Atherosclerotic Renovascular Disease Research Articles

Management of Renal Artery Stenosis: The Case for Intervention, Defending Current Guidelines, and Screening (Drive-By) Renal Angiography at the Time of Catheterization

There is little debate that an untreated significant obstruction of blood flow to the kidney, most often due to atherosclerosis, is potentially hazardous to the health of patients. The treatment of atherosclerotic renovascular disease has evolved over the past 20 years from open surgery with its inherent morbidity and risk of mortality to percutaneous endovascular treatment with stents. The current debate is on the question of which patients are offered any additional advantage by revascularization for renal artery stenosis over medications alone. The primary issue is patient selection, including the most appropriate screening strategies for renal artery stenosis, which must be balanced against the risk of procedure-related complications. The goal of this paper is to explore the most appropriate utilization of revascularization with renal stent placement.

Does stenting for atherosclerotic renovascular disease improve blood pressure and kidney function better than medical treatment?

Does stenting for atherosclerotic renovascular disease improve blood pressure and kidney function better than medical treatment?

Atherosclerotic renovascular disease among hypertensive adults

This report describes the change in atherosclerotic renovascular disease (AS-RVD) among hypertensive adults referred for renal duplex sonography (RDS) scan. From Oct 1993 through July 2008, 20,994 patients had RDS at our center. A total of 434 hypertensive patients with two or more RDS exams without intervention comprised the study cohort. Patient demographics (blood pressures, medications, serum creatinine levels, and data from RDS) were collected. Analyses of longitudinal changes in Doppler scan parameters, blood pressures, and renal function were performed by fitting linear growth-curve models. After confirming the linearity of change in Doppler scan parameters among patients with variable number of studies, estimates of mean slopes were calculated using maximum likelihood techniques. For changes in renal function, quadratic growth curves were required to describe longitudinal change. A total of 434 subjects (212 men [49%] and 222 women [51%]; mean age, 64.6 +/- 12.2 years) provided 1351 studies (mean, 3.2 +/- 2.4; range, 2 to 18) for 863 kidneys over a mean follow-up of 34.4 +/- 25.1 months. At baseline, 20.6% of kidneys demonstrated hemodynamically significant stenosis. On follow-up, 72 kidneys (9.1%) demonstrated anatomic progression of disease. A total of 54 kidneys (6.9%) progressed to significant stenosis and 18 (2.3%) progressed to occlusion. Controlling for progression of disease, baseline renal artery status demonstrated a strong association with baseline kidney length (P = .0006). Significant annualized change in renal length was observed (cm change/year +/- standard error of the mean [SEM]: 0.042 +/- 0.011; P = .0002) among both kidneys with and without critical disease at baseline, however, decline in length was significantly greater among kidneys exhibiting progression of renovascular disease (-0.152 +/- 0.028 cm/year; comparison of slopes between groups P = .0005). In the absence of progression, the presence or absence of critical renal artery stenosis at baseline did not affect the rate of decline in renal length. Fitted models for the natural log transform of serum creatinine demonstrated a significant increase during follow-up (P < .0001). No association was observed between change in serum creatinine and baseline renovascular disease status, or its progression. A total of 32% of hypertensive adults referred for RDS demonstrated hemodynamically significant renal artery stenosis. Regardless of the presence or absence of baseline disease, a small percentage of patients demonstrated anatomic progression of AS-RVD. A total of 9.1% demonstrated anatomic progression and 2.3% progressed to occlusion. Although anatomic progression of AS-RVD was associated with an increased rate of decline in renal length, progression did not predict a decline in excretory renal function. Intervention for AS-RVD should be selective and reserved for strict indications.

Progression of cardiac dysfunction in patients with atherosclerotic renovascular disease

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. 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). 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. 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.

Severe Paradoxical Hypertension With Angiotensin-Converting Enzyme Inhibitors: An Unusual Feature of Renal Artery Stenosis

To the Editor: Angiotensin-converting enzyme (ACE) inhibitors are frequently used in the treatment of hypertension, heart failure, and renal disease but may cause acute renal failure in patients with renal artery stenosis (RAS).1 We describe a novel adverse effect of ACE inhibitors in patients with advanced chronic kidney disease (CKD) and RAS. We observed 4 episodes of severe paradoxical hypertension in 3 patients with CKD (Table) and bilateral RAS, during initiation or titration of the ACE inhibitor ramipril (Tritace, Sanofi-Aventis). The etiology of CKD was atherosclerotic renovascular disease in each case. Bilateral, hemodynamically significant RAS had been demonstrated previously with both Doppler ultrasound and renal angiography in all 3 of the patients and magnetic resonance angiography in 2 patients. Blood pressure (BP) measurement using …

Corriere MA, Pearce JD, Edwards MS, et al. Endovascular management of atherosclerotic renovascular disease: early results following primary intervention. J Vasc Surg. 2008;48:580-7

Corriere MA, Pearce JD, Edwards MS, et al. Endovascular management of atherosclerotic renovascular disease: early results following primary intervention. J Vasc Surg. 2008;48:580-7

Proteinuria as a predictor of renal functional outcome after revascularization in atherosclerotic renovascular disease (ARVD)

Renal revascularization is performed in 16% of newly diagnosed patients with atherosclerotic renovascular disease (ARVD). Although there may be some improvement in hypertension control as a result of intervention, renal functional outcomes are known to vary. Pre-existing renal parenchymal injury, as manifested by proteinuria, is associated with poor functional outcome in conservatively managed ARVD patients, but this association has not been investigated in patients undergoing revascularization. Retrospective case note review of 83 ARVD patients who underwent renal revascularization in four centres within a renal network between 1998 and 2003 was undertaken. Amongst other parameters, baseline proteinuria was correlated with renal functional outcome post revascularization. Renal functional outcome was determined over a mean follow up of 22 months by rate of change of estimated glomerular filtration rate (eGFR) over time. Univariate analysis showed that proteinuria >0.6 g/day was the only significant predictor of poor outcome after revascularization. The relationship persisted with multivariate analysis, and linear regression showed a correlation between baseline proteinuria and decline in eGFR with time (r(2) = 0.058, P = 0.039). This study confirms that prior renal parenchymal injury, here reflected by proteinuria at baseline, is a major arbiter of renal functional outcome after renal revascularization in ARVD.

Clinical utility of the resistive index in atherosclerotic renovascular disease

This retrospective study examines the relationship between the renal resistive index (RI) and blood pressure and renal function response after open and percutaneous intervention for atherosclerotic renovascular disease (AS-RVD). From March 1997 to December 2005, 86 patients (46 women, 40 men; mean age, 68 +/- 10 years) underwent renal duplex sonography (RDS), including main renal artery and hilar vessel Doppler interrogation, before treatment of AS-RVD. Of these, 56 patients had open operative repair, and 30 had percutaneous intervention. The RI (1-[EDV/PSV]) was calculated from the kidney with the highest peak systolic velocity (PSV). Hypertension response was graded from preprocedural and postprocedural blood pressure measurements and medication requirements. Renal function response was graded by a >or=20% change in estimated glomerular filtration rate (eGFR) calculated from the serum creatinine concentration. Comorbid conditions, baseline blood pressure, and preoperative renal function were not significantly different between open and percutaneous groups. Baseline characteristics that differed between the percutaneous vs open group were higher mean age (71 +/- 11 years vs 67 +/- 9 years; P = .05), kidney length (11.3 +/- 1.3 cm vs 10.7 +/- 1.2 cm; P = .02), proportion of patients with RI >or=0.8 (50% vs 21%; P = .01), and proportion of bilateral AS-RVD (37% vs 80%; P < .01). After controlling for preintervention blood pressure and extent of repair, postoperative eGFR differed significantly for RI <0.8 or >or=0.8 when all patients (P = .003) and percutaneous intervention (P = .008) were considered. Specifically, eGFR declined from preprocedure to postprocedure in the patients with RI >or=0.8 after percutaneous repair and in the group analyzed as a whole. Neither systolic nor diastolic pressure after intervention demonstrated an association with RI. Considering all patients and both groups, multivariable proportional hazards regression models demonstrated that RI was predictive of all-cause mortality. RI was the most powerful predictor of death during follow-up (hazard ratio, 6.7; 95% confidence interval, 2.6-17.2; P < .001). After intervention for AS-RVD, RI was associated with renal function, but not blood pressure response. A strong, independent relationship between RI and mortality was observed for all patients and both treatment groups.

Career choices in 21st-century healthcare: Aiming for a moving target

Modernising Medical Careers (MMC) has introduced a training pathway in which surgical trainees are required to commit to their desired specialties at an increasingly early stage.1 For many this is a frightening prospect. Medical students and junior doctors are, however, offered reassurance in the form of common ST1 and ST2 stems for higher sub-specialty training. Against this background, early decisions need only concern fundamental choices between careers in medicine, surgery or general practice. Whilst it is true that some trainees may select their prospective careers by the nature of the job, with preferences towards medical or surgical lifestyles; many will be drawn towards their career by an affinity, not towards the job per se but rather towards the treatment of a particular disease process or group of patients. Previously medics have been able to make the informed decisions necessary before dedicating their lives to a given specialty. With recent advances in technology, many specialties have been the subject of ‘turf wars’; in particular, many surgical operations have been threatened by equally effective minimally invasive procedures. This competition has resulted in a haze of uncertainty over the direction of many specialties, jeopardising accurate choices by applicants. The innovations of Charles Dotter, widely considered the father of interventional radiology, set in motion an endovascular revolution that has transformed the treatment of peripheral vascular disease. Predictions that endovascular techniques will constitute 60–90% of vascular procedures in the future,2 have resulted in competition between vascular surgeons and interventional radiologists, which threatens to become a destructive force for vascular surgery and ultimately patients. Percutaneous revascularisation of the renal arteries, for example, has almost entirely replaced open surgical management of patients with atherosclerotic renovascular disease (ARVD).3 The management of ischaemic heart disease has faced similar uncertainty. Cardiothoracic surgeons were traditionally the guardians of the coronary arteries, bypassing diseased coronary arteries and inserting grafts. When patients were offered the alternative of angioplasty, a procedure thought to be equally effective but significantly less invasive, the cardiologists took ownership of these vessels. The debate regarding the best treatment of ischaemic heart disease is ongoing. Recent trial data suggesting higher re-stenosis

Pleiotropic Effects of Statins May Improve Outcomes in Atherosclerotic Renovascular Disease

Atherosclerotic renovascular disease (ARD) coexists with arterial obstructive disease in the coronary, cerebral, and peripheral arteries that may remain underdiagnosed and untreated. This retrospective study compares overall survival and renal survival (i.e., time to doubling of serum creatinine or end-stage renal disease (ESRD)) over an 11-year period in 104 ARD patients of whom 68 received statin therapy (group S) because of elevated lipid levels and 36 had no statin (group NS) because of normal lipid profile at entry. Atherosclerosis in another vascular bed was documented in 84%. Lipid profiles at end point were virtually identical in both the groups. Group S had mean survival 123months (confidence interval (CI) 113-134) with four deaths, and mean renal survival 122months (CI 113-131). Group NS had mean survival 33 months (CI 23-42) with 13 deaths, and mean renal survival 27 months (CI 17-37). Statin therapy was associated with lesser rate of progression of renal insufficiency (with 7.4% of S patients reaching renal end points vs. 38.9% of NS patients) and lower overall mortality (5.9 % in S vs. 36.1% in NS patients), P < 0.001 for both. Although both groups received what was deemed optimal therapy, they did have other differences that may have affected the outcomes (a limitation addressed by Cox multiple regression analysis). These results suggest the need for prospective randomized controlled studies in ARD patients in order to explore potential benefits of statins that may not be attributable solely to lipid lowering.

Endovascular management of atherosclerotic renovascular disease: Early results following primary intervention

This retrospective review examines periprocedural morbidity and early functional responses to primary renal artery angioplasty and stenting (RA-PTAS) for patients with atherosclerotic renovascular disease (RVD). Consecutive patients undergoing primary RA-PTAS for hemodynamically significant atherosclerotic RVD with hypertension and/or ischemic nephropathy were identified from a prospectively maintained registry. Hypertension responses were determined based on pre- and post-intervention blood pressure measurements and medication requirements. Estimated glomerular filtration rate (eGFR) was used to determine renal function responses. Both hypertension and renal function responses were assessed at least three weeks after RA-PTAS. Stepwise multivariable regression analysis was used to examine associations between blood pressure and renal function responses to RA-PTAS and select clinical variables. One-hundred ten primary RA-PTAS were performed on 99 patients with atherosclerotic RVD with a mean angiographic diameter-reducing stenosis of 79.2 +/- 12.9%. All patients had hypertension (mean of 3.4 +/- 1.3 antihypertensive agents). Mean pre-intervention eGFR was 49.9 +/- 22.7 mL/min/1.73 m(2), and 74 patients had a pre-intervention eGFR < 60 mL/min/1.73 m(2). The technical success rate for RA-PTAS was 94.5%. The periprocedural complication rate was 5.5%; there were no periprocedural deaths. Statistically significant decreases in mean systolic blood pressure (161.3 +/- 25.2 vs. 148.5 +/- 25.2 post-intervention, P < .0001), diastolic blood pressure (78.6 +/- 13.3 versus 72.5 +/- 13.5 post-intervention, P < .0001), and number of antihypertensive agents (3.3 +/- 1.2 versus 3.1+/- 1.3 post-intervention, P = .009) were observed. Assessed categorically, hypertension response to RA-PTAS was cured in 1.1%, improved in 20.5%, and unchanged in 78.4%. Categorical eGFR response to RA-PTAS was improved in 27.7%, unchanged in 65.1%, and worsened in 7.2%. Multivariable stepwise regression revealed associations between pre- and post-intervention systolic blood pressure (P < .0001), diastolic blood pressure (P < .0001), and eGFR (P < .0001), as well as a trend toward improved diastolic blood pressure response among patients managed with staged bilateral intervention (P = .0589). Primary RA-PTAS for atherosclerotic RVD was associated with low peri-procedural morbidity and mortality but only modest early improvements in blood pressure and renal function. Results from ongoing prospective trials are needed to assess the long term outcomes associated with RA-PTAS and clarify its role in the management of atherosclerotic RVD.

Simvastatin abates development of renal fibrosis in experimental renovascular disease

Epithelial-to-mesenchymal transition contributes to renal fibrogenesis, which is regulated by profibrogenic and antifibrogenic mediators. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors can prevent epithelial-to-mesenchymal transition in some models. Therefore, we tested the hypothesis that epithelial-to-mesenchymal transition participates in renal injury in porcine atherosclerotic renovascular disease and can be attenuated by simvastatin. Renal hemodynamics, function, and endothelial function were quantified in vivo in pigs after 12 weeks of combined hypercholesterolemia + renal artery stenosis without (n = 8) or with oral simvastatin supplementation (1.2 mg/kg, n = 6), and in controls (n = 8). Ex-vivo studies assessed renal immunoreactivity to fibrogenic factors and renal histology. Blood pressure, cholesterol levels, and basal renal function were similar in treated and untreated pigs with hypercholesterolemia + renal artery stenosis. Hypercholesterolemia + renal artery stenosis significantly upregulated renal transforming growth factor-beta signaling and elicited epithelial-to-mesenchymal transition, accompanied by glomerulosclerosis and renal fibrosis. Simvastatin did not affect smad 2/3 expression but upregulated expression of hepatocyte growth factor, bone morphogenetic factor-7, and smad 7 and prevented most of these renal structural and functional alterations. Furthermore, simvastatin improved renal blood flow response to endothelium-dependent challenge (+111.3 +/- 35.5 vs. -30.4 +/- 18.7 ml/min in untreated pigs, P < 0.05). Simvastatin upregulates inhibitors of transforming growth factor-beta signaling, attenuates epithelial-to-mesenchymal transition, and decreases renal fibrosis in hypercholesterolemia + renal artery stenosis. These lipid-lowering-independent effects result in improvement of renal function, suggesting clinically valuable potential for statins in preserving the stenotic kidney and limiting deterioration of renal function in atherosclerotic renovascular disease.

Simvastatin, an inhibitor of epithelial-to-mesenchymal transition in experimental atherosclerotic renovascular disease?

Simvastatin, an inhibitor of epithelial-to-mesenchymal transition in experimental atherosclerotic renovascular disease?

Treatment of Atherosclerotic Renovascular Disease

Treatment of atherosclerotic renovascular disease is controversial and revascularization is not a beneficial approach to all patients. Conditions as progressive deterioration of renal function, refractory hypertension or accelerated cardiovascular disease, especially recurrent pulmonary edema, could profit from renal angioplasty with stent placement. Surgical revascularization is a good option for patients who will need concomitant surgical corrections of abdominal aortic lesions. Treatment of all other patients must be individualized. Medical therapy is indicated for all patients with atherosclerotic renovascular disease. Observational studies pointed out to the beneficial effect of controlling blood pressure ( < 130/80 mm Hg), glucose and lipids profile, lifestyle modifications, specific use of platelet antiaggregant therapy, Angiotensin Conversion Enzyme Inhibitors (ACEI) and statins. All others cardiovascular risk factors must be controlled. The evaluation and management of other systemic atherosclerotic vascular lesions is important, especially coronary, carotid and abdominal aortic. This paper presents a review of evidences to rationale the atherosclerotic renovascular disease treatment.

Predictive Factors and Therapeutic Approach of Renovascular Disease: Four Years’ Follow-Up

Background. There is no consensus about the renal function outcome after revascularization with stenting in atherosclerotic renovascular disease. In the present study, the outcome in BP control and renal function in patients with renovascular disease treated with percutaneous angioplasty and stent placement is compared with the outcome in patients with renovascular disease treated with medical treatment only. Additionally, the impact of oxidative stress and eosinophil count in peripheral blood as predictors of renal function deterioration in renovascular disease irrespective of treatment is investigated. Methods. Eighty-two patients with renovascular disease were enrolled into a follow-up study (47.5±35.4 months). Thirty-six patients (group 1) underwent revascularization and stenting, and 46 patients (group 2) were on medical treatment only. In all patients, serum creatinine concentration, eosinophil count (EO) in peripheral blood, and estimation of oxidative stress with dROMs test were determined before and at the end of the follow-up. Results. In revascularized patients (group 1), hypertension was cured in 11.1% and improved in 66.6%. Renal function improved in 30.5% and worsened in 36.2% of patients. In the medical treatment arm (group 2), hypertension improved in 71.4% of the patients. Renal function remained stable in 69.8% of patients and worsened in 30.2%. Cox regression analysis showed that higher levels of eosinophil count and higher levels of ROS, irrespectively of mode of treatment, were associated with renal function deterioration (i.e., serum creatinine increase more than 20% during follow-up). Conclusions. Revascularization was not superior to medical treatment in renal survival but had a greater positive impact on blood pressure control. Eosinophil count and oxidative stress were the stronger predictive factors for serum creatinine increase.

Progression of atherosclerotic renovascular disease: a prospective population-based study

Progression of atherosclerotic renovascular disease: a prospective population-based study

Anuric acute renal failure and pulmonary oedema: A case for urgent action

Atherosclerotic renovascular disease (ARVD) is a common manifestation of atheromatous disease. Whilst it usually displays a chronic and asymptomatic course, it is increasingly recognised as playing a significant pathophysiological role in a number of clinical presentations. Anuric acute renal failure (ARF), due to thrombotic renal artery occlusion (RAO) or progression to critical narrowing, however, is a rare complication of this. We report a patient who presented with anuric ARF and pulmonary oedema secondary to bilateral renal artery disease (one chronic RAO, one highly critical renal artery stenosis (RAS)). She showed a good response to renal revascularisation with restoration of renal function, even when this was performed after six days of anuria.

Recovery of renal function after 90 d on dialysis: implications for transplantation in patients with potentially reversible causes of renal failure

Late recovery of renal function in patients requiring dialysis is a well recognized but uncommon phenomenon. Moves to increase the number of live donor transplants and the recognition that early transplantation is associated with better graft survival means it is possible that patients who are going to recover renal function may be transplanted unnecessarily. Prospective survey of patients receiving dialysis for more than 90 d in south west Scotland from 1 January 1994 to 31 December 2005. Routine measurement of residual renal function by combined urea and creatinine clearance allowed us to detect late recovery whenever this occurred. Eight of 202 (4%) patients recovered sufficient renal function to stop dialysing after 90-d treatment. The likely cause of the renal failure in five of these patients was atheroembolism. One with atherosclerotic renovascular disease had been stented and would have received a live related renal transplant had his sister not had second thoughts about the procedure. It may be sensible to postpone transplantation in patients with certain types of renal failure, perhaps particularly patients with renovascular disease who have recently undergone a failed revascularization procedure.

The Effects of Statins on the Progression of Atherosclerotic Renovascular Disease

Background/Aims: The aim was to examine the influence of statin therapy on the natural history of atherosclerotic renal artery stenosis (RAS). Methods: Our hospital atherosclerotic renovascular disease (ARVD) database was analysed for patients who underwent repeat renal angiography during clinical follow-up. Patients with ≧1 RAS lesion and ≧4 months between baseline and repeat renal angiography were analysed. 79 patients were included. Baseline renal arterial anatomy was classified as normal, ≤50% RAS, >50% RAS or renal artery occlusion. Results: Mean follow-up time between angiograms was 27.8 ± 22.3 (4.0–101.9) months. Progression of RAS occurred in 28 (23%) vessels, regression in 14 (12%) and no significant change in 79 (65%). Multivariate regression analysis showed that baseline proteinuria >0.6 g/day increased the risk of progressive disease (relative risk, RR, 3.8; 95% confidence interval, CI, 1.2–12.1), treatment with statin reduced the risk of progression (RR 0.28; 95% CI 0.10–0.77). 14 renal arteries from 12 patients showed RAS regression with a greater proportion on statin [statin treatment 10 (83%) versus no statin treatment 2 (17%), p = 0.001]. Change in estimated glomerular filtration rate (eGFR) per year was not different between statin- and no-statin-treated groups. Conclusions: Progression or development of RAS was significantly less likely to occur with statin therapy. ΔeGFR did not correlate with progression of RAS, reflecting the importance of intrarenal injury in the aetiology of renal dysfunction. Our results suggest statin therapy can alter the natural history of ARVD.

End-Stage Renal Disease in the United States

Patients with ESRD consume a vastly disproportionate amount of financial and human resources. Approximately 0.03% of the US population began renal replacement therapy in 2004, an adjusted incidence rate of 339 per million. Declining incidence rates were observed for most primary causes of ESRD and in most major demographic categories; the worry is that rates of diabetic ESRD continue to rise in younger black adults. Although diabetes and hypertension remain the most commonly reported cause of ESRD, rates of end-stage atherosclerotic renovascular disease seem to be on the rise in older patients. Although clinical care indicators, such as the proportion of hemodialysis patients using fistulas, continue to improve gradually, the proportion of patients overshooting target hemoglobin levels under epoetin therapy may be a source of concern. Survival probabilities have improved steadily in the US ESRD population since the late 1980s, which is remarkable when one considers the ever-expanding burden of comorbidity in incident patients. However, although first-year dialysis mortality rates have clearly improved since 1987, meaningful improvements do not seem to have accrued since 1993, in contrast to steady annual improvements in years 2 through 5. Although most of these findings are grounds for cautious optimism, the same cannot be said for issues of cost; reflecting the growth in the size of the ESRD population, associated costs grew by 57% between 1999 and 2004 and now account for 6.7% of total Medicare expenditures.