Prevention of recurrent pulmonary edema in patients with bilateral renovascular disease through renal artery stent placement

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.

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

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

[Treatment of renal artery stenosis in the year 2021]

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

Combination of Renal Angioplasty and Angiotensin-converting-enzyme Inhibitor Can Reduce Proteinuria in Patients with Bilateral Renal Artery Disease

Recent large clinical trials failed to show clear benefits of percutaneous transluminal renal angioplasty (PTRA) as compared with medical therapy on patients with renal artery stenosis. It was also reported that proteinuria is an adverse prognostic factor after PTRA, and PTRA is less effective in patients with overt proteinuria. From the renoprotective point of view, to reduce proteinuria after PTRA is an important therapeutic goal in patients with renal artery stenosis with overt proteinuria. We hereby describe two patients successfully treated by combination therapy with PTRA and administration of angiotensin-converting enzyme (ACE) inhibitor for bilateral renal artery disease with overt proteinuria.

Cardiac function response to stenting in atherosclerotic renal artery disease with and without heart failure: results from the Carmel study

Aims

Consensus‐derived guidelines recommend renal stenting for patients with atherosclerotic renal artery disease (ARAD) and heart failure (HF). The aim of this prospective multi‐centre observational study was to verify our hypothesis that changes in E/e′, an echocardiographic correlate of left ventricular (LV) filling pressure, following renal stenting may differ between ARAD patients with and without HF.

Methods and results

This study enrolled de novo ARAD patients undergoing renal stenting at 14 institutions. The primary endpoint was the difference in E/e′ change between ARAD patients with and without HF. Clinical and echocardiographic data were prospectively collected at baseline, the day following renal stenting, and 1 month and 6 months afterwards. ARAD patients with HF were defined as patients with New York Heart Association (NYHA) Class 2 and more, or a history of HF hospitalization. A total of 76 patients were included, and 39% were ARAD patients with HF. ARAD patients with HF had significantly lower estimated glomerular filtration rate (P = 0.028) and higher NYHA functional class (P < 0.001) and Minnesota Living with Heart Failure Questionnaire (MLHFQ) score (P = 0.001) than ARAD patients without HF. Also, ARAD patients with HF had significantly lower LV ejection fraction (P = 0.003) and e′‐velocity (P = 0.003) and higher E/e′ ratio (P = 0.001), left atrial volume index (LAVI) (P = 0.046), LV end‐diastolic volume (LVEDV) (P = 0.001), LV end‐systolic volume (LVESV) (P = 0.001), and LV mass index (P = 0.009) than ARAD patients without HF. All procedures were successful. In contrast to blood pressure and renal function, there was a significant interaction in E/e′ (P_interaction < 0.001) between time and HF, and ARAD patients with HF showed a significant (P < 0.001) decrease in E/e′ albeit those without HF. By the same token, there was a significant interaction in NYHA class (P_interaction < 0.001), MLHFQ score (P_interaction = 0.018), E‐velocity (P_interaction = 0.002), LAVI (P_interaction = 0.001), LVEDV (P_interaction = 0.003), and LVESV (P_interaction = 0.001) between time and HF with a significant improvement in all these variables in ARAD patients with HF (NYHA class, P = 0.001; MLHFQ score, P = 0.002; E‐velocity, P = 0.005; LAVI, P = 0.001; LVEDV, P = 0.017; and LVESV, P = 0.011).

Conclusions

Change in LV filling pressure after renal stenting differed between ARAD patients with and without HF, with a significant improvement in LV filling pressure in patients with HF‐ARAD. These unique findings might support clinical cardiac benefits of renal stenting in ARAD patients with HF.

Predictors of cardiac benefits of renal artery stenting from a multicentre retrospective registry

OBJECTIVES

There have been limited data regarding the prediction of cardiac benefits after renal artery stenting for patients with atherosclerotic renal artery disease (ARAD). The aim of this multicentre retrospective study was to identify clinical or echocardiographic factors associated with improvements of cardiac symptoms after renal artery stenting.

METHODS

We enrolled 58 patients with de novo ARAD undergoing successful renal artery stenting for heart failure, angina or both between January 2000 and August 2015 at 13 hospitals.

RESULTS

Improvement of cardiac symptoms was observed in 86.2% of patients during a mean follow-up of 6.0±2.7 months. Responders demonstrated significantly lower New York Heart Association functional class, higher estimated glomerular filtration rate, lower serum creatinine and lower interventricular septal wall thickness (IVS), lower left ventricular mass index, lower left atrial dimension and lower E-velocity than non-responders. Backward stepwise multivariate analysis identified IVS as an independent predictor of improvement of cardiac symptoms (OR 0.451, 95% CI 0.209 to 0.976; p=0.043). According to receiver operating characteristic curve analysis, an IVS cut-off of 11.9 mm provided the best predictive value, with sensitivity of 71.4%, specificity of 75.5% and accuracy of 73.5%. The positive predictive value was 74.5% and the negative predictive value was 72.5%.

CONCLUSIONS

This multicentre retrospective study shows that the echocardiographic index of IVS is an independent predictor for improvement of cardiac symptoms after renal artery stenting.

Longterm Outcomes of Renal Artery Involvement in Takayasu Arteritis

OBJECTIVE

Takayasu arteritis (TA) involving the renal artery can result in hypertension (HTN), renal dysfunction, and premature death. The aim of this study was to investigate the longterm outcomes and factors that predict outcomes in patients with TA with renal artery stenosis.

METHODS

The medical records of patients diagnosed with TA between January 1997 and December 2014 were reviewed retrospectively. Renal artery involvement was based on computed tomography and/or angiography findings. Poor outcome was defined as refractory HTN, chronic renal insufficiency, or death.

RESULTS

Of the 62 TA patients with renal artery involvement, 11 (17.7%) underwent renal artery revascularization. Younger age, male sex, and more severe stenosis (> 70%) were associated with vascular intervention. After a median followup of 90.6 months, 11 (17.7%) of the 62 patients had refractory HTN and 6 (9.7%) had chronic renal insufficiency. Renal insufficiency [5/15 (33.3%) vs 3/47 (6.4%), p = 0.016] and bilateral involvement [12/15 (80.0%) vs 23/47 (48.9%), p = 0.041] were significantly more frequent in patients with poor than good outcomes. Multivariate Cox analysis revealed that renal insufficiency at presentation (HR 13.778, 95% CI 3.530-53.786, p < 0.001) and bilateral renal artery involvement (HR 5.053, 95% CI 1.179-21.661, p = 0.029) were significant risk factors for poor outcomes at followup, but performance of revascularization procedure was not (HR 0.663, 95% CI 0.176-2.498, p = 0.543).

CONCLUSION

Bilateral lesions and renal functional impairment at presentation, but not implementation of revascularization procedures, were significant factors for outcomes in TA patients with renal artery involvement.

Renal Artery Stenosis: Optimal Therapy and Indications for Revascularization

Atherosclerotic renal artery stenosis (ARAS) is associated with increased cardiovascular risk and overall mortality. Manifestations of ARAS include resistant or malignant hypertension, progressive deterioration of renal function, and cardiac dysfunction syndromes of flash pulmonary edema and angina. Diagnosis rests upon non-invasive studies such as duplex ultrasonography and is confirmed using invasive renal arteriography. Regardless of the severity of ARAS, management of this entity has been a topic of contentious debate. For over two decades, the use of percutaneous revascularization to treat ARAS has been studied with various clinical trials. Though case series seem to demonstrate favorable clinical response to revascularization, the overwhelming majority of randomized clinical trials have not mirrored a robust outcome. In these trials, poor correlation is noted between the reduction of stenosis and the improvement of renovascular hypertension and glomerular filtration rate, and decrease in cardiovascular outcomes and mortality. With dichotomizing results, the explanation for these discrepant findings has been attributed to improper trial design and inappropriate patient selection. An overview of the treatment options available will be provided, with a focus on the methodology and design of clinical trials investigating the efficacy of percutaneous revascularization. Emphasis is placed on appropriate patient selection criteria, which may necessitate the use of hemodynamic lesion assessment and clinical correlation based on individualized care. When clinical equipoise exists between optimal medical therapy and revascularization, the current paradigm supports ongoing medical therapy as the treatment of choice. However, renal artery stenting remains a viable therapeutic option for those who continue to have clinical syndromes consistent with renal hypoperfusion while adequately treated with optimal medical therapy. Despite observational studies suggesting clinical benefit for this specific patient population, there remains a paucity of randomized clinical trial data. Further trials targeting the patients who are inadequately treated with optimal medical therapy need to be undertaken to confirm the efficacy of revascularization.

Renovascular heart failure: heart failure in patients with atherosclerotic renal artery disease

Atherosclerotic renal artery disease presents with a broad spectrum of clinical features, including heart failure as well as hypertension, and renal failure. Although recent randomized controlled trials failed to demonstrate renal artery stenting can reduce blood pressure or the number of cardiovascular or renal events more so than medical therapy, increasing attention has been paid to flash pulmonary edema and congestive heart failure associated with atherosclerotic renal artery disease. This clinical entity "renovascular heart failure" is diagnosed retrospectively. Given the increasing global burden of heart failure, this review highlights the background and catheter-based therapeutic aspects for renovascular heart failure.

Transradial Peripheral Arterial Procedures

Increased understanding and increased adoption of transradial catheterization across the world have led to further exploring of radial artery access for transradial endovascular interventions in peripheral artery disease (PAD). This article discusses the advantages and limitations of the transradial approach for endovascular medicine by using case examples, illustrations, and videos. The details about how to use a radial approach for PAD intervention, including and tips tricks, are discussed.

[Ischemic renal disease and renal artery stenosis]

Severe renal artery stenosis may cause renovascular hypertension; in case of bilateral narrowing or in a stenotic solitary or transplant kidney, renal insufficiency (ischemic renal disease) or rarely pulmonary flash edema may occur. In most cases arteriosclerotic disease is the underlying cause; less prevalent are the various manifestations of fibromuscular disease. Renal artery stenosis may be treated by revasularization, using either percutaneous (balloon angioplasty, stenting) or rarely open surgical procedures, both with excellent primary patency rates. However, randomized trials of renal artery angioplasty or stenting in patients with arteriosclerotic lesions have failed to demonstrate a longer-term benefit with regard to hypertension control and renal dysfunction over medical management alone. Careful patient selection is essential to maximize the potential benefit (e.g., in patients with refractory hypertension, progressive renal failure or recurrent pulmonary flash edema).

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.

Renal artery stenosis-when to screen, what to stent?

Renal artery stensosis (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. Evidence from large clinical trials has led clinicians away from recommending interventional revascularisation towards aggressive medical management. 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 oedema, rapidly declining renal function and severe resistant hypertension. The potential benefits in terms of improving hard cardiovascular outcomes may outweigh the risks of intervention in this group, and further research is needed.

Renal artery stenosis: epidemiology and treatment

Renal artery stenosis (RAS) is a frequently encountered problem in clinical practice. The disease encompasses a broad spectrum of pathophysiologies and is associated with three major clinical syndromes: ischemic nephropathy, hypertension, and destabilizing cardiac syndromes. The two most common etiologies are fibromuscular dysplasia and atherosclerotic renal artery disease with atherosclerotic disease accounting for the vast majority of cases. Atherosclerotic renovascular disease has considerable overlap with atherosclerotic disease elsewhere and is associated with a poor prognosis. A wide range of diagnostic modalities and treatment approaches for RAS are available to clinicians, and with the advent of endovascular interventions, selecting the best course for a given patient has only grown more challenging. Several clinical trials have demonstrated some benefit with revascularization but not to the extent that many had hoped for or expected. Furthermore, much of the existing data is only marginally useful given significant flaws in study design and inherent bias. There remains a need for further identification of subgroups and appropriate indications in hopes of maximizing outcomes and avoiding unnecessary procedures in patients who would not benefit from treatment. In recent decades, the study of RAS has expanded and evolved rapidly. In this review, we will attempt to summarize the amassed body of literature with a focus on the epidemiology of RAS including prevalence, overlap with other atherosclerotic disease, and prognosis. We will also outline existing diagnostic and treatment approaches available to clinicians as well as summarize the findings of several major clinical trials. Finally, we will offer our perspective on future directions in the field.

[Current management of renal artery stenosis]

Severe renal artery stenosis may cause renovascular hypertension; in case of bilateral narrowing or in a stenotic solitary kidney, renal insufficiency (ischemic kidney disease) or rarely pulmonary flush edema may occur. Renal artery stenosis may be treated by revascularization, using either percutaneous (balloon angioplasty, stenting) or less common open surgical procedures, both with excellent primary patency rates. However, randomized trials of renal artery angioplasty or stenting have failed to demonstrate a longer-term benefit with regard to blood pressure control and renal function over medical management alone (except for fibromuscular disease). Furthermore, endovascular procedures are associated with substantial risks. It has not yet been demonstrated that renal revascularization leads to a prolongation of event-free survival. Careful patient selection is essential to maximize the potential benefit.

Cranio-caudal (transradial) approach for renal artery intervention

This report describes the technique of transradial renal angiography and interventions. We illustrate the approach using typical case images. We believe cranio-caudal approach to the renal artery for diagnostic and therapeutic catheterization offers advantages over the traditional femoral approach.

Determinants of renal function in patients with renal artery stenosis

Renal artery stenosis (RAS) is an important cause of renal failure; however, the factors associated with loss of kidney function in patients with RAS are poorly described, as are the predictors of an improvement in kidney function after stenting. One hundred patients at seven centers undergoing renal stenting were randomly assigned to an embolic protection device or double-blind use of a platelet glycoprotein IIb/IIIa inhibitor. The glomerular filtration rate (GFR) was measured using the creatinine-derived modified Modification of Diet in Renal Disease (MDRD) equation, cystatin C, and iohexol clearance. In univariate and multivariate models, baseline MDRD and cystatin C GFR were associated with congestive heart failure (CHF) (p = 0.01), lesion length (p = 0.01), and percent stenosis (-0.27, p = 0.01). In multivariate models, MDRD-estimated GFR 1 month after stenting was associated with bilateral stenosis (p < 0.05) and lesion length (p < 0.05), whereas with cystatin C the multivariate model included angiotensin receptor blocker (ARB) (p < 0.05) and minimal luminal diameter (MLD) (p < 0.05). The improvement in GFR from baseline to 1 month, measured as percent change, was related to baseline MDRD (p = 0.009) and cystatin C (p = 0.03) GFR. For MDRD GFR combined treatment with abciximab and Angioguard(®) embolic protection (p = 0.02) remained significant in multivariate analysis as did CHF, which was also significant with cystatin C (p = 0.05). In conclusion, CHF and lesion characteristics (MLD, percent stenosis and lesion length) are determinants of renal function in patients with RAS. In contrast, the acute improvement in renal function after revascularization is most strongly influenced by baseline GFR, and to a lesser degree CHF and combined procedural treatment with abciximab and embolic protection but not lesion characteristics. Clinical Trial Registration - URL:http://www.clinicaltrials.gov. Unique identifier: NCT00234585.

Management of heart failure with renal artery ischemia

With improved treatment, patients are surviving longer with impaired ventricular function. Hypertension results in ventricular remodeling in many patients. More than 5 million people have heart failure and are likely to have one or more co-existent diseases associated with aging, one of which is chronic kidney disease (CKD). Renal artery stenosis is fraught with varying opinions. Nephrologists, cardiologists, and interventional radiologists all manage these diseases with different strategies. This article outlines renovascular disease as it relates to CKD, the pathophysiology of development of renovascular disease and effects leading to congestive heart failure, treatment modalities, and outcomes of treatment regimens.

Role of the kidneys in resistant hypertension

Resistant hypertension is a failure to achieve goal BP (<140/90 mm Hg for the overall population and <130/80 mm Hg for those with diabetes mellitus or chronic kidney disease) in a patient who adheres to maximum tolerated doses of 3 antihypertensive drugs including a diuretic. The kidneys play a critical role in long-term regulation of blood pressure. Blunted pressure natriuresis, with resultant increase in extracellular fluid volume, is an important cause of resistant hypertension. Activation of the renin-angiotensin-aldosterone system, increased renal sympathetic nervous system activity and increased sodium reabsorption are important renal mechanisms. Successful treatment requires identification and reversal of lifestyle factors or drugs contributing to treatment resistance, diagnosis and appropriate treatment of secondary causes of hypertension, use of effective multidrug regimens and optimization of diuretic therapy. Since inappropriate renal salt retention underlies most cases of drug-resistant hypertension, the therapeutic focus should be on improving salt depleting therapy by assessing and, if necessary, reducing dietary salt intake, optimizing diuretic therapy, and adding a mineralocorticoid antagonist if there are no contraindications.

Atherosclerotic renovascular disease and the heart

The detrimental link between cardiac and renal pathophysiology in atherosclerotic renovascular disease (ARVD) is well described. Patients with ARVD usually have significant atherosclerotic disease in other vascular beds including the coronary circulation, and structural and functional cardiac changes are highly prevalent. This excess cardiovascular burden probably contributes to the increased cardiac morbidity and mortality seen in these patients. In this review we describe the associations of cardiovascular disease and ARVD and treatment thereof. The clinical debate of which patients are offered any additional advantage by revascularisation over medications alone remains to be answered. The close link between cardiac and renal pathophysiology in ARVD raises the possibility that renal revascularisation might confer a benefit to cardiac morphology and function. This is the subject of ongoing randomised controlled trials.

Prevalence of renal artery stenosis in flash pulmonary oedema: determination using gadolinium-enhanced MRA

PURPOSE

The primary purpose was to determine the prevalence of renal artery stenosis (RAS) in patients presenting with acute ("flash") pulmonary oedema (FPE), without identifiable cause using contrast-enhanced magnetic resonance angiography (CE-MRA) of renal arteries. A secondary goal was to correlate clinical parameters at presentation with the presence or absence of RAS.

MATERIALS AND METHODS

Patients presenting with acute pulmonary oedema without identifiable cause prospectively underwent CE-MRA. >50% renal artery stenosis was considered significant. Clinical parameters (blood pressure, serum creatinine, history of hypertension/hyperlipidaemia) were compared in patients with and without RAS using an unpaired t-test. Results expressed; mean (+/-SD).

RESULTS

20 patients (4 male, 16 female, age 78.5+/-11 years) underwent CE-MRA. 9 patients (45%) had significant RAS (6 (30%) bilateral, 3 (15%) unilateral). Systolic BP was higher in patients with RAS (192+/-38 mm Hg) than those without (134+/-30 mm Hg) (p<.005). Diastolic BP was higher in patients with RAS (102+/-23 mm Hg) than those without (76+/-17 mm Hg) (p<.01). All patients with RAS and 6/11(55%) patients without RAS had a history of hypertension. No significant difference in creatinine or hyperlipidaemia history was observed.

CONCLUSION

The prevalence of RAS in patients presenting with FPE is 45%. The diagnosis should be considered in patients presenting with unexplained acute pulmonary oedema, particularly if hypertensive at presentation.

Primary stenting for atherosclerotic renal artery stenosis

INTRODUCTION

Endovascular treatment for atherosclerotic renal artery stenosis (ARAS) was first performed >30 years ago and its use has increased rapidly since then. However, only recently have large randomized trials rigorously evaluated its clinical benefit.

METHODS

We systematically reviewed the controlled studies on primary stenting for atherosclerotic renal artery stenosis. Studies were included if they compared the outcome of stenting with other treatments, or the outcome associated with different stent characteristics or stenting methods.

RESULTS

Stenting is preferred over angioplasty alone and over surgery when revascularization is indicated for ostial ARAS, except in cases of coexistent aortic disease indicating surgery. Randomized controlled trials showed no significant benefit and substantial risk of renal artery stenting over medication alone in patients with atherosclerotic ARAS without a compelling indication. Improvements in the procedure, such as with distal embolic protection devices and coated stents, are not associated with better clinical outcomes after stent placement for ARAS.

CONCLUSION

Recent evidence shows that impaired renal function associated with ARAS is more stable over time than previously observed. Optimal medical treatment should be the preferred option for most patients with ARAS. Only low-level evidence supports compelling indications for revascularization in ARAS, including rapidly progressive hypertension or renal failure and flash pulmonary edema.

Epidemiology and natural history of atherosclerotic renovascular disease

Atheromatous renovascular disease (ARVD) is increasingly suspected and diagnosed, and it commonly presents to several different clinical specialties. In this review, the epidemiology, risk factors, comorbid disease associations, natural history, and prognosis of ARVD is described. Atheromatous renovascular disease is strongly associated with macrovascular pathology in other important vascular beds, especially the coronary, aortoiliac and iliofemoral circulations, and also with structural and functional heart disease. These clinicopathologic relationships contribute to the high morbidity and mortality associated with the condition. Understanding of the natural history of renal artery stenosis may enable intensified treatment strategies to reduce associated risk and improve patient prognosis.

Flash pulmonary edema

Flash pulmonary edema (FPE) is a general clinical term used to describe a particularly dramatic form of acute decompensated heart failure. Well-established risk factors for heart failure such as hypertension, coronary ischemia, valvular heart disease, and diastolic dysfunction are associated with acute decompensated heart failure as well as with FPE. However, endothelial dysfunction possibly secondary to an excessive activity of renin-angiotensin-aldosterone system, impaired nitric oxide synthesis, increased endothelin levels, and/or excessive circulating catecholamines may cause excessive pulmonary capillary permeability and facilitate FPE formation. Renal artery stenosis particularly when bilateral has been identified has a common cause of FPE. Lack of diurnal variation in blood pressure and a widened pulse pressure have been identified as risk factors for FPE. This review is an attempt to delineate clinical and pathophysiological mechanisms responsible for FPE and to distinguish pathophysiologic, clinical, and therapeutic aspects of FPE from those of acute decompensated heart failure.

Experience of stenting for atherosclerotic renal artery stenosis in a cardiac catheterization laboratory: technical considerations and complications

BACKGROUND

Atherosclerotic renal artery (RA) stenosis contributes to hypertension, renal insufficiency and end stage renal disease, and is independently associated with adverse cardiovascular events. Percutaneous renal intervention is efficacious in treating renovascular hypertension and may be effective in stabilizing or improving renal function, thereby reducing cardiovascular risk. However, high rates of procedural complications have been reported.

OBJECTIVES

To determine the nature and frequency of complications of percutaneous renal intervention using contemporary techniques and equipment in a high-volume cardiac catheterization laboratory.

METHODS

Consecutive patients undergoing attempted RA stenting for atherosclerotic RA stenosis in the cardiac catheterization laboratory at the Vancouver General Hospital (Vancouver, British Columbia) between June 2000 and March 2007 were enrolled in a prospective registry. Baseline clinical characteristics, procedural and technical information, and complications were recorded.

RESULTS

A total of 132 RAs were stented in 106 patients during 108 procedures. The procedural success rate was 100%, with no related death, myocardial infarction, nephrectomy or dialysis. Major complications included three pseudoaneurysms (2.8%) and acute deterioration in renal function in six patients (5.5%), although renal function returned to baseline in one patient at 12 months.

CONCLUSIONS

RA stenting can be successfully and safely performed using contemporary techniques, and the low complication rates described should be the minimum standard for contemporary trials evaluating RA stenting.

Progression of cardiac dysfunction in patients with atherosclerotic renovascular disease

BACKGROUND

Patients with atherosclerotic renovascular disease (ARVD) are at increased risk of heart disease because of the association with hypertension, coronary artery disease, cardiac failure and chronic kidney disease (CKD). A previous echocardiographic cross-sectional study showed that only 5% of patients with ARVD had normal cardiac structure and function at baseline. In this longitudinal study of the same patient cohort the progression of cardiac dysfunction and factors which predict declining cardiac function in patients with ARVD were delineated.

METHODS

Seventy-nine patients were available for baseline analysis, but 16 withdrew from follow-up during the study. Forty-three patients (27M and 16F, age at study entry [mean +/- SD] 69.7 +/- 8.0 years) who were managed conservatively and 8 (age 69.8 +/- 5.7) who were managed with renal revascularization underwent echocardiography and 24 h ambulatory blood pressure investigations at baseline and 12 months thereafter. The two data sets were interrogated to determine changes in blood pressure and cardiac status (morphological and functional); baseline factors which predicted such changes were ascertained. Twelve patients underwent baseline investigation but did not complete follow-up because of death (nine patients) or requirement of dialysis (three patients).

RESULTS

Conservatively managed patients: At 12 months eGFR, (38.6 +/- 18.3 vs 35.0 +/- 18.5 ml/min; P = 0.001) had fallen whilst proteinuria had increased (0.3 +/- 0.4 vs 0.6 +/- 0.8 g/24 h; P = 0.001). Despite no increase in the number of blood pressure medications there was a fall in blood pressure between baseline and follow-up investigations (140.0 +/- 16.5/75.3 +/- 11.8, MAP 98.6 +/- 12.3 mmHg vs 135.7 +/- 16.1/69.6 +/- 9.1, MAP 92.5 +/- 10.2 mmHg; P < 0.001 for diastolic blood pressure and MAP). At 12 months, there was an increase in the number of patients with LVH (72.9% vs 81.4%). There were increases in left ventricular dimensions [left ventricular end diastolic diameter (5.1 +/- 0.8 vs 5.5 +/- 0.8 cm; P = 0.009), and left ventricular end diastolic volume (140.9 +/- 39.5 vs 163.3 +/- 61.0 ml; P = 0.01)]. There was no significant relationship of these changes in cardiac parameters to anatomical severity of renal artery disease but patients with severe renal dysfunction at baseline had an increase in left ventricular dilatation at follow-up. Linear regression analysis revealed an association between elevated time-averaged PTH and LV dilatation [beta-coefficient and 95% confidence intervals, 0.18 (0.04, 0.32); P = 0.01]. Revascularization: No significant changes in any biochemical or echocardiographic parameters were seen between baseline and 1 year investigations in this small sub-group.

CONCLUSION

Patients with ARVD exhibit a high prevalence of LVH at diagnosis and progressive left ventricular dilatation over the first year after diagnosis. This dilatation is associated with severe renal impairment at baseline and not associated with anatomical severity of renal artery disease.

Percutaneous revascularization of persistent renal artery in-stent restenosis

Abstract

Percutaneous renal artery stenting is a common means of treating atherosclerotic renal artery stenosis. However, renal artery restenosis remains a frequent problem. The optimal treatment of restenosis has not been established and may involve percutaneous renal artery angioplasty or deployment of a second stent. Other modalities include cutting balloon angioplasty, repeat stenting with drug-eluting stents or endovascular brachytherapy. Most recently, use of polytetrafluoroethylene (PTFE)-covered stents may offer a new and innovative way to treat recurrent renal artery stenosis. We describe a case in a patient who initially presented with renal insufficiency and multi-drug hypertension in the setting of severe bilateral renal artery stenosis. Her renal artery stenosis was initially successfully treated by percutaneous deployment of bilateral bare metal renal artery stents. After initial improvement of her hypertension and renal insufficiency, both parameters declined and follow-up duplex evaluation confirmed renal artery in-stent restenosis. Owing to other medical co-morbidities she was felt to be a poor surgical candidate and was subsequently treated first with bilateral cutting balloon angioplasty and second with drug-eluting stent deployment. Each procedure was associated with initial improvement of renal function and blood pressure control, which then later deteriorated with the development of further significant in-stent restenosis. It was then decided to treat the restenosis using PTFE-covered stents. At 12 months of follow-up, the blood pressure had remained stable and renal function had normalized. The covered stents remained free of any significant neointimal tissue or obstruction.

Management of heart failure with renal artery ischemia

With improved treatment, patients are surviving longer with impaired ventricular function. Hypertension results in ventricular remodeling in many patients. More than 5 million people have heart failure and are likely to have one or more co-existent diseases associated with aging, one of which is chronic kidney disease (CKD). Renal artery stenosis is fraught with varying opinions. Nephrologists, cardiologists, and interventional radiologists all manage these diseases with different strategies. This article outlines renovascular disease as it relates to CKD, the pathophysiology of development of renovascular disease and effects leading to congestive heart failure, treatment modalities, and outcomes of treatment regimens.