease from baseline to either 3 months, 6 months, or both. In the medical therapy–only cohort, eGFR was available in 359 subjects at all time points, the subjects were followed for a median of 4.72 years, and 66 of 359 (18%) subjects experienced an early RD. Baseline log cystatin C (odds ratio, 1.78 [1.11–2.85]; P=0.02), age (odds ratio, 1.04 [1.00–1.07]; P<0.05), and Chronic Kidney Disease Epidemiology Collaboration creatinine eGFR (odds ratio, 1.86 [1.15–3.0]; P=0.01) were associated with an early RD. Despite continued medical therapy only, the RD group had an improvement in eGFR at 1 year (6.9%; P=0.04). The RD and nondecline groups were not significantly different for clinical events and all‐cause mortality (P=0.78 and P=0.76, respectively). Similarly, renal replacement therapy occurred in 1 of 66 (1.5%) of the RD patients and in 6 of 294 (2%) of the nondecline patients. The regression to the mean of improvement in eGFR at 1 year in the RD group was estimated at 5.8±7.1%.

Conclusions

Early rapid declines in kidney function may occur in patients with renal artery stenosis when medical therapy is initiated, and their clinical outcomes are comparable to those without such a decline, when medical therapy only is continued.

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Safety of sofosbuvir-based regimens after liver transplantation: longitudinal assessment of renal function in the prospective ANRS CO23 CUPILT study

BACKGROUND

In liver transplant recipients with hepatitis C virus recurrence, there is concern about renal safety of sofosbuvir-based regimens. Changes in serum creatinine or in the estimated glomerular filtration rate (eGFR) under treatment are used to look for possible renal toxicity. However, serum creatinine and eGFR are highly variable.

AIM

To analyse renal function trajectory with numerous assays of serum creatinine over a long period of time.

METHODS

In a multicentre cohort of 139 patients, the eGFR was obtained from serum creatinine using the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation. Slopes of eGFR were defined as a change in eGFR during a period divided by time. Pre-treatment, on-treatment and post-treatment periods were 9 months, 3-9 months and 4.5 months. Interactions between eGFR slopes and the pre-treatment eGFR, use of ribavirin or mycophenolate mofetil, and stage of fibrosis were addressed. On-treatment eGFR slopes were separated in tertiles. Pre- and post-treatment eGFR slopes were compared globally and according to tertiles.

RESULTS

The post-treatment eGFR slope was significantly better than pre-treatment eGFR slope (+0.18 (IQR -0.76 to +1.32) vs -0.11 (IQR -1.01 to +0.73) mL/min/1.73 m² /month, P = 0.03) independently of the pre-treatment eGFR (P = 0.99), ribavirin administration (P = 0.26), mycophenolate mofetil administration (P = 0.51) and stage of fibrosis (F3 and F4 vs lower stages, P = 0.18; F4 vs lower stages, P = 0.08; F4 Child-Pugh B and C vs lower stages, P = 0.38). Tertiles of on-treatment eGFR slopes were -1.71 (IQR -2.54 to -1.48), -0.78 (IQR -1.03 to -0.36) and +0.75 (IQR +0.28 to +1.47) mL/min/1.73 m² /month. Pre- and post-treatment eGFR slopes were not significantly different according to tertiles (respectively, P = 0.34, 0.08, 0.73).

CONCLUSION

The eGFR varies during treatment and gives a confusing picture of the renal safety of sofosbuvir-based regimens. In contrast, longitudinal assessment of the eGFR shows a rising trajectory over longer time, meaning that these therapies are safe for the kidneys in our cohort of liver transplant recipients.

Total Renal Artery Occlusion: Recovery of Function After Revascularization

Current trends in managing atherosclerotic renal artery stenosis favor medical therapy, on account of negative results from prospective trials of revascularization, such as CORAL and ASTRAL. One result of this trend has been encountering occasional patients with progressive disease, sometimes leading to total arterial occlusion. We illustrate a case of accelerated hypertension with complete renal artery occlusion in which the patient recovered function after surgical bypass and we review the clinical approach used and the advanced imaging modalities available to us. A high index of suspicion and careful radiologic imaging play important roles in selecting patients who may have residual function and may benefit from revascularization. This case illustrates an example whereby restoring renal artery perfusion for carefully selected patients can be life changing, with recovery of kidney function and improved blood pressure, pill burden, and overall quality of life.

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.

Endovascular Management of Atherosclerotic Renal Artery Stenosis: Post-Cardiovascular Outcomes in Renal Atherosclerotic Lesions Era Winner or False Alarm?

Renal artery stenosis (RAS) is frequently associated with severe comorbidities such as reduced renal perfusion, hypertension, and end-stage renal failure. In approximately 90% of patients, renal artery atherosclerosis is the main cause for RAS, and it is associated with an increased risk for fatal and non-fatal cardiovascular and renal complications. Endovascular management of atherosclerotic RAS (ARAS) has been recently evaluated by several randomized controlled trials that failed to demonstrate benefit of stenting. Furthermore, the Cardiovascular Outcomes in Renal Atherosclerotic Lesions study did not demonstrate any benefit over the revascularization approach. In this review, we summarized the available data from retrospective, prospective and randomized trials on ARAS to provide clinicians with sufficient data in order to produce useful conclusions for everyday clinical practice.

Renal Artery Stenosis: When to Revascularize in 2017

Atherosclerotic renal artery stenosis is the leading cause of secondary hypertension; it can also cause progressive renal insufficiency and cardiovascular complications such as refractory heart failure and flash pulmonary edema. Medical therapy including risk factor modification, renin-angiotensin-aldosterone system antagonists, lipid lowering agents, and antiplatelet therapy is the first line of treatment in all patients. Patients with uncontrolled renovascular hypertension despite optimal medical therapy, ischemic nephropathy, and cardiac destabilization syndromes who have severe renal artery stenosis are likely to benefit from renal artery revascularization. Screening for renal artery stenosis can be done with Doppler ultrasonography, computed tomographic angiography and magnetic resonance angiography. Invasive physiologic measurements are useful to confirm the severity of renal hypoperfusion and therefore improve the selection patients likely to respond to renal artery revascularization. Primary patency exceeds 80% at 5 years and surveillance for in-stent restenosis can be done with periodic clinical, laboratory, and imaging follow-up.

Approach to atherosclerotic renovascular disease: 2016

The management of atherosclerotic renal artery stenosis in patients with hypertension or impaired renal function remains a clinical dilemma. The current general consensus, supported by the results of the Angioplasty and Stenting for Renal Atherosclerotic Lesions and Cardiovascular Outcomes for Renal Artery Lesions trials, argues strongly against endovascular intervention in favor of optimal medical management. We discuss the limitations and implications of the contemporary clinical trials and present our approach and formulate clear recommendations to help with the management of patients with atherosclerotic narrowing of the renal artery.

Effects of Stenting for Atherosclerotic Renal Artery Stenosis on eGFR and Predictors of Clinical Events in the CORAL Trial

BACKGROUND AND OBJECTIVES

Atherosclerotic renal artery stenosis may cause kidney function loss, but effects of stenting on eGFR and clinical events associated with CKD are uncertain. Our study objectives were to determine effects of stenting on eGFR and predictors of clinical events.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Participants (n=931) in the Cardiovascular Outcomes in Renal Artery Stenosis Trial (from May of 2005 to September of 2012) had >60% atherosclerotic renal artery stenosis and systolic hypertension on two or more antihypertensive drugs and/or stage ≥3 CKD. The intervention was stenting versus no stenting on a background of risk factor management: renin-angiotensin system inhibition, statin, antiplatelet therapy, and smoking cessation education. The effect of stenting on eGFR by the serum creatinine-cystatin C Chronic Kidney Disease Epidemiology Collaboration equation was the prespecified analysis of kidney function. Predictors of eGFR and CKD outcomes (≥30% eGFR loss, ESRD, and death) and cardiovascular disease outcomes (stroke, myocardial infarction, heart failure, and death) controlling for eGFR and albuminuria were also determined.

RESULTS

eGFR was 59±24 ml/min per 1.73 m(2) (mean±SD) at baseline. Over 3 years, eGFR change, assessed by generalized estimating equations, was -1.5±7.0 ml/min per 1.73 m(2) per year in the stent group versus -2.3±6.3 ml/min per 1.73 m(2) per year in the medical therapy only group (P=0.18). eGFR predictors (multiple variable generalized estimating equations) were age, albuminuria, systolic BP, and diabetes (inverse associations) as well as men, total cholesterol, and HDL cholesterol (positive associations). CKD outcomes events occurred in 19% (175 of 931), and predictors (Cox proportional hazards models) included albuminuria (positive association), systolic BP (positive association), and HDL cholesterol (inverse association). Cardiovascular disease outcomes events occurred in 22% (207 of 931), and predictors included age, albuminuria, total cholesterol, prior cardiovascular disease, and bilateral atherosclerotic renal artery stenosis (positive associations).

CONCLUSIONS

Stenting did not influence eGFR in participants with atherosclerotic renal artery stenosis receiving renin-angiotensin system inhibition-based therapy. Predictors of clinical events were traditional risk factors for CKD and cardiovascular disease.

Endovascular versus medical therapy for atherosclerotic renovascular disease

The diagnosis of renal artery stenosis (RAS) has become increasingly common in part due to greater awareness of ischemic renal disease and increased use of diagnostic techniques. Over 90 % of RAS cases are caused by atherosclerotic renovascular disease (ARVD). Patients with ARVD are at high risk for fatal and nonfatal cardiovascular and renal events. The mortality rate in patients with ARVD is high, especially with other cardiovascular or renal comorbidities. Recent clinical studies have provided substantial evidence concerning medical therapy and endovascular interventional therapeutic approaches for ARVD. Despite previous randomized clinical trials, the optimal therapy for ARVD remained uncertain until the results of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial were released recently. CORAL demonstrated that optimal medical therapy was equally effective to endovascular therapy in the treatment of ARVD. Clinicians can now practice with more evidence-based medicine to treat ARVD and potentially decrease mortality in patients with ARVD using optimal medical therapy.

Emergent unilateral renal artery stenting for treatment of flash pulmonary edema: fact or fiction?

Flash pulmonary edema is characteristically sudden in onset with rapid resolution once appropriate therapy has been instituted (Messerli et al., 2011). Acute increase of left ventricular (LV) end diastolic pressure is the usual cause of sudden decompensated cardiac failure in this patient population. Presence of bilateral renal artery stenosis or unilateral stenosis in combination with a single functional kidney in the susceptible cohort is usually blamed for this condition. We describe a patient who presented with flash pulmonary edema in the setting of normal coronary arteries. Our case is distinct as our patient developed flash pulmonary edema secondary to unilateral renal artery stenosis in the presence of bilateral functioning kidneys. Percutaneous stent implantation in the affected renal artery resulted in rapid resolution of pulmonary edema.

Atherosclerotic renal artery stenosis and revascularization

Atherosclerotic renovascular disease is the most common cause of secondary hypertension. The patients with renovascular disease are at increased risk for adverse cardiac outcomes. Recent trials comparing medical therapy alone to medical therapy with stenting are flawed, but lay to rest any existing debate that unselected revascularization is unwarranted; however, revascularization may be appropriate in high-risk populations. Defining an appropriate population for revascularization is an area of ongoing study. Furthermore, delivery of optimal medical therapy in this population is inadequate. This review describes recent developments in renal artery revascularization.

SCAI expert consensus statement for renal artery stenting appropriate use

The pathophysiology of atherosclerotic renal artery stenosis (RAS) includes activation of the renin-angiotensin-aldosterone axis with resultant renovascular hypertension. Renal artery stenting has emerged as the primary revascularization strategy in most patients with hemodynamically significant atherosclerotic RAS. Despite the frequency with which hemodynamically significant RAS is observed and high rates of technical success of renal artery stenting, there remains considerable debate among experts regarding the role of medical therapy versus revascularization for renovascular hypertension. Modern, prospective, multicenter registries continue to demonstrate improvement in systolic and diastolic blood pressure with excellent safety profiles in patients with RAS. Modern randomized, controlled clinical trials of optimal medical therapy versus renal stenting particularly designed to demonstrate preservation in renal function after renal artery stenting have demonstrated limited benefit. However, these trials frequently excluded patients that may benefit from renal artery stenting. This document was developed to guide physicians in the modern practical application of renal stenting, to highlight the current limitations in the peer-reviewed literature, to suggest best-practices in the performance of renal stenting and to identify opportunities to advance the field.

Management of Renal Arterial Disease

Severe atherosclerotic renal artery stenosis can manifest as treatment-resistant hypertension, ischemic nephropathy and/or cardiac disturbance syndromes of recurrent flash pulmonary edema and refractory angina. Renal artery revascularization can dramatically impact patient outcome. However, patient selection for revascularization can be challenging. Renal artery stenting is most commonly used for renal revascularization and is a safe procedure when performed in carefully selected patients. This review addresses the pathophysiology of renal artery stenosis and the data supporting revascularization in such patients.

Attending rounds: a patient with accelerated hypertension and an atrophic kidney

This case represents an individual with accelerating hypertension and declining kidney function associated with atherosclerotic renal artery stenosis. Key features include loss of GFR (reaching stage V CKD) during intensified antihypertensive drug therapy including agents that block the renin-angiotensin system and failure to appreciate the extent to which moderate renal artery stenosis was affecting his better kidney. Interpretation of duplex ultrasound studies was complicated by a discrepancy between near-normal peak systolic velocities and markedly abnormal segmental arterial waveforms. It was essential to recognize that both kidneys were abnormal and focus on recovery of perfusion to the better of these kidneys. Successful revascularization of one kidney allowed major improvement in GFR and BP control.

Marked improvement of renal failure and severe hypertension after renal artery stenting in the solitary functioning kidney

Atherosclerotic renal artery stenosis (ARAS) can cause resistant hypertension, progressive renal failure and/or cardiorenal syndrome. Although no randomized study to demonstrate the superiority of renal stenting over medical treatment is available, a case-sensitive approach is required for the treatment of ARAS. Here, we describe a case report of a symptomatic ARAS patient with a solitary functioning kidney in which successful detection of ARAS by ultrasonography examination with the Doppler method and timely renal artery stenting were performed. <Learning objective: The clinical efficacy of renal artery stenting for symptomatic ARAS as a method of lowering blood pressure and preventing deterioration in renal function remains unproven. However, renal artery stenting performed based on enough investigation of clinical course and information by ultrasonography examination with Doppler method results in benefit to the patient with ARAS.>.

Percutaneous revascularization for ischemic nephropathy: the past, present, and future

Occlusion of the renal arteries can threaten the viability of the kidney when severe, in addition to accelerating hypertension and circulatory congestion. Renal artery stenting procedures have evolved from a treatment mainly for renovascular hypertension to a maneuver capable of recovering threatened renal function in patients with “ischemic nephropathy” and improving management of congestive heart failure. Improved catheter design and techniques have reduced, but not eliminated hazards associated with renovascular stenting. Expanded use of endovascular stent grafts to treat abdominal aortic aneurysms has introduced a new indication for renal artery stenting to protect the renal circulation when grafts cross the origins of the renal arteries. Although controversial, prospective randomized trials to evaluate the added benefit of revascularization to current medical therapy for atherosclerotic renal artery stenosis until now have failed to identify major benefits regarding either renal function or blood pressure control. These studies have been limited by selection bias and have been harshly criticized. While studies of tissue oxygenation using blood oxygen level dependent (BOLD) MR establish that kidneys can adapt to reduced blood flow to some degree, more severe occlusive disease leads to cortical hypoxia associated with microvascular rarefication, inflammatory injury and fibrosis. Current research is directed toward identifying pathways of irreversible kidney injury due to vascular occlusion and to increase the potential for renal repair after restoring renal artery patency. The role of nephrologists likely will focus upon recognizing the limits of renal adaptation to vascular disease and identifying kidneys truly at risk for ischemic injury at a time point when renal revascularization can still be of benefit to recovering kidney function.

Changes in glomerular filtration rate after renal revascularization correlate with microvascular hemodynamics and inflammation in Swine renal artery stenosis

BACKGROUND

The selection of patients with renal artery stenosis (RAS) likely to improve glomerular filtration rate (GFR) after percutaneous transluminal renal angioplasty is difficult. We examined basal hemodynamic and inflammatory factors linked to improved stenotic kidney (STK) function after percutaneous transluminal renal angioplasty in swine RAS.

METHODS AND RESULTS

Fifteen pigs after 6 weeks of hemodynamically significant RAS were studied before and 4 weeks after technically successful percutaneous transluminal renal angioplasty+stenting. STK and contralateral kidney hemodynamics and function were evaluated by multidetector computed-tomography before and after acetylcholine challenge. Single-kidney deoxyhemoglobin (R2*, reciprocal to blood relaxation) and energy-dependent tubular function were assessed using blood-oxygen-level-dependent magnetic resonance imaging before and after furosemide. Baseline renal vein and inferior vena cava levels of inflammatory markers were measured and their gradient and net release calculated. Baseline parameters were compared with normal (n=7) and sham-RAS (n=7) pigs and correlated with the change in STK-GFR after revascularization (ΔGFR). Four weeks after percutaneous transluminal, renal angioplasty blood pressure was normalized in all animals, but STK-GFR improved in 10 of 15 (ΔGFR =+22.0±8.5 mL/min). ΔGFR correlated inversely with basal STK-GFR, renal release of inflammatory markers, and medullary R2* response to furosemide, but directly with GFR response to acetylcholine. Basal contralateral kidney GFR correlated directly with ΔGFR.

CONCLUSIONS

Low basal STK-GFR with preserved response to acetylcholine may predict benefit from revascularization in RAS, whereas renal inflammation and robust STK-R2* responses to furosemide (possibly reflecting avid tubular oxygen consumption) are associated with less favorable outcomes. These tools may be useful for identification of patients likely to improve renal function after revascularization.

Significant reduction in systolic blood pressure following renal artery stenting in patients with uncontrolled hypertension: results from the HERCULES trial

BACKGROUND

Atherosclerotic renal artery stenosis (ARAS) causes hypertension (HTN) and threatens renal function (RF). The HERCULES Trial is a prospective, multicenter trial of renal stenting in patients with uncontrolled HTN and ARAS evaluating the safety and effectiveness of the RX Herculink Elite Renal Stent System (Abbott Vascular, Santa Clara, CA).

METHODS

A total of 202 patients (241 total lesions; 78 bilateral lesions) were enrolled between August 2007 and October 2009. The primary endpoint was 9-month binary restenosis determined by duplex ultrasound and/or angiography. Secondary endpoints included changes in blood pressure, antihypertensive medications, and RF between baseline and 9 months. Brain natriuretic peptide (BNP) was measured at baseline, 24 hr and 30 days postprocedure.

RESULTS

Mean systolic blood pressure (SBP) at baseline was 162 mm Hg. Nearly 70% of patients were receiving three or more antihypertensive medications (mean 3.4 medications per patient). Baseline serum creatinine was 1.2 ± 0.4 and 61.5% of subjects had estimated glomerular filtration <60. The restenosis rate was 10.5% at 9 months. The study device, procedure, and clinical success rates were 96.0, 99.2, and 98.0%, respectively. Freedom from major adverse events was 94.8%. At 9 months, the mean SBP significantly decreased (mean 145, paired t test P < 0.0001) after stenting with no change in medications. There was no correlation between SBP reduction and baseline BNP or BNP reduction.

CONCLUSIONS

HERCULES demonstrates clinically and statistically significant SBP reduction in patients with uncontrolled HTN, low in-stent restenosis, and complication rates. This study highlights that when appropriate patients are selected for renal artery stenting, impressive reductions in blood pressure may be anticipated. Although the magnitude of absolute reduction in SBP was related to baseline SBP, elevated baseline BNP levels were not predictive of reduction in SBP. Further studies for predictors of clinical response following percutaneous renal revascularization are needed.