Renal Arterial Disease and Hypertension

Impact of exercise training associated with enalapril treatment on blood pressure variability and renal dysfunctions in an experimental model of arterial hypertension and postmenopause

OBJECTIVE

In this study, we aimed to investigate the effects of the concurrent exercise training (CET) associated with the enalapril maleate on blood pressure variability (BPV) and renal profile in an experimental model of arterial hypertension (AH) and postmenopause.

METHODS

Female ovariectomized spontaneously hypertensive rats (SHR) were distributed into 4 groups (n = 8/group): sedentary (SO), sedentary + enalapril (SOE), trained (TO) and trained + enalapril (TOE). Both enalapril (3mg/kg) and CET (3 days/week) were conducted during 8 weeks. Blood pressure (BP) was directly recorded for BPV analyses. Renal function, morphology, inflammation and oxidative stress were assessed.

RESULTS

The SOE, TO e TOE groups presented decreased systolic BP compared with SO. Both trained groups (TO and TOE) presented lower BPV and increased baroreflex sensitivity (TO: 0.76 ± 0.20 and TOE: 1.02 ± 0.40 vs. SO: 0.40 ± 0.07 ms/mmHg) compared with SO group, with additional improvements in TOE group. Creatinine and IL-6 levels were reduced in SOE, TO and TOE compared with SO group, while IL-10 was increased only in TOE group (vs. SO). Enalapril combined with CET promote reduction in lipoperoxidation (TOE: 1.37 ± 0.26 vs. SO: 2.08 ± 0.48 and SOE: 1.84 ± 0.35 μmol/mg protein) and hydrogen peroxide (TOE: 1.89 ± 0.40 vs. SO: 3.70 ± 0.19 and SOE: 2.73 ± 0.70 μM), as well as increase in catalase activity (vs. sedentary groups). The tubulointerstitial injury was lower in interventions groups (SOE, TO and TOE vs. SO), with potentialized benefits in the trained groups.

CONCLUSIONS

Enalapril combined with CET attenuated BPV and baroreflex dysfunctions, probably impacting on end-organ damage, as demonstrated by attenuation in the AH-induced renal inflammations, oxidative stress and morphofunctional impairments in postmenopausal rats.

Adrenal Ganglioneuroma: Diagnosis, Presentation, and Management of a Rare Tumor

Adrenal ganglioneuromas are rare tumors arising from sympathetic ganglion cells that may present similarly to other adrenal tumors, making preoperative diagnosis challenging. We present a case of a young woman with a history of Hashimoto's thyroiditis who presented with hypertension and headaches. An abdominal CT scan revealed a large left adrenal mass, and while laboratory tests for catecholamines and metanephrines were normal, the suspicion for pheochromocytoma remained high given the size of the mass and persistent hypertension. The patient was started on alpha-blockers and beta-blockers in preparation for surgical removal. Pathology revealed a mature ganglioneuroma without evidence of malignancy, and postoperative blood pressure was normalized. We hypothesize that vessel compression from the large mass created functional stenosis, resulting in persistent hypertension. This case highlights the importance of a thorough workup for hypertension in young adults and routine preventative care visits to avoid delayed management. Adrenalectomy with histopathological examination remains the gold standard for treatment and diagnosis, and patients have a good prognosis following resection, with minimal need for recurrent therapy.

Primary and secondary paediatric hypertension

High blood pressure (BP) or hypertension is a well known risk factor for developing heart attack, stroke, atrial fibrillation and renal failure. Although in the past hypertension was supposed to develop at middle age, it is now widely recognized that it begins early during childhood. As such, approximately 5-10% of children and adolescents are hypertensive. Unlike that previously reported, it is now widely accepted that primary hypertension is the most diffuse form of high BP encountered even in paediatric age, while secondary hypertension accounts just for a minority of the cases. There are significant differences between that outlined by the European Society of Hypertension (ESH), the European Society of Cardiology (ESC), and the last statement by the American Academy of Pediatrics (AAP) concerning the BP cut-offs to identify young hypertensive individuals. Not only that, but the AAP have also excluded obese children in the new normative data. This is undoubtedly a matter of concern. Conversely, both the AAP and ESH/ESC agree that medical therapy should be reserved just for nonresponders to measures like weight loss/salt intake reduction/increase in aerobic exercise. Secondary hypertension often occurs in aortic coarctation or chronic renal disease patients. The former can develop hypertension despite early effective repair. This is associated with significant morbidity and is arguably the most important adverse outcome in about 30% of these subjects. Also, syndromic patients, for example those with Williams syndrome, may suffer from a generalized aortopathy, which triggers increased arterial stiffness and hypertension. This review summarizes the state-of-the-art situation regarding primary and secondary paediatric hypertension.

A 50-year-old refugee woman with a lithopedion and a lifetime of trauma: a case report

BACKGROUND

Lithopedion is a term that refers to a fetus that has calcified or changed to bone. The calcification may involve the fetus, membranes, placenta, or any combination of these structures. It is an extremely rare complication of pregnancy and can remain asymptomatic or present with gastrointestinal and/or genitourinary symptoms.

CASE PRESENTATION

A 50-year-old Congolese refugee with a nine-year history of retained fetus after a fetal demise was resettled to the United States (U.S.). She had chronic symptoms of abdominal pain and discomfort, dyspepsia, and gurgling sensation after eating. She experienced stigmatization from healthcare professionals in Tanzania at the time of the fetal demise and subsequently avoided healthcare interaction whenever possible. Upon arrival to the U.S., evaluation of her abdominal mass included abdominopelvic imaging which confirmed the diagnosis of lithopedion. She was referred to gynecologic oncology for surgical consultation given intermittent bowel obstruction from underlying abdominal mass. However, she declined intervention due to fear of surgery and elected for symptom monitoring. Unfortunately, she passed away due to severe malnutrition in the context of recurrent bowel obstruction due to the lithopedion and continued fear of seeking medical care.

CONCLUSION

This case demonstrated a rare medical phenomenon and the impact of medical distrust, poor health awareness, and limited access to healthcare among populations most likely to be affected by a lithopedion. This case highlighted the need for a community care model to bridge the gap between the healthcare team and newly resettled refugees.

A new threshold for kidney asymmetry improves association with abnormal renal-aortic ratio for diagnosis of renal artery stenosis

BACKGROUND

Renal artery stenosis (RAS) reflects more widespread atherosclerosis deposition and is associated with high morbidity and mortality. According to the guidelines, a discrepancy in the size of the kidneys of over 15 mm found in an ultrasound should initiate the RAS diagnostic algorithm. This study aims to find the optimal threshold for renal asymmetry that better reflects the frequency of a significantly abnormal renal-aortic ratio (RAR), justifying further RAS diagnostic workup, than the currently used cut-off of 15 mm difference in renal diameters.

METHODS

The analysis included 1175 patients (mean age: 52 years, IQR: 38-66, men/women: 597/578) who underwent Doppler ultrasonography screening of renal arteries with recorded kidney size and RAR calculation. Ultrasound features of RAS were defined as a RAR greater than 3.5 or signs of renal artery occlusion. Receiver operating characteristic (ROC) curves were created and analyzed for absolute differences in kidney size and abnormal RAR. We calculated the area under the curve (AUC) and optimal cut-off values for sensitivity and specificity analysis.

RESULTS

The final analysis included 169 patients with a significant difference in renal dimension. RAS features were met in 61 patients. According to ROC curve analysis, the optimal index of renal asymmetry was 12 mm. The sensitivity and specificity for this method were 82.0% and 83.3%, respectively, and AUC was 86.3%.

CONCLUSION

Changing the definition of a significant difference in kidney size from 15 mm to 12 mm increases sensitivity and specificity for abnormal RAR and this finding may accelerate the diagnosis of RAS.

Concurrent Primary Aldosteronism and Renal Artery Stenosis: An Overlooked Condition Inducing Resistant Hypertension

To explore the clinical features of coexisting primary aldosteronism (PA) and renal artery stenosis (RAS), we retrospectively analyzed records from 71 patients with PA with RAS and a control group of 121 patients with PA without RAS. Aldosterone-to-renin concentration ratio tests and computerized tomography (CT) scanning of the adrenal and renal arteries were routinely conducted to screen for PA and RAS. Color Doppler flow and/or magnetic resonance imaging were used as substitute testing of patients for whom CT was contraindicated. Standard percutaneous renal arteriography (PTRA) was considered for patients with RAS exceeding 70% based on non-invasive tests and for those without PTRA contraindications. The patients with PA with RAS were further divided into severe (RAS>70%) and moderate (50% < RAS <70%) RAS groups. The prevalence of RAS among PA patients was 6.9% (71/1,033), including 3.2% (33/1,033) with severe RAS. Compared with the PA without RAS group, the severe RAS group showed higher levels of systolic blood pressure (SBP) (171.82 ± 18.24 vs. 154.11 ± 18.96 mmHg; P < 0.001) and diastolic BP(DBP) (110.76 ± 15.90 vs. 91.73 ± 12.85 mmHg; P < 0.001) and prevalence of resistant hypertension (RH) (90.9 vs. 66.9%; P = 0.008), whereas the moderate RAS group merely showed higher DBP (98.63 ± 14.90 vs. 91.73 ± 12.85 mmHg; P = 0.006). The direct renin concentrations (DRCs) (5.37 ± 3.94 vs. 3.71 ± 2.10 μU/mL; P < 0.001) and false-negative rate (33.8 vs. 3.3%; P < 0.01) of PA screening tests were significantly higher in the PA with RAS group than in the control group, but only in severe RAS group, in subgroup analysis. Among patients who underwent successful treatment for severe RAS, mean DRC decreased from 11.22 ± 9.10 to 3.24 ± 2.69 μIU/mL (P < 0.001). Overall, the prevalence of RH decreased from 81.7 to 2.8% (P < 0.001) when both PA and RAS were treated with standard methods. PA with concurrent severe RAS is a condition that induces RH. PA can be easily missed in patients with coexisting RAS. RAS patients with RH after successful revascularization for RAS should be evaluated for coexisting PA.

Genistein alleviates renin-angiotensin system mediated vascular and kidney alterations in renovascular hypertensive rats

Genistein is a bioflavonoid mainly found in soybean. This study evaluated the effect of genistein on vascular dysfunction and kidney damage in two-kidney, one-clipped (2K1C) hypertensive rats. Male Sprague-Dawley-2K1C hypertensive rats were treated with genistein (40 or 80 mg/kg) or losartan 10 mg/kg (n = 8/group). Genistein reduced blood pressure, attenuated the increase in sympathetic nerve-mediated contractile response and endothelial dysfunction in the mesenteric vascular beds and aorta of 2K1C rats. Increases in the intensity of tyrosine hydroxylase (TH) in the mesentery and plasma norepinephrine (NE) were alleviated in the genistein-treated group. Genistein also improved renal dysfunction, hypertrophy of the non-clipped kidney (NCK) and atrophy of the clipped kidney (CK) in 2K1C rats. Upregulation of angiotensin II receptor type I (AT₁R), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit 4 (Nox4) and Bcl2-associated X protein (BAX) and downregulation of B-cell lymphoma 2 (Bcl2) protein found in CK were restored by genistein. It also suppressed the overexpression of AT₁R, transforming growth factor beta I (TGF-β1), smad2/3 and p-smad3 in NCK. Genistein reduced serum angiotensin converting enzyme (ACE) activity and plasma angiotensin II (Ang II) in 2K1C rats. Low levels of catalase activity as well as high levels of superoxide generation and malondialdehyde (MDA) in 2K1C rats were restored by genistein treatment. In conclusion, genistein suppressed renin-angiotensin system-mediated sympathetic activation and oxidative stress in 2K1C rats. It alleviated renal atrophy in CK via modulation of AT₁R/NADPH oxidase/Bcl-2/BAX pathways and hypertrophy in NCK via AT₁R/TGF-β1/smad-dependent signalling pathways.

Cardio-protective effect of Cocculus hirsutus in experimental hypertension in rats

BACKGROUND

Ayurdvedic derived medicines are most promising and effective in the treatment of several cardiovascular diseases. Cocculus hirsutus (CH) has been reported for broad spectrum of activities like anticancer, antidiabetic, antioxidant, cardiotonic and hypotensive etc. OBJECTIVES: The present study aimed to find the cardio-protective effect of CH in experimental hypertension in rats.

MATERIALS AND METHODS

For acute renal hypertension, CH animals were pre-treated with CH-1 (250 mg/kg) and CH-2 (500 mg/kg) p. o. for 14 days. On the 15th day, hypertension was induced by renal occlusion and the mean arterial blood pressure (MABP) was recorded. For CAL pretreatment of CH-1 and CH-2 was given for 7 days on the 8th day animals were operated on for ligation. The MABP and the time of onset of ventricular tachycardia (VT), premature ventricular systole (PVS) were recorded. For induction of hypercholesterolemia, animals were fed with a high cholesterol diet (CD) with CH-1 and CH-2 for 21 days. The antioxidant potential of CH was done using the assay of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx).

RESULTS

CH treatment significantly decreases the MABP, the onset of VT and PVS. The histology show intact cardiac muscle with minimum necrosis and inflammation. CH treatment shows significant decrease in cholesterol, triglycerides, and glucose while HDL levels are significantly increased. The aortic section of CH-treated animals shows the intact layers of the artery, normal thickness and restoration of antioxidant enzymatic activity.

CONCLUSION

The study shows significant cardio protective effect of CH in experimental animals.

Insights of Worsening Renal Function in Type 1 Cardiorenal Syndrome: From the Pathogenesis, Biomarkers to Treatment

Type-1 cardiorenal syndrome refers to acute kidney injury induced by acute worsening cardiac function. Worsening renal function is a strong and independent predictive factor for poor prognosis. Currently, several problems of the type-1 cardiorenal syndrome have not been fully elucidated. The pathogenesis mechanism of renal dysfunction is unclear. Besides, the diagnostic efficiency, sensitivity, and specificity of the existing biomarkers are doubtful. Furthermore, the renal safety of the therapeutic strategies for acute heart failure (AHF) is still ambiguous. Based on these issues, we systematically summarized and depicted the research actualities and predicaments of the pathogenesis, diagnostic markers, and therapeutic strategies of worsening renal function in type-1 cardiorenal syndrome.

Free-Breathing Three-Dimensional Isotropic-Resolution MR sequence for simultaneous vessel wall imaging of bilateral renal arteries and abdominal aorta: Feasibility and reproducibility

PURPOSE

Many diseases can simultaneously involve renal arteries and the adjacent abdominal aorta. The study proposed a free-breathing three-dimensional (3D) isotropic-resolution MR sequence for simultaneous vessel wall imaging of bilateral renal arteries and adjacent abdominal aorta.

METHODS

A respiratory triggered isotropic-resolution sequence which combined the improved motion-sensitized driven-equilibrium (iMSDE) preparation with the spoiled gradient recalled (SPGR) readout (iMSDE-SPGR) was proposed for simultaneous vessel wall imaging of renal arteries and abdominal aorta. The proposed iMSDE-SPGR sequence was optimized by positioning spatial saturation pulses (i.e. REST slabs) elaborately to further alleviate respiratory and gastrointestinal motion artifacts and selecting appropriate first-order gradient moment (m₁ ) of the iMSDE preparation. Thirteen healthy subjects and thirteen patients with renal artery stenosis (RAS) underwent simultaneous vessel wall imaging with the optimized iMSDE-SPGR sequence at 3.0T. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and morphology of renal arterial wall and aortic wall were measured. Reproducibility of intra-observer, inter-observer and scan-rescan (n = 13 healthy subjects) in measuring SNR, CNR and morphology was evaluated. For the reproducibility test, the agreement was determined using intraclass correlation coefficients (ICC) and the differences were compared using paired-t test or non-parametric Wilcoxon test when appropriate. Bland-Altman plots were used to calculate the bias between observers and between scans.

RESULTS

The proposed iMSDE-SPGR sequence was feasible for simultaneous vessel wall imaging both in the healthy subjects and the patients. The sequence showed good to excellent inter-observer (ICC:0.615-0.999), excellent intra-observer (ICC:0.801-0.998) and scan-rescan (ICC:0.768-0.998) reproducibility in measuring morphology, SNR and CNR. There were no significant differences in SNR, CNR and morphology measurements between observers and between scans (all P>0.05). Bland-Altman plots showed small bias in assessing SNR, CNR and morphology.

DATA CONCLUSION

The proposed free-breathing 3D isotropic-resolution iMSDE-SPGR technique is feasible and reproducible for simultaneous vessel wall imaging of bilateral renal arteries and adjacent abdominal aorta. This article is protected by copyright. All rights reserved.

ANG II and Aldosterone Acting Centrally Participate in the Enhanced Sodium Intake in Water-Deprived Renovascular Hypertensive Rats

Renovascular hypertension is a type of secondary hypertension caused by renal artery stenosis, leading to an increase in the renin–angiotensin–aldosterone system (RAAS). Two-kidney, 1-clip (2K1C) is a model of renovascular hypertension in which rats have an increased sodium intake induced by water deprivation (WD), a common situation found in the nature. In addition, a high-sodium diet in 2K1C rats induces glomerular lesion. Therefore, the purpose of this study was to investigate whether angiotensin II (ANG II) and/or aldosterone participates in the increased sodium intake in 2K1C rats under WD. In addition, we also verified if central AT1 and mineralocorticoid receptor blockade would change the high levels of arterial pressure in water-replete (WR) and WD 2K1C rats, because blood pressure changes can facilitate or inhibit water and sodium intake. Finally, possible central areas activated during WD or WD followed by partial rehydration (PR) in 2K1C rats were also investigated. Male Holtzman rats (150–180 g) received a silver clip around the left renal artery to induce renovascular hypertension. Six weeks after renal surgery, a stainless-steel cannula was implanted in the lateral ventricle, followed by 5–7 days of recovery before starting tests. Losartan (AT1 receptor antagonist) injected intracerebroventricularly attenuated water intake during the thirst test. Either icv losartan or RU28318 (mineralocorticoid receptor antagonist) reduced 0.3 M NaCl intake, whereas the combination of losartan and RU28318 icv totally blocked 0.3 M NaCl intake induced by WD in 2K1C rats. Losartan and RU28318 icv did not change hypertension levels of normohydrated 2K1C rats, but reduced the increase in mean arterial pressure (MAP) produced by WD. c-Fos expression increased in the lamina terminalis and in the NTS in WD condition, and increased even more after WD-PR. These results suggest the participation of ANG II and aldosterone acting centrally in the enhanced sodium intake in WD 2K1C rats, and not in the maintenance of hypertension in satiated and fluid-replete 2K1C rats.

Renal Arteriography via Radial Artery Access with a 125 cm Long Angiographic Catheter

A 125 cm long catheter makes it possible to perform renal arteriography via radial artery, but its feasibility and safety remain unclear. Our study recruited 1,323 patients grouped by two different vascular accesses to renal arteriography, i.e., femoral artery access and radial artery access. The success rate of angiography was 100% in both groups. Differential analysis showed that the overall complication incidence of radial artery access group was significantly lower (2.5% for radial artery access vs. 4.8% for femoral artery access, p = 0.03). From this study, we suggest that using the 125 cm angiographic catheter to perform renal arteriography via radial artery access is feasible and safe.

Stem Cell Therapy for Microvascular Injury Associated with Ischemic Nephropathy

Ischemic nephropathy reflects progressive loss of kidney function due to large vessel atherosclerotic occlusive disease. Recent studies indicate that this process is characterized by microvascular rarefaction, increased tissue hypoxia and activation of inflammatory processes of tissue injury. This review summarizes the rationale and application of functional MR imaging to evaluate tissue oxygenation in human subjects that defines the limits of renal adaptation to reduction in blood flow, development of increasingly severe tissue hypoxia and recruitment of inflammatory injury pathways in ischemic nephropathy. Human mesenchymal stromal/stem cells (MSC) are capable of modifying angiogenic pathways and immune responses, but the potency of these effects vary between individuals and various clinical characteristics including age and chronic kidney disease and levels of hypoxia. We summarize recently completed first-in-human studies applying intrarenal infusion of autologous adipose-derived MSC in human subjects with ischemic nephropathy that demonstrate a rise in blood flow and reduction in tissue hypoxia consistent with partial repair of microvascular injury, even without restoring main renal arterial blood flow. Inflammatory biomarkers in the renal vein of post-stenotic kidneys fell after MSC infusion. These changes were associated with modest but significant dose-related increments in kidney function. These data provide support a role for autologous MSC in repair of microvascular injury associated with tissue hypoxia.

An Outline of Renal Artery Stenosis Pathophysiology-A Narrative Review

Renal artery stenosis (RAS) is conditioned mainly by two disturbances: fibromuscular dysplasia or atherosclerosis of the renal artery. RAS is an example of renovascular disease, with complex pathophysiology and consequences. There are multiple pathophysiological mechanisms triggered in response to significant renal artery stenosis, including disturbances within endothelin, kinin-kallikrein and sympathetic nervous systems, with angiotensin II and the renin-angiotensin-aldosterone system (RAAS) playing a central and key role in the pathogenesis of RAS. The increased oxidative stress and the release of pro-inflammatory mediators contributing to pathological tissue remodelling and renal fibrosis are also important pathogenetic elements of RAS. This review briefly summarises these pathophysiological issues, focusing on renovascular hypertension and ischemic nephropathy as major clinical manifestations of RAS. The activation of RAAS and its haemodynamic consequences is the primary and key element in the pathophysiological cascade triggered in response to renal artery stenosis. However, the pathomechanism of RAS is more complex and also includes other disturbances that ultimately contribute to the development of the diseases mentioned above. To sum up, RAS is characterised by different clinical pictures, including asymptomatic disorders diagnosed in kidney imaging, renovascular hypertension, usually characterised by severe course, and chronic ischemic nephropathy, described by pathological remodelling of kidney tissue, ultimately leading to kidney injury and chronic kidney disease.

Hepatorenal bypass resulting in dialysis independence in case of acute renal failure

In the present case report, we have described a patient with bilateral renal artery occlusion resulting in the acute onset of refractory hypertension and renal failure requiring hemodialysis. Endovascular stenting of the renal arteries was not feasible owing to extensive aortic and renal orifice calcification. After consultation with nephrology and medical optimization, the patient underwent unilateral hepatorenal bypass, with subsequent improvement in renal function and sustained freedom from dialysis. Although percutaneous revascularization has become the preferred option for surgical management of renal artery occlusion, the findings from the present case have demonstrated that hepatorenal bypass remains a viable alternative for more complex cases.

Renovascular Hypertension

Renovascular hypertension (RVH) is relatively common but underrecognized cause of resistant hypertension in clinical practice. Most patients with RVH have suboptimal control of hypertension in spite of being on multiple anti hypertensive medications. Prompt diagnosis and management is crucial to prevent long term morbidity and mortality. Initial evaluation by primary care physicians can expedite this to improve patient outcomes by co-managing hypertension specialists. In addition to pharmacologic and nonpharmacologic measures, some patients may benefit from angioplasty. This article discusses various definitions of hypertension, approach to diagnosis of RVH, and management. Data from clinical trials are discussed with evidence-based medicine practice recommendations.

What Is the Most Common Cause of Secondary Hypertension?: An Interdisciplinary Discussion

PURPOSE OF REVIEW

Traditional statements in medical textbooks pointed that 90 to 95% of cases of hypertension is essential or primary. However, secondary hypertension seems to be common in those patients with resistant forms of hypertension. Appropriate investigation and treatment may have prognostic impact but frequently hypertension remission did not occur raising concerns about the real meaning of secondary hypertension. Here, we provided an interdisciplinary and critical discussion comprising an endocrinologist, a nephrologist, and a cardiologist with expertise in resistant hypertension. We reviewed the literature approaching each one of the recognizable cause of hypertension.

RECENT FINDINGS

Recent studies pointed that the most common causes of secondary hypertension are those who overall responses to their treatments do not promote hypertension remission including obstructive sleep apnea (OSA), chronic kidney disease, renovascular hypertension and primary aldosteronism. The authors raised concerns regarding the lack of inclusion of obesity by several societies as a formal cause of hypertension considering not only the biologic plausibility but also the huge impact of weight loss therapies such as bariatric surgery on hypertension remission. In contrast, there is no discussion that a very rare condition-namely pheochromocytoma-is the most "typical" cause of hypertension by promoting hypertension remission in the majority of patients after surgical procedure. Hypertension is a complex condition with multiple environmental and genetics interactions. In clinical practice, it is challenging to prove causality in hypertension. Common conditions largely acceptable as causes of hypertension (OSA, chronic kidney disease, renovascular hypertension, and primary aldosteronism) frequently occur in a setting of an established hypertension background and therefore do not promote hypertension remission in a significant proportion of patients. If obesity becomes largely accepted by several societies as a secondary form of hypertension, this pandemic condition will be certainly the most common cause of hypertension.

Left ventricular mass reduction and hypertrophy regression following renal artery revascularization: a meta-analysis

AIM

Few echocardiographic studies have focused on regression of left ventricular hypertrophy (LVH) in patients with renal artery stenosis after revascularization, with inconsistent results. We performed a systematic meta-analysis of these studies in order to offer a comprehensive information on this topic.

METHODS

The PubMed, OVID-MEDLINE, and Cochrane library databases were analyzed to search English-language articles published from 1 January 1990 up to 31 March 2020. Studies were identified by crossing the following terms: 'renal artery stenosis', 'renovascular hypertension', 'fibromuscular dysplasia', 'renal artery stenting', 'renal artery surgery' with 'cardiac damage', 'hypertensive heart disease' 'left ventricular mass', 'left ventricular hypertrophy', 'echocardiography'.

RESULTS

A total of 726 hypertensive patients with renal artery stenosis (mean age 61 years, 64% men, 98% treated, 10% with fibromuscular dysplasia) were included in 13 studies. Baseline and postintervention pooled mean LVM values were 220 ± 15 and 203 ± 19 g, respectively (SMD -0.24 ± 0.06, CI -0.37 to -0.21, P<0.0001); corresponding values for LV mass index were 129.0 ± 6 and 115 ± 7 g/m, respectively (SMD -0.28 ± 0.04, CI -0.36 to 0.21, P < 0.0001). Renal revascularization was associated with a 40% lower risk of LVH. This trend was accompanied by a reduction in the number of antihypertensive drugs (SMD -0.27 ± 0.04, CI -0.37 to 0.17, P < 0.0001).

CONCLUSION

The present meta-analysis suggests that renal artery revascularization added to antihypertensive therapy promotes a favourable effect on LV structure, as reflected by a significant decrease in absolute and indexed LV mass index as well by a lower risk of LVH. Limitations include: high prevalence of modest renal artery stenosis (≥50%); small sample of fibromuscular dysplasia; lack of randomized design of most studies.

Experimental Renovascular Disease Induces Endothelial Cell Mitochondrial Damage and Impairs Endothelium-Dependent Relaxation of Renal Artery Segments

BACKGROUND

Mitochondria modulate endothelial cell (EC) function, but may be damaged during renal disease. We hypothesized that the ischemic and metabolic constituents of swine renovascular disease (RVD) induce mitochondrial damage and impair the function of renal artery ECs.

METHODS

Pigs were studied after 16 weeks of metabolic syndrome (MetS), renal artery stenosis (RAS), or MetS + RAS, and Lean pigs served as control (n = 6 each). Mitochondrial morphology, homeostasis, and function were measured in isolated primary stenotic-kidney artery ECs. EC functions were assessed in vitro, whereas vasoreactivity of renal artery segments was characterized in organ baths.

RESULTS

Lean + RAS and MetS + RAS ECs showed increased mitochondrial area and decreased matrix density. Mitochondrial biogenesis was impaired in MetS and MetS + RAS compared with their respective controls. Mitochondrial membrane potential similarly decreased in MetS, Lean + RAS, and MetS + RAS groups, whereas production of reactive oxygen species increased in MetS vs. Lean, but further increased in both RAS groups. EC tube formation was impaired in MetS, RAS, and MetS + RAS vs. Lean, but EC proliferation and endothelial-dependent relaxation of renal artery segments were blunted in MetS vs. Lean, but further attenuated in Lean + RAS and MetS + RAS.

CONCLUSIONS

MetS and RAS damage mitochondria in pig renal artery ECs, which may impair EC function. Coexisting MetS and RAS did not aggravate EC mitochondrial damage in the short time of our in vivo studies, suggesting that mitochondrial injury is associated with impaired renal artery EC function.

Renal ischemia alters expression of mitochondria-related genes and impairs mitochondrial structure and function in swine scattered tubular-like cells

Scattered tubular-like cells (STCs) are dedifferentiated surviving tubular epithelial cells that repair neighboring injured cells. Experimental renal artery stenosis (RAS) impairs STC reparative potency by inducing mitochondrial injury, but the exact mechanisms of mitochondrial damage remain unknown. We hypothesized that RAS alters expression of mitochondria-related genes, contributing to mitochondrial structural damage and dysfunction in swine STCs. CD24⁺/CD133⁺ STCs were isolated from pig kidneys after 10 wk of RAS or sham (n = 3 each). mRNA sequencing was performed, and nuclear DNA (nDNA)-encoded mitochondrial genes and mitochondrial DNA (mtDNA)-encoded genes were identified. Mitochondrial structure, ATP generation, biogenesis, and expression of mitochondria-associated microRNAs were also assessed. There were 96 nDNA-encoded mitochondrial genes upregulated and 12 mtDNA-encoded genes downregulated in RAS-STCs versus normal STCs. Functional analysis revealed that nDNA-encoded and mtDNA-encoded differentially expressed genes were primarily implicated in mitochondrial respiration and ATP synthesis. Mitochondria from RAS STCs were swollen and showed cristae remodeling and loss and decreased ATP production. Immunoreactivity of the mitochondrial biogenesis marker peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and expression of the mitochondria-associated microRNAs miR-15a, miR-181a, miR-196a, and miR-296-3p, which target several mtDNA genes, were higher in RAS-STCs compared with normal STCs, suggesting a potential modulation of mitochondria-related gene expression. These results demonstrate that RAS induces an imbalance in mtDNA- and nDNA-mitochondrial gene expression, impairing mitochondrial structure and function in swine STCs. These observations support development of gene gain- and loss-of-function strategies to ameliorate mitochondrial damage and preserve the reparative potency of STCs in patients with renal ischemia.

Renal Artery Stenosis As Etiology of Recurrent Flash Pulmonary Edema and Role of Imaging in Timely Diagnosis and Management

Renal hypoperfusion from renal artery stenosis (RAS) activates the renin-angiotensin system, which in turn causes volume overload and hypertension. Atherosclerosis and fibromuscular dysplasia are the most common causes of renal artery stenosis. Recurrent flash pulmonary edema, also known as Pickering syndrome, is commonly associated with bilateral renal artery stenosis. There should be a high index of clinical suspicion for renal artery stenosis in the setting of recurrent flash pulmonary edema and severe hypertension in patients with atherosclerotic disease. Duplex ultrasonography is commonly recommended as the best initial test for the detection of renal artery stenosis. Computed tomography (CT) angiography (CTA) or magnetic resonance (MR) angiography (MRA) are useful diagnostic imaging studies for the detection of renal artery stenosis in patients where duplex ultrasonography is difficult. If duplex ultrasound, CTA, and MRA are indeterminate or pose a risk of significant renal impairment, renal angiography is useful for a definitive diagnosis of RAS. The focus of medical management for RAS relies on controlling renovascular hypertension and aggressive lifestyle modification with control of atherosclerotic disease risk factors. The restoration of renal artery patency by revascularization in the setting of RAS due to atherosclerosis may help in the management of hypertension and minimize renal dysfunction.

Österreichischer Blutdruckkonsens 2019

Erhöhter Blutdruck bleibt eine Hauptursache von kardiovaskulären Erkrankungen, Behinderung und frühzeitiger Sterblichkeit in Österreich, wobei die Raten an Diagnose, Behandlung und Kontrolle auch in rezenten Studien suboptimal sind. Das Management von Bluthochdruck ist eine häufige Herausforderung für Ärztinnen und Ärzte vieler Fachrichtungen. In einem Versuch, diagnostische und therapeutische Strategien zu standardisieren und letztendlich die Rate an gut kontrollierten Hypertoniker/innen zu erhöhen und dadurch kardiovaskuläre Erkrankungen zu verhindern, haben 13 österreichische medizinische Fachgesellschaften die vorhandene Evidenz zur Prävention, Diagnose, Abklärung, Therapie und Konsequenzen erhöhten Blutdrucks gesichtet. Das hier vorgestellte Ergebnis ist der erste Österreichische Blutdruckkonsens. Die Autoren und die beteiligten Fachgesellschaften sind davon überzeugt, daß es einer gemeinsamen nationalen Anstrengung bedarf, die Blutdruck-assoziierte Morbidität und Mortalität in unserem Land zu verringern.

Successful endovascular treatment of chronic renal artery occlusion: a preliminary retrospective case series including 15 patients

PURPOSE

To evaluate in a retrospective, single-center, case series if percutaneous transluminal renal angioplasty/stenting of chronic renal artery occlusion is beneficial to renal function and blood pressure control, which remains controversial.

METHODS

Data from 15 consecutive patients with renal artery stump who underwent successful percutaneous transluminal renal angioplasty/stenting only for unilateral chronic renal artery occlusion at our center from January 2007 to February 2018 and completed follow-up were retrospectively evaluated. Of the 15 patients, 14 (93.3%) were treated with stenting and 1 with only balloon angioplasty. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) formula corrected for Chinese, and changes in blood pressure and need for antihypertensive medications were recorded.

RESULTS

At median 1.5-year (interquartile range 0.5-5.0) follow-up, restenosis rate was 20.0%. Renal function improved or remained stable in 26.7% and 53.3% of patients, respectively, and blood pressure normalized or improved in 13.3% and 40.0% of patients, respectively. Young patients with Takayasu's arteritis or fibromuscular dysplasia appeared to benefit the most from revascularization.

CONCLUSIONS

In this preliminary retrospective series of select patients with renal artery stump, endovascular treatment of chronic renal artery occlusion appeared to preserve renal function and improve blood pressure.

Non-invasive Stenotic Renal Artery Haemodynamics by in silico Medicine

Background: Measuring the extent to which renal artery stenosis (RAS) alters renal haemodynamics may permit precision medicine by physiologically guided revascularization. This currently requires invasive intra-arterial pressure measurement with associated risks and is rarely performed. The present proof-of-concept study investigates an in silico approach that uses computational fluid dynamic (CFD) modeling to non-invasively estimate renal artery haemodynamics from routine anatomical computed tomography (CT) imaging of RAS.

Methods: We evaluated 10 patients with RAS by CT angiography. Intra-arterial renal haemodynamics were invasively measured by a transducing catheter under resting and hyperaemic conditions, calculating the translesional ratio of distal to proximal pressure (Pd/Pa). The diagnostic and quantitative accuracy of the CFD-derived virtual Pd/Pa ratio (vPd/Pa) was evaluated against the invasively measured Pd/Pa ratio (mPd/Pa).

Results: Hyperaemic haemodynamics was infeasible and CT angiography in 4 patients had insufficient image resolution. Resting flow data is thus reported for 7 stenosed arteries from 6 patients (one patient had bilateral RAS). The comparison showed a mean difference of 0.015 (95% confidence intervals of ± 0.08), mean absolute error of 0.064, and a Pearson correlation coefficient of 0.6, with diagnostic accuracy for a physiologically significant Pd/Pa of ≤ 0.9 at 86%.

Conclusion: We describe the first in silico estimation of renal artery haemodynamics from CT angiography in patients with RAS, showing it is feasible and diagnostically accurate. This provides a methodological framework for larger prospective studies to ultimately develop non-invasive precision medicine approaches for studies and interventions of RAS and resistant hypertension.

Renal artery stenosis and left ventricular hypertrophy: an updated review and meta-analysis of echocardiographic studies

AIM

Data on left ventricular hypertrophy (LVH) in patients with renal artery stenosis (RAS) and its regression following renal revascularization are scanty. We performed a meta-analysis to provide comprehensive information on this clinically relevant issue.

METHODS

Full articles providing data on: LVH, as assessed by echocardiography, in RAS patients as compared with essential hypertensive counterparts; changes of left ventricular (LV) mass index after renal artery revascularization were considered.

RESULTS

A total of 905 study participants (RAS = 446, essential hypertensive = 459) of both sex were included in nine studies. Pooled LV mass index was higher in RAS than in essential hypertensive patients (140.4 ± 11.1 g/m versus 121.8 ± 6.2 g/m, standard mean difference being 0.41 ± 0.07 [95% confidence interval (CI) 0.27-0.51, P < 0.001]. Among 360 RAS patients undergone renal revascularization from eight studies, baseline and post-intervention pooled mean LV mass index values were 129.0 ± 10.2 g/m and 115.5 ± 9.9 g/m, respectively, the standard mean difference being-0.36 ± 0.06 (95% CI from -0.47 to -0.25, P < 0.001). These findings were unaffected by publication bias or single study effect.

CONCLUSION

Our meta-analysis indicates that RAS patients have an increased likelihood of LVH compared with essential hypertensive counterparts and renal artery revascularization has a beneficial effect on LV structure, as reflected by a significant decrease in LV mass index.

Hypertension as a cardiovascular risk factor in autoimmune rheumatic diseases

Evidence for the increased risk of cardiovascular morbidity and mortality in patients with chronic inflammatory and systemic autoimmune diseases has accumulated during the past 15 years. In these patients, an interplay between several mechanisms, including premature acceleration of subclinical atherosclerotic damage, inflammation, and dysregulation of the immune system, is involved in the induction and progression of atherosclerosis. Moreover, traditional cardiovascular risk factors are also likely to contribute, at least in part, to the excess cardiovascular risk. Among traditional cardiovascular risk factors, hypertension is an important predictor of cardiovascular events in the general population and in patients with chronic inflammatory and autoimmune diseases. Evidence supports the idea that the pathogenic mechanisms underlying the increased blood pressure in these diseases are multifactorial and not only related to the mechanical injury of the arterial wall. In particular, chronic inflammation and immune-mediated mechanisms have been demonstrated to affect blood-pressure control in patients with systemic autoimmune disease. In this Review, we discuss the available evidence on the relationship between hypertension and autoimmune diseases, and describe the multiple factors that might affect blood-pressure control in patients with chronic inflammatory and systemic autoimmune diseases. We also discuss the effect of hypertension and antirheumatic therapies on cardiovascular outcome.