Atheromatous Renal Artery Stenosis Research Articles

Cardiovascular Disease Prevention in Patients With Atherosclerotic Renovascular Disease-Induced Resistant Hypertension: Further Considerations for 24-Hour BloodPressure Profiles.

Cardiovascular Disease Prevention in Patients With Atherosclerotic Renovascular Disease-Induced Resistant Hypertension: Further Considerations for 24-Hour BloodPressure Profiles.

Tabac et pression artérielle : une relation complexe à mieux connaître

Hypertension and tobacco smoking are two major modifiable risk factors for atheromatous disease and its cardiovascular complications. If systolic hypertension (SBP≥140mmHg and DBP<90mmHg) is the leading risk factor for stroke, smoking (nicotine) has a more powerful impact on coronary events, aortic aneurysms, and peripheral artery disease. Smoking can transiently modify the regulation of blood pressure (BP) by a swift effect on the autonomic nervous system. It also accelerates arterial aging, which plays a role in chronic hypertension. Chronic sympathetic activation induced by tobacco smoking also has some involvement in lipid metabolism and insulin resistance, both implicated in atheromatous disease. Thus, smoking can contribute to the development of atheromatous renal artery stenosis, which is an aggravating cause of hypertension. It may also reduce the effectiveness of most antihypertensive drugs. Finally, it is often associated with increased alcohol consumption. All these factors may contribute to poor blood pressure control in these high-risk CV patients. Smoking cessation is effective regardless of patient age and length of consumption. Every effort should thus be made to support smoking cessation. This is the objective of the French "Plan Sans Tabac" (No Tobacco Plan) and the related actions conducted by the French Federation of Cardiology.

Kidney volume to GFR ratio predicts functional improvement after revascularization in atheromatous renal artery stenosis.

BackgroundRandomized controlled trials (RCT) have shown no overall benefit of renal revascularization in atherosclerotic renovascular disease (ARVD). However, 25% of patients demonstrate improvement in renal function. We used the ratio of magnetic resonance parenchymal volume (PV) to isotopic single kidney glomerular filtration rate (isoSKGFR) ratio as our method to prospectively identify "improvers" before revascularizationMethodsPatients with renal artery stenosis who were due revascularization were recruited alongside non-ARVD hypertensive CKD controls. Using the controls, 95% CI were calculated for expected PV:isoSK-GFR at given renal volumes. For ARVD patients, “improvers” were defined as having both >15% and >1ml/min increase in isoSK-GFR at 4 months after revascularization. Sensitivity and specificity of PV:isoSK-GFR for predicting improvers was calculated.Results30 patients (mean age 68 ±8 years), underwent revascularization, of whom 10 patients had intervention for bilateral RAS. Stented kidneys which manifested >15% improvement in function had larger PV:isoSK-GFR compared to controls (19±16 vs. 6±4ml/ml/min, p = 0.002). The sensitivity and specificity of this equation in predicting a positive renal functional outcome were 64% and 88% respectively. Use of PV:isoSK-GFR increased prediction of functional improvement (area under curve 0.93). Of note, non-RAS contralateral kidneys which improved (n = 5) also demonstrated larger PV:isoSK-GFR (15.2±16.2 ml/ml/min, p = 0.006).ConclusionThis study offers early indicators that the ratio of PV:isoSK-GFR may help identify patients with kidneys suitable for renal revascularization which could improve patient selection for a procedure associated with risks. Calculation of the PV:isoSK-GFR ratio is easy, does not require MRI contrast agent.

Current approaches to atherosclerotic obstructive renal artery stenosis.

Increased lifespan in the last few decades has substantially changed the scenario for renal artery stenosis. Indeed, because older populations show a higher prevalence of atherosclerotic disease, the incidence of atheromatous renal artery stenosis has also increased. Intuitively, one could surmise that stenosis removal should void both the hypertension and the kidney damage resulting from the obstructive stenosis. Surprisingly, a number of important clinical trials have failed to show the reversion seen in experimental models. The reasons for these differences may be linked to chronicity and inflammation associated with the atherosclerotic lesion. However, the failure to obtain a favorable response may also be related to abnormalities in the contralateral kidney. Indeed, this apparently normal kidney should work to compensate the hemodynamic effects of the ipsilateral stenosed kidney. Instead, structure and function in the contralateral kidney can be altered in renal artery stenosis to the point that this nonstenotic kidney may sustain both, hypertension and progressive kidney disease. Certainly, comparing the effects of clip removal in the Goldblatt model to angioplasty in clinical settings with atherosclerotic lesions may be totally inappropriate. Nevertheless, there remain certain clinical situations such as bilateral renal arterial disease, congestive heart failure, and progressive renal failure, where angioplasty may be an alternative. These approaches however are yet to be tested.

Angioplastie rénale : état des lieux en 2014

Atherosclerotic renal artery stenosis can cause ischaemic nephropathy and arterial hypertension. Renal artery stenosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Many patients with RAS may be managed effectively with medical therapy for several years without endovascular stenting, as demonstrated by randomized, prospective trials including the cardiovascular outcomes in Renal Atherosclerotic Lesions (CORAL) trial, the Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) trial. These trials share the limitation of excluding subsets of patients with high-risk clinical presentations, including episodic pulmonary edema and rapidly progressing renal failure and hypertension. Blood pressure control and medication adjustment may become more difficult with declining renal function and may prevent the use of angiotensin receptor blocker and angiotensin-converting enzyme inhibitors. The objective of this review is to evaluate the current management of RAS for cardiologists in the context of recent randomized clinical trials. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary edema, rapidly declining renal function and severe resistant hypertension.

Renal artery stenting in patients with uncontrolled hypertension: should we? And to whom?

In this issue of the Journal, Chrysant and colleagues evaluated the longer-term efficacy of renal artery stenting with respect to blood pressure (BP) control by analyzing the results of the Safety and Effectiveness Study of the Herculink Elite Renal Stent to Treat Renal Artery Stenosis (HERCULES) trial after 36 months of follow-up. 1 The HERCULES trial was a multicenter, single-arm trial of 202 patients with uncontrolled hypertension caused by atherosclerotic renovascular disease (ARVD) treated by percutaneous renal artery dilatation and renal stent placement. In the original HERCULES trial, the authors found that the absolute reduction in systolic BP (SBP) after 9 months was related to the severity of the baseline hypertension before intervention. In ARVD patients with preprocedure SBP >180 mm Hg and a postprocedure reduction in SBP, the mean reduction recorded at 9 months was 48 mm Hg, while patients with ARVD with a baseline SBP between 140 mm Hg and 160 mm Hg had a decrease of only 23 mm Hg in SBP at 9 months. In addition, this trial demonstrated excellent procedurerelated safety, with a 30-day composite safety endpoint rate of 1.5%. 2 Chrysant and colleagues further hypothesized that if the renal stent used in the initial HERCULES trial maintained renal artery patency over time, then the clinical benefit confirmed in the initial trial should be sustained over time. Based on this hypothesis, the

Accuracy of multi-detector computed tomographic angiography assisted by post-processing software for diagnosis atheromatous renal artery stenosis

To compare the diagnostic performance of MDCTA versus renal angiography in the detection of>50% renal artery stenosis in patients suspected of reno-vascular hypertension. Between January 2005 and January 2010, 92 MDCTA and renal arteriographies were retrospectively analysed. Renal angiographies were read by one interventional radiologist. Three blinded independent readers (two senior radiologists and one technician) scored MDCTA images using three different approaches. Reader 1 scored stenosis using only MPR and MIP. Reader 2 (technician) used only proprietary automatic arterial segmentation software. Reader 3 used the cited software, using manual diameter measurements. A total of 92 patients, (235 renal arteries) were assessed in which 48 significant stenosis were found by arteriography. Sensitivity, specificity, of MDCTA compared to renal arteriography were respectively per patient for reader 1: (88%; 80%); for reader 2: (58%; 80%); for reader 3: (96%; 90%) (P<.02). When using automated vessel analysis software edited by a radiologist, MDCTA studies had a Sensibility/Specificity of 96%/90% to detect>50% renal artery stenosis.

Blockade of the Renin-Angiotensin System in Hypertensive Patients with Atherosclerotic Renal Artery Stenosis

Renin angiotensin system (RAS) blockers are generally considered as contraindicated when an atheromatous renal artery stenosis (ARAS) is diagnosed. The main reason is the fear of inducing renal ischemia and, hence, accelerating renal fibrosis and the progression towards end stage renal disease, albeit RAS blocker have been shown to be highly effective in controlling blood pressure. Part of the solution came by the development of the revascularization. There is now growing evidence showing no superiority of angioplasty over medical treatment on cardiovascular events and mortality, renal function and blood pressure control. Hence, RAS blockers resurfaced based on their proven beneficial effects on blood pressure control and cardiovascular prevention in high risk atherosclerotic patients. Thus, RAS blockers belong today to the standard treatment of hypertensive patients with ARAS. However they were not systematically prescribed in trials focusing on ARAS. The ongoing CORAL trial will give us further information on the place of this class of antihypertensive drugs in patients with ARAS.

Diagnosis and therapy of atheromatous renal artery stenosis

Atheromatous renal artery stenosis (ARAS), a lesion of systemic atherosclerotic disease, is the leading cause of stenotic lesions in the renal artery, followed by fibromuscular dysplasia, a primary abnormality of the renal artery. As a result of several clinical trails, which failed to show an additional benefit of renal revascularization to medical therapy in ARAS, the treatment of ARAS has shifted, and renal revascularization is less commonly performed for ARAS. However, it is recognized that renal revascularization benefits some patients with ARAS. Advances in imaging modalities would allow more frequent detection of ARAS in a society with a growing elderly population, a group with an increased prevalence of systemic atherosclerotic disease. Therefore, it is imperative to identify the patients with ARAS who could benefit from renal revascularization. This review presents a strategy for the treatment of ARAS based on the results of our analysis.

Stage of chronic kidney disease is an outcome-predicting factor of angioplasty for atheromatous renal artery stenosis

Angioplasty with insertion of an endoprosthesis is an effective treatment for atheromatous renal artery stenosis (ARAS). However, this procedure may cause deterioration in renal function, and it is imperative to define the cases that could benefit from angioplasty. From 456 suspected renovascular hypertension cases, 33 were given a diagnosis of unilateral ARAS on renal arteriography. These unilateral ARAS cases were treated by angioplasty, and their baseline variables were evaluated with respect to the improvement achieved in post-angioplastic renal function of the treated side as measured by renal scintigram. The estimated glomerular filtration rate (eGFR) was the only variable that was significantly different between cases that showed improvement in renal function and those that did not. Cases that showed improvement in renal function had lower pre-angioplasty eGFR compared with cases that did not show improvement (59±24 ml min⁻¹ 1.73 m⁻² vs. 76±12 ml min⁻¹ 1.73 m⁻², P=0.04), and cases showing improvement were generally at later stages of chronic kidney disease (CKD). Most patients without improvement, who were generally at earlier stages of CKD, had a systemic blood pressure reduction after angioplasty. The present findings indicate that the baseline CKD stage could be used to predict the outcome of angioplasty for ARAS.

Hemodynamic Index of Atheromatous Renal Artery Stenosis for Angioplasty

Trans-stenotic pressure gradient across the constriction (PG), a hemodynamic variable of atheromatous renal artery stenosis (ARAS), is a widely used indicator for angioplasty, but its association with the outcome of angioplasty has not been fully investigated. In 34 hypertensive cases with unilateral ARAS, we evaluated hemodymanic variables of ARAS with reference to the systemic BP reduction after angioplasty as the outcome. In each phase, PG divided by its corresponding prestenotic arterial BP (PG/preBP) had better association with the outcome than PG. The mean phase PG/preBP had the largest area under the curve in the receiver operating characteristic analysis (0.794) with the sensitivity/specificity of 0.957/0.545 for its cut-off >0.15. Although the plasma renin activity, which reflects the perfusion to renal parenchyma, was higher in the angioplasty-efficacious cases than in the angioplasty-inefficacious cases before angioplasty (7.8 +/- 6.6 versus 3.4 +/- 3.8 ng/ml/h, P = 0.049), it was not generally reduced by angioplasty independent of the outcome. As the index to select ARAS for angioplasty, PG/preBP was better than PG and the mean phase PG/preBP could be the best. However, other factors such as the microvascular kidney disease, which affect the perfusion to renal parenchyma, would influence the outcome.

Sténoses de l’artère rénale athéromateuses et fibrodysplasiques

Renal artery stenosis may be due to atheromatous disease or renal fibromuscular dysplasia (FMD). Management of both diseases requires treatment of hypertension usually observed in such patients; however, clinical presentation, mechanism and treatment of these 2 diseases are usually different. Renal FMD is now considered as a systemic disease, the cause of which may be genetic (although the exact cause is still elusive). Renal arteries are the most frequent localizations of FMD, but extra renal arteries may also be involved (usually carotid arteries). Risk factors of hypertension-induced renal FMD include estrogen treatment and smoking. Renal FMD are mostly found in young women and in children who present with recent severe and/or refractory symptomatic hypertension. Diagnosis is usually easy (Doppler, CT-scan), and treatment of renal FMD is angioplasty in most cases. Atheromatous renal artery stenosis is usually found in patients with other atheromatous disease (peripheral artery disease, carotid, coronary artery disease...). Clinical presentation include severe or refractory hypertension, recurrent flash pulmonary edema in a patient with hypertension, progressive renal dysfunction spontaneously or after medical treatment with converting-enzyme inhibition or angiotensin II blockade, hypertension in a patient (usually smoker or ex-smoker) with diffuse atheromatous vascular disease. Management of atheromatous renal artery disease is medical treatment in all patients (aggressive treatment of cardiovascular risk factors, control of arterial pressure); revascularization is required in some patients only since it rarely cures hypertension: the goal of revascularization is mostly renal function protection, which may be observed in selected patients. Revascularization must be decided by physicians or teams involved in the care of such patients. Patients with atheromatous renal artery disease are at very high renal and cardiovascular risk : aggressive management of cardiovascular risk factors is crucial.

Angiographic Index for Angioplasty-Treatable Atheromatous Renal Artery Stenosis

The relative reduction of the lumen diameter by an atheromatous lesion (% diameter reduction) is generally used as an angiographic index for atheromatous renal artery stenosis (ARAS), but its association with the clinical outcome of angioplasty has not been sufficiently evaluated. This study aimed to identify an angiographic index(ices) that can be used to identify angioplasty-treatable ARAS. We evaluated the clinical outcome of angioplasty in 27 patients who had unilateral ARAS without renal insufficiency by assessing the reduction in systemic arterial blood pressure (BP) after angioplasty and examined its association with various angiographic indices. In the receiver operating characteristic analysis for BP reduction, the area under the curve was larger for the absolute value of the lumen diameter at the narrowest part of its constriction (the narrowest diameter), an angiographic index introduced in this study, than for % diameter reduction (0.770 vs. 0.731). At a 3-mm maximum threshold, the narrowest diameter identified cases with BP reduction; the sensitivity/specificity was 0.89/0.75 (p < 0.001). Furthermore, the narrowest diameter correlated better than % diameter reduction with hemodynamic indices of ARAS. In conclusion, the narrowest diameter is an angiographic index that can effectively identify angioplasty-treatable ARAS in patients without renal insufficiency.

2007 Charles T. Dotter Memorial Lecture—Renal Artery Stenosis and Cardiovascular Risks—The New Paradigms in Diagnosis and Treatment

Renal artery stenosis (RAS), hypertension, and renal insufficiency are each frequently present especially in the elderly population. RAS is often present without any clinical signs or symptoms, and even when hypertension or renal insufficiency is also present, these conditions may be coincidental rather than causally related. However, when RAS is physiologically significant (10% peak systolic trans-stenotic pressure gradient), it is one of the few potentially reversible causes of renal insufficiency and hypertension. RVH is mediated by angiotensin II, a powerful vaso-constrictor producing systemic hypertension, cellular hypertrophy, proliferation of vascular smooth muscle cells, vascular and left ventricular hypertrophy, accelerated atherosclerosis, and progressive glomerular sclerosis, independent of the level of hypertension. Physiologically significant RAS also has direct effects on sympathetic nerve activity, nitric oxide production, and intrarenal prostaglandin concentration. Patients with atheromatous RAS (ARAS) and end-stage renal disease have a significantly higher mortality rate than the general dialysis population. Some advocate prophylactic intervention for asymptomatic and hemodynamically insignificant ARAS; however, ARAS is a marker for but not an independent risk factor for major adverse cardiac events. Aggressive statin therapy arrests progression and produces regression of coronary and carotid atheroma. Patients with asymptomatic and hemodynamically nonsignificant ARAS should be treated with aggressive statin and glucose control therapy, aspirin, and lifestyle modifications. This would likely produce all the potential benefits of prophylactic stenting, the very long-term durability and fate of which are unknown, and without any of its known major risks such as cholesterol embolisation and the 15% to 20% restenosis that can occur even in “low-risk” patients. In summary, appropriately selected patients with ARAS and renal insufficiency benefit from interventional therapy, whereas those with clinically and hemodynamically nonsignificant stenoses should be treated by aggressive medical therapy, including statins and life style modifications.

Angioplasty for atheromatous renal artery stenosis: current knowledge and trial results awaited

Angioplasty for atheromatous renal artery stenosis: current knowledge and trial results awaited

A Study on the Outcome of Percutaneous Transluminal Renal Angioplasty in Patients with Renal Failure

Background: The indications for percutaneous transluminal renal angioplasty (PTRA) in renovascular disease, as well as its benefits, remain a matter of debate. The aim of this study was to evaluate the outcome of angioplasty and to identify risk factors associated with less successful outcomes in patients with atheromatous renal artery stenosis and renal failure of varying degrees. Methods: The results of PTRA were analyzed retrospectively in 144 patients with serum creatinine levels of >130 µmol/l. Patients were divided into 5 groups according to their indication for angioplasty: (1) deteriorating renal function; (2) accelerating hypertension; (3) a combination of 1 and 2; (4) peripheral vascular disease, and (5) miscellaneous conditions. Results: The baseline mean (± SD) systolic and diastolic blood pressures of the entire group were lowered from 180 ± 32 and 95 ± 16 mm Hg to 162 ± 23 and 86 ± 12 mm Hg, respectively (p < 0.0005), 12 months after angioplasty. The blood pressure level was unaffected by angioplasty in patients with claudication. The mean number of antihypertensive drugs was reduced in the group with accelerating hypertension from 2.9 ± 0.8 to 2.4 ± 1.2 (p = 0.019), and in the group with unilateral renal artery stenosis and two kidneys from 2.4 ± 1.0 to 1.8 ± 1.1 (p = 0.002), 12 months after PTRA. Glomerular filtration rate at 3-month follow-up had increased from 23 ± 11 to 27 ± 14 ml/min/1.73 m² (p = 0.021) in group 1, from 25 ± 11 to 28 ± 14 ml/min/1.73 m² (p = 0.031) in the combined group of patients consisting of groups 1 and 3, and from 32 ± 13 to 35 ± 14 ml/min/1.73 m² (p = 0.019) in the group with unilateral renal artery stenosis. No statistically significant difference was found in any of these 3 groups 1 year after angioplasty. The first patient group had an increased prevalence of cardiovascular disease, aortic aneurysm, carotid occlusive disease, and peripheral vascular disease compared to the other patient groups (p < 0.05). Patients with baseline creatinine levels of >300 µmol/l had a lower survival rate at 12, 60, and 120 months after PTRA than patients with serum creatinine levels of <300 µmol/l (p < 0.005). Survival was also lower in patients with bilateral renal artery stenosis and those with a single kidney, compared to patients with a unilateral stenosis at both 5 and 10 years after PTRA (p < 0.05). Regression analysis of predictor variables of mortality rate showed that the relative risk (RR) associated with increased serum creatinine was 4.7 (CI 2.0–11.0; p < 0.0005). The RR for older patients was 1.1 (CI 1.0–1.2; p = 0.008), and the RR for former smokers was 6.0 (CI 1.6–24.0; p = 0.009). Conclusion: The results of the present study indicate that glomerular filtration can be improved in patients who primarily undergo angioplasty to rescue renal function. Renal function with creatinine levels of >300 µmol/l was associated with a lower survival rate. It is, therefore, possible that patients selected after a thorough evaluation of their renal function and comorbid disease factors may benefit from PTRA, even when the indication for angioplasty is to salvage renal function.

Simultaneous aortic and renal artery reconstruction

Nine patients presenting with combined aortic and renal artery disease underwent simultaneous infrarenal aortic reconstruction and renal revascularization. Seven patients had aneurysmal and two had occlusive aortic disease in association with unilateral (four cases) or bilateral (five cases) atheromatous renal artery stenosis. The indications for renal revascularization were hypertension (n = 8) refractory to medical treatment or associated with renal functional impairment and chronic renal failure alone (n = 1). Five patients developed postoperative complications with one fatality. Eight patients were followed up for between 7 months and 4 years. Control of blood pressure had improved in six of seven hypertensive patients. Serum creatinine levels were stabilized or had fallen in five patients. Simultaneous aortic and renal artery reconstruction is widely recognized as having a high postoperative morbidity rate but can improve control of hypertension and stabilize renal function in carefully selected patients.

When should atheromatous renal artery stenosis be considered? A guide for the general physician

When should atheromatous renal artery stenosis be considered? A guide for the general physician

PERCUTANEOUS TRANSLUMINAL RENAL ARTERY ANGIOPLASTY: WHO BENEFITS MOST?

SUMMARYWe set out to assess the long‐term benefits of renal percutaneous transluminal angioplasty (PTA) in 107 consecutive hypertensive patients with atheromatous renal artery stenosis. During 12‐month follow‐up, blood pressure fell to normal levels in 10 (8.8%) patients and improved in 76 (67.3%); renal function improved or remained stable in 74% of patients. In patients with atheromatous disease, renal angioplasty was most successful in those with stenosis in a single functioning kidney, and in nine patients who presented with symptoms and signs of heart failure, in the absence of overt ischaemic or valvular heart disease. In the latter group, renal PTA resulted in a large loss of sodium and water, resolution of the ‘apparent’ heart failure, and a marked improvement in blood pressure and renal function. It is suggested that all hypertensive patients with haemodynamically significant renal artery stenosis (and/or mild to moderate impairment in renal function), should be considered for renal PTA. Patients with atheromatous stenosis in a single functioning kidney, and those who present with signs of sodium and water retention, are likely to benefit most.

Homocysteine and atheromatous renal artery stenosis.

Hyperhomocysteinemia is an independent risk factor for vascular disease, frequently observed in patients with severe renal impairment. Hyperhomocysteinemia has never been considered as a possible risk factor in renal artery stenosis. We investigated plasma folate and vitamin B12, methylenetetrahydrofolate reductase (MTHFR) C677T and cystathionine beta-synthase (CBS) 844ins68 polymorphisms, and homocysteine levels before and after methionine (100 mg/kg) loading in 58 patients with angiographically documented renal artery stenosis and mildly impaired renal function. One hundred and two normotensive subjects with angiographically normal coronary arteries and no history or clinical or angiographic evidence of atherosclerosis in other vascular districts, were considered as a control group. Mean total homocysteine levels were significantly higher in patients than in controls (P<0.01), as was the prevalence of hyperhomocysteinemia (51.7% vs. 32.3%, P<0.05). However, MTHFR alleles and genotypes as well as CBS 844ins68 mutation frequencies were similar in the two groups, whereas a lower folate level was observed in the patients. Moreover, patients with MTHFR A/A genotype showed a poorer folate status than control subjects, suggesting that a subclinical folate deficiency may be very frequent in renal artery stenosis, regardless of C677T mutation. In conclusions, hyperhomocysteinemia is common in patients with atheromatous renal artery stenosis; a subclinical folate deficiency seems to be involved, regardless of MTHFR thermolabile or CBS insertion genotypes. Folate supplementation might be useful in the management of overall vascular risk of these patients.