Blood pressure reduction after renal denervation in patients with or without chronic kidney disease.

Background: Renal denervation (RDN) has emerged as an adjacent option for the treatment of hypertension. This analysis of the Erlanger registry aimed to compare the blood pressure (BP)-lowering effects and safety of RDN in patients with and without chronic kidney disease (CKD). Methods: In this single-center retrospective analysis, 47 patients with and 127 without CKD underwent radiofrequency-, ultrasound- or alcohol-infusion-based RDN. Office and 24-h ambulatory BP and estimated glomerular filtration rate (eGFR) were measured at baseline, and after 6 and 12 months. Results: A total of 174 patients with a mean age of 59.0 ± 10 years were followed up for 12 months. At baseline, mean eGFR was 55.8 ± 21 mL/min/1.73 m2 in patients with CKD and 87.3 ± 13 mL/min/1.73 m2 in patients without CKD. There was no significant eGFR decline in either of the groups during 12 months of follow-up. In patients without CKD, office systolic and diastolic BP were reduced by -15.3 ± 17.5/-7.9 ± 10.8 mmHg 6 months after RDN and by -16.1 ± 18.2/-7.7 ± 9.6 mmHg 12 months after RDN. In patients with CKD, office systolic and diastolic BP were reduced by -10.7 ± 24.0/-5.8 ± 13.2 mmHg 6 months after RDN and by -15.1 ± 24.9/-5.9 ± 12.9 mmHg 12 months after RDN. Accordingly, in patients without CKD, 24-h ambulatory systolic and diastolic BP were reduced by -7.2 ± 15.8/-4.9 ± 8.8 mmHg 6 months after RDN and by -9.0 ± 17.0/-6.2 ± 9.8 mmHg 12 months after RDN. In patients with CKD, 24-h systolic and diastolic BP were reduced by -7.4 ± 12.9/-4.2 ± 9.9 mmHg 6 months after RDN and by -8.0 ± 14.0/-3.6 ± 9.6 mmHg 12 months after RDN. There was no difference in the reduction of office and 24-h ambulatory BP between the two groups at any time point (all P > .2). Similar results have been found for the 6 months data. With exception of rare local adverse events, we did not observe any safety signals. Conclusion: According to our single-center experience, we observed a similar reduction in 24-h, day and night-time ambulatory BP as well as in-office BP in patients with and without CKD at any time point up to 12 months. We conclude that RDN is an effective and safe treatment option for patients with hypertension and CKD.

Relation between waist circumference and the renal hemodynamic in healthy individuals.

BACKGROUND AND AIMS: Obesity has been shown to be an independent risk factor for the development of CKD. Little is known about pathways of interaction of visceral fat mass estimated by waist circumference (WC) and metabolic factors with the renal and intraglomerular hemodynamic profile in healthy, non-obese individuals. METHODS AND RESULTS: The study population of this post-hoc analysis in 80 healthy individuals, who participated in a randomized, controlled clinical trial (www. CLINICALTRIALS: gov: NCT02783456) was divided into two groups based on median of WC (high WC and low WC group). Renal hemodynamic profiles were analyzed using steady state input clearance (infusion of para-amino-hippuric acid and inulin). Intraglomerular pressure (IGP) and resistances of the afferent (RA) and efferent (RE) arterioles were calculated (Gomez equation). The analysis included healthy, non-smoking individuals, aged 27 ± 9 years with median WC of 84.75 ± 9 cm. Glomerular filtration rate (GFR) (110 ± 15 vs. 127 ± 16 ml/min/m2, p < 0.001), renal plasma flow (RPF) (620 ± 109 vs. 700 ± 104 ml/min, p = 0.001) and IGP (36.7 ± 2.3 vs. 38.5 ± 3.1 mmHg, p = 0.003) were lower in the high WC compared to the low WC group. Patients in the high WC group showed higher renal vascular resistance (RVR) (85 ± 19 vs. 70 ± 12 mmHg/(ml/min), p < 0.001), higher RA (4034 ± 1177 vs. 3069 ± 786 dyn∗s/cm5, p < 0.001) and higher RE (2283 ± 339 vs. 2118 ± 280 dyn∗s/cm5, p = 0.021) compared to the low WC group. Individuals in the high WC group showed higher leptin levels (p = 0.003) and higher HOMA-IR (p = 0.024) compared to the low WC group. CONCLUSION: Increased WC in healthy young individuals was associated with reduced GFR and RPF likely mediated by increased RVR.

Skin sodium content as a predictor of blood pressure response to renal denervation.

Patients with treatment resistant hypertension (TRH) are known to have elevated sodium (Na) content in muscle and skin. Renal denervation (RDN) emerged as an adjacent therapeutic option in this group of patients. This analysis aimed at evaluating whether tissue Na content predicts blood pressure (BP) response after RDN in patients with TRH. Radiofrequency-device based RDN was performed in 58 patients with uncontrolled TRH. Office and 24-h ambulatory BP were measured at baseline and after 6 months. To assess tissue Na content Na magnetic resonance imaging (Na-MRI) was performed at baseline prior to RDN. We splitted the study cohort into responders and non-responders based on the median of systolic 24-h ambulatory blood pressure (ABP) reduction after 6 months and evaluated the association between BP response to RDN and tissue Na content in skin and muscle. The study was registered at http://www.clinicaltrials.gov (NCT01687725). Six months after RDN 24-h ABP decreased by -8.6/-4.7 mmHg. BP-Responders were characterized by the following parameters: low tissue sodium content in the skin (p = 0.040), female gender (p = 0.027), intake of aldosterone antagonists (p = 0.032), high baseline 24-h night-time heart rate (p = 0.045) and high LDL cholesterol (p < 0.001). These results remained significant after adjustment for baseline 24-h systolic BP. Similar results were obtained when the median of day-time and night-time ABP reduction after 6 months were used as cut-off criteria for defining BP response to RDN. We conclude that in addition to clinical factors including baseline 24-h ABP Na-MRI may assist to select patients with uncontrolled TRH for RDN treatment.

Rapid assessment of changes in phage bioactivity using dynamic light scattering.

Extensive efforts are underway to develop bacteriophages as therapies against antibiotic-resistant bacteria. However, these efforts are confounded by the instability of phage preparations and a lack of suitable tools to assess active phage concentrations over time. In this study, we use dynamic light scattering (DLS) to measure changes in phage physical state in response to environmental factors and time, finding that phages tend to decay and form aggregates and that the degree of aggregation can be used to predict phage bioactivity. We then use DLS to optimize phage storage conditions for phages from human clinical trials, predict bioactivity in 50-y-old archival stocks, and evaluate phage samples for use in a phage therapy/wound infection model. We also provide a web application (Phage-Estimator of Lytic Function) to facilitate DLS studies of phages. We conclude that DLS provides a rapid, convenient, and nondestructive tool for quality control of phage preparations in academic and commercial settings.

Rapid assessment of changes in phage bioactivity using dynamic light scattering.

Extensive efforts are underway to develop bacteriophages as therapies against antibiotic-resistant bacteria. However, these efforts are confounded by the instability of phage preparations and a lack of suitable tools to assess active phage concentrations over time. Here, we use Dynamic Light Scattering (DLS) to measure changes in phage physical state in response to environmental factors and time, finding that phages tend to decay and form aggregates and that the degree of aggregation can be used to predict phage bioactivity. We then use DLS to optimize phage storage conditions for phages from human clinical trials, predict bioactivity in 50-year-old archival stocks, and evaluate phage samples for use in a phage therapy/wound infection model. We also provide a web-application (Phage-ELF) to facilitate DLS studies of phages. We conclude that DLS provides a rapid, convenient, and non-destructive tool for quality control of phage preparations in academic and commercial settings.

Developing Phage Therapy That Overcomes the Evolution of Bacterial Resistance.

The global rise of antibiotic resistance in bacterial pathogens and the waning efficacy of antibiotics urge consideration of alternative antimicrobial strategies. Phage therapy is a classic approach where bacteriophages (bacteria-specific viruses) are used against bacterial infections, with many recent successes in personalized medicine treatment of intractable infections. However, a perpetual challenge for developing generalized phage therapy is the expectation that viruses will exert selection for target bacteria to deploy defenses against virus attack, causing evolution of phage resistance during patient treatment. Here we review the two main complementary strategies for mitigating bacterial resistance in phage therapy: minimizing the ability for bacterial populations to evolve phage resistance and driving (steering) evolution of phage-resistant bacteria toward clinically favorable outcomes. We discuss future research directions that might further address the phage-resistance problem, to foster widespread development and deployment of therapeutic phage strategies that outsmart evolved bacterial resistance in clinical settings.

Determinants of arterial stiffness in patients with type 2 diabetes mellitus: a cross sectional analysis.

In patients with type 2 diabetes mellitus (T2DM) arterial stiffness is associated with increased cardiovascular and total mortality. Little is known about determinants of arterial stiffness in clinical routine. Identification of potential determinants of arterial stiffness will help to address treatment targets for patients in the early state of T2DM. This is a cross-sectional analysis of arterial stiffness in 266 patients in the early stage of T2DM who did not have cardiovascular or renal complications. Parameters of arterial stiffness such as central systolic blood pressure (cSBP), central pulse pressure (cPP) and pulse wave velocity (PWV) were measured with the SphygmoCor System (AtCor Medical). We investigated the influence of parameters of glucose metabolism, lipid status, body constitution, blood pressure (BP) and inflammation on the stiffness parameters using multivariate regression analysis. The study cohort consisted of male and female patients aged 61 ± 8 years with mean diabetes duration of 6.4 ± 5.1 years, mean HbA1c 7.1 ± 0.9%, mean cSBP 121 ± 12 mmHg, mean cPP 44 ± 10 mmHg and mean PWV 8.9 ± 1.8 m/s. Multiple regression analysis identified waist circumference (WC) (beta = 0.411, p = 0.026), LDL-cholesterol (beta = 0.106, p = 0.006), systolic office BP (beta = 0.936, p < 0.001) and diabetes duration (beta = 0.233, p = 0.043) as potential determinants of cSBP. cPP was determined by sex (beta = 0.330, p = 0.008), age (beta = 0.383, p < 0.001), systolic office BP (beta = 0.370, p < 0.001) and diabetes duration (beta = 0.231, p = 0.028) whereas for PWV the following determinants could be identified: age (beta = 0.405, p < 0.001), systolic office BP (beta = 0.421, p < 0.001) and diabetes duration (beta = 0.073, p = 0.038). In addition to the known parameters age, sex and systolic office BP serum LDL-cholesterol, WC and diabetes duration have been identified as determinants of arterial stiffness in patients with T2DM. Treatment of patients in the early stage of T2DM should focus on these clinical parameters to prevent progression of arterial stiffness and as a consequence reduce cardiovascular mortality.Trial registration: The patients included in the analysis participated in one of the following clinical trials NCT02752113 (registered 26.4.2016), NCT02383238 (09.03.2015), NCT02471963 (15.06.2015), NCT01319357 (21.03.2011) ( http://www.clinicaltrials.gov ).

Angiotensin pathways under therapy with empagliflozin in patients with chronic heart failure.

AIMS: Large outcome studies demonstrated a reduction of heart failure hospitalization or cardiovascular death in patients with chronic heart failure (CHF). The renin-angiotensin system (RAS) is a key player in fluid and sodium regulation. The classic angiotensin-converting enzyme-angiotensin II-angiotensin-1 receptor axis (Ang I-ACE-Ang II receptor axis) is predominantly angiotensin II (Ang-II) induced and promotes vasoconstriction. In contrast, the angiotensin-converting-enzyme-2-angiotensin-(1-7)-Mas axis (Mas-axis) is mediated by the metabolites angiotensin-1-7 (Ang-(1-7)) and angtiotensin-1-5 (Ang-(1-5)) and exerts cardioprotective effects. METHODS: We previously investigated the effect of empagliflozin on the systemic haemodynamic in patients with stable CHF (NYHA II-III) in a randomized placebo-controlled clinical trial 'Analysing the Effect of Empagliflozin on Reduction of Tissue Sodium Content in Patients With Chronic Heart Failure (ELSI)'. In a post hoc analysis, we now analysed whether empagliflozin has an effect on the RAS by measuring detailed RAS profiles (LC-MS/MS-based approach) in 72 patients from ELSI. We compared RAS parameters after 1-month and 3-months treatment with empagliflozin or placebo to baseline. The secondary goal was to analyse whether the effect of empagliflozin on RAS parameters was dependent on angiotensin-receptor-blocking (ARB) or angiotensin-converting-enzyme-inhibitor (ACEI) co-medication. RESULTS: Empagliflozin medication induced a significant rise in Ang-II [68.5 pmol/L (21.3-324.2) vs. 131.5 pmol/L (34.9-564.0), P = 0.001], angiotensin-I (Ang-I) [78.7 pmol/L (21.5-236.6) vs. 125.9 pmol/L (52.6-512.9), P < 0.001], Ang-(1-7) [3.0 pmol/L (3.0-15.0) vs. 10.1 pmol/L (3.0-31.3), P = 0.006], and Ang-(1-5) [5.4 pmol/L (2.0-22.9) vs. 9.9 pmol/L (2.8-36.4), P = 0.004], which was not observed in the placebo group (baseline to 3-months treatment). A significant rise in Ang-II (206.4 pmol/L (64.2-750.6) vs. 568.2 pmol/L (164.7-1616.4), P = 0.001), Ang-(1-7) (3.0 pmol/L (3.0-14.1) vs. 15.0 pmol/L (3.0-31.3), P = 0.017), and Ang-(1-5) [12.2 pmol/L (3.8-46.6) vs. 36.4 pmol/L (11.1-90.7), P = 0.001] under empagliflozin treatment was only seen in the subgroup of patients with ARB co-medication, whereas no change of Ang-II (16.7 pmol/L (2.0-60.8) vs. 26.4 pmol/L (10.7-63.4), P = 0.469), Ang-(1-7) (6.6 pmol/L (3.0-20.7) vs. 10.5 pmol/L (3.0-50.5), P = 0.221), and Ang-(1-5) (2.7 pmol/L (2.0-8.4) vs. 2.8 pmol/L (2.0-6.9), P = 0.851) was observed in patients with empagliflozin that were on ACEI co-medication (baseline to 3-months treatment). CONCLUSIONS: Our data indicate that empagliflozin might lead to an activation of both the Ang I-ACE-Ang II receptor axis and the Mas-axis pathway. Activation of the Ang I-ACE-Ang II receptor axis and the protective Mas-axis pathway after initiating treatment with empagliflozin was only seen in patients with ARB co-medication, in contrast to co-medication with ACEI.

The SGLT2 inhibitor empagliflozin reduces tissue sodium content in patients with chronic heart failure: results from a placebo-controlled randomised trial.

INTRODUCTION: Sodium-glucose co-transporter 2 (SGLT2) inhibitors have cardiovascular protective properties in addition to the metabolic effects and represent a cornerstone of treating patients with chronic heart failure (CHF). We hypothesised that empagliflozin reduces tissue sodium content in patients with CHF. METHODS: In a double-blind, randomised (2:1), placebo-controlled, parallel-group, clinical trial, 74 patients with NYHA class II-III CHF and an ejection fraction of 49% or less received empagliflozin 10 mg once daily or placebo for 3 months. In each patient, tissue sodium content of the lower leg was assessed non-invasively by sodium-MRI (23Na-MRI) at baseline, after 1 and 3 months of treatment. RESULTS: After 1 and 3 months treatment with empagliflozin (n = 48), a significant decrease in skin sodium content was observed (1 month: 22.8 ± 6.1 vs. 21.6 ± 6.0 AU, p = 0.039; 3 months: 22.9 ± 6.1 vs. 21.6 ± 6.1 AU, p = 0.013), while there was no change in muscle sodium and muscle water content. In direct comparison, the change in skin sodium content between baseline and 3 months was - 1.3 ± 3.5 AU in the empagliflozin group versus 0.6 ± 3.5 AU in the placebo group (p for between-group difference = 0.022). No significant difference regarding change in muscle sodium and in muscle water content was observed after 3 months treatment between the two groups. CONCLUSION: This trial showed a significant decrease in skin sodium content after 1 and 3 months of treatment with empagliflozin. The decrease in skin sodium content may reflect a decrease in subclinical micro-oedema or/and in non-osmotic bound tissue sodium, both reported to impair left ventricular function. TRIAL REGISTRATION NUMBER: NCT03128528 ( http://www. CLINICALTRIALS: gov ). TRIAL REGISTRATION DATE: 25th April 2017.

Is vascular remodelling in patients with chronic heart failure exaggerated?

BACKGROUND: Vascular remodelling of large arteries increases afterload of the left ventricle. The aim of this study was to analyse whether vascular remodelling and function under laboratory and 24-hour ambulatory conditions is impaired in patients with chronic heart failure (CHF) independently of cardiovascular risk factors. METHODS AND RESULTS: In this monocentric cross-sectional observational study, 105 patients with CHF and an ejection fraction ≤49% (CHF+) were compared to 118 subjects without CHF (CHF-). After adjustment for age, gender, arterial hypertension, hyperlipidaemia, type 2 diabetes, obesity and smoking, vascular function and structure parameters, as assessed by pulse wave analysis (SphygmoCor) and the UNEX EF device, respectively, between the CHF+ and the CHF- group differed for resting pulse wave velocity (PWV) (P = 0.010), 24-h ambulatory PWV (P = 0.011), central systolic blood pressure (cSBP) (P = <0.001), 24-h ambulatory cSBP (P = <0.001), resting central augmentation index (P = 0.002), and brachial intima-media thickness (P = 0.022). In CHF+ patients, higher levels of NT-proBNP, taken as a marker for the severity of CHF, were related to a higher PWV (r = 0.340, P = <0.001), a higher cSBP (r = 0.292, P = 0.005), and a trend to higher central pulse pressure (cPP) (r = 0.198, P = 0.058), higher 24-h brachial PP (r = 0.322, P = 0.002), and 24-h total peripheral resistance (s = 0.227, P = 0.041) after full adjustment for covariates. CONCLUSIONS: In CHF+ patients we observed augmented vascular remodelling and functional impairment compared with CHF- patients independently of cardiovascular risk factors, age, and gender, and the extent of vascular remodelling and impairment was related to the severity of CHF.

Bacteriophage genome engineering with CRISPR-Cas13a.

Jumbo phages such as Pseudomonas aeruginosa ФKZ have potential as antimicrobials and as a model for uncovering basic phage biology. Both pursuits are currently limited by a lack of genetic engineering tools due to a proteinaceous 'phage nucleus' structure that protects from DNA-targeting CRISPR-Cas tools. To provide reverse-genetics tools for DNA jumbo phages from this family, we combined homologous recombination with an RNA-targeting CRISPR-Cas13a enzyme and used an anti-CRISPR gene (acrVIA1) as a selectable marker. We showed that this process can insert foreign genes, delete genes and add fluorescent tags to genes in the ФKZ genome. Fluorescent tagging of endogenous gp93 revealed that it is ejected with the phage DNA while deletion of the tubulin-like protein PhuZ surprisingly had only a modest impact on phage burst size. Editing of two other phages that resist DNA-targeting CRISPR-Cas systems was also achieved. RNA-targeting Cas13a holds great promise for becoming a universal genetic editing tool for intractable phages, enabling the systematic study of phage genes of unknown function.

Change of renal function after short-term use of cardioprotective agents in patients with type 2 diabetes is not accurately assessed by the change of estimated glomerular filtration rate: an observational study.

BACKGROUND: After initiating cardioprotective agents, a fall of estimated glomerular filtration rate (eGFR) has been reported in several studies. Our goal was to evaluate the accuracy of change of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFR in patients with type 2 diabetes (T2D) after short-term pharmacological intervention with angiotensin-converting enzyme inhibitor, angiotensin-receptor blocker, gliptin or sodium-glucose cotransporter-2 inhibitor. METHODS: We analyzed 190 patients with T2D in the early stage of the disease, having no overt renal impairment by CKD-EPI equation. In each patient, we measured GFR (mGFR) by applying the constant infusion input clearance technique with sinistrin (Inutest; Fresenius, Linz, Austria) at baseline and after short-term (4-12 weeks) pharmacological intervention with cardioprotective agents (ramipril, telmisartan, linagliptin, metformin, empagliflozin) that potentially lead to an alteration of renal function. Simultaneously, a standardized analysis of serum creatinine was performed and eGFR was estimated by the CKD-EPI equation. RESULTS: Average mGFR was 111 ± 20 ml/min/1.73m2, whereas eGFR was lower with 93 ± 13 ml/min/1.73m2. The ratio eGFR/mGFR in relation to mGFR was almost curvilinear, showing an underestimation of renal function by eGFR in the upper normal range. At baseline only 80 patients (42%) lay within ± 10% of mGFR and the concordance correlation coefficient (CCC) was extremely low (- 0.07). After short-term pharmacological intervention changes in eGFR and mGFR correlated with each other (r = 0.286, p < 0.001). For example, for a given mGFR of 111 ml/min/1.73m2, a change of mGFR by ± 10% corresponded to ± 11 ml/min/1.73m2, but the confidence interval of eGFR was 25 ml/min/1.73m2. The CCC was low (0.22). CONCLUSION: The agreement between eGFR by CKD-EPI and mGFR is modest and the change of renal function after short-term pharmacological intervention is not accurately and precisely reflected by the change of eGFR in patients with T2D in the early stage of their disease.

Effects of treatment with SGLT-2 inhibitors on arginine-related cardiovascular and renal biomarkers.

BACKGROUND: In patients with type 2 diabetes (T2D) sodium-glucose cotransporter 2 (SGLT-2) inhibitors improve glycaemic control as well as cardiovascular and renal outcomes. Their effects on L-arginine (Arg) related risk markers asymmetric and symmetric dimethylarginine (ADMA and SDMA) and the protective biomarker L-homoarginine (hArg) linking T2D to cardiovascular and renal disease have not yet been reported. METHODS: Plasma and 24-h urine samples taken before and after 6 weeks of treatment were available from two prospective, randomized, double-blind, placebo-controlled, cross-over trials with empagliflozin (71 patients analyzed, NCT02471963) and dapagliflozin (59 patients analyzed, NCT02383238). In these samples, concentrations of hArg, Arg, ADMA, SDMA, and creatinine were determined by liquid-chromatography coupled to tandem mass-spectrometry. Additionally, intraindividual changes of the biomarkers in plasma were correlated with intraindividual changes of clinical parameters. RESULTS: Treatment with empagliflozin and dapagliflozin was associated with a reduction of plasma hArg by 17.5% and 13.7% (both p < 0.001), respectively, and increase in plasma SDMA concentration of 6.7% and 3.6%, respectively (p < 0.001 and p < 0.05), while plasma Arg and ADMA concentrations were not significantly altered. 24-h urinary excretion of ADMA was reduced by 15.2% after treatment with empagliflozin (p < 0.001) but not after dapagliflozin treatment, while excretion of the other markers was not significantly altered. Renal clearance of SDMA was reduced by 9.1% and 3.9% for both drugs (both p < 0.05). A reduction in ADMA clearance was observable after empagliflozin treatment only (- 15.5%, p < 0.001), but not after dapagliflozin. Renal clearance of hArg and Arg was not significantly altered. Treatment effects on L-arginine related biomarkers were not constantly correlated with effects on glycated hemoglobin, fasting plasma glucose, body mass index, and systolic blood pressure. CONCLUSIONS: Treatment with SGLT-2 inhibitors has divergent effects on Arg-related biomarkers and could affect risk estimates associated with these markers. The observed effects are unlikely to explain the known cardiovascular and renal benefits of treatment with empagliflozin or dapagliflozin but still may indicate new therapeutic approaches in patients treated with SGLT-2 inhibitors. Trial registration http://www.clinicaltrials.gov : NCT02471963 (registered 15th June 2015, retrospectively registered) and NCT02383238.

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

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.

Renal hemodynamic effects differ between antidiabetic combination strategies: randomized controlled clinical trial comparing empagliflozin/linagliptin with metformin/insulin glargine.

BACKGROUND: Type 2 diabetes causes cardio-renal complications and is treated with different combination therapies. The renal hemodynamics profile of such combination therapies has not been evaluated in detail. METHODS: Patients (N = 97) with type 2 diabetes were randomized to receive either empagliflozin and linagliptin (E+L group) or metformin and insulin glargine (M+I group) for 3 months. Renal hemodynamics were assessed with para-aminohippuric acid and inulin for renal plasma flow (RPF) and glomerular filtration rate (GFR). Intraglomerular hemodynamics were calculated according the Gomez´ model. RESULTS: Treatment with E+L reduced GFR (p = 0.003), but RPF remained unchanged (p = 0.536). In contrast, M+I not only reduced GFR (p = 0.001), but also resulted in a significant reduction of RPF (p < 0.001). Renal vascular resistance (RVR) decreased with E+L treatment (p = 0.001) but increased with M+I treatment (p = 0.001). The changes in RPF and RVR were different between the two groups (both padjust < 0.001). Analysis of intraglomerular hemodynamics revealed that E+L did not change resistance of afferent arteriole (RA) (p = 0.116), but diminished resistance of efferent arterioles (RE) (p = 0.001). In M+I group RA was increased (p = 0.006) and RE remained unchanged (p = 0.538). The effects on RA (padjust < 0.05) and on RE (padjust < 0.05) differed between the groups. CONCLUSIONS: In patients with type 2 diabetes and preserved renal function treatment with M+I resulted in reduction of renal perfusion and increase in vascular resistance, in contrast to treatment with E+I that preserved renal perfusion and reduced vascular resistance. Moreover, different underlying effects on the resistance vessels have been estimated according to the Gomez model, with M+I increasing RA and E+L predominantly decreasing RE, which is in contrast to the proposed sodium-glucose cotransporter 2 inhibitor effects. TRIAL REGISTRATION: The study was registered at www.clinicaltrials.gov (NCT02752113) on April 26, 2016.

Effects of the sodium-glucose cotransporter 2 inhibitor empagliflozin on vascular function in patients with chronic heart failure.

AIMS: Impairment of vascular function contributes to the progression of chronic heart failure (HF) by increasing the afterload. Treatment with selective sodium-glucose cotransporter 2 (SGLT2) inhibitors improves the prognosis of HF, but the precise mechanisms remain unclear. The aim of this study was to analyse the effect of empagliflozin on vascular function in patients with HF. METHODS AND RESULTS: In an investigator initiated, double-blind, randomized, placebo-controlled, parallel-group, clinical study, patients with HF NYHA II-III and an ejection fraction of 49% or less were randomized 2:1 to receive empagliflozin 10 mg once daily or placebo for 3 months. A total of 74 patients (15% female), aged 66 ± 9 years, with a mean ejection fraction of 39 ± 8% and a median NTproBNP of 558 pg/mL (IQR 219-1051 pg/mL), were included. Vascular parameters such as central systolic blood pressure (cSBP), central pulse pressure (cPP), forward (FPH), and reflected pressure pulse height (RPH) decreased under resting conditions after 1 and 3 months (1 month: cSBP -6.4 ± 8.3 mmHg, P < 0.001, cPP -3.0 ± 6.6 mmHg, P = 0.004, FPH -2.5 ± 4.5 mmHg, P = 0.001, RPH -1.6 ± 3.0 mmHg, P = 0.001; 3 months: cSBP -4.6 ± 8.4 mmHg, P = 0.001, cPP -3.1 ± 4.8 mmHg, P < 0.001, FPH -1.7 ± 3.7 mmHg, P = 0.004, RPH -1.4 ± 2.5 mmHg, P = 0.001) in patients treated with empagliflozin (n = 45). In accordance, cSBP and cPP decreased in patients with empagliflozin treatment under 24 h ambulatory conditions after 1 and 3 months (1 month: cSBP -4.8 ± 10.1 mmHg, P = 0.003, cPP -2.0 ± 5.7 mmHg, P = 0.026; 3 months: cSBP -4.7 ± 9.0 mmHg, P = 0.002, cPP -2.1 ± 6.4 mmHg, P = 0.044). In the placebo group, there was no significant change after 1 and 3 months. The decrease in cSBP under resting conditions (-5.7 ± 2.4 mmHg, P = 0.019) after 1 month and in cSBP (-6.0 ± 2.6, P = 0.027) as well as in pulse wave velocity (-0.5 ± 0.2 m/s, P = 0.021) under 24 h ambulatory conditions after 3 months was greater in the empagliflozin group than in the placebo group. CONCLUSIONS: We found an improvement of vascular function after treatment with empagliflozin that indicates decreased afterload of the left ventricle and may contribute to the beneficial effects of SGLT2 inhibition in HF.

Association of Noise Annoyance with Measured Renal Hemodynamic Changes.

BACKGROUND: Chronic mental stress is recognized as a modifiable risk factor for cardiovascular disease. The aim of this study was to demonstrate that noise annoyance-induced stress is associated with changes in renal hemodynamics. METHODS: Renal hemodynamic parameters were measured using steady-state input clearance with infusion of para-aminohippuric acid and inulin in individuals with normal, high normal, and elevated blood pressure. All individuals ranked subjective annoyance due to noise in everyday life on a 7-grade Likert scale. The median of all rankings was used as a cutoff point to divide the group into noise-annoyed and non-noise-annoyed individuals. Different renal hemodynamic parameters were calculated based on the Gomez equation. RESULTS: Noise-annoyed individuals (n = 58) showed lower renal plasma flow (599 ± 106 vs. 663 ± 124 mL/min, p = 0.009), lower renal blood flow (1,068 ± 203 vs. 1,172 ± 225 mL/min, p = 0.047), higher filtration fraction (22.7 ± 3.3 vs. 21.3 ± 3.0, p = 0.012), higher renal vascular resistance (88.9 ± 25.6 vs. 75.8 ± 22.9 mm Hg/[mL/min], p = 0.002), and higher resistance of afferent arteriole (2,439.5 ± 1,253.4 vs. 1,849.9 ± 1,242.0 dyn s-1 cm-5, p = 0.001) compared to non-noise-annoyed individuals (n = 55). There was no difference in measured glomerular filtration rate (133 ± 11.8 vs. 138 ± 15 mL/min, p = 0.181), resistance of efferent arteriole (2,419.4 ± 472.2 vs. 2,245.8 ± 370.3 dyn s-1 cm-5, p = 0.060), and intraglomerular pressure (64.0 ± 3.1 vs. 64.6 ± 3.5 mm Hg, p = 0.298) between the groups. After adjusting for age, renal plasma flow, renal blood flow, and renal vascular resistance remained significantly different between the groups, with a trend in increased afferent arteriolar resistance and filtration fraction. CONCLUSION: In this study, noise annoyance was associated with reduced renal perfusion attributed to increased renal vascular resistance predominantly at the afferent site. Long-term consequences of this renal hemodynamic pattern due to noise annoyance need to be investigated.

Hypertrophic remodelling of retinal arterioles in patients with congestive heart failure.

AIMS: Analysis of microvascular parameters in the retinal circulation-known to reflect those in the systemic circulation-allows us to differentiate between eutrophic and hypertrophic remodelling of small arteries. This study aimed to examine microvascular changes in patients with congestive heart failure (CHF) and reduced as well as mid-range ejection fraction. METHODS AND RESULTS: Forty subjects with CHF underwent measurement of retinal capillary flow (RCF), wall-to-lumen ratio (WLR), vessel and lumen diameter, wall thickness, and wall cross-sectional area (WCSA) of retinal arterioles of the right eye by scanning laser Doppler flowmetry (SLDF). Applying a matched pair approach, we compared this group with reference values of age-matched controls from a random sample in the population of Pilsen, Czech Republic. There was no significant difference in RCF and WLR between the groups (RCF: P = 0.513; WLR: P = 0.106). In contrast, wall thickness and WCSA, indicators of hypertrophic remodelling, were higher in CHF subjects (WT: 15.0 ± 4.2 vs. 12.7 ± 4.2 µm, P = 0.021; WCSA: 4437.6 ± 1314.5 vs. 3615.9 ± 1567.8 µm2 , P = 0.014). Similarly, vessel (109.4 ± 11.1 vs. 100.5 ± 14.4 µm, P = 0.002) and lumen diameter (79.0 ± 7.9 vs. 75.2 ± 8.5 µm, P = 0.009) were increased in CHF. CONCLUSIONS: In CHF subjects, we observed hypertrophic remodelling of retinal arterioles indicative of similar changes of small resistance arteries in the systemic circulation. Microvascular structure and function assessed by SLDF may thereby represent a useful, non-invasive method for monitoring of microvascular damage in patients with CHF and may offer innovative treatment targets for new CHF therapies.

Detection of Changes in Renal Blood Flow Using Arterial Spin Labeling MRI.

BACKGROUND: Alteration in kidney perfusion is an early marker of renal damage. The purpose of this study was to evaluate if changes in renal blood flow (RBF) could be detected using MRI with arterial spin labeling (ASL) technique. METHODS: RBF as assessed by cortical (CRBF), medullary, and total renal blood flow (TRBF) were measured by MRI with arterial spin labeling (ASL-MRI) using flow-sensitive alternating inversion recovery true fast imaging with steady-state precession sequence. In 11 normotensive healthy individuals (NT) and 11 hypertensive patients (HT), RBF was measured at baseline and after both feet were covered with cold ice packs (cold pressor test) that activates the sympathetic nervous system. In another experiment, RBF was measured in 10 patients with CKD before and after a pharmacological intervention. We compared RBF measurements between the 3 study populations. RESULTS: A significant reduction in CRBF (p = 0.042) and a trend in TRBF (p = 0.053) were observed in response to the activation of the sympathetic nervous system. A trend toward reduction of CRBF (p = 0.051) and TRBF (p = 0.059) has been detected after pharmacological intervention. TRBF was significantly lower in patients with HT and CKD patients compared to NT individuals (NT vs. HT, p = 0.014; NT vs. CKD, p = 0.004). TRBF was lower in patients with CKD compared to HT (p = 0.047). CONCLUSION: Our data indicate that both acute and short-term changes in RBF could be detected using ASL-MRI. We were able to detect differences in RBF between healthy and diseased individuals by needing only small sample size per group. Thus, ASL-MRI offers an advantage in conducting clinical trials compared to other technologies.