Renal Artery Stenosis in Patients with Resistant Hypertension: Stent It or Not?

Atherosclerotic renovascular disease: a clinical practice document by the European Renal Best Practice (ERBP) board of the European Renal Association (ERA) and the Working Group Hypertension and the Kidney of the European Society of Hypertension (ESH)

Atherosclerotic renovascular disease (ARVD) is the most common type of renal artery stenosis. It represents a common health problem with clinical presentations relevant to many medical specialties and carries a high risk for future cardiovascular and renal events, as well as overall mortality. The available evidence regarding the management of ARVD is conflicting. Randomized controlled trials failed to demonstrate superiority of percutaneous transluminal renal artery angioplasty (PTRA) with or without stenting in addition to standard medical therapy compared with medical therapy alone in lowering blood pressure levels or preventing adverse renal and cardiovascular outcomes in patients with ARVD, but they carried several limitations and met important criticism. Observational studies showed that PTRA is associated with future cardiorenal benefits in patients presenting with high-risk ARVD phenotypes (i.e. flash pulmonary oedema, resistant hypertension or rapid loss of kidney function). This clinical practice document, prepared by experts from the European Renal Best Practice (ERBP) board of the European Renal Association (ERA) and from the Working Group on Hypertension and the Kidney of the European Society of Hypertension (ESH), summarizes current knowledge in epidemiology, pathophysiology and diagnostic assessment of ARVD and presents, following a systematic literature review, key evidence relevant to treatment, with an aim to support clinicians in decision making and everyday management of patients with this condition.

The impact of renal artery stenting on therapeutic aims

Renal artery stenosis manifests as poorly-controlled hypertension, impaired renal function or pulmonary oedema, therefore the success of treatment is dependent on indication. This study aims to determine the outcomes of patients undergoing renal artery stenting (RASt) based on therapeutic aim compared to criteria used in the largest randomised trial. Retrospective case-note review of patients undergoing RASt between 2008-2021 (n = 74). The cohort was stratified by indication for intervention (renal dysfunction, hypertension, pulmonary oedema) and criteria employed in the CORAL trial, with outcomes and adverse consequences reported. Intervention for hypertension achieved significant reduction in systolic blood pressure and antihypertensive agents at 1 year (median 43 mmHg, 1 drug), without detrimental impact on renal function. Intervention for renal dysfunction reduced serum creatinine by a median 124 μmol/L, sustained after 6 months. Intervention for pulmonary oedema was universally successful with significant reduction in SBP and serum creatinine sustained at 1 year. Patients who would have been excluded from the CORAL trial achieved greater reduction in serum creatinine than patients meeting the inclusion criteria, with equivalent blood pressure reduction. There were 2 procedure-related mortalities and 5 procedural complications requiring further intervention. 5 patients had reduction in renal function following intervention and 7 failed to achieve the intended therapeutic benefit. Renal artery stenting is effective in treating the indication for which it has been performed. Previous trials may have underestimated the clinical benefits by analysis of a heterogenous population undergoing a procedure rather than considering the indication, and excluding patients who would maximally benefit.

Transradial Renal Angioplasty and Stent Placement for Systemic Hypertension Caused by Severe Unilateral Renovascular Stenosis

Percutaneous transluminal angioplasty and stent placement for renovascular hypertension is a recognized albeit seldom used therapy. We present a case of severe renovascular hypertension, due to renal artery atherosclerosis, treated successfully with stent placement via the radial artery access approach.

Renal artery stenting in the correct patients with atherosclerotic renovascular disease: time for a proper renal and cardiovascular outcome study?

Atherosclerotic renovascular disease (ARVD) represents the most common type of renal artery stenosis. In the last decade, a few large trials failed to demonstrate the superiority of standard medical therapy plus percutaneous transluminal renal angioplasty (PTRA) compared with medical therapy alone in lowering blood pressure levels or preventing adverse renal and cardiovascular outcomes in patients with ARVD. However, this issue remains controversial and an ongoing debate focusses on the benefits that selected patients could experience from renal revascularization procedures. In this regard, several pieces of observational data show that PTRA is associated with future cardiorenal benefits in patients presenting with high-risk ARVD phenotypes. Such evidence resulted in a progressive shift in relevant recommendations, with most recent not-graded suggestions supporting that revascularization should be offered in these high-risk subjects. Existing evidence clearly calls for a properly designed randomized controlled trial with selected patients presenting high-risk ARVD phenotypes, in order to confirm the superiority of PTRA versus non-invasive management in this patient group and objectively guide everyday clinical practice.

Bilateral renal artery stenosis in a young man

A 34-year-old patient with a short history of severe hypertension was admitted to our hospital. Considering the young age and the severity of hypertension, we investigated the most common causes of secondary hypertension. Exposure to a single dose of an ACE inhibitor resulted in a rapid decline of the renal function. Further MRIrevealed a tight stenosis of both renal arteries closely to the ostium. In young patients, the most common cause of bilateral renal artery stenosis might be expected to be fibromuscular dysplasia. After recovery of renal function, invasive angiography, however, confirmed severe atherosclerotic lesion of both renal arteries. Therefore, angioplasty of both renal arteries was performed as a staged procedure. Hence, renal function showed rapid improvement and the patient had to be treated with a combination of a low-dose calcium antagonist and valsartan and especially a high-intensity statin.

Long-Term Mortality After Renal Artery Stenting in Patients With Severe Atherosclerotic Renal Artery Stenosis and High-Risk Clinical Manifestations

BACKGROUND

Atherosclerotic renal artery stenosis is a risk factor for cardiovascular death. Observational studies support the benefit of renal revascularization on outcomes in patients with high-risk clinical manifestations. In this context, we evaluated the factors associated with long-term mortality after renal artery stenting in patients with severe renal artery stenosis, impaired kidney function, and/or uncontrolled hypertension.

METHODS

The medical records of patients undergoing renal artery stenting between 2004 and 2014 were extracted. Blood pressure and creatinine were recorded at baseline, 24 hours poststenting and in the 1-month to 1-year interval that followed revascularization. Long-term follow-up was performed in March 2020.

RESULTS

The cohort consisted of 65 patients. Median follow-up was 120 months. In the first year after stenting, less patients had chronic kidney disease (CKD) class 3b-5 as compared with baseline (35.3% vs. 56.9%, P = 0.01). The number of patients with controlled blood pressure after revascularization increased with 69.2% (P < 0.001). Long-term all-cause mortality reached 44.6%. Age (odds ratio (OR) 1.1; 95% confidence interval (CI) 1.0-1.2; P = 0.01), male gender (OR 7.9; 95% CI 1.9-43.5; P = 0.008), poststenting CKD class 3b-5 (OR 5.8; 95% CI 1.5-27.9; P = 0.01), and postrevascularization uncontrolled hypertension (OR 8.9; 95% CI 1.7-63.5; P = 0.01) were associated with long-term mortality independent of diabetes mellitus and coronary artery disease.

CONCLUSIONS

Improved CKD class and blood pressure were recorded in the first year after renal artery stenting in patients with severe renal artery stenosis and high-risk clinical manifestations. The lack of improvement in kidney function and blood pressure was independently associated with long-term mortality.

Açaí Reverses Adverse Cardiovascular Remodeling in Renovascular Hypertension: A Comparative Effect With Enalapril

ABSTRACT

This study aimed to determine if açai seed extract (ASE) could reverse pre-existing cardiovascular and renal injury in an experimental model of renovascular hypertension (2 kidney, 1 clip, 2K1C). Young male rats (Wistar) were used to obtain 2K1C and sham groups. Animals received the vehicle, ASE (200 mg/kg/d), or enalapril (30 mg/kg/d) in drinking water from the third to sixth week after surgery. We evaluated systolic blood pressure by tail plethysmography, vascular reactivity in the rat isolated mesenteric arterial bed (MAB), serum and urinary parameters, plasma inflammatory cytokines by ELISA, MAB expression of endothelial nitric oxide synthase and its active form peNOS by Western blot, plasma and MAB oxidative damage and antioxidant activity by spectrophotometry, and vascular and cardiac structural changes by histological analysis. ASE and enalapril reduced the systolic blood pressure, restored the endothelial and renal functions, and decreased the inflammatory cytokines and the oxidative stress in 2K1C rats. Furthermore, both treatments reduced vascular and cardiac remodeling. ASE substantially reduced cardiovascular remodeling and recovered endothelial dysfunction in 2K1C rats probably through its antihypertensive, antioxidant, and anti-inflammatory actions, supplying a natural resource for the treatment of renovascular hypertension.

Renal Artery Stenosis in the Patient with Hypertension: Prevalence, Impact and Management

Atherosclerosis is the primary cause of renal artery stenosis. Atherosclerotic renal artery stenosis (ARAS) is associated with three clinical problems: renovascular hypertension, ischemic nephropathy and cardiac destabilization syndrome which pose huge healthcare implications. There is a significant rate of natural disease progression with worsening severity of renal artery stenosis when renal revascularization is not pursued in a timely manner. Selective sub-groups of individuals with ARAS have had good outcomes after percutaneous renal artery stenting (PTRAS). For example, individuals that underwent PTRAS and had improved renal function were reported to have a 45% survival advantage compared to those without improvement in their renal function. Advances in the imaging tools have allowed for better anatomic and physiologic measurements of ARAS. Measuring translesional hemodynamic gradients has allowed for accurate assessment of ARAS severity. Renal revascularization with PTRAS provides a survival advantage in individuals with significant hemodynamic renal artery stenosis lesions. It is important that we screen, diagnosis, intervene with invasive and medical treatments appropriately in these high-risk patients.

Design of a clinical risk calculator for major clinical outcomes in patients with atherosclerotic renovascular disease

BACKGROUND

Risk stratification in atherosclerotic renovascular disease (ARVD) can influence treatment decisions and facilitate patient selection for revascularization. In this study, we aim to use variables with the best predictive value to design a risk calculator that can assist clinicians with risk stratification and outcome prediction.

METHODS

Patients with a radiological diagnosis of ARVD referred to our tertiary renal centre were recruited into this prospective cohort study between 1986 and 2014. Primary clinical endpoints included: death, progression to end-stage kidney disease and cardiovascular events (CVE). A stepwise regression model was used to select variables with the most significant hazard ratio for each clinical endpoint. The risk calculator was designed using Hypertext Markup Language. Survival and CVE-free survival were estimated at 1, 5 and 10 years.

RESULTS

In total, 872 patients were recruited into the Salford ARVD study with a median follow-up period of 54.9 months (interquartile range 20.2-96.0). Only models predicting death and CVE showed good performance (C-index >0.80). Survival probabilities obtained from the risk calculator show that most patients with ARVD have reduced long-term survival. Revascularization improved outcomes in patients with higher baseline estimated glomerular filtration rate and lower proteinuria but not in those with co-existing comorbidities and higher levels of baseline proteinuria.

CONCLUSIONS

Although this risk calculator requires further independent validation in other ARVD cohorts, this study shows that a small number of easily obtained variables can help predict clinical outcomes and encourage a patient-specific therapeutic approach.

Successful endovascular treatment of chronic renal artery occlusion: a preliminary retrospective case series including 15 patients

PURPOSE

To evaluate in a retrospective, single-center, case series if percutaneous transluminal renal angioplasty/stenting of chronic renal artery occlusion is beneficial to renal function and blood pressure control, which remains controversial.

METHODS

Data from 15 consecutive patients with renal artery stump who underwent successful percutaneous transluminal renal angioplasty/stenting only for unilateral chronic renal artery occlusion at our center from January 2007 to February 2018 and completed follow-up were retrospectively evaluated. Of the 15 patients, 14 (93.3%) were treated with stenting and 1 with only balloon angioplasty. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) formula corrected for Chinese, and changes in blood pressure and need for antihypertensive medications were recorded.

RESULTS

At median 1.5-year (interquartile range 0.5-5.0) follow-up, restenosis rate was 20.0%. Renal function improved or remained stable in 26.7% and 53.3% of patients, respectively, and blood pressure normalized or improved in 13.3% and 40.0% of patients, respectively. Young patients with Takayasu's arteritis or fibromuscular dysplasia appeared to benefit the most from revascularization.

CONCLUSIONS

In this preliminary retrospective series of select patients with renal artery stump, endovascular treatment of chronic renal artery occlusion appeared to preserve renal function and improve blood pressure.

Long-Term Renal and Cardiac Outcomes after Stenting in Patients with Resistant Hypertension and Atherosclerotic Renal Artery Stenosis

BACKGROUND/AIMS

Atherosclerotic renal artery stenosis (ARAS) is frequently detected in patients with resistant hypertension (RHTN), but the evidence supporting the utility of renal revascularization in these patients is limited. This prospective, observational study investigates the outcomes of renal stenting in patients with RHTN and hemodynamically significant ARAS.

METHODS

Fifty-four patients with RHTN were selected because of angiographic evidence of ARAS >70% and were followed for 4 years after renal stenting. Renal function and echocardiographic variables were assessed at baseline and during follow-up.

RESULTS

Blood pressure decreased rapidly after renal stenting and was normalized in 67% of patients at six months, with significant reduction in the number of antihypertensive drugs. Creatinine clearance increased in 39% of patients, decreased in 52%, and remained stable in the remaining 9%, with an average value that had a nonsignificant decrease during follow-up. Urinary albumin excretion did not change throughout the study. After 4 years, left ventricular (LV) wall thickness and concentric geometry decreased significantly and variables of LV diastolic function improved.

CONCLUSION

In patients with RHTN, stenting of hemodynamically significant ARAS decreases blood pressure, preserves renal function in a substantial proportion of patients, and improves LV structure and function, suggesting the opportunity for timely identification of ARAS in these patients.