Showing papers by "Roland E. Schmieder published in 2020"

Proceedings from the 3rd European Clinical Consensus Conference for clinical trials in device-based hypertension therapies.

Abstract: Abstract

Alcohol-Mediated Renal Denervation Using the Peregrine System Infusion Catheter for Treatment of Hypertension

Abstract: Objectives The aim of this multicenter, open-label trial was to evaluate the safety and efficacy of alcohol-mediated renal denervation using a novel catheter system (the Peregrine System I...

Medication adherence in hypertension.

Abstract: Suboptimal adherence to antihypertensive medication is a major contributor to poor blood pressure control. Several methods, direct or indirect, are available for measuring adherence, including the recently developed biochemical screening, although there is no gold-standard method routinely used in clinical practice to accurately assess the different facets of adherence. Adherence to treatment is a complex phenomenon and several of the barriers to adherence will need to be addressed at the healthcare system level; however, when looking at adherence from a more practical side and from the practitioner's perspective, the patient-practitioner relationship is a key element both in detecting adherence and in attempting to choose interventions tailored to the patient's profile. The use of single-pill combinations enabling simplification of treatment regimen, the implementation of a collaborative team-based approach and the development of electronic health tools also hold promise for improving adherence, and thus impacting cardiovascular outcomes and healthcare costs.

Resting heart rate and cardiovascular outcomes in diabetic and non-diabetic individuals at high cardiovascular risk analysis from the ONTARGET/TRANSCEND trials.

Abstract: AIMS Resting heart rate (RHR) has been shown to be associated with cardiovascular outcomes in various conditions. It is unknown whether different levels of RHR and different associations with cardiovascular outcomes occur in patients with or without diabetes, because the impact of autonomic neuropathy on vascular vulnerability might be stronger in diabetes. METHODS AND RESULTS We examined 30 937 patients aged 55 years or older with a history of or at high risk for cardiovascular disease and after myocardial infarction, stroke, or with proven peripheral vascular disease from the ONTARGET and TRANSCEND trials investigating ramipril, telmisartan, and their combination followed for a median of 56 months. We analysed the association of mean achieved RHR on-treatment with the primary composite outcome of cardiovascular death, myocardial infarction, stroke, hospitalization for heart failure, the components of the composite primary outcome, and all-cause death as continuous and categorical variables. Data were analysed by Cox regression analysis, ANOVA, and χ2 test. These trials were registered with ClinicalTrials.gov.number NCT00153101. Patients were recruited from 733 centres in 40 countries between 1 December 2001 and 31 July 2008 (ONTARGET) and 1 November 2001 until 30 May 2004 (TRANSCEND). In total, 19 450 patients without diabetes and 11 487 patients with diabetes were stratified by mean RHR. Patients with diabetes compared to no diabetes had higher RHRs (71.8 ± 9.0 vs. 67.9 ± 8.8, P < 0.0001). In the categories of <60 bpm, 60 ≤ 65 bpm, 65 ≤ 70 bpm, 70 ≤ 75 bpm, 75 ≤ 80 bpm and ≥80 bpm, non-diabetic patients had an increased hazard of the primary outcome with mean RHR of 75 ≤ 80 bpm (adjusted hazard ratio [HR] 1.17 (1.01-1.36)) compared to RHR 60 ≤ 65 bpm. For patients with in-trial RHR ≥80 bpm the hazard ratios were highest (diabetes: 1.96 (1.64-2.34), no diabetes: 1.73 (1.49-2.00), For cardiovascular death hazards were also clearly increased at RHR ≥80 bpm (diabetes [1.99, (1.53-2.58)], no diabetes [1.73 (1.38-2.16)]. Similar results were obtained for hospitalization for heart failure and all-cause death while the effect of RHR on myocardial infarction and stroke was less pronounced. Results were robust after adjusting for various risk indicators including beta-blocker use and atrial fibrillation. No significant association to harm was observed at lower RHR. CONCLUSION Mean RHR above 75-80 b.p.m. was associated with increased risk for cardiovascular outcomes except for stroke. Since in diabetes, high RHR is associated with higher absolute event numbers and patients have higher RHRs, this association might be of particular clinical importance in diabetes. These data suggest that RHR lowering in patients with RHRs above 75-80 b.p.m. needs to be studied in prospective trials to determine if it will reduce outcomes in diabetic and non-diabetic patients at high cardiovascular risk. CLINICAL TRIAL REGISTRATION http://clinicaltrials.gov.Unique identifier: NCT00153101.

12-Month Results From the Unblinded Phase of the RADIANCE-HTN SOLO Trial of Ultrasound Renal Denervation

Abstract: Objectives This study reports the 12-month results of the RADIANCE-HTN (A Study of the ReCor Medical Paradise System in Clinical Hypertension) SOLO trial following unblinding of patients at 6 months. Background The blood pressure (BP)–lowering efficacy and safety of endovascular ultrasound renal denervation (RDN) in the absence (2 months) and presence (6 months) of antihypertensive medications were previously reported. Methods Patients with daytime ambulatory BP ≥135/85 mm Hg after 4 weeks off medication were randomized to RDN (n = 74) or sham (n = 72) and maintained off medication for 2 months. A standardized medication escalation protocol was instituted between 2 and 5 months (blinded phase). Between 6 and 12 months (unblinded phase), patients received antihypertensive medications at physicians’ discretion. Outcomes at 12 months included medication burden, change in daytime ambulatory systolic BP (dASBP) and office or home systolic BP (SBP), visit-to-visit variability in SBP, and safety. Results Sixty-five of 74 RDN patients and 67 of 72 sham patients had 12-month dASBP measurements. The proportion of patients on ≥2 medications (27.7% vs. 44.8%; p = 0.041), the number of medications (1.0 vs. 1.4; p = 0.015), and defined daily dose (1.4 vs. 2.2; p = 0.007) were less with RDN versus sham. The decrease in dASBP from baseline in the RDN group (−16.5 ± 12.9 mm Hg) remained stable at 12 months. The RDN versus sham adjusted difference at 12 months was −2.3 mm Hg (95% confidence interval [CI]: −5.9 to 1.3 mm Hg; p = 0.201) for dASBP, −6.3 mm Hg (95% CI: −11.1 to −1.5 mm Hg; p = 0.010) for office SBP, and −3.4 mm Hg (95% CI: −6.9 to 0.1 mm Hg; p = 0.062) for home SBP. Visit-to-visit variability in SBP was smaller in the RDN group. No renal artery injury was detected on computed tomographic or magnetic resonance angiography. Conclusions Despite unblinding, the BP-lowering effect of RDN was maintained at 12 months with fewer prescribed medications compared with sham.

Influence of Age on Upper Arm Cuff Blood Pressure Measurement

Abstract: Blood pressure (BP) is a leading global risk factor. Increasing age is related to changes in cardiovascular physiology that could influence cuff BP measurement, but this has never been examined systematically and was the aim of this study. Cuff BP was compared with invasive aortic BP across decades of age (from 40 to 89 years) using individual-level data from 31 studies (1674 patients undergoing coronary angiography) and 22 different cuff BP devices (19 oscillometric, 1 automated auscultation, 2 mercury sphygmomanometry) from the Invasive Blood Pressure Consortium. Subjects were aged 64±11 years, and 32% female. Cuff systolic BP overestimated invasive aortic systolic BP in those aged 40 to 49 years, but with each older decade of age, there was a progressive shift toward increasing underestimation of aortic systolic BP (P<0.0001). Conversely, cuff diastolic BP overestimated invasive aortic diastolic BP, and this progressively increased with increasing age (P<0.0001). Thus, there was a progressive increase in cuff pulse pressure underestimation of invasive aortic PP with increasing decades of age (P<0.0001). These age-related trends were observed across all categories of BP control. We conclude that cuff BP as an estimate of aortic BP was substantially influenced by increasing age, thus potentially exposing older people to greater chance for misdiagnosis of the true risk related to BP.

Cardiovascular outcomes, bleeding risk, and achieved blood pressure in patients on long-term anticoagulation with the thrombin antagonist dabigatran or warfarin: data from the RE-LY trial.

Abstract: AIMS A J-shaped association of cardiovascular events to achieved systolic (SBP) and diastolic (DBP) blood pressure was shown in high-risk patients. This association on oral anticoagulation is unknown. This analysis from RELY assessed the risks of death, stroke or systemic emboli, and bleeding according to mean achieved SBP and DBP in atrial fibrillation on oral anticoagulation. METHODS AND RESULTS RE-LY patients were followed for 2 years and recruited between 22 December 2005 until 15 December 2007. 18.113 patients were randomized in 951 centres in 54 countries and 18,107 patients with complete blood pressure (BP) data were analysed with a median follow-up of 2.0 years and a complete follow-up in 99.9%. The association between achieved mean SBP and DBP on all-cause death, stroke and systemic embolic events (SSE), major, and any bleeding were explored. On treatment, SBP >140 mmHg and 130 mmHg. Similar patterns were observed for DBP with an increased risk at 90 mmHg (HR 1.88; 1.43-2.46) for all-cause death compared to 70 to <80 mmHg (reference). Risk for any bleeding was increased at low DBP <70 mmHg (HR 1.46; 1.37-1.56) at DBP 80 to <90 mmHg (HR 1.13; 1.06-1.31) without increased risk at higher achieved DBP. Dabigatran 150 mg twice daily showed an advantage in all patients for all-cause death and SSE and there was an advantage for 110 mg dabigatran twice daily for major bleeding and any bleeding irrespective of SBP or DBP achieved. Similar results were obtained for baseline BP, time-updated BP, and BP as time-varying covariate. CONCLUSION Low achieved SBP associates with increased risk of death, SSE, and bleeding in patients with atrial fibrillation on oral anticoagulation. Major bleeding events did not occur at higher BP. Low BP might identify high-risk patients not only for death but also for high bleeding risks. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov-Identifier: NCT00262600.

Confounding Factors in Renal Denervation Trials: Revisiting Old and Identifying New Challenges in Trial Design of Device Therapies for Hypertension.

Abstract: Recent randomized sham-controlled trials have demonstrated significant blood pressure reductions following renal denervation (RDN) in patients with hypertension, both in the presence and absence of antihypertensive therapy. These new data encouraged us to revisit previously published insights into potential clinical trial confounding factors that informed the design and conduct of forthcoming trials. Initially identified confounders related to procedural technique, medication variability, and selected patient subgroups have been addressed in contemporary trial design. Regarding procedural method and technology, blood pressure reductions may be improved by ensuring circumferential lesion creation in the distal renal arteries and branch vessels. Safety of the RDN procedure has been demonstrated in multiple independent meta-analyses including thousands of treated patients with low reported rates of renal vessel complications and maintenance of renal function. However, a newer generation of RDN trials has also introduced insights related to medication adherence, patient selection, and the definition of treatment response. Evolving evidence indicates that RDN therapy may be considered in higher risk populations of uncontrolled hypertension regardless of ethnicity and in patients expressing a strong preference for a nondrug therapy option. Despite advances in procedural technique and clinical trial conduct, inconsistent antihypertensive-drug adherence behavior remains perhaps the most critical clinical trial design issue for device-based hypertension therapies. As the balance in clinical equipoise increasingly favors RDN, justification of sham-controlled trial designs will be revisited, and novel study designs may be required to evaluate the safety and efficacy of novel devices and procedures intended to address the escalating prevalence of poorly controlled hypertension.

Rationale and design of two randomized sham-controlled trials of catheter-based renal denervation in subjects with uncontrolled hypertension in the absence (SPYRAL HTN-OFF MED Pivotal) and presence (SPYRAL HTN-ON MED Expansion) of antihypertensive medications: a novel approach using Bayesian design

Abstract: The SPYRAL HTN clinical trial program was initiated with two 80-patient pilot studies, SPYRAL HTN-OFF MED and SPYRAL HTN-ON MED, which provided biological proof of principle that renal denervation has a blood pressure-lowering effect versus sham controls for subjects with uncontrolled hypertension in the absence or presence of antihypertensive medications, respectively. Two multicenter, prospective, randomized, sham-controlled trials have been designed to evaluate the safety and efficacy of catheter-based renal denervation for the reduction of blood pressure in subjects with hypertension in the absence (SPYRAL HTN-OFF MED Pivotal) or presence (SPYRAL HTN-ON MED Expansion) of antihypertensive medications. The primary efficacy endpoint is baseline-adjusted change from baseline in 24-h ambulatory systolic blood pressure. The primary safety endpoint is incidence of major adverse events at 1 month after randomization (or 6 months in cases of new renal artery stenosis). Both trials utilize a Bayesian design to allow for prespecified interim analyses to take place, and thus, the final sample sizes are dependent on whether enrollment is stopped at the first or second interim analysis. SPYRAL HTN-OFF MED Pivotal will enroll up to 300 subjects and SPYRAL HTN-ON MED Expansion will enroll up to 221 subjects. A novel Bayesian power prior approach will leverage historical information from the pilot studies, with a degree of discounting determined by the level of agreement with data from the prospectively powered studies. The Bayesian paradigm represents a novel and promising approach in device-based hypertension trials. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02439749 (SPYRAL HTN-OFF MED Pivotal) and NCT02439775 (SPYRAL HTN-ON MED Expansion).

Arteriovenous fistula thrombosis is associated with increased all-cause and cardiovascular mortality in haemodialysis patients from the AURORA trial.

Abstract: Background: The impact of arteriovenous fistula (AVF) or graft (AVG) thrombosis on mortality has been sparsely studied. This study investigated the association between AVF/AVG thrombosis and all-cause and cardiovascular mortality. Methods: The data from 2439 patients with AVF or AVG undergoing maintenance haemodialysis (HD) included in the A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events trial (AURORA) were analysed using a time-dependent Cox model. The incidence of vascular access (VA) thrombosis was a pre-specified secondary outcome. Results: During follow-up, 278 AVF and 94 AVG thromboses were documented. VA was restored at 22 ± 64 days after thrombosis (27 patients had no restoration with subsequent permanent central catheter). In multivariable survival analysis adjusted for potential confounders, the occurrence of AVF/AVG thrombosis was associated with increased early and late all-cause mortality, with a more pronounced association with early all-cause mortality {hazard ratio [HR] 90 days 1.47 [1.20–1.80], P < 0.001}. In addition, the occurrence of AVF thrombosis was significantly associated with higher all-cause mortality, whether VA was restored within 7 days [HR 1.34 (95% CI 1.02–1.75), P = 0.036] or later than 7 days [HR 1.81 (95% CI 1.29–2.53), P = 0.001]. Conclusions: AVF/AVG thrombosis should be considered as a major clinical event since it is strongly associated with increased mortality in patients on maintenance HD, especially in the first 90 days after the event and when access restoration occurs >7 days after thrombosis. Clinicians should pay particular attention to the timing of VA restoration and the management of these patients during this high-risk period. The potential benefit of targeting overall patient risk with more aggressive treatment after AVF/AVG restoration should be further explored.

Renal denervation: where do we stand and what is the relevance to the nephrologist?

Abstract: Catheter-based renal denervation to reduce high blood pressure (BP) has received well-deserved attention after a recent series of sham-controlled trials reported significant antihypertensive efficacy and very favourable tolerability and safety of the intervention. This emerging treatment option is of high relevance to nephrologists. Patients with chronic kidney disease (CKD) are at elevated risk of cardiovascular adverse events and often present with hypertension, which is very difficult to control with medication. Renal denervation promises a new tool to reduce BP and to prevent loss of renal function in this population. The current review considers the role of the kidney and neurohormonal activation in the development of hypertension and the rationale for renal denervation. The current state of the evidence for the effectiveness and tolerability of the procedure is considered from the nephrologists' perspective, with a focus on the potential future role of renal denervation in the management of CKD patients with hypertension.

Facing the Challenge of Lowering Blood Pressure and Cholesterol in the Same Patient: Report of a Symposium at the European Society of Hypertension

Abstract: A symposium held at the 29th European Meeting on Hypertension and Cardiovascular Protection in Milan, Italy, discussed the potential impact and long-term benefits of early active management of cardiovascular disease (CVD) risk in patients with hypertension, and potential barriers to this strategy. Hypertension often aggregates with other cardiovascular risk factors, exponentially increasing morbidity and mortality. While effective therapies to treat hypertension exist, a substantial number of patients still experience major cardiovascular events. Two major issues account for these disappointing results: interventions initiated too late in the disease trajectory and lack of effective translation of the research findings into daily clinical practice. Results from genetic studies suggest that lifetime exposure to lower blood pressure (BP) and cholesterol levels due to protective gene mutations, can provide greater cardiovascular benefits than middle-/late-age interventions. Clinical guidelines suggest adding statins to BP-lowering therapies for further cardiovascular benefits in most hypertensive patients; however, real-world data show that physicians' compliance with these recommendations and patients' adherence to BP- and lipid-lowering treatments remain poor, resulting in poor risk factor control and an increased risk of adverse outcomes. The use of single-pill combinations (SPC) can partially mitigate these issues, as they are associated with increased patient adherence and improved BP control. Treatment with SPC has been recommended in the European Hypertension Guidelines, but optimization of the total CVD risk may need adoption of more ambitious treatment strategies aimed to deliver single pills that control multiple CVD risk factors. Amlodipine, perindopril and atorvastatin have been shown to improve BP and lipid levels to a great extent when given separately, and this combination has also been shown to improve cardiovascular outcomes. Overall, early intervention in patients with hypertension with use of an effective, high-intensity cardiovascular risk reduction regimen and attention to medication adherence through reducing pill burden are likely to result in optimal outcomes.

Improved cardiovascular risk prediction in patients with end-stage renal disease on hemodialysis using machine learning modeling and circulating microribonucleic acids.

Abstract: Rationale: To test whether novel biomarkers, such as microribonucleic acids (miRNAs), and nonstandard predictive models, such as decision tree learning, provide useful information for medical decision-making in patients on hemodialysis (HD). Methods: Samples from patients with end-stage renal disease receiving HD included in the AURORA trial were investigated (n=810). The study included two independent phases: phase I (matched cases and controls, n=410) and phase II (unmatched cases and controls, n=400). The composite endpoint was cardiovascular death, nonfatal myocardial infarction or nonfatal stroke. miRNA quantification was performed using miRNA sequencing and RT-qPCR. The CART algorithm was used to construct regression tree models. A bagging-based procedure was used for validation. Results: In phase I, miRNA sequencing in a subset of samples (n=20) revealed miR-632 as a candidate (fold change=2.9). miR-632 was associated with the endpoint, even after adjusting for confounding factors (HR from 1.43 to 1.53). These findings were not reproduced in phase II. Regression tree models identified eight patient subgroups with specific risk patterns. miR-186-5p and miR-632 entered the tree by redefining two risk groups: patients older than 64 years and with hsCRP<0.827 mg/L and diabetic patients younger than 64 years. miRNAs improved the discrimination accuracy at the beginning of the follow-up (24 months) compared to the models without miRNAs (integrated AUC [iAUC]=0.71). Conclusions: The circulating miRNA profile complements conventional risk factors to identify specific cardiovascular risk patterns among patients receiving maintenance HD.

Visit-to-visit blood pressure variability and renal outcomes: results from ONTARGET and TRANSCEND trials.

Abstract: AIMS There is conflicting evidence on whether in treated hypertensive patients the risk of renal outcomes is associated with visit-to-visit SBP variability. Furthermore, limited evidence is available on how important is SBP variability for prediction of renal outcomes compared with on-treatment mean SBP. We addressed these issues in 28 790 participants of the Ongoing Treatment Alone and in combination with Ramipril Global End point Trial and Telmisartan Randomized Assessment Study in ace iNtolerant Subjects with Cardiovascular Disease trials. METHODS AND RESULTS SBP variability was expressed as the coefficient of variation of the mean with which it showed no relationship. SBP variability and mean values were obtained from five visits during the first 2 years of treatment after the end of the titration phase. Incidence of several renal outcomes (end-stage renal disease, doubling of serum creatinine, new microalbuminuria, new macroalbuminuria and their composite) was calculated from the third year of treatment onward. Patients were divided in quintiles of SBP-coefficient of variation (SBP-CV) or mean SBP, which exhibited superimposable mean blood pressure and SBP-CV values, respectively. A progressive increase of SBP-CV was not accompanied by a parallel increase in a widely adjusted (baseline and on-treatment confounders) risk of most renal outcomes (end-stage renal disease, new macroalbuminuria, new microalbuminuria and their composite) in the subsequent on-treatment years. In contrast, the adjusted risk of most renal outcomes increased progressively from the lowest to the highest quintile of on-treatment mean SBP. Progression from lowest to highest mean on-treatment SBP, but not SBP-CV, was also associated with a less frequent return to normoalbuminuria in patients with initial micro or macroalbuminuria. Renal outcome prediction was slightly improved by the combined use of SBP-CV and mean SBP quintiles. CONCLUSION Visit-to-visit SBP variability had no major predictive value for the risk of renal outcomes, which, in contrast, was sensitively predicted by mean on-treatment SBP. A further slight increase in prediction of renal outcomes was seen by combining on-treatment mean SBP and variability.

Combination of empagliflozin and linagliptin improves blood pressure and vascular function in type 2 diabetes.

Abstract: Aims Preserved vascular function represents a key prognostic factor in type 2 diabetes mellitus (T2DM), but data on vascular parameters in this patient cohort are scarce. Patients with T2DM often need more than one drug to achieve optimal glucose control. The aim of this study was to analyse the efficacy of two combination therapies on vascular function in subjects with T2DM. Methods and results This prospective, randomized study included 97 subjects with T2DM. Subjects were randomized to either the combination therapy empagliflozin (E) 10 mg with linagliptin (L) 5 mg once daily or metformin (M) 850 or 1000 mg twice daily with insulin glargine (I) once daily. At baseline and after 12 weeks, subjects had peripheral office and 24-h ambulatory blood pressure (BP) measurement and underwent vascular assessment by pulse wave analysis under office and ambulatory conditions. Office, 24-h ambulatory and central BP as well as pulse pressure (PP) decreased after 12 weeks of treatment with E + L, whereas no change was observed in M + I. There were greater decreases in 24-h ambulatory peripheral systolic (between-group difference: -5.2 ± 1.5 mmHg, P = 0.004), diastolic BP (-1.9 ± 1.0 mmHg, P = 0.036), and PP (-3.3 ± 1.0 mmHg, P = 0.007) in E + L than M + I. Central office systolic BP (-5.56 ± 1.9 mmHg, P = 0.009), forward pressure height of the pulse wave (-2.0 ± 0.9 mmHg, P = 0.028), 24-h ambulatory central systolic (-3.6 ± 1.4 mmHg, P = 0.045), diastolic BP (-1.95 ± 1.1 mmHg, P = 0.041), and 24-h pulse wave velocity (-0.14 ± 0.05m/s, P = 0.043) were reduced to a greater extent with E + L. Conclusion Beyond the effects on glycaemic control, the combination therapy of E + L significantly improved central BP and vascular function compared with the classic combination of M + I. Clinicaltrials.gov NCT02752113.

Changes in Stroke Volume After Renal Denervation: Insight From Cardiac Magnetic Resonance Imaging.

Abstract: Recent trial results support catheter-based renal denervation (RDN) for treatment of hypertension, while the exact mechanisms causing blood pressure to fall remain incompletely understood. Cardiac magnetic resonance imaging was used to assess the effects of RDN on cardiac function in patients with hypertension undergoing RDN and compared with sham treatment. Cardiac magnetic resonance imaging was used to assess stroke volume index, cardiac index, heart rate, systemic vascular resistance index, and stroke work index from aortic flow measurements. Patients with resistant hypertension from a randomized, sham-controlled RDN trial underwent cardiac magnetic resonance imaging before RDN and at follow-up (randomized cohort). Results were then validated in a cohort of patients with resistant hypertension undergoing RDN and cardiac magnetic resonance imaging (validation cohort). In total, 162 patients were included 52 patients in the randomized trial (27 shams) and 110 patients in the validation cohort. In the randomized cohort, stroke volume index was reduced by 4.7±9.8 mL/m2 in the RDN cohort and remained unchanged in the sham cohort (P=0.008 for between-group comparison), while cardiac index and stroke work index tended to be reduced in RDN patients but not in sham patients (-0.10±5.9 versus 0.17±0.51 L/min per m2 and -7.1±12.5 versus -1.4±10.4 g/m2, P=0.08 for both). In contrast, systemic vascular resistance index and heart rate remained unchanged after RDN. In the validation cohort, reduction of stroke volume index was confirmed, and cardiac index and stroke work index were also reduced significantly, whereas systemic vascular resistance index and heart rate remained unchanged at follow-up. In this study of patients with resistant hypertension, RDN resulted in a reduction of stroke volume when compared with sham.

Retinal neurodegeneration in patients with end-stage renal disease assessed by spectral-domain optical coherence tomography

Abstract: Spectral-domain optical coherence tomography (SD-OCT) represents a reliable tool for retinal layer volume and thickness measurement. The aim of this study was to evaluate retinal changes indicating neurodegenerative processes in patients with end-stage renal disease (ESRD) compared to healthy controls. This was a cross-sectional, single-center study comprising 32 ESRD patients and 38 controls. Sectoral retinal nerve fiber layer (RNFL) thickness and retinal layer volumes were obtained by SD-OCT. Age- and gender-adjusted retinal layer volumes such as total retinal volume (p = 0.037), ganglion cell layer volume (GCL, p = 0.003), ganglion cell layer – inner plexiform layer volume (GCL-IPL, p = 0.005) and inner retinal layer volume (IRL, p = 0.042) of the right eye were lower in ESRD patients. Inner plexiform layer volume of both eyes (IPL, right eye: p = 0.017; left eye: 0.044) was reduced, as was RNFL thickness in the temporal superior sector (right eye: p = 0.016). A subgroup analysis excluding patients with diabetes revealed that GCL (p = 0.014) and GCL-IPL volume of the right eye (p = 0.024) and temporal superior sector of the RNFL scan (p = 0.021) in ESRD patients were still significantly thinner. We observed a decrease in several retinal layer volumes and temporal RNFL thickness indicative of retinal neurodegenerative processes in patients with ESRD.

Variability of MRI Aortic Stiffness Measurements in a Multicenter Clinical Trial Setting: Intraobserver, Interobserver, and Intracenter Variability of Pulse Wave Velocity and Aortic Strain Measurement.

Abstract: With the use of standardized scanning protocols, the aortic stiffness assessed with MRI had acceptable variability and can be used for scientific assessment of vascular dynamic function.

Neurogenic tachykinin mechanisms in experimental nephritis of rats.

Abstract: We demonstrated earlier that renal afferent pathways combine very likely “classical” neural signal transduction to the central nervous system and a substance P (SP)–dependent mechanism to control sympathetic activity. SP content of afferent sensory neurons is known to mediate neurogenic inflammation upon release. We tested the hypothesis that alterations in SP-dependent mechanisms of renal innervation contribute to experimental nephritis. Nephritis was induced by OX-7 antibodies in rats, 6 days later instrumented for recording of blood pressure (BP), heart rate (HR), drug administration, and intrarenal administration (IRA) of the TRPV1 agonist capsaicin to stimulate afferent renal nerve pathways containing SP and electrodes for renal sympathetic nerve activity (RSNA). The presence of the SP receptor NK-1 on renal immune cells was assessed by FACS. IRA capsaicin decreased RSNA from 62.4 ± 5.1 to 21.6 ± 1.5 mV s (*p < 0.05) in controls, a response impaired in nephritis. Suppressed RSNA transiently but completely recovered after systemic administration of a neurokinin 1 (NK1-R) blocker. NK-1 receptors occurred mainly on CD11+ dendritic cells (DCs). An enhanced frequency of CD11c+NK1R+ cell, NK-1 receptor+ macrophages, and DCs was assessed in nephritis. Administration of the NK-1R antagonist aprepitant during nephritis reduced CD11c+NK1R+ cells, macrophage infiltration, renal expression of chemokines, and markers of sclerosis. Hence, SP promoted renal inflammation by weakening sympathoinhibitory mechanisms, while at the same time, substance SP released intrarenally from afferent nerve fibers aggravated immunological processes i.e. by the recruitment of DCs.

Lumen narrowing and increased wall to lumen ratio of retinal microcirculation are valuable biomarkers of hypertension-mediated cardiac damage

Abstract: Purpose: In the course of hypertension, left ventricular hypertrophy and diastolic dysfunction develop very often and may progress toward heart failure. The aim of the study was to analyze the rela...

Afferent renal innervation in anti-Thy1.1 nephritis in rats.

Abstract: Afferent renal nerves exhibit a dual function controlling central sympathetic outflow via afferent electrical activity and influencing intrarenal immunological processes by releasing peptides such ...

Tissue sodium content in hypertension and related organ damage.

Abstract: Most textbooks state that sodium (Na) accumulation goes hand in hand with fluid retention to maintain the environmental isotonicity. In the last century, several studies found, however, that Na is stored in the extravascular space leading to an activation of the monocyte phagocytic system cells that work as a regulator of the interstitial electrolyte homeostasis. Na-MRI was developed to quantify noninvasively, accurately and reliably tissue Na content. In this review, we give an up-to-date overview of clinical studies utilizing this Na-MRI technique to elucidate the importance of tissue Na content in patients with cardiovascular risk factors leading to microvascular and macrovascular complications. Na storage leads ultimately to organ damage such as left ventricular hypertrophy or hypertrophic vascular remodeling of resistance vessels. Elevated Na content in muscle and skin has been detected in patients with treatment resistant hypertension, type 2 diabetes mellitus, acute and chronic heart failure, chronic kidney disease and end-stage renal failure. Pharmacological interventions have shown that a mobilization of extracellular accumulated Na is possible and may emerge as a new therapeutic approach in some diseases.

The influence of aircraft noise exposure on the systemic and renal haemodynamics.

Abstract: AIMS Epidemiological studies found a link between aircraft noise exposure and increased incidence of arterial hypertension and cardiovascular disease, but the underlying pathophysiological mechanisms are not fully understood. Clinical studies have shown that mental stress affects the systemic and renal haemodynamic, but no such study was performed with noise exposure as stress factor. We analysed systemic and renal effects of 25 min standardized aircraft noise in a sham controlled clinical study including 80 healthy men and 34 male patients with hypertension. METHODS AND RESULTS Systemic haemodynamic parameters were measured using electrocardiography and impedance cardiography. The renal haemodynamic was assessed using steady state input clearance with infusion of para-aminohippuric acid and inulin for glomerular filtration rate and renal plasma flow, respectively. In the systemic circulation of hypertensive patients, there was an increase in total peripheral resistance (TPR) (1420 ± 387 vs. 1640 ± 516 dyn·s·cm-5, P = 0.001) and a decrease in cardiac index (CI) (2.9 ± 0.8 vs. 2.6 ± 0.8 L/(min·m2, P < 0.001) 25 min after the start of noise exposure, which was not present during sham procedure (P = 0.10, P = 0.86). In healthy individuals a procedure induced increase in TPR and decrease in CI was present after noise (TPR: 995 ± 239 vs. 1106 ± 308 dyn·s·cm-5, P = 0.001, CI: 3.6 ± 0.7 vs. 3.3 ± 0.9 L/(min·m2, P < 0.001) and sham application (TPR: P = 0.002, CI: P < 0.001). However, in healthy individuals changes in TPR (P = 0.450) and CI (P = 0.605) from baseline until 25 min after the start of the intervention did not differ between noise and sham exposure. In the renal circulation of hypertensive patients and healthy individuals the response did not differ between noise and sham procedure. CONCLUSIONS In hypertensive but not healthy men we observed a systemic vasoconstrictive response after aircraft noise exposure accompanied by a decrease in CI. No significant changes were observed in the renal circulation. Our results suggest that male hypertensive patients are more susceptible for noise-induced changes of vascular resistance in the systemic circulation.

Relationship Between Ubiquitin-Specific Peptidase 18 and Hypertension in Polish Adult Male Subjects: A Cross-Sectional Pilot Study

Abstract: BACKGROUND Arterial hypertension (HT) is a leading cause of cardiac hypertrophy and heart failure. Ubiquitin-specific peptidase 18 (USP18) has been recently described as a factor that prevents myocardial dysfunction. The present study measured serum USP18 levels in normotensive (n=29), isolated diastolic hypertensive (n=20), and systolic-diastolic hypertensive (n=30) male participants and correlated these results with biochemical parameters that are included in routine assessments of patients with hypertension. MATERIAL AND METHODS Seventy-nine men, aged 24 to 82 years (mean=50.8±11.4 years), were included in the study. None of the participants had ever been treated for HT. Blood and urine parameters were assessed using routine techniques. Serum USP18 levels were measured by enzyme-linked immunosorbent assay. RESULTS The means and 95% confidence intervals (CIs) of USP18 levels in the HT(-), iDHT(+), and HT(+) groups were 69.3 (22.1-116.5) pg/ml, 90.1 (29.0-151.3) pg/ml, and 426.7 (163.1-690.3) pg/ml, respectively. In the HT(+) group, the mean serum USP18 level was 6.2-times higher than in the HT(-) group (p=0.014) and 4.7-times higher than in the iDHT(+) group (p=0.19). The partial correlation analysis that was adjusted for risk factors of arteriosclerosis indicated that USP18 levels were correlated with systolic blood pressure, pulse pressure, and heart rate. CONCLUSIONS This preliminary study found that serum USP18 levels were significantly higher in drug-naive male participants with arterial hypertension compared with normotensive controls. USP18 exerts cardiovascular-protective effects. Elevations of USP18 levels may indicate a counterregulatory process that is engaged during increases in pressure in the left ventricle.

Retinal arterial remodeling in patients with pheochromocytoma or paraganglioma and its reversibility following surgical treatment.

Abstract: OBJECTIVE Structural abnormalities in resistance arteries are a hallmark of patients with hypertension. In hypertensive patients with pheochromocytoma or paraganglioma (PPGL), it is still a matter of debate whether structural vascular changes are because of elevated blood pressure (BP) or to toxic effects of elevated circulating catecholamines. Hence, the aim of our study was to assess whether catecholamine excess and/or elevated BP affect the structure of small retinal arteries in patients with catecholamine-producing tumors. METHODS The study included 27 patients with PPGL and 27 hypertensive patients. All patients underwent biochemical tests for catecholamine excess, echocardiography and analyses of scanning-laser-Doppler-flowmetry (SLDF) both at baseline and 12 months following surgical resection of PPGL. RESULTS Baseline retinal arterial diameter, arterial wall thickness and wall cross sectional area (WCSA) were higher in patients with PPGL as compared with subjects without PPGL (arterial diameter: 110 ± 16.5 vs. 99.5 ± 10.8 μm, wall thickness: 16.3 ± 6.0 vs. 13.5 ± 4.0 μm, WCSA: 4953.9 ± 2472.8 vs. 3784.1 ± 1446.3 μm, P < 0.05). Significant correlations were noted between wall thickness and WCSA and echocardiographic parameters assessing diastolic and systolic function of left ventricle. No correlations between retinal parameters, BP level and plasma concentrations of metanephrines were observed. In patients with PPGL, there were postoperative decreases in wall thickness (16.4 ± 15.8 vs. 14.8 ± 4.7 μm; P = 0.011) and WLR (0.42 ± 0.13 vs. 0.37 ± 0.10; P = 0.003) at 12 months after surgical removal of tumors. CONCLUSION This is the first study to demonstrate that catecholamine excess is related to thickening of retinal arteries independent of BP and reversible after surgical cure. These data support a role of catecholamines in vascular remodeling in PPGL patients.

Assessment of Retinal Arteriolar Morphology by SLDF

Abstract: The analysis of retinal vessels offers the exceptional opportunity to assess human microcirculation in vivo. However, for the assessment of vascular remodeling in vivo, two interrelated and indistinguishable features have to be taken into account, which are morphological changes (i.e., rearrangement and hypertrophy of vascular smooth muscle cells), but also changes in vascular tone (i.e., endothelial function). In the last years, several methods have been introduced for the assessment of retinal changes. One promising approach, introduced about two decades ago, is scanning laser Doppler flowmetry (SLDF) allowing both the dynamic assessment of structural and functional parameters repeatedly, directly, noninvasively, and safely in vivo with high reliability.