Renal artery stenosis in minority patients undergoing diagnostic cardiac catheterization: prevalence and risk factors

Is Incidental Renal Arteriography Justified in a Population of Patients with Symptomatic Peripheral Arterial Disease?

Renal artery stenosis is a consequence of generalized atherosclerosis and many specialists perform routine selective renal angiography to detect and treat renal artery stenosis. The incidence of clinically important renal artery stenosis is not well defined in patients with symptomatic peripheral arterial disease. The purpose of this study was to better delineate the incidence of and the risk factors associated with renal artery stenosis, renovascular hypertension, and ischemic nephropathy incidentally discovered during angiography for symptomatic peripheral arterial disease. Two hundred consecutive patients undergoing angiographic evaluation of symptomatic lower extremity peripheral arterial disease were studied retrospectively. Angiograms were reviewed for the presence of renal artery stenosis (defined as ≥ 25% diameter reduction in either renal artery) and findings were then correlated to the clinical diagnosis of renovascular hypertension (> 50% renal artery stenosis and ≥ 3-drug resistive hypertension) and ischemic nephropathy (defined as > 50% bilateral renal artery stenosis, 3-drug hypertension, and creatinine ≥ 1.5). Angiographic findings were also correlated with risk factors to determine if a relationship correlated to the presence of and degree of renal artery stenosis. Data were analyzed using the Student's t test, Chi-square model, and multiple logistic regression analysis. The overall incidence of any degree of renal artery stenosis in this study population was 26% (52 patients). Only 24 (12%) patients had an incidental finding of ≥ 50% stenosis in either renal artery. Six (3%) of these patients were found to have associated renovascular hypertension. Additionally, 9 (4.5%) patients had coexistent renal insufficiency and significant renal artery stenosis; five with end-stage renal disease on chronic hemodialysis. Only one patient with end-stage renal disease had poorly controlled 3-drug hypertension. Thus definitive ischemic nephropathy was present in only one (0.5%) patient. Statistically significant risk factors associated with the presence of renal artery stenosis include hypertension ( P < .001), coronary disease ( P = .024), female gender ( P = .010), diabetes ( P = .039), aorto-iliac disease ( P = .031), multiple levels of peripheral arterial disease ( P < .001), and age over 60 ( P < .001). While the incidence of renal artery stenosis in patients being evaluated for symptomatic peripheral arterial disease is similar to that reported in the cardiology literature, the incidence of renovascular hypertension and ischemic nephropathy is exceedingly low (3% and 0.5%, respectively)—findings similar to data reported in the general hypertensive population. These data suggest that incidental selective renal angiography is not justified in patients with symptomatic peripheral arterial disease.

Renal artery stenosis and its predictors in hypertensive patients undergoing coronary artery angiography

Background

Renal artery stenosis (RAS) has been increasingly recognized in the recent years, especially in patients with coronary artery disease (CAD). RAS affects the patients with hypertension (HTN), but the exact prevalence is not known.

Objectives

This study was performed to determine the prevalence and to identify the predictors of RAS in hypertensive patients undergoing coronary artery angiography.

Patients and Methods

In a cross-sectional study from August 2008 to August 2009, 481 patients with HTN and suspected CAD underwent selective coronary and renal angiography for screening and predicting RAS. RAS was defined as a higher than 50% stenosis in the renal artery lumen. Multivariate analysis of factors associated with the presence of RAS were examined using a logistic regression model.

Results

The mean ± standard deviation of age was 59.25 ± 10.81 years and 50.3% were men. According to angiographic data, 425 patients (88.4%) had CAD, while 56 (11.6%) had normal coronary arteries. RAS was seen in 94 (22%) patients with CAD. The multivariate logistic regression analysis identified only age (P < 0.001) and the number of significant coronary lesions (P < 0.001) as independent predictors of RAS. Gender, smoking, congestive heart failure, diabetes mellitus (DM), hyperlipidemia (HLP) and body mass index (BMI) were not independent predictors.

Conclusions

This study suggests that in the management of patients with RAS, risk factors should most likely be considered as beneficial. In addition, the clinical and angiographic features are helpful in predicting its presence in elderly patients with CAD.

Is race a risk factor for the development of renal artery stenosis?

Atherosclerotic renal artery disease is a common cause of hypertension and chronic kidney disease that may progress into end stage renal failure if not diagnosed and treated early. Renal artery stenosis (RAS) has been shown to be an independent risk factor for mortality in patients with coronary artery disease. We sought to determine whether race is an independent risk factor for developing RAS. A retrospective study was conducted including 324 patients with resistant hypertension who underwent renal angiography with or without coronary angiography. In univariate analysis, Caucasian race was associated with significant risk of RAS (OR = 2.3, P = .01). However, this association was no longer significant after correcting for additional clinical variables in a multivariate model (OR = 1.5, P = .07). There was a strong association between smoking and RAS (OR 2.0, P = .02). We conclude that traditional risk factors, especially smoking, rather than race, are the most important predictors of RAS development.

Renal artery stenosis and chronic ischemic nephropathy: epidemiology and diagnosis

Atherosclerotic renal artery stenosis (RAS) is the most common primary disease of the renal arteries and results in renovascular hypertension and ischemic nephropathy. Ischemic nephropathy from atherosclerotic RAS is increasingly recognized as a cause of chronic kidney disease (CKD) and in severe cases can lead to end-stage renal disease. The exact prevalence of atherosclerotic RAS is unknown because the disease is often asymptomatic and few are screened unless they have significant traditional cardiac risk factors or symptoms. A high prevalence of atherosclerotic RAS is seen in patients with advanced age, congestive heart failure, and extrarenal atherosclerosis. The primary reason for diagnosing ischemic nephropathy from renovascular disease is that the loss of kidney function is potentially reversible through treatment of the occlusion with surgical revascularization or percutaneous transluminal renal angioplasty. However, the benefits of revascularization have to be considered in the context of other comorbid disease and remain controversial. There are several tests available for the screening and diagnosis of atherosclerotic RAS; however, the diagnostic test of choice should be based on patient factors and institutional expertise because the best test is the one performed most often at the individual medical facility.

Renal artery calcium is independently associated with hypertension

OBJECTIVES

We tested the hypothesis that renal artery calcium (RAC), a marker of atherosclerotic plaque burden, is also significantly associated with higher blood pressure levels and a diagnosis of hypertension.

BACKGROUND

In the nonrenal systemic vasculature, atherosclerotic plaque burden has been shown to be significantly associated with hypertension.

METHODS

A total of 1,435 consecutive patients were evaluated at a university-affiliated disease prevention center for the extent of calcified atherosclerosis in the systemic vasculature.

RESULTS

The overall prevalence of calcium in either renal artery was 17.1%, with men having a significantly higher prevalence (19.0%, 153 of 804) than women (14.7%, 93 of 631) (p = 0.03). After adjustment for age and gender, subjects with a RAC score >0 had a significantly higher prevalence of hypertension (41.2 vs. 29.5, p < 0.01). In a logistic model that adjusted for age, gender, body mass index, percent body fat, diabetes, smoking, dyslipidemia, and the extent of calcified atherosclerosis in the nonrenal vasculature, those with any RAC had a significantly higher odds ratio (1.61, p = 0.01) for hypertension than those with no RAC.

CONCLUSIONS

The results of this study suggest that the presence of RAC is associated with higher odds for prevalent hypertension, independent of CVD risk factors and the extent of calcified atherosclerosis in the nonrenal vasculature.

[Prevalence of renal artery stenosis in patients with critical limb ischemia]

BACKGROUND AND OBJECTIVE

Our purpose was to evaluate the prevalence of renal artery stenosis in patients with critical limb ischemia and to study any clinical or laboratory indicator that could predict this association.

PATIENTS AND METHOD

One hundred consecutive patients with critical limb ischemia evaluated by angiogram were included in the study from January to July 2003. Cardiovascular risk factors and renal function were analyzed.

RESULTS

One hundred angiographic studies have been analyzed. Thirty nine (39%) of our patients had some type of pathology of the renal artery but the rest, 61 (61%), had normal and healthy renal arteries. In 5 patients, a bilateral renal pathology was found. Severe disease (> 60% stenosis, bilateral or renal occlusion) was present in 15 cases including 6 occlusions. Once we compared the patients with healthy renal arteries with the patients with different degrees of stenosis, we did not appreciate significant differences in hypertension, diabetes, coronary disease or smoking habit, nor with laboratory data such as creatinine, urea, c-reactive protein, total cholesterol or atherogenic index. No differences were found either comparing patients with normal renal artery with patients with bilateral pathology or with unilateral occlusion.

CONCLUSIONS

There is a high prevalence of renal artery pathology in patients with critical limb ischemia although we have not found any clinical or laboratory factors useful to identify them.

Efficacy and safety of gadodiamide (Gd-DTPA-BMA) in renal 3D-magnetic resonance angiography (MRA): a phase II study

PURPOSE

To determine the most efficacious dose of gadodiamide for three-dimensional (3D) contrast-enhanced (CE) magnetic resonance angiography (MRA) of the renal arteries on a patient level based on the sensitivity in detecting the main hemodynamically relevant (> or =50% or occlusion) renal artery stenosis (RAS) using intra-arterial digital subtraction angiography (IA DSA) as the gold standard.

MATERIALS AND METHODS

This prospective, randomized, double-blind, parallel-group, multicenter study included 273 patients referred to IA DSA for suspected RAS. Patients underwent 3D CE MRA after injection of 0.01, 0.05, 0.1, or 0.2mmol/kg of body weight gadodiamide (0.5mmol/ml). The images were assessed for location and degree of RAS by independent blinded readers (MRA: three readers, IA DSA: one reader). Hypothesis testing for a significant trend in sensitivity across dose groups was based on the one-sided Cochran-Armitage style trend test for each independent MRA reader.

RESULTS

The lowest dose group (0.01mmol/kg) proved non-efficacious in detecting hemodynamically relevant (i.e., > or =50% or occlusion) RAS. A statistically significant dose trend (p<0.001) was shown for each of the three independent readers. Depending on reader, the sensitivity obtained with 0.05, 0.1, and 0.2mmol/kg was 63.9-86.1%, 75.8-91.4% and 80.6-90.6%, the specificity was 66.7-73.9%, 59.3-75.0%, and 59.3-75.0% and accuracy was 67.8-78.9%, 75.4-77.4%, and 76.3-81.0%, for the three dose groups, respectively. There were eight non-severe adverse events (AEs). Three serious AEs occurring in one patient were judged not related to gadodiamide by the on-site investigator.

CONCLUSION

A significant dose trend between the four doses examined was observed. The lowest dose (0.01mmol/kg) differed significantly from those of the other three doses. Based on the analysis of the primary and secondary endpoints, 0.1mmol/kg gadodiamide appears to be the most suitable dose in diagnosing hemodynamically relevant RAS. The present study also demonstrated gadodiamide to be safe and well tolerated.

Cardiovascular risk factors in hypertensive patients with coronary artery disease and coexisting renal artery stenosis

OBJECTIVE

The aim of our study was to examine the association between the presence of atherosclerotic renal artery stenosis (RAS) and coexisting cardiovascular risk factors in hypertensive patients with coronary artery disease (CAD).

METHODS

A total of 333 consecutive hypertensive patients (239 men, 94 women) with CAD underwent clinically indicated non-emergency coronary angiography, followed by renal angiography. Before catheterization clinical examination was performed to determine demographics, cardiac history, known duration of hypertension, cardiovascular risk factors, features of extracoronary vascular disease and related comorbidities. Blood samples for all biochemical evaluations--including highly sensitive C-reactive protein (hsCRP), fibrinogen and homocysteine--were taken. Ambulatory blood pressure monitoring (ABPM), echocardiography and carotid and femoral ultrasound followed by a duplex colour Doppler examination were performed.

RESULTS

Significant RAS (> 50% lumen narrowing) was identified in 40 patients (12%) and non-significant RAS (< 50%) was found in 45 (13.5%) subjects. Patients with significant RAS were older (59.8 versus 56.6 years, P < 0.05) and were characterized by higher systolic ambulatory blood pressure level. Patients with RAS had significantly higher levels of creatinine, hsCRP, fibrinogen and homocysteine and lower creatinine clearance than patients without RAS. Multivessel coronary artery disease (MVD) was more frequent in patients with significant RAS. Patients with significant RAS had significantly higher left ventricular mass index (LVMI) and lower ejection fraction (EF) as compared with those without RAS. Patients with RAS were more often characterized by the presence of carotid and femoral artery atherosclerosis and significantly more pronounced increase in carotid intima-media thickness (IMT) as compared with non-RAS subjects. In a multivariate stepwise logistic regression model carotid IMT [odds ratio (OR) 1.15; 95% confidence interval (CI) 1.03-1.29, P < 0.05], number of coronary arteries stenosed (OR 1.61; 95% CI 1.01-2.56, P < 0.05), creatinine concentration (for 10 micromol/l increase, OR 1.15; 95% CI 1.04-1.28, P < 0.01), body mass index (BMI) (OR 0.86; 95% CI 0.75-0.97, P < 0.05) and number of antihypertensive drugs (OR 1.76; 95% CI 1.18-2.62, P < 0.05) were independently associated with RAS. The areas under receiver operating characteristic curves for carotid IMT, number of coronary arteries stenosed, creatinine concentration, BMI and number of antihypertensive drugs were 0.749, 0.633, 0.703, 0.350 and 0.677, respectively (P < 0.01 for all values).

CONCLUSIONS

In conclusion, renal artery stenosis is prevalent in a significant proportion of patients undergoing cardiac catheterization. Renal angiography should be considered particularly in hypertensive patients with multivessel coronary disease coexisting with cardiovascular risk factors, even moderately impaired renal function and increased carotid IMT or vascular disease elsewhere.

Renovascular disease imaging: Today more than ever the invasive cardiologist may make the difference

Doppler ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) are gaining wide acceptance as gold standard for diagnosing peripheral artery disease at thoracic and abdominal aorta level and infrainguinal arteries. A different case is that of renal artery stenosis (RAS): noninvasive techniques, CT and MRI in particular, failed to become the new gold standard. Image interpretation and artifacts seems to invalidate MRI and CT sensitivity and specificity that remain quite low. The debacle of noninvasive imaging of renal arteries may have important reflexes on the invasive cardiology practice. In the light of the results of noninvasive tests for renal artery stenosis, the angiography of renal vessels performed at the time of coronary artery angiography may became a new tool for invasive professional to optimize the diagnosis of renal artery stenosis at least in patients scheduled for coronary angiography. The invasive cardiologist, today more than ever, has the chance to really impact the diagnosis and therapy of patients with renovascular disease and the prognosis of patients with both coronary artery and renal artery disease.

Malpractice in Invasive Cardiology: Is Angiography of Abdominal Aorta or Subclavian Artery Appropriate in Patients Undergoing Coronary Angiography?

BACKGROUND

Identification of peripheral vascular disease by angiography in patients undergoing coronary angiography may be considered as malpractice but sometimes seems to be justified under clear entry criteria. The present mata-analysis is aimed to analyze the appropriateness and results of screening angiography of subclavian or abdominal aorta performed at the time of coronary angiography.

METHODS

A search of published literature for peripheral angiography in patients undergoing coronary angiography over the last 10 years was performed using the MEDLINE database. No language restriction was employed. Only studies enrolling more than 100 patients for abdominal aortography and 50 patients for subclavian/internal mammary artery angiography were considered. Reference lists from identified studies were also reviewed to identify other potentially relevant references.

RESULTS

Twenty-nine studies were retrieved: 8 articles about subclavian artery (SA) and internal mammary (IMA) angiography and 21 about renal (RA) and aortoiliac (AOI) angiography. The total number of patients enrolled was 27,936. Nine studies out of 29 were prospective. Defined entry criteria were reported in 24 out of 29 studies. Significant SA and IMA stenosis were reported in 5.5 and 9% of patients, respectively. RA stenosis >50% was present in 12.7% of patients with CAD. Finally, undetected AOI disease was reported in 35.5% of patients undergoing coronary angiography. Mean complication rate was 0.8 +/- 0.6%. Predictors of SA and IMA stenosis were unclear. Age, multi-risk profile, multi-vessel CAD, history of PVD or carotid disease, severe hypertension, unexplained renal dysfunction or decreased creatinine clearance have been reported most frequently as predictors of RA and AOI disease in patients undergoing coronary angiography.

CONCLUSIONS

Consistent evidence of appropriateness of renal angiography in selected patients undergoing coronary angiography have been produced in literature. IMA and AOI angiography seem to be not justified unless they are part of SA in patients scheduled for arterial conduit with brachial differential pressure, thoracic irradiation or surgery, or of abdominal angiography to detect RA stenosis in laboratories with radiological digital peripheral equipment.

Influence of smoking on predictors of vascular disease

Beyond the already well-established strong causative relationship with cancer, smoking increases the risk for vascular disease. Smoking may act directly or adversely influence risk factors contributing to the development of vascular disease. Smoking causes endothelial dysfunction, dyslipidemia (decreased high-density lipoprotein cholesterol levels, hypertriglyceridemia and increased oxidation of low-density lipoprotein cholesterol) and platelet activation leading to a prothrombotic state. Smoking increases emerging risk factors (eg, fibrinogen, homocysteine, and high-sensitivity C-reactive protein) and increases insulin resistance and the risk of developing type 2 diabetes mellitus. The beneficial effects of statins and antioxidants (eg, vitamins C and E, beta-carotene) are counteracted by smoking. Smoking-induced alterations in growth factors, adhesion molecules, and even in genes can accelerate the progression of atherosclerosis. The aim of this review is to consider the adverse consequences of smoking on the factors predisposing to vascular disease and to emphasize the beneficial effects of smoking cessation.

Current issues in the diagnosis and management of patients with renal artery stenosis: a cardiologic perspective

Renal artery stenosis most often is caused by atherosclerosis. Although patients with renal artery stenosis can be managed conservatively, renal revascularization may be indicated, particularly in patients with refractory hypertension on a multidrug regimen and patients with declining renal function. Duplex ultrasonography of the renal arteries and magnetic resonance angiography are currently the most efficient noninvasive methods for the evaluation of renal artery stenosis. Selective digital subtraction renal arteriography remains the gold standard for the definitive diagnosis. In selected patients undergoing coronary studies and angiography immediately after the coronary procedure can be efficient. Atherosclerotic renal artery lesions, which commonly affect the renal artery ostium, can be treated safely and effectively with balloon-expandable stents. Successful angioplasty commonly results in improved control of hypertension, but an overall benefit on renal function and/or patient survival has not been shown. Generally the risk/benefit ratio of renal artery stenting seems favorable, but further randomized studies are needed for evidence-based decision making. All patients with atherosclerotic renal artery stenosis should receive rigorous secondary prevention measures including platelet inhibitors, statins, and beta-blockers.

Prevalence of renal artery stenosis in high-risk veterans referred to cardiac catheterization

OBJECTIVE

The prevalence of atherosclerotic renal artery stenosis (RAS) varies depending on patient selection with no specific guidelines on indications for selective renal angiography in patients referred for coronary angiography. The goal of this study is to determine the prevalence and predictors of renal artery stenosis in hypertensive veterans referred for coronary angiography.

DESIGN

Prospective study.

SETTING

Tertiary care veterans' administration facility in the USA.

PATIENTS, PARTICIPANTS

A total of 90 veterans referred for coronary angiography with an initial ascending aortic pressure > 135 mmHg.

INTERVENTIONS

Selective renal angiography was performed following coronary angiography.

RESULTS

We found that 28% of the patients had single RAS (> or = 50% stenosis), while 16% had single RAS > or = 70% stenosis, 10% had bilateral RAS >or = 50% and 6% had bilateral RAS > or = 70%. Significant positive univariate predictors of RAS (> or = 50%) were age, peripheral vascular disease (PVD), creatinine level (Cr) and myocardial infarction. Significant multivariate predictors of RAS (> or = 50%) were age > 65 years [relative risk (RR), 3.6; 95% confidence interval (CI), (1.2-10.6)], PVD [RR 3.2, 95% CI (1.1-9.1)] and Cr > 1 mg/dl [RR 4.9, 95% CI (1.53-15.9)]. No complications related to renal angiography were noted.

CONCLUSIONS

Selective renal angiography during routine coronary angiography in hypertensive veterans with coronary artery disease is safe and uncovers RAS in many older patients with PVD and renal insufficiency.

Prevalence of renal artery stenosis requiring revascularization in patients initially referred for coronary angiography

To evaluate the prevalence of clinically significant renal artery stenosis (RAS) in patients referred for coronary angiography, we analyzed data on 2,439 consecutive patients. Patients underwent selective renal angiography in conjunction with coronary angiography if refractory hypertension (blood pressure > 140/90 on two drugs) or flash pulmonary edema was present. A total of 1,089 renal arteries of 534 patients were evaluated. Twelve percent (137/1,089) of the renal arteries in 19% (101/534) of patients had > 70% diameter stenosis in at least one vessel. Bilateral renal artery stenosis was present in 26% (26/101) of patients. One hundred and thirty-two of the 137 vessels underwent stent revascularization due to clinical renovascular hypertension. Acute clinical success (< 20% diameter stenosis without death or urgent surgery) was 98% (99/101). Due to high prevalence and effective available treatment, we recommend routine screening for RAS in all patients with refractory hypertension referred for coronary angiography.

The impact of atherosclerotic renovascular disease on diabetic renal failure

Atherosclerotic renovascular disease (ARVD) is common in the general population, and its prevalence increases with age. Parallel studies show it is also common in patients with diabetes. The widespread use of angiotensin converting enzyme inhibitors and angiotensin receptor antagonists for heart and kidney disease might therefore expose arteriopathic diabetic patients to potential harm if they had critical renal artery stenosis. This review looks at the natural history of ARVD in the diabetic and non-diabetic populations: while it is common, it only rarely leads to renal failure. Hence intervention to revascularize ischaemic kidney son the basis of radiological appearances alone may subject some patients to unnecessary therapy. Although untested by randomized trial, a policy of watchful waiting may be the simplest strategy for most diabetic patients with suspected ARVD, reserving angiography and angioplasty (usually backed up by a stent) for those with an abrupt decline in renal function and no other cause for renal deterioration. Future clinical trials may better define subgroups of patients who will truly benefit from renal revascularization.

Prevalence and predictors of renal artery stenosis in patients undergoing cardiac catheterization

Renal artery stenosis (RAS) is recognized as a major co-morbid condition for patients with cardiovascular disease. Although the prevalence of RAS in Western countries has been reported as 13.5-18% in patients with suspected coronary artery disease (CAD) undergoing coronary angiography, there is little information available about the prevalence of RAS in Asian populations, which are less susceptible to atherosclerosis. To evaluate the prevalence of RAS in Japanese patients suspected of cardiovascular disease and the relationships among RAS and vascular risk factors, especially hypertension, renal artery angiography was performed in a total of 289 consecutive patients receiving diagnostic cardiac catheterization. RAS with a stenosis diameter greater than 50% was considered significant. The prevalence of RAS was 21/289 (7%) including 18 (6%) cases of unilateral stenosis and 3 (1%) of bilateral stenosis. RAS accompanied 14/220 (6%) cases of CAD, 4/34 (12%) cases of valvular heart disease and 1/14 (7%) cases of cardiomyopathy. In the subgroups of CAD, the prevalence of RAS was 5%, 10%, 9%, and 19% in cases of 0, 1, 2 and 3-vessel disease, respectively. Hypertension was more frequent among patients with than among those without RAS (86% vs. 45%, p=0.0003). The prevalence of RAS was 13% in hypertensives and 2% in normotensives (p = 0.004). Thus RAS was frequent in patients with established CAD, and particularly in those with 3-vessel disease. Together, the results showed that hypertension was closely associated with RAS, appearing as both a risk factor and a possible clinical manifestation of the disease. We conclude that more attention should be paid to RAS in Japanese patients with hypertension and cardiovascular disease.