Resveratrol Supplants Captopril's Protective Effect on Cardiac Remodeling in a Hypertension Model Elicited by Renal Artery Stenosis.

Background: Renovascular hypertension elicits cardiac damage and remodeling. Two-kidney, one-clip (2K1C) is an experimental model used to study hypertension pathophysiology. In this model, the renin-angiotensin-system (RAS) is overactive due to renal artery stenosis, leading to cardiac remodeling. Redox mechanisms underlying RAS activation mediate hypertension-induced cardiovascular damage. Preclinical studies and clinical trials demonstrated resveratrol's protective effects in cardiovascular diseases, mainly attributed to its antioxidant properties. We hypothesized resveratrol alone or in combination with an angiotensin-converting enzyme (ACE) inhibitor would be beneficial against cardiac damage caused by renovascular hypertension. Objective: We investigated the benefits of resveratrol against cardiac remodeling in 2K1C rats compared with captopril. Methods: Male Wistar rats underwent unilateral renal stenosis - 2K1C Goldblatt model of hypertension. Systolic Blood Pressure (SBP) was measured before and 6 weeks after surgery. Hypertensive 2K1C rats presented SBP≥160 mmHg. From the 6th week after the surgery, the animals received oral resveratrol (20 mg/kg), captopril (12 mg/kg), or their combination for 3 times per week for 3 weeks. Whole heart hypertrophy was evaluated. Histological assays assessed left ventricle hypertrophy and fibrosis. Results: Renovascular hypertension caused cardiac hypertrophy, accompanied by increased myocyte diameter and collagen deposition. Resveratrol reduced 2K1C rats' SBP and whole heart hypertrophy, independently of captopril. Resveratrol caused a higher reduction in ventricular hypertrophy than captopril. Collagen deposition was greater reduced by 2K1C treated only with resveratrol than with captopril alone or combined with resveratrol. Conclusion: Independent of captopril, resveratrol prompts cardioprotective effects on cardiomyocyte remodeling and fibrosis resulting from renovascular hypertension in 2K1C rats.

Recovery of Renal Function following Kidney-Specific VEGF Therapy in Experimental Renovascular Disease.

BACKGROUND: Chronic renovascular disease (RVD) can lead to a progressive loss of renal function, and current treatments are inefficient. We designed a fusion of vascular endothelial growth factor (VEGF) conjugated to an elastin-like polypeptide (ELP) carrier protein with an N-terminal kidney-targeting peptide (KTP). We tested the hypothesis that KTP-ELP-VEGF therapy will effectively recover renal function with an improved targeting profile. Further, we aimed to elucidate potential mechanisms driving renal recovery. METHODS: Unilateral RVD was induced in 14 pigs. Six weeks later, renal blood flow (RBF) and glomerular filtration rate (GFR) were quantified by multidetector CT imaging. Pigs then received a single intrarenal injection of KTP-ELP-VEGF or vehicle. CT quantification of renal hemodynamics was repeated 4 weeks later, and then pigs were euthanized. Ex vivo renal microvascular (MV) density and media-to-lumen ratio, macrophage infiltration, and fibrosis were quantified. In parallel, THP-1 human monocytes were differentiated into naïve macrophages (M0) or inflammatory macrophages (M1) and incubated with VEGF, KTP-ELP, KTP-ELP-VEGF, or control media. The mRNA expression of macrophage polarization and angiogenic markers was quantified (qPCR). RESULTS: Intrarenal KTP-ELP-VEGF improved RBF, GFR, and MV density and attenuated MV media-to-lumen ratio and renal fibrosis compared to placebo, accompanied by augmented renal M2 macrophages. In vitro, exposure to VEGF/KTP-ELP-VEGF shifted M0 macrophages to a proangiogenic M2 phenotype while M1s were nonresponsive to VEGF treatment. CONCLUSIONS: Our results support the efficacy of a new renal-specific biologic construct in recovering renal function and suggest that VEGF may directly influence macrophage phenotype as a possible mechanism to improve MV integrity and function in the stenotic kidney.

Renal arteriography with endovascular ultrasound for the management of renal infarction patients.

BACKGROUND: Renal infarction (RI) is a rare disease with poor prognosis. Appropriate secondary prevention treatment is essential and requires an exhaustive etiological assessment. We aimed to determine whether invasive endovascular explorations may improve the diagnostic process and change the secondary prevention treatment strategy in RI patients. METHODS: We report a retrospective observational study of 25 RI patients referred to Tours University Hospital between 2011 and 2018 for etiological investigation including renal arteriography and intravascular ultrasonography (IVUS). We sought for antithrombotic treatment regimen, vital status, bleeding and ischemic outcomes during the median follow-up of 59 months. RESULTS: Invasive explorations showed local arterial disease in 14 patients (56%). This led to a diagnosis or change in diagnosis in 9 patients (36%) and to a change in antithrombotic strategy in 56% of cases, with an increased prescription of antiplatelet therapy. No patient died, only two patients (8%) had persistent mild renal insufficiency. One IVUS complication was reported and treated without any significant long-term consequences. CONCLUSION: Invasive endovascular investigations of RI may modify the secondary prevention treatment through a better assessment of the aetiology of RI. Multicentric randomized studies are necessary to advocate the hypothesis that invasive exploration of renal artery can improve long-term prognosis.

Mitochondrial Protection Partly Mitigates Kidney Cellular Senescence in Swine Atherosclerotic Renal Artery Stenosis.

BACKGROUND/AIMS: Atherosclerotic renal artery stenosis (ARAS) may cause kidney injury and mitochondrial dysfunction, which is linked to cellular senescence. Elamipretide, a mitochondria-targeted peptide, improves renal function in ARAS, but whether it alleviates senescence is unknown. We hypothesized that elamipretide would reduce senescence stenotic kidney (STK) in ARAS. METHODS: Domestic pigs were randomized to control and unilateral ARAS untreated or treated with subcutaneous elamipretide (5d/wk) for 4 weeks starting after 6 weeks of ARAS or sham (n=6 each). After completion of treatment, STK renal blood flow (RBF) and glomerular filtration rate (GFR) were assessed in-vivo using multi-detector computed-tomography. Renal fibrosis and oxidative stress were analyzed in trichrome- and dihydroethidium-stained slides, respectively. Mitochondrial markers involved in the electrontransport chain (COX4, ATP/ADP ratio), biogenesis (PGC1α, PPARα), dynamics (MFN2, DRP1), and mitophagy (parkin, p62) were measured in the kidney using ELISA, western-blot, and immunohistochemistry. Cellular senescence (senescence-associated ß-galactosidase and heterochromatin foci, phosphorylated-H2AX, and p16/21/53) and senescence-associated secretory phenotype (SASP; PAI-1, MCP-1, TGFß, and TNFα) markers were studied by microscopy, quantitative reverse transcription-polymerase chain reaction, and western-blot. RESULTS: Blood pressure was elevated whereas STK-RBF and GFR were decreased in ARAS pigs, and tissue scarring was increased. ARAS induced STK cellular senescence and accumulated dysfunctional mitochondria, which were associated with cardiolipin loss, upregulated mitochondrial biogenesis, and defective mitophagy. Elamipretide normalized STK-RBF and GFR, alleviated fibrosis and oxidative stress, and restored mitochondrial cardiolipin, biogenesis, and mitophagy in ARAS, but did not change SASP markers, and attenuated only senescenceassociated ß-galactosidase activity and p53 gene expression. CONCLUSION: Mitochondrial protection improved renal function and fibrosis in the ARAS STK, but only partly mitigated cellular senescence. This finding suggests that mitochondrial dysfunction may not be a major determinant of cellular senescence in the early stage of ARAS.

Systemic biopolymer-delivered vascular endothelial growth factor promotes therapeutic angiogenesis in experimental renovascular disease.

We recently developed a therapeutic biopolymer composed of an elastin-like polypeptide (ELP) fused to vascular endothelial growth factor (VEGF) and showed long-term renoprotective effects in experimental renovascular disease after a single intra-renal administration. Here, we sought to determine the specificity, safety, efficacy, and mechanisms of renoprotection of ELP-VEGF after systemic therapy in renovascular disease. We tested whether kidney selectivity of the ELP carrier would reduce off-target binding of VEGF in other organs. In vivo bio-distribution after systemic administration of ELP-VEGF in swine was determined in kidneys, liver, spleen, and heart. Stenotic-kidney renal blood flow and glomerular filtration rate were quantified in vivo using multi-detector computed tomography (CT) after six weeks of renovascular disease, then treated with a single intravenous dose of ELP-VEGF or placebo and observed for four weeks. CT studies were then repeated and the pigs euthanized. Ex vivo studies quantified renal microvascular density (micro-CT) and fibrosis. Kidneys, liver, spleen, and heart were excised to quantify the expression of angiogenic mediators and markers of progenitor cells. ELP-VEGF accumulated predominantly in the kidney and stimulated renal blood flow, glomerular filtration rate, improved cortical microvascular density, and renal fibrosis, and was accompanied by enhanced renal expression of VEGF, downstream mediators of VEGF signaling, and markers of progenitor cells compared to placebo. Expression of angiogenic factors in liver, spleen, and heart were not different compared to placebo-control. Thus, ELP efficiently directs VEGF to the kidney after systemic administration and induces long-term renoprotection without off-target effects, supporting the feasibility and safety of renal therapeutic angiogenesis via systemic administration of a novel kidney-specific bioengineered compound.

Antiphospholipid syndrome and kidney disease.

The antiphospholipid syndrome is a common autoimmune disease caused by pathogenic antiphospholipid antibodies, leading to recurrent thrombosis and/or obstetrical complications. Importantly for nephrologists, antiphospholipid antibodies are associated with various renal manifestations including large renal vessel thrombosis, renal artery stenosis, and a constellation of intrarenal lesions that has been termed antiphospholipid nephropathy. This last condition associates various degrees of acute thrombotic microangiopathy, proliferative and fibrotic lesions of the intrarenal vessels, and ischemic modifications of the renal parenchyma. The course of the disease can range from indolent nephropathy to devastating acute renal failure. The pejorative impact of antiphospholipid antibody-related renal complication is well established in the context of systemic lupus erythematous or after renal transplantation. In contrast, the exact significance of isolated antiphospholipid nephropathy remains uncertain. The evidence to guide management of the renal complications of antiphospholipid syndrome is limited. However, the recent recognition of the heterogeneous molecular mechanisms underlying the progression of intrarenal vascular lesions in antiphospholipid syndrome have opened promising tracks for patient monitoring and targeted therapeutic intervention.

Stenting and medical therapy for atherosclerotic renal-artery stenosis.

BACKGROUND: Atherosclerotic renal-artery stenosis is a common problem in the elderly. Despite two randomized trials that did not show a benefit of renal-artery stenting with respect to kidney function, the usefulness of stenting for the prevention of major adverse renal and cardiovascular events is uncertain. METHODS: We randomly assigned 947 participants who had atherosclerotic renal-artery stenosis and either systolic hypertension while taking two or more antihypertensive drugs or chronic kidney disease to medical therapy plus renal-artery stenting or medical therapy alone. Participants were followed for the occurrence of adverse cardiovascular and renal events (a composite end point of death from cardiovascular or renal causes, myocardial infarction, stroke, hospitalization for congestive heart failure, progressive renal insufficiency, or the need for renal-replacement therapy). RESULTS: Over a median follow-up period of 43 months (interquartile range, 31 to 55), the rate of the primary composite end point did not differ significantly between participants who underwent stenting in addition to receiving medical therapy and those who received medical therapy alone (35.1% and 35.8%, respectively; hazard ratio with stenting, 0.94; 95% confidence interval [CI], 0.76 to 1.17; P=0.58). There were also no significant differences between the treatment groups in the rates of the individual components of the primary end point or in all-cause mortality. During follow-up, there was a consistent modest difference in systolic blood pressure favoring the stent group (-2.3 mm Hg; 95% CI, -4.4 to -0.2; P=0.03). CONCLUSIONS: Renal-artery stenting did not confer a significant benefit with respect to the prevention of clinical events when added to comprehensive, multifactorial medical therapy in people with atherosclerotic renal-artery stenosis and hypertension or chronic kidney disease. (Funded by the National Heart, Lung and Blood Institute and others; ClinicalTrials.gov number, NCT00081731.).

Kidney disease in primary anti-phospholipid antibody syndrome.

APS is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for aPL. APS can be isolated (primary APS) or associated with other autoimmune diseases. The kidney is a major target organ in APS, and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal vasculature and renal veins). Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal involvement in patients with definite APS is treated with long-term anticoagulants as warfarin, but new treatments are being tried. The aim of this article is to review the links between primary APS and kidney disease.

Comparative Effectiveness of Management Strategies for Renal Artery Stenosis: An Updated Systematic Review.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is associated with high blood pressure (BP), decreased kidney function, renal replacement therapy (RRT), and death. PURPOSE: To compare benefits and harms of percutaneous transluminal renal angioplasty with stent placement (PTRAS) versus medical therapy alone in adults with ARAS. DATA SOURCES: MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from 1993 to 16 March 2016; gray literature; and prior systematic reviews. STUDY SELECTION: Randomized, controlled trials (RCTs); nonrandomized, comparative studies (NRCSs); single-group studies; and selected case reports that reported all-cause and cardiovascular mortality, RRT, kidney function, BP, and adverse events. DATA EXTRACTION: Six researchers extracted data on design, interventions, outcomes, and study quality into a Web-based database. DATA SYNTHESIS: Eighty-three studies met eligibility criteria. In 5 of 7 RCTs, PTRAS and medical therapy led to similar BP control in patients with ARAS, and no RCTs showed statistically significant differences in kidney function, mortality, RRT, cardiovascular events, or pulmonary edema. Eight NRCSs had more variable results, finding mostly no significant differences in mortality, RRT, or cardiovascular events but heterogeneous effects on kidney function and BP. Procedure-related adverse events were rare, and medication-related adverse events were not reported. Two RCTs found no patient characteristics that were associated with outcomes with either PTRAS or medical therapy. Single-group studies found various but inconsistent factors that predict outcomes. Case reports provided examples of clinical improvement after PTRAS in patients with acute decompensation. LIMITATION: Limited clinical applicability and power in RCTs, and possible publication bias and lack of adjusted analyses in NRCSs. CONCLUSION: The strength of evidence regarding the relative benefits and harms of PTRAS versus medical therapy alone for patients with ARAS is low. Studies have generally focused on patients with less severe ARAS. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.

Renal Therapeutic Angiogenesis Using a Bioengineered Polymer-Stabilized Vascular Endothelial Growth Factor Construct.

Renovascular disease (RVD) induces renal microvascular (MV) rarefaction that drives progressive kidney injury. In previous studies, we showed that renal vascular endothelial growth factor (VEGF) therapy attenuated MV damage, but did not resolve renal injury at practical clinical doses. To increase the bioavailability of VEGF, we developed a biopolymer-stabilized elastin-like polypeptide (ELP)-VEGF fusion protein and determined its in vivo potential for therapeutic renal angiogenesis in RVD using an established swine model of chronic RVD. We measured single-kidney blood flow (RBF) and GFR and established the degree of renal damage after 6 weeks of RVD. Pigs then received a single stenotic kidney infusion of ELP-VEGF (100 µg/kg), a matching concentration of unconjugated VEGF (18.65 µg/kg), ELP alone (100 µg/kg), or placebo. Analysis of organ distribution showed high renal binding of ELP-VEGF 4 hours after stenotic kidney infusion. Therapeutic efficacy was determined 4 weeks after infusion. ELP-VEGF therapy improved renal protein expression attenuated in RVD, restoring expression levels of VEGF, VEGF receptor Flk-1, and downstream angiogenic mediators, including phosphorylated Akt and angiopoietin-1 and -2. This effect was accompanied by restored MV density, attenuated fibrogenic activity, and improvements in RBF and GFR greater than those observed with placebo, ELP alone, or unconjugated VEGF. In summary, we demonstrated the feasibility of a novel therapy to curtail renal injury. Recovery of the stenotic kidney in RVD after ELP-VEGF therapy may be driven by restoration of renal angiogenic signaling and attenuated fibrogenic activity, which ameliorates MV rarefaction and improves renal function.

Blockade of CCR2 reduces macrophage influx and development of chronic renal damage in murine renovascular hypertension.

Renovascular hypertension (RVH) is a common cause of both cardiovascular and renal morbidity and mortality. In renal artery stenosis (RAS), atrophy in the stenotic kidney is associated with an influx of macrophages and other mononuclear cells. We tested the hypothesis that chemokine receptor 2 (CCR2) inhibition would reduce chronic renal injury by reducing macrophage influx in the stenotic kidney of mice with RAS. We employed a well-established murine model of RVH to define the relationship between macrophage infiltration and development of renal atrophy in the stenotic kidney. To determine the role of chemokine ligand 2 (CCL2)/CCR2 signaling in the development of renal atrophy, mice were treated with the CCR2 inhibitor RS-102895 at the time of RAS surgery and followed for 4 wk. Renal tubular epithelial cells expressed CCL2 by 3 days following surgery, a time at which no significant light microscopic alterations, including interstitial inflammation, were identified. Macrophage influx increased with time following surgery. At 4 wk, the development of severe renal atrophy was accompanied by an influx of inducible nitric oxide synthase (iNOS)+ and CD206+ macrophages that coexpressed F4/80, with a modest increase in macrophages coexpressing arginase 1 and F4/80. The CCR2 inhibitor RS-102895 attenuated renal atrophy and significantly reduced the number of dual-stained F4/80+ iNOS+ and F4/80+ CD206+ but not F4/80+ arginase 1+ macrophages. CCR2 inhibition reduces iNOS+ and CD206+ macrophage accumulation that coexpress F4/80 and renal atrophy in experimental renal artery stenosis. CCR2 blockade may provide a novel therapeutic approach to humans with RVH.

Three Decades of Atherosclerotic Reno-vascular Disease Management - Changing Outcomes in an Observational Study.

BACKGROUND/AIMS: Optimized medical therapy has improved cardiovascular outcomes in the general population. To investigate whether changes in the management of atherosclerotic renovascular disease (ARVD) have had an impact on clinical outcomes. METHODS: Recruitment into this single-center prospective cohort study started in 1986. Data was analyzed retrospectively. Patients were divided into four groups based on relationship of diagnosis year to landmark randomized controlled trials (RCT); group 1 - pre-large RCT data (1986-2000); group 2 - post-early RCT (2001-2004); group 3 - ASTRAL study recruitment era (2004-2009); group 4 - post-ASTRAL (2009-2014). RESULTS: In total, 872 patients were followed for a median 54.9 months (IQR 20.2-96.2). Over successive time-periods, there was an increase in baseline utilization of renin angiotensin blockade (RAB) (group 4: 69% vs. group 1: 31%, p<0.001), statins (74% vs 20%, p<0.001) and beta-blockers (43% vs 30%, p=0.024). Median time to death, end-stage kidney disease and cardiovascular events improved except in group 4, which displayed more baseline cardiovascular comorbidities. The number of investigative angiograms performed decreased from 139 per year between 2006 and 2008 to 74 per year in group 4. CONCLUSIONS: Although fewer patients are being investigated for ARVD in our center, these have more cardiovascular comorbidities. Nonetheless, optimized medical therapy may have contributed towards improved proteinuria, renal function and clinical outcomes in patients diagnosed with ARVD.

Renal vascular thrombosis in the newborn.

Neonatal renal vascular thrombosis is rare but has devastating sequelae. The renal vein is more commonly affected than the renal artery. Most neonates with renal vein thrombosis present with at least one of the three cardinal signs, namely, abdominal mass, macroscopic hematuria and thrombocytopenia, while unilateral renal artery thrombosis presents with transient hypertension. Contrast angiography is the gold standard for diagnosis but because of exposure to radiation and contrast agents, Doppler ultrasound scan is widely used instead. Baseline laboratory tests for platelet count, prothrombin time, activated partial thromboplastin time and fibrinogen concentration are essential before therapy is initiated. Maternal blood is tested for lupus anticoagulant and anticardiolipin antibody. Evaluation for prothrombotic disorders is warranted when thrombosis is clinically significant, recurrent or spontaneous. Management should involve a multidisciplinary team that includes neonatologists, radiologists, pediatric hematologists and nephrologists. In addition to supportive therapy, recent guidelines recommend at least prophylactic heparin therapy in the majority of cases to prevent thrombus extension. Thrombolytic therapy is reserved for bilateral thrombosis compromising kidney function. Long-term sequelae, such as kidney atrophy, systemic hypertension and chronic kidney disease, are common, and follow-up by pediatric nephrologists is recommended for monitoring of kidney function, early detection and management of hypertension and chronic kidney disease.

To intervene or not? A man with multidrug-resistant hypertension, endovascular abdominal aneurysm repair, bilateral renal artery stenosis and end-stage renal disease salvaged with renal artery stenting.

We report the case of a 69-year-old man with uncontrolled multidrug-resistant secondary hypertension following a 10 year history of endovascular abdominal aortic aneurysm repair, with suprarenal fixation and concurrent angioplasty with stenting of the left renal artery for atherosclerotic renal disease, and progressive chronic kidney disease. Renal scintigraphy revealed complete loss of the right kidney's and severe reduction of the left kidney's perfusion and function. Following recent evidence and consultation with vascular surgeons regarding the technical difficulties of any procedure, escalation of antihypertensive treatment was initially chosen. Careful drug adjustments significantly improved but did not fully control blood pressure (BP); further, the patient experienced an acute ischaemic stroke and renal function deterioration towards end-stage renal disease within a few months. At this point, revascularization of the left renal artery coupled with three haemodialysis sessions to remove contrast media was justified as rescue therapy against permanent renal replacement therapy. Successful intervention achieved an immediate BP reduction, with BP fully controlled, despite a > 70% decrease in antihypertensive treatment, while renal function improved at 6 months from 11.5 to 22 ml/min/1.73 m(2). Renal angioplasty confers undisputed benefits in BP control and nephroprotection, and should be offered without delay to patients with renovascular hypertension and/or ischaemic nephropathy.

Endothelin-a receptor antagonism after renal angioplasty enhances renal recovery in renovascular disease.

Percutaneous transluminal renal angioplasty/stenting (PTRAS) is frequently used to treat renal artery stenosis and renovascular disease (RVD); however, renal function is restored in less than one half of the cases. This study was designed to test a novel intervention that could refine PTRAS and enhance renal recovery in RVD. Renal function was quantified in pigs after 6 weeks of chronic RVD (induced by unilateral renal artery stenosis), established renal damage, and hypertension. Pigs with RVD then underwent PTRAS and were randomized into three groups: placebo (RVD+PTRAS), chronic endothelin-A receptor (ET-A) blockade (RVD+PTRAS+ET-A), and chronic dual ET-A/B blockade (RVD+PTRAS+ET-A/B) for 4 weeks. Renal function was again evaluated after treatments, and then, ex vivo studies were performed on the stented kidney. PTRAS resolved renal stenosis, attenuated hypertension, and improved renal function but did not resolve renal microvascular rarefaction, remodeling, or renal fibrosis. ET-A blocker therapy after PTRAS significantly improved hypertension, microvascular rarefaction, and renal injury and led to greater recovery of renal function. Conversely, combined ET-A/B blockade therapy blunted the therapeutic effects of PTRAS alone or PTRAS followed by ET-A blockade. These data suggest that ET-A receptor blockade therapy could serve as a coadjuvant intervention to enhance the outcomes of PTRAS in RVD. These results also suggest that ET-B receptors are important for renal function in RVD and may contribute to recovery after PTRAS. Using clinically available compounds and techniques, our results could contribute to both refinement and design of new therapeutic strategies in chronic RVD.

Anti-platelet and anti-hypertension medication use in patients with fibromuscular dysplasia: Results from the United States Registry for Fibromuscular Dysplasia.

Fibromuscular dysplasia (FMD), a non-inflammatory arterial disease, may lead to renovascular hypertension (HTN) and cerebrovascular disease. Little is known about medication use in FMD. Clinical features and medication use were reviewed in a national FMD registry (12 US sites). Medication usage was assessed in raw and adjusted analyses. Covariates included demographic characteristics, co-morbid conditions and vascular bed involvement. A total of 874 subjects (93.6% female) were included in the analysis. Mean age was 55.6±13.1 years, 74.5% had HTN, 25.4% had a history of transient ischemic attack or stroke, and 7.5% had a history of coronary artery disease (CAD). Renal and cerebrovascular arteries were affected in 70.4% and 74.7%, respectively. Anti-platelet agents were administered to 72.9% of patients. In multivariate analyses, factors associated with a greater likelihood of anti-platelet agent use were older age (OR=1.02 per year, p=0.005), CAD (OR=3.76, p=0.015), cerebrovascular artery FMD involvement in isolation (OR=2.31, p<0.0001) or a history of previous intervention for FMD (OR=1.52, p=0.036). A greater number of anti-HTN medications was evident in isolated renal versus isolated cerebrovascular FMD patients. Factors associated with a greater number of anti-HTN medications were older age (OR=1.03 per year, p<0.0001), history of HTN (OR=24.04, p<0.0001), history of CAD (OR=2.71, p=0.0008) and a history of a previous therapeutic procedure (OR=1.72, p=0.001). In conclusion, in FMD, medication use varies based on vascular bed involvement. Isolated renal FMD patients receive more anti-HTN agents and there is greater anti-platelet agent use among patients with cerebrovascular FMD. Further studies correlating medication use in FMD with clinically meaningful patient outcomes are necessary.

Long-term follow-up results of acute renal embolism after anticoagulation therapy.

BACKGROUND: Acute renal embolism (ARE) is a rare cause of acute abdominal pain. However, there are only a few studies on the clinical course of ARE. We attempted to investigate the clinical manifestations and long-term follow-up results of ARE. METHODS: From September 2006 to August 2012, 47 patients, who were diagnosed with ARE by computed tomography (CT), were enrolled. Patient demographic and clinical data were retrospectively reviewed. For the long-term outcomes, change in the serum creatinine (s-Cr) level, change in renal infarction on follow-up CT, recurrent embolism, and dialysis-free survival were investigated. RESULTS: The mean age of patients was 61 years (range, 29-89 years), and 51% of the patients were men. All the patients presented with abdominal or flank pain. The sites of ARE were the right kidney in 57% of the patients, the left kidney in 36% of the patients, and both the kidneys in 6% of the patients. The infarction volume was less than 50% of renal volume in 54% of infarcted kidneys. Six patients had a concurrent infarction in other organs (3 cases of splenic infarction and 3 cases of cerebral infarction). Etiology of embolism was cardiogenic in 55% and idiopathic in 45%. Mean s-Cr level was 1.2 mg/dL (range, 0.6-3.7 mg/dL). s-Cr elevation >0.5 mg/dL was detected in 19% of patients during the follow-up (6 of 31 patients; mean duration, 31 months). Follow-up CT was performed in 23 patients (mean duration, 29 months). The infarcted lesions showed atrophic changes in all the cases except for 1 case. During the mean follow-up period of 41 months (1-118 months), recurrent embolism developed in 8 patients (6 cases of cerebral artery embolism, 1 case of superior mesenteric artery embolism, and 1 case of renal artery embolism). Dialysis was necessary in 1 patient, and dialysis-free survival rates were 91%, 82%, and 64% at 1 year, 3 years, and 5 years, respectively. CONCLUSIONS: Although ARE causes irreversible loss of renal mass, it rarely leads to end-stage renal disease or long-term mortality. Therefore, the treatment should focus on the prevention of subsequent embolism to other vital organs.

Kidney microcirculation response to adenosine stimulation in renal artery stenosis.

The purpose of this study was to assess the vasoconstrictive effects of adenosine in the kidney microcirculation in hypertensive patients with renal artery stenosis (RAS). Twelve patients with resistant hypertension and moderate RAS were selected for the study. In all patients, systolic, diastolic and mean translesional pressure gradients, distal pressure (Pd), aortic pressure (Pa) and Pd/Pa ratio were measured using a pressure guidewire at baseline and after intrarenal bolus administration of 400 µg adenosine. We observed significant changes in mean translesional pressure gradient and systolic Pd after pharmacological stimulation. The results suggest that in hypertensive patients with RAS, vasomotor activity of the kidney microcirculation may be preserved.

Disparate effects of single endothelin-A and -B receptor blocker therapy on the progression of renal injury in advanced renovascular disease.

We hypothesized that chronic specific endothelin-A (ET-A) receptor blockade therapy would reverse renal dysfunction and injury in advanced experimental renovascular disease. To test this, unilateral renovascular disease was induced in 19 pigs, and after 6 weeks, single-kidney hemodynamics and function was quantified in vivo using computed tomography. All pigs with renovascular disease were divided such that seven were untreated, seven were treated with ET-A blockers, and five were treated with ET-B blockers. Four weeks later, all pigs were restudied in vivo, and then killed and ex vivo studies performed on the stenotic kidney to quantify microvascular density, remodeling, renal oxidative stress, inflammation, and fibrosis. Renal blood flow, glomerular filtration rate, and redox status were significantly improved in the stenotic kidney after ET-A but not ET-B blockade. Furthermore, only ET-A blockade therapy reversed renal microvascular rarefaction and diminished remodeling, which was accompanied by a marked decreased in renal inflammatory and fibrogenic activity. Thus, ET-A but not ET-B blockade ameliorated renal injury in pigs with advanced renovascular disease by stimulating microvascular proliferation and decreasing the progression of microvascular remodeling, renal inflammation, and fibrosis in the stenotic kidney. These effects were functionally consequential as ET-A blockade improved single kidney microvascular endothelial function, renal blood flow, and glomerular filtration rate, and decreased albuminuria.

Thrombotic microangiopathy in a patient with adult-onset Still's disease.

BACKGROUND: Since there are many disorders that can present with thrombotic microangiopathy (TMA), establishing a correct diagnosis is important to offer the most appropriate therapy. CASE REPORT: A 26-year-old woman was transferred to our hospital with fragmentation hemolytic anemia, thrombocytopenia, and acute kidney failure. History revealed that she was recently diagnosed with adult-onset Still's disease (AOSD) and received intraocular injections of bevacizumab to treat acute retinal artery occlusion. At our hospital, she underwent extensive investigations and was treated with high-dose steroids, hemodialysis, and therapeutic plasma exchange. For recurrent disease, she received a single dose of eculizumab. RESULTS: The patient's ADAMTS13 activity was normal and she had evidence of complement activation. Genetic testing identified a benign polymorphism in the C3 gene. Pathophysiology of TMA in AOSD is briefly discussed and an overview of the literature is presented. CONCLUSION: Work-up of a new fragmentation hemolytic anemia and thrombocytopenia should include careful review of past history, including medications, as well as relevant laboratory investigations with aim to establish a correct diagnosis. Occasionally, the correct diagnosis is not the obvious one and there could be multiple contributors to the pathogenesis. Establishing diagnosis is important for counseling patient on disease prognosis and to guide treatment.