Feasibility and acceptability of the ShareD dEciSIon making for patients with kidney failuRE to improve end-of-life care intervention: A pilot multicentre randomised controlled trial.

Background: Kidney failure is associated with a high disease burden and high mortality rates. National and international guidelines recommend health professionals involve patients with kidney failure in making decisions about end-of-life care, but implementation of these conversations within kidney services varies. We developed the DESIRE (ShareD dEciSIon-making for patients with kidney failuRE to improve end-of-life care) intervention from our studies investigating multiple decision maker needs and experiences of end-of-life care in kidney services. The DESIRE intervention's three components are a training programme for health professionals, a patient decision aid, and a kidney service consultation held to facilitate shared decision-making conversations about planning end-of-life care. Objectives: To assess the feasibility and acceptability of integrating the DESIRE intervention within kidney services. Design: A pilot study using a multicentre randomised controlled design. Setting: Four Danish nephrology departments. Participants: Patients with kidney failure who were 75 years of age or above, their relatives, and health professionals. Methods: Patients were randomised to either the intervention or usual care. Feasibility data regarding delivering the intervention, the trial design, and outcome measures were collected through questionnaires and audio recordings at four points in time: before, during, post, and 3 months after the intervention. Acceptability data were collected through semi-structured interviews with patients and relatives, as well as a focus group with health professionals post the intervention. Results: Twenty-seven patients out of the 32 planned were randomised either to the intervention (n= 14) or usual care (n= 13). In addition, four relatives and 12 health professionals participated. Follow-up was completed by 81 % (n= 22) of patient participants. We found that both feasibility and acceptability data suggested health professionals improved their decision support and shared decision-making skills via the training. Patient and relative participants experienced the intervention as supporting a shared decision-making process; from audio recordings, we showed health professionals were able to support proactively decision-making about end-of-life care within these consultations. All stakeholders perceived the intervention to be effective in promoting shared decision-making and relevant for supporting end-of-life care planning. Conclusions: Participant feedback indicated that the DESIRE intervention can be integrated into practice to support patients, relatives, and health professionals in planning end-of-life care alongside the management of worsening kidney failure. Minimising exhaustion and enhancing engagement with the intervention should be a focus for subsequent refinement of the intervention. Registration: The study has been registered at ClinicalTrials.gov with the identifier: NCT05842772. Date of first recruitment: March 20, 2023.

Shared decision making for patients with kidney failure to improve end-of-life care: Development of the DESIRE intervention.

AIM: To describe the development of a shared decision making intervention for planning end-of-life care for patients with kidney failure, their relatives and health professionals in kidney services. BACKGROUND: End-of-life care conversations within standard disease management consultations are challenging for patients with kidney failure, their relatives and health professionals. End-of-life care planning is about making difficult decisions in advance, which is why health professionals need shared decision making skills to be able to initiate end-of-life conversations. Health professionals report needing more skills to raise the issue of end-of-life care options within consultations and patients want to be able to discuss issues important to them about future care plans. METHODS: The development design was guided by the UK Medical Research Council's framework and a user-centred approach was applied. Four workshops were conducted with end users. The Template for Intervention Description and Replication for Population Health and Policy interventions was used to shape which questions needed to be answered through the workshops and to present the intervention. The International Patient Decision Aid Standards (IPDAS) criteria set the standards to be achieved. RESULTS: Areas considered significant to a shared decision making intervention were training of health professionals, conversations about end-of-life care, planning and evaluation of the decisions, reporting decisions in health records and repetition of consultation. The development process went through 14 iterations. CONCLUSION: An intervention named DESIRE was developed that comprises: (1) a training programme for health professionals; (2) shared decision making conversations; and (3) a patient decision aid. The intervention met 30 out of 33 IPDAS criteria. IMPLICATIONS FOR PRACTICE: DESIRE is intended to support shared decision making about planning end-of-life care among patients with kidney failure, their relatives and health professionals. The study provides important tools for the stakeholders engaged that can be used within different models of care. IMPACT: What problem did the study address? International guidelines recommend health professionals involve patients with kidney failure in making decisions about end-of-life care, but there is variation in how this is implemented within and across kidney services. Furthermore, patients, relatives and health professionals find it challenging to initiate conversations about end-of-life care. What were the main findings? The study resulted in the development of a complex intervention, called DESIRE, about shared decision making and planning end-of-life care for patients with kidney failure, their relatives and health professionals in kidney services, including a training programme for health professionals, shared decision making conversations and a patient decision aid. Where and on whom will the research have an impact? The research contributes a shared decision making intervention to patients in the later stage of kidney failure, their relatives and health professionals. We believe that the DESIRE intervention could be introduced during consultations with health professionals at an earlier stage of the patient's illness trajectory, as well as being applied to other chronic diseases. REPORTING METHOD: This intervention development research is reported according to the GUIDance for the rEporting of intervention Development (GUIDED) checklist and the DEVELOPTOOLS Reporting Checklist. PATIENT OR PUBLIC CONTRIBUTION: Patients, relatives and health professionals have been involved throughout the research process as part of the research team and advisory board. For this study, the advisory board has particularly contributed to the development process of the DESIRE intervention by actively participating in the four workshops, in the iterations between the workshops and in the preparation of the manuscript.

Decisional needs in people with kidney failure, their relatives and health professionals about end-of-life care options: A qualitative interview study.

AIM: To investigate the decisional needs in Denmark of people with kidney failure, relatives, and health professionals when planning end-of-life care. DESIGN: A qualitative interview study. METHODS: Individual semi-structured interviews were carried out with people with kidney failure, relatives and health professionals from November 2021 to June 2022. Malterud's systematic text condensation was used to analyse transcripts. RESULTS: A total of 13 patients, 10 relatives, and 12 health professionals were interviewed. Overall, four concepts were agreed on: (1) Talking about end of life is difficult, (2) Patients and relatives need more knowledge and information, (3) Health professionals need more tools and training, and (4) Experiencing busyness as a barrier to conversations about end of life. CONCLUSION: People with kidney failure, relatives, and health professionals shared certain decisional needs while also having some different decisional needs about end-of-life care. To meet these various needs, end-of-life conversations should be systematic and organized according to the patients' needs and wishes. IMPACT: Non-systematic end-of-life care decision-making processes limit patients' involvement. Patients and relatives need more knowledge about end-of-life care, and health professionals need more competences and time to discuss decisional needs. A shared decision-making intervention for people with kidney failure when making end-of-life care decisions will be developed. REPORTING METHOD: This empirical qualitative research is reported according to the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist. PATIENT OR PUBLIC CONTRIBUTION: Patients, relatives, and health professionals have been involved throughout the research process as part of the research team and advisory board. The patients are people with kidney failure and the relatives are relatives of a person with kidney failure. For this study, the advisory board has particularly contributed to the validation of the invitation letter for participation, the interview guides and the preparation of the manuscript.

Patient involvement interventions for patients with kidney failure making end-of-life care decisions: a scoping review.

OBJECTIVE: The objective of this review was to investigate and map empirical evidence of patient involvement interventions to support patients with kidney failure making end-of-life care decisions in kidney services. INTRODUCTION: Clinical guidance integrating end-of-life care within kidney failure management pathways varies. Advance care planning interventions aimed at involving patients with kidney failure in their end-of-life care planning are established in some countries. However, there is limited evidence of the other types of patient involvement interventions integrated within services to support patients with kidney failure in making decisions about their end-of-life care. INCLUSION CRITERIA: This scoping review included studies exploring patient involvement interventions evaluated for patients with kidney failure considering end-of-life care, their relatives, and/or health professionals in kidney services. Studies of children under the age of 18 years were excluded. METHODS: The review was informed by JBI methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review guidelines. MEDLINE, Scopus, Embase, and CINAHL were searched for full-text studies in English, Danish, German, Norwegian, or Swedish. Two independent reviewers assessed the literature against the inclusion criteria. A relational analysis framework was used to synthesize the data extracted from the included studies, and to investigate and map different patient involvement interventions. RESULTS: The search identified 1628 articles, of which 33 articles met the inclusion criteria. A total of 23 interventions were described. Interventions targeted patients (n=3); health professionals (n=8); patients and health professionals (n=5); and patients, relatives, and health professionals (n=7). Intervention components included patient resources (eg, information, patient decision aids), consultation resources (eg, advance care planning, shared decision-making), and practitioner resources (eg, communication training). Patient involvement interventions were delivered within hospital-based kidney services. CONCLUSIONS: The review identified several ways to support patients with kidney failure to be involved in end-of-life care decisions. Future interventions may benefit from adopting a complex intervention framework to engage multiple stakeholders in the research and design of an intervention for shared decision-making between patients with kidney failure, their relatives, and health professionals about integrating end-of-life care options into their kidney disease management pathway.

Prediction of CKD Progression and Cardiovascular Events Using Albuminuria and Pulse Wave Velocity.

INTRODUCTION: Chronic kidney disease (CKD) is associated with cardiovascular disease (CVD) and death. Albuminuria is an established risk factor, but additional biomarkers predicting CKD progression or CVD are needed. Arterial stiffness is an easily measurable parameter that has been associated with CVD and mortality. We evaluated the ability of carotid-femoral pulse wave velocity (PWV) and urine albumin-creatinine (UAC) ratio to predict CKD progression, cardiovascular events, and mortality in a cohort of CKD patients. METHODS: In CKD stage 3-5 patients, PWV and UAC were measured at baseline. CKD progression was defined as 50% decline in estimated glomerular filtration rate (eGFR), initiation of dialysis, or renal transplantation. A composite endpoint was defined as CKD progression, myocardial infarction, stroke, or death. Endpoints were analyzed using Cox regression analysis adjusted for possible confounders. RESULTS: We included 181 patients (median age 69 [interquartile range 60-75] years, 67% males) with a mean eGFR of 37 ± 12 mL/min/1.73 m2 and UAC 52 (5-472) mg/g. Mean PWV was 10.6 m/s. Median follow-up until first event was 4 (3-6) years with 44 and 89 patients reaching a CKD progression or composite endpoint, respectively. UAC (g/g) significantly predicted both CKD progression (HR 1.5 [1.2; 1.8]) and composite endpoints (HR 1.4 [1.1; 1.7]) in adjusted Cox regression. In contrast, PWV (m/s) was not associated with neither CKD progression (HR 0.99 [0.84; 1.18]) nor the composite endpoint (HR 1.03 [0.92; 1.15]). CONCLUSION: In an aging CKD population, UAC predicted both CKD progression and a composite endpoint of CKD progression, cardiovascular events, or death, while PWV did not.

Effects of enhanced versus reduced vasodilating treatment on brachial and central blood pressure in patients with chronic kidney disease: a randomized controlled trial.

BACKGROUND: Blood pressure (BP) control is important in chronic kidney disease (CKD), but a reduction in brachial BP may not mirror changes in central aortic BP (cBP) during antihypertensive medication. We hypothesize that a fall in cBP is better reflected during enhanced vasodilation treatment (EVT) compared with reduced vasodilation treatment (RVT) because of different hemodynamic actions of these interventions. METHODS: Eighty-one hypertensive CKD stage 3-4 patients (mean measured glomerular filtration rate 36 ml/min per 1.73 m2) were randomized to either EVT based on renin--angiotensin blockade and/or amlodipine or RVT based on nonvasodilating ß-blockade (metoprolol). Before randomization and following 18 months of treatment, we performed 24-h ambulatory BP measurements (ABPM) and radial artery pulse wave analysis for estimation of cBP and augmentation index (AIx). Forearm resistance (Rrest) was determined by venous occlusion plethysmography and arterial stiffness by carotid--femoral pulse wave velocity (PWV). Matched healthy controls were studied once for comparison. RESULTS: Compared with controls, CKD patients had elevated ABPM, cBP and PWV. Although ABPM remained unchanged from baseline to follow-up in both treatment groups, cBP decreased 4.7/2.9 mmHg (systolic/diastolic) during EVT and increased 5.1/1.5 mmHg during RVT (Δ=9.8/4.4 mmHg, P=0.02 for SBP, P = 0.05 for DBP). At follow-up, the difference between systolic cBP and 24-h ABPM (ΔBPsyst) was negatively associated with heart rate and positively associated with AIx and Rrest (all P < 0.01) but not PWV (P = 0.32). CONCLUSION: In CKD patients, EVT and RVT have opposite effects on cBP and the difference between cBP and ambulatory BP is larger for EVT than RVT.

Correction to: Phase-contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper.

The article Phase­contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper, written by Giulia Villa, Steffen Ringgaard, Ingo Hermann, Rebecca Noble, Paolo Brambilla, Dinah S. Khatir, Frank G. Zöllner, Susan T. Francis, Nicholas M. Selby, Andrea Remuzzi and Anna Caroli, was originally published electronically on the publisher's internet portal on 17 August 2019 without open access.

Phase-contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper.

OBJECTIVE: Phase-contrast magnetic resonance imaging (PC-MRI) is a non-invasive method used to compute blood flow velocity and volume. This systematic review aims to discuss the current status of renal PC-MRI and provide practical recommendations which could inform future clinical studies and its adoption in clinical practice. METHODOLOGY: A comprehensive search of all the PC-MRI studies in human healthy subjects or patients related to the kidneys was performed. RESULTS: A total of 39 studies were included in which PC-MRI was used to measure renal blood flow (RBF) alongside other derivative hemodynamic parameters. PC-MRI generally showed good correlation with gold standard methods of RBF measurement, both in vitro and in vivo, and good reproducibility. Despite PC-MRI not being routinely used in clinical practice, there are several clinical studies showing its potential to support diagnosis and monitoring of renal diseases, in particular renovascular disease, chronic kidney disease and autosomal dominant polycystic kidney disease. DISCUSSION: Renal PC-MRI shows promise as a non-invasive technique to reliably measure RBF, both in healthy volunteers and in patients with renal disease. Future multicentric studies are needed to provide definitive normative ranges and to demonstrate the clinical potential of PC-MRI, likely as part of a multi-parametric renal MRI protocol.

[Diagnosis, monitoring and treatment of tuberous sclerosis complex].

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder with highly varying disease manifestations, many of which cause extensive morbidity. There are international consensus criteria for the diagnosis, monitoring and treatment of TSC, and approved medical treatment for some of the most serious disease manifestations. However, organisation of a rational and coordinated care of TSC patients involves many different medical specialities and is only sparsely described. This review describes the interdisciplinary care of TSC patients at Aarhus University Hospital, Denmark.

Aortic Calcification Affects Noninvasive Estimates of Central Blood Pressure in Patients with Severe Chronic Kidney Disease.

BACKGROUND: Central blood pressure (BP) assessed noninvasively considerably underestimates true invasively measured aortic BP in chronic kidney disease (CKD) patients. The difference between the estimated and the true aortic BP increases with decreasing estimated glomerular filtration rates (eGFR). The present study investigated whether aortic calcification affects noninvasive estimates of central BP. METHODS: Twenty-four patients with CKD stage 4-5 undergoing coronary angiography and an aortic computed tomography scan were included (63% males, age [mean ± SD ] 53 ± 11 years, and eGFR 9 ± 5 mL/min/1.73 m2). Invasive aortic BP was measured through the angiography catheter, while non-invasive central BP was obtained using radial artery tonometry with a SphygmoCor® device. The Agatston calcium score (CS) in the aorta was quantified on CT scans using the CS on CT scans. RESULTS: The invasive aortic systolic BP (SBP) was 152 ± 23 mm Hg, while the estimated central SBP was 133 ± 20 mm Hg. Ten patients had a CS of 0 in the aorta, while 14 patients had a CS >0 in the aorta. The estimated central SBP was lower than the invasive aortic SBP in patients with aortic calcification compared to patients without (mean difference 8 mm Hg, 95% CI 0.3-16; p = 0.04). The brachial SBP was lower than the aortic SBP in patients with aortic calcification compared to patients without (mean difference 10 mm Hg, 95% CI 2-19; p = 0.02). CONCLUSION: In patients with advanced CKD the presence of aortic calcification is associated with a higher difference between invasively measured central aortic BP and non-invasive estimates of central BP as compared to patients without calcifications.

Effects of additional vasodilatory or nonvasodilatory treatment on renal function, vascular resistance and oxygenation in chronic kidney disease: a randomized clinical trial.

AIM: Progression of chronic kidney disease (CKD) may be accelerated by tissue hypoxia due to impaired blood supply. This could be induced by small artery narrowing resulting in abnormally high intrarenal vascular resistance (RVR). We investigated whether a reduction in RVR achieved by adding vasodilating medical therapy (AVT) is superior to adding nonvasodilating medical therapy (AnonVT) regarding tissue oxygenation and preservation of kidney function. METHODS: Eighty-three grade 3 and 4 CKD patients [estimated glomerular filtration rate (GFR) 34.6 ml/min per 1.73 m] were randomized to either AVT with amlodipine and/or renin angiotensin blockade or AnonVT with the nonvasodilating beta-blocker metoprolol. Investigations were performed at baseline and after 18 months of therapy. Systemic vasodilation was documented in the forearm vasculature using resting venous occlusion plethysmography. GFR was measured as Chrome-EDTA plasma clearance. Using MRI, renal artery blood flow was measured for calculation of RVR and for estimating renal oxygenation (R2*). RESULTS: AVT and AnonVT achieved as planned similar blood pressure levels throughout the study. At follow-up, resistance had decreased by 7% (P < 0.05) and RVR by 12% (P < 0.05) in the AVT group, whereas in the AnonVT group, resistance increased by 39% (P < 0.01), whereas RVR remained unchanged. At follow-up, no significant differences in cortical or medullary R2* values between AVT and AnonVT were observed, and the GFR decline was similar in the two groups (3.0 vs. 3.3 ml/min per 1.73 m). CONCLUSION: Long-term intensified vasodilation treatment reduced peripheral and RVR, but this was not associated with improvement of R2* or protection against loss of kidney function in CKD patients.

Arterial stiffness and peripheral vascular resistance in offspring of hypertensive parents: influence of sex and other confounders.

AIM: Established essential hypertension is associated with increased arterial stiffness and peripheral resistance, but the extent of vascular changes in persons genetically predisposed for essential hypertension is uncertain. METHODS: Participants from the Danish Hypertension Prevention Project (DHyPP) (both parents hypertensive) (n = 95, 41 ±â€Š1 years, 53% men) were compared with available spouses (n = 45, 41 ±â€Š1 years) using measurements of ambulatory blood pressure (BP), left ventricular mass index (LVMI), pulse wave velocity, central BP and augmentation index (AIx) in addition to forearm resting and minimal resistance [forearm resting vascular resistance (Rrest) and forearm minimal vascular resistance (Rmin)]. RESULTS: DHyPP patients with participating spouses had higher 24-h mean BP (94 ±â€Š1 vs. 88 ±â€Š1 mmHg, P < 0.01), LVMI (94 ±â€Š3 vs. 80 ±â€Š2 g/m, P < 0.01), central SBP (121 ±â€Š2 vs. 111 ±â€Š2 mmHg, P < 0.01) and AIx (16.0 ±â€Š1.2 vs. 10.5 ±â€Š1.7%, P < 0.01), but similar carotid-femoral pulse wave velocity (7.5 ±â€Š0.2 vs. 7.1 ±â€Š0.2 m/s), Rrest (53 ±â€Š3 vs. 51 ±â€Š3 mmHg/ml/min/100 ml) and log Rmin (0.58 ±â€Š0.02 vs. 0.55 ±â€Š0.02 mmHg/ml/min/100 ml) when compared with spouses. Using multiple linear regression analysis (adjusting for sex, age, BMI, creatinine clearance and 24-h BP, heart rate and sodium excretion) AIx and LVMI remained elevated in DHyPP patients [4.2% (0.7; 7.7), P = 0.02 and 6.3 g/m (0.7; 11.9), P = 0.03]. For the entire DHyPP cohort AIx, Rrest and Rmin were higher in women than men (P < 0.01), and the same was true for AIx and Rmin among spouses (P < 0.05). Furthermore, AIx was linearly associated with Rrest and Rmin. CONCLUSION: Young to middle-aged individuals genetically predisposed for essential hypertension display increased AIx and LVMI, although vascular stiffness and peripheral resistance are still normal.

Urine liver fatty acid binding protein and chronic kidney disease progression.

Excretion of the tubular protein liver fatty acid binding protein (L-FABP) is a potential novel biomarker of renal dysfunction. We examined whether urine L-FABP excretion adds prognostic information to the well-established risk markers, blood pressure (BP), albumin excretion and baseline GFR, regarding progression of chronic kidney disease (CKD). In a prospective study design a cohort of 74 stage 3-4 CKD patients (age 61 ± 13 years) were included. Glomerular filtration ratio (GFR, 51Cr-EDTA-clearance), 24-hour ambulatory BP, 24-hour urinary albumin/creatinine ratio (UAC) and urinary L-FABP/creatinine ratio (U-L-FABP/C) were determined at baseline and after 18 months of follow-up. For comparison 25 age-matched healthy controls were included. The U-L-FABP/C was elevated in CKD patients when compared to controls (mean U-L-FABP/C 2.3 [95% CI 1.7-2.9] µg/mmol vs 0.6 [0.5-0.7] µg/mmol, p < .001). In CKD patients, log U-L-FABP/C at baseline and at follow-up were positively associated (Pearson correlation coefficient r = 0.74, p < .001). Baseline log U-L-FABP/C was negatively correlated with baseline GFR (r = -0.32, p < .001) and directly correlated with UAC (r = 0.67, p < .001). The relative change in GFR from baseline to follow-up correlated with baseline UAC (p < .001), 24-hour systolic BP (p = 0.05) and log U-L-FABP/C (p < .001). Using multiple regression analysis adjusting for baseline GFR, UAC, BP, age and gender, baseline log U-L-FABP/C was associated with a decline in GFR only in patients with UAC <3 mg/mmol (n = 29, p = 0.001) and not in patients with UAC ≥3 mg/mmol (n = 44, p = 0.21). In conclusion urine L-FABP/C is permanently elevated in CKD patients, but only associated with GFR decline in those without albuminuria.

Estimated aortic blood pressure based on radial artery tonometry underestimates directly measured aortic blood pressure in patients with advancing chronic kidney disease staging and increasing arterial stiffness.

Central blood pressure (BP) can be assessed noninvasively based on radial tonometry and may potentially be a better predictor of clinical outcome than brachial BP. However, the validity of noninvasively obtained estimates has never been examined in patients with chronic kidney disease (CKD). Here we compared invasive aortic systolic BP (SBP) with estimated central SBP obtained by radial artery tonometry and examined the influence of renal function and arterial stiffness on this relationship. We evaluated 83 patients with stage 3 to 5 CKD (mean estimated glomerular filtration rate [eGFR] 30 ml/min/1.73 m(2)) and 41 controls without renal disease undergoing scheduled coronary angiography. BP in the ascending aorta was measured through the angiography catheter and simultaneously estimated using radial tonometry. The mean difference between estimated central and aortic SBP was -13.2 (95% confidence interval -14.9 to -11.4) mm Hg. Arterial stiffness was evaluated by carotid-femoral pulse wave velocity (cf-PWV) and was significantly increased in CKD patients compared with (versus) control patients (mean 10.7 vs. 9.3 m/s). The difference in BP significantly increased 1.0 mm Hg for every 10 ml/min decrease in eGFR and by 1.6 mm Hg per 1 m/s increase in cfPWV. Using multivariate regression analysis including both eGFR and cfPWV, the difference between estimated central and invasive aortic SBP was significantly increased by 0.7 mm Hg. For the entire cohort brachial SBP significantly better reflected invasive SBP than estimated SBP. Thus, tonometry-based estimates of central BP progressively underestimate invasive central SBP with decreasing renal function and increasing arterial stiffness in CKD patients.

Evaluation of Renal Blood Flow and Oxygenation in CKD Using Magnetic Resonance Imaging.

BACKGROUND: Animal studies suggest that progression of chronic kidney disease (CKD) is related to renal hypoxia. With renal blood supply determining oxygen delivery and sodium absorption being the main contributor to oxygen consumption, we describe the relationship between renal oxygenation, renal artery blood flow, and sodium absorption in patients with CKD and healthy controls. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: 62 stable patients with CKD stages 3 to 4 (mean age, 61±13 [SD] years) and 24 age- and sex-matched controls. PREDICTORS: CKD versus control status. OUTCOMES: Renal artery blood flow, tissue oxygenation (relative changes in deoxyhemoglobin concentration of the renal medulla [MR2*] and cortex [CR2*]), and sodium absorption. MEASUREMENTS: Renal artery blood flow was determined by phase-contrast magnetic resonance imaging (MRI); MR2* and CR2* were determined by blood oxygen level-dependent MRI. Ultrafiltered and reabsorbed sodium were determined from measured glomerular filtration rate (mGFR) and 24-hour urine collections. RESULTS: mGFR in patients was 37% that of controls (36±15 vs 97±23 mL/min/1.73 m(2); P < 0.001), and reabsorbed sodium was 37% that of controls (6.9 vs 19.1 mol/24 h; P < 0.001). Single-kidney patient renal artery blood flow was 72% that of controls (319 vs 443 mL/min; P < 0.001). Glomerular filtration fraction was 9% in patients and 18% in controls (P < 0.001). Patients and controls had similar CR2* (13.4 vs 13.3 s(-1)) and medullary MR2* (26.4 vs 26.5 s(-1)) values. Linear regression analysis demonstrated no associations between R2* and renal artery blood flow or sodium absorption. Increasing arterial blood oxygen tension by breathing 100% oxygen had very small effects on CR2*, but reduced MR2* in both groups. LIMITATIONS: Only renal artery blood flow was determined and thus regional perfusion could not be related to CR2* or MR2*. CONCLUSIONS: In CKD, reductions of mGFR and reabsorbed sodium are more than double that of renal artery blood flow, whereas cortical and medullary oxygenation are within the range of healthy persons. Reduction in glomerular filtration fraction may prevent renal hypoxia in CKD.

Differential effects of age on large artery stiffness and minimal vascular resistance in normotensive and mildly hypertensive individuals.

Large artery stiffness and small artery structural changes are both cardiovascular risk factors. Arterial stiffness increases with age and blood pressure (BP), but it is unclear in which way large artery pulse wave velocity (PWV) and peripheral vascular resistance are related and whether age has any influence. In a cross-sectional study, PWV and forearm minimum vascular resistance (Rmin ) was compared with emphasis on the impact of age. Normotensive (n = 53) and untreated hypertensive (n = 23) subjects were included based on 24-h BP measurements. Age ranged from 21 to 79 years with an even distribution from each age decade. PWV was assessed using tonometry. Forearm Rmin was measured by venous occlusion plethysmography at maximal vasodilatation induced by 10 min of ischaemia in combination with skin heating and hand grip exercise. In both normotensive and hypertensive subjects, PWV correlated significantly with age and BP. Based on median age, both groups were assigned into two equally large subgroups. Normotensive older (66 ± 7 years) and younger (35 ± 10 years) persons had different carotid-femoral PWV (7.9 ± 1.8 versus 5.7 ± 0.9 m/s, P<0.01), but similar Rmin values (3.7 ± 0.9 versus 3.6 ± 1.2 mmHg/ml/min/100 ml). Hypertensive older (63 ± 6 years) and younger (40 ± 10 years) also had different PWV (8.0 ± 1.5 versus 6.7 ± 1.1 m/s, P<0.05), but the older had lower Rmin (3.1 ± 0.8 versus 4.7 ± 2.2 mmHg/ml/min/100 ml, P<0.05). In a regression analysis adjusting for age, BP, gender and heart rate, no correlation was seen between PWV and Rmin . The data suggest that age differentially affects PWV and Rmin and that BP can increase in older persons without affecting Rmin .

Reproducibility of MRI renal artery blood flow and BOLD measurements in patients with chronic kidney disease and healthy controls.

PURPOSE: Determine the reproducibility of renal artery blood flow (RABF) and blood-oxygenation level dependent (R2 *) in patients with chronic kidney disease (CKD) and healthy controls. MATERIALS AND METHODS: RABF and R2 * were measured in 11 CKD patients and 9 controls twice with 1- to 2-week interval. R2 * in the cortex and medulla were determined after breathing atmospheric air and 100% oxygen. Reproducibility was evaluated by coefficients of variation (CV), limits of agreements and intra-class coefficient calculated by variance components by maximum likelihood modeling. RESULTS: Single-kidney RABF (mL/min) for patients was: 170 ± 130 and 186 ± 137, and for controls: 365 ± 119 and 361 ± 107 (P < 0.05 versus patients), for first and second scans, respectively. RABF measurements were reproducible with a CV of 12.9% and 8.3% for patients and controls, respectively. Renal cortical R2 * was: 13.6 ± 0.9 and 13.5 ± 1.2 in patients (CV = 8.0%), and 13.8 ± 1.6 and 14.0 ± 1.5 in controls (CV = 5.6%), while medullary R2 *(s(-1) ) was: 26.9 ± 2.0 and 27.0 ± 4.0 (CV = 8.0%) in patients, and 26.0 ± 2.4 and 26.1 ± 2.1 (CV = 3.6%) in controls, for first and second scans, respectively. In both groups R2 * in medulla decreased after breathing 100% oxygen. CONCLUSION: The reproducibility was high for both RABF and R2 * in patients and controls, particularly in the cortex. Inhalation of 100% oxygen reduced medullary R2 *.

[Participation in dinner at a medical conference reduces vascular age and is recommended]. / Deltagelse i konferencemiddag reducerer den vaskulære alder og anbefales af helbredsmæssige grunde

A total of 60 attendees at a medical conference had their peripheral and central blood pressure measured before and after the conference dinner. While heart rate increased, all measurements of peripheral and central blood pressure showed lower values after dinner. Furthermore, attendees' central vascular age was reduced by 13 years after dinner when augmentation index was evaluated in relation to age. Although 13% experienced postprandial hypotension, the present study motivates attendance at medical conference dinners due to the health implications of lowered blood pressure.