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BACKGROUNDHypertension plus obstructive sleep apnea (OSA) is recommended in some guidelines as an indication to screen for primary aldosteronism (PA), yet prior data has brought the validity of this recommendation into question. Given this context, it remains unknown whether this screening recommendation is being implemented into clinical practice.METHODSWe conducted a population-based retrospective cohort study of all adult Ontario (Canada) residents with hypertension plus OSA from 2009 to 2020 with follow-up through 2021 utilizing provincial health administrative data. We measured the proportion of individuals who underwent PA screening via the aldosterone-to-renin ratio by year. We further examined screening rates among patients with hypertension plus OSA by the presence of concurrent hypokalemia and resistant hypertension. Clinical predictors associated with screening were assessed via Cox regression modeling.RESULTSThe study cohort included 53,130 adults with both hypertension and OSA, of which only 634 (1.2%) underwent PA screening. Among patients with hypertension, OSA, and hypokalemia, the proportion of eligible patients screened increased to 2.8%. Among patients ≥65 years with hypertension, OSA, and prescription of ≥4 antihypertensive medications, the proportion of eligible patients screened was 1.8%. Older age was associated with a decreased likelihood of screening while hypokalemia and subspecialty care with internal medicine, cardiology, endocrinology, or nephrology were associated with an increased likelihood of screening. No associations with screening were identified with sex, rural residence, cardiovascular disease, diabetes, or respirology subspecialty care.CONCLUSIONSThe population-level uptake of the guideline recommendation to screen all patients with hypertension plus OSA for PA is exceedingly low.

BACKGROUND Reservoir-wave analysis (RWA) separates the arterial waveform into reservoir and excess pressure (XSP) components, where XSP is analogous to flow and related to left ventricular workload. RWA provides more detailed information about the arterial tree than traditional blood pressure (BP) parameters. In end-stage renal disease (ESRD), we have previously shown that XSP is associated with increased mortality and is higher in patients with arteriovenous fistula (AVF). In this study, we examined whether XSP increases after creation of an AVF in ESRD. METHODS Before and after a mean of 3.9 ± 1.2 months following creation of AVF, carotid pressure waves were recorded using arterial tonometry. XSP and its integral (XSPI) were derived using RWA through pressure wave analysis alone. Aortic stiffness was assessed by carotid–femoral pulse wave velocity (CF-PWV). RESURLTS In 38 patients (63% male, age 59 ± 15 years), after AVF creation, brachial diastolic BP decreased (79 ± 10 vs. 72 ± 12 mm Hg, P = 0.002), but the reduction in systolic BP, was not statistically significant (133 ± 20 vs. 127 ± 26 mm Hg, P = 0.137). However, carotid XSP (14 [12–19] to 17 [12–22] mm Hg, P = 0.031) and XSPI increased significantly (275 [212–335] to 334 [241–439] kPa∙s, P = 0.015), despite a reduction in CF-PWV (13 ± 3.6 vs. 12 ± 3.5 m/s, P = 0.025). CONCLUSIONS Creation of an AVF resulted in increased XSP in this population, despite improvement in diastolic BP and aortic stiffness. These findings underline the complex hemodynamic impact of AVF on the cardiovascular system., Graphical Abstract Graphical Abstract

Cellular immune defects associated with suboptimal responses to SARS-CoV-2 mRNA vaccination in people receiving hemodialysis (HD) are poorly understood. We longitudinally analyzed antibody, B cell, CD4+ and CD8+ T cell vaccine responses in 27 HD patients and 26 low-risk control individuals (CI). The first two doses elicit weaker B cell and CD8+ T cell responses in HD than in CI, while CD4+ T cell responses are quantitatively similar. In HD, a third dose robustly boosts B cell responses, leads to convergent CD8+ T cell responses and enhances comparatively more Thelper (TH) immunity. Unsupervised clustering of single-cell features reveals phenotypic and functional shifts over time and between cohorts. The third dose attenuates some features of TH cells in HD (TNFα/IL-2 skewing), while others (CCR6, CXCR6, PD-1 and HLA-DR overexpression) persist. Therefore, a third vaccine dose is critical to achieve robust multifaceted immunity in hemodialysis patients, although some distinct TH characteristics endure.

OBJECTIVE Although brachial cuff SBP is universally used to guide hypertension management, it can differ significantly from intraarterial SBP. We examine the potential impacts of cuff-to-intraarterial brachial SBP (bSBP) mismatch on hypertension treatment and accuracy towards central SBP. METHODS In 303 individuals, cuff bSBP (CUFF-bSBP) and central SBP were measured using a Mobil-o-Graph simultaneously to intraarterial bSBP (IA-bSBP) and aortic SBP. According to the difference between CUFF-bSBP and IA-bSBP, we identified three phenotypes: Underestimation (CUFF-bSBP 10 mmHg); No Mismatch (CUFF-bSBP within 10 mmHg of IA-bSBP); Overestimation (CUFF-bSBP > IA-bSBP by >10 mmHg) phenotypes. Risk of overtreatment and undertreatment, and accuracy (ARTERY society criteria: mean difference ≤5 ± 8 mmHg) were determined. A multiple linear regression model was used to assess variables associated with the bSBP difference. RESULTS Underestimation (n = 142), No Mismatch (n = 136) and Overestimation (n = 25) phenotypes had relatively similar characteristics and CUFF-bSBP (124 ± 17, 122 ± 14, 127 ± 19 mmHg, P = 0.19) but different aortic SBP (133 ± 21, 120 ± 16, 112 ± 18 mmHg, P

Introduction Quality training is a core component of successful home hemodialysis (HHD) and training duration varies significantly between dialysis centers as well as at the patient level. This study aimed to assess the adverse outcomes associated with HHD training duration. Methods All HHD patients successfully trained in a single dialysis center between January 2005 and July 2017 were included. A multivariable multiple-events (Andersen-Gill) survival model was built to evaluate the association between training time and main adverse events, including hospitalizations, technique failure, and death on HHD. Potential confounding factors were defined a priori (age, diabetes, coronary artery disease, and year of training start). Adjusted risk of vascular interventions (arteriovenous fistula angioplasties and central venous catheter replacements) was assessed as the secondary outcome in a negative binomial regression. Findings Forty-eight patients were included in the study. Median HHD training duration was 86 (67-108) days, using a thrice weekly training schedule. Over a follow-up median time of 2.0 (0.7-3.3) years, three patients died while on HHD, 10 had a definitive transfer to HD, and 18 experienced a least 1 hospitalization (38 hospitalizations in total). Training duration was associated with a higher risk of hospitalization, technique failure, and death in unadjusted (hazard ratio [HR] 1.16 per month, 95% confidence interval [CI] 1.08-1.24) and adjusted multiple events model (HR 1.21, 95% CI 1.04-1.43). Risk of vascular access intervention was also significantly higher with increased training time (adjusted incidence rate ratio 1.31, 95% CI 1.03-1.64, per training month). Discussion In this single-center observational study, HHD training duration was associated with a higher risk of adverse events including, death, technique failure, hospitalizations, and vascular access intervention. Enhanced clinical follow-up and home support should be offered to these more vulnerable patients to mitigate this heightened risk.

Women are at higher risk of cardiovascular events than men with similar blood pressure (BP). Whether this discrepancy in risk is associated with the accuracy of brachial cuff BP measurements is unknown.To examine the difference in brachial cuff BP accuracy in men and women compared with invasively measured aortic BP and to evaluate whether noninvasive central BP estimation varies with sex.This cross-sectional study enrolled 500 participants without severe aortic stenosis or atrial fibrillation from January 1 to December 31, 2019, who were undergoing nonurgent coronary angiography at a tertiary care academic hospital.Simultaneous measurements of invasive aortic BP and noninvasive BP.Sex differences in accuracy were determined by calculating the mean difference between the noninvasive measurements (brachial and noninvasive central BP) and the invasive aortic BP (reference). Linear regression and mediation analyses were performed to identify mediators between sex and brachial cuff accuracy.This study included 500 participants (145 female [29%] and 355 male [71%]; 471 [94%] White; mean [SD] age, 66 [10] years). Baseline characteristics were similar for both sexes apart from body habitus. Despite similar brachial cuff systolic BP (SBP) (mean [SD], 124.5 [17.7] mm Hg in women vs 124.4 [16.4] in men; P = .97), invasive aortic SBP was higher in women (mean [SD], 130.9 [21.7] in women vs 124.7 [20.1] mm Hg in men; P .001). The brachial cuff was relatively accurate compared with invasive aortic SBP estimation in men (mean [SD] difference, -0.3 [11.7] mm Hg) but not in women (mean [SD] difference, -6.5 [12.1] mm Hg). Noninvasive central SBP (calibrated for mean and diastolic BP) was more accurate in women (mean [SD] difference, 0.6 [15.3] mm Hg) than in men (mean [SD] difference, 8.3 [14.2] mm Hg). This association of sex with accuracy was mostly mediated by height (3.4 mm Hg; 95% CI, 1.1-5.6 mm Hg; 55% mediation).In this cross-sectional study, women had higher true aortic SBP than men with similar brachial cuff SBP, an association that was mostly mediated by a shorter stature. This difference in BP measurement may lead to unrecognized undertreatment of women and could partly explain why women are at greater risk for cardiovascular diseases for a given brachial cuff BP than men. These findings may justify the need to study sex-specific BP targets or integration of sex-specific parameters in BP estimation algorithms.

BACKGROUND: Patients receiving in-centre hemodialysis are at high risk of exposure to SARS-CoV-2 and death if infected. One dose of the BNT162b2 SARS-CoV-2 vaccine is efficacious in the general population, but responses in patients receiving hemodialysis are uncertain. METHODS: We obtained serial plasma from patients receiving hemodialysis and health care worker controls before and after vaccination with 1 dose of the BNT162b2 mRNA vaccine, as well as convalescent plasma from patients receiving hemodialysis who survived COVID-19. We measured anti-receptor binding domain (RBD) immunoglobulin G (IgG) levels and stratified groups by evidence of previous SARS-CoV-2 infection. RESULTS: Our study included 154 patients receiving hemodialysis (135 without and 19 with previous SARS-CoV-2 infection), 40 controls (20 without and 20 with previous SARS-CoV-2 infection) and convalescent plasma from 16 patients. Among those without previous SARS-CoV-2 infection, anti-RBD IgG was undetectable at 4 weeks in 75 of 131 (57%, 95% confidence interval [CI] 47% to 65%) patients receiving hemodialysis, compared with 1 of 20 (5%, 95% CI 1% to 23%) controls (p < 0.001). No patient with nondetectable levels at 4 weeks developed anti-RBD IgG by 8 weeks. Results were similar in non-immunosuppressed and younger individuals. Three patients receiving hemodialysis developed severe COVID-19 after vaccination. Among those with previous SARS-CoV-2 infection, median anti-RBD IgG levels at 8 weeks in patients receiving hemodialysis were similar to controls at 3 weeks (p = 0.3) and to convalescent plasma (p = 0.8). INTERPRETATION: A single dose of BNT162b2 vaccine failed to elicit a humoral immune response in most patients receiving hemodialysis without previous SARS-CoV-2 infection, even after prolonged observation. In those with previous SARS-CoV-2 infection, the antibody response was delayed. We advise that patients receiving hemodialysis be prioritized for a second BNT162b2 dose at the recommended 3-week interval.

Compared with brachial blood pressure (BP), central systolic BP (SBP) can provide a better indication of the hemodynamic strain inflicted on target organs, but it is unclear whether this translates into improved cardiovascular risk stratification. We aimed to assess which of central or brachial BP best predicts cardiovascular risk and to identify the central SBP threshold associated with increased risk of future cardiovascular events. This study included 13 461 participants of CARTaGENE with available central BP and follow-up data from administrative databases but without cardiovascular disease or antihypertensive medication. Central BP was estimated by radial artery tonometry, calibrated for brachial SBP and diastolic BP (type I), and a generalized transfer function (SphygmoCor). The outcome was major adverse cardiovascular events. Cox proportional-hazards models, differences in areas under the curves, net reclassification indices, and integrated discrimination indices were calculated. Youden index was used to identify SBP thresholds. Over a median follow-up of 8.75 years, 1327 major adverse cardiovascular events occurred. The differences in areas under the curves, net reclassification indices, and integrated discrimination indices were of 0.2% ([95% CI, 0.1–0.3] P P =0.01), and 0.0004 ([95% CI, −0.0001 to 0.0014] P =0.3), all likely not clinically significant. Central and brachial SBPs of 112 mm Hg (95% CI, 111.2–114.1) and 121 mm Hg (95% CI, 120.2–121.9) were identified as optimal BP thresholds. In conclusion, central BP measured with a type I device is statistically but likely not clinically superior to brachial BP in a general population without prior cardiovascular disease. Based on the risk of major adverse cardiovascular events, the optimal type I central SBP appears to be 112 mm Hg.

Background The debate over acetylsalicylic acid (ASA) therapy for primary prevention of cardiovascular disease (CVD) has recently resurfaced, but scarce data are available on prophylactic ASA use in Canada for this purpose. This study aimed to evaluate the prevalence and factors associated with ASA use, and the potential impact of implementing the most recent (2016) US Preventive Services Task Force recommendations for primary CVD prevention in a Canadian setting. Methods We performed a cross-sectional analysis using data from the CARTaGENE study, which included a representative sample (n = 20 004) of the 2018 general population of the province of Quebec. We assessed eligibility for ASA treatment using US Preventive Services Task Force criteria (age 50-69 yr, no past history of myocardial infarction or stroke, and 10-year risk of CVD of at least 10%). We extrapolated to the entire 2018 Quebec population the number of people who would need to start ASA treatment. Results A total of 6231 respondents in the CARTaGENE study (54.2% of those aged 50-69 yr with no prior history of CVD) were found to be potentially eligible for ASA use for primary CVD prevention. Of the 6231, 1379 (22.1%) were receiving prophylactic ASA treatment. Factors found to be related to ASA use included age, male sex, regular medical visits, lower education level, obesity, hypertension, diabetes and dyslipidemia. Income and smoking status were not found to be significantly associated with ASA use. Our results indicate that 885 261 people would potentially have started ASA treatment if the US Preventive Services Task Force recommendations had been implemented in Quebec in 2018. Interpretation Prevalent ASA use for primary CVD prevention was low. Implementation of the 2016 US Preventive Services Task Force recommendations would require initiating ASA treatment in a substantial proportion of people, with undetermined potential benefits.

Primary aldosteronism is a common, yet highly underdiagnosed, cause of hypertension that leads to disproportionately high rates of cardiovascular disease. Hypertension plus hypokalemia is a guideline-recommended indication to screen for primary aldosteronism, yet the uptake of this recommendation at the population level remains unknown. We performed a population-based retrospective cohort study of adults ≥18 years old in Ontario, Canada, with hypertension plus hypokalemia (potassium

BackgroundPatients receiving in-center hemodialysis (HD) are at high risk of exposure to SARS-CoV-2 with high mortality, and response to vaccination is uncertain.MethodsWe obtained serial plasma from 58 HD patients and 32 health-care workers (HCW) before and after vaccination with one dose of the BNT162b2 mRNA vaccine; as well as convalescent plasma from 11 HD patients who survived COVID-19. Anti-RBD (region binding domain of the SARS-CoV-2 Spike protein) IgG and IgM levels were measured by ELISA. Groups were stratified by evidence of prior SARS-CoV-2 infection.ResultsIn HD patients without prior SARS-CoV-2, antiRBD levels were significantly lower at 4 and 8 weeks after vaccination, compared to in HCWs after 3 weeks (pInterpretationWhile the BNT162b2 vaccine was well-tolerated in hemodialysis patients, a single dose failed to elicit a humoral immune response in the majority of SARS-CoV-2 naïve patients even after prolonged observation. In those with prior SARS-CoV-2 infection, the humoral response after vaccination was delayed. Whether HD patients develop T-cell responses requires further study. Until then, we advise the second dose be administered to all HD patients at the recommended 3-week time interval, and that rigorous SARS-CoV-2 infection prevention and control measures be continued in dialysis units until vaccine efficacy is proven.

Pulse wave velocity (PWV) is used to evaluate regional stiffness of large and medium-sized arteries. Here, we examine the feasibility and reliability of radial-digital PWV (RD-PWV) as a measure of regional stiffness of small conduit arteries and its response to changes in hydrostatic pressure. In 29 healthy subjects, we used Complior Analyse piezoelectric probes to record arterial pulse wave at the radial artery and the tip of the index. We determined transit time by second-derivative and intersecting tangents using the device-embedded algorithms and in-house MATLAB-based analyses of only reliable waves and by numerical simulation using a one-dimensional (1-D) arterial tree model coupled with a heart model. Second-derivative RD-PWV was 4.68 ± 1.18, 4.69 ± 1.21, and 4.32 ± 1.19 m/s for device-embedded, MATLAB-based, and numerical simulation analyses, respectively. Intersecting-tangent RD-PWV was 4.73 ± 1.20, 4.45 ± 1.08, and 4.50 ± 0.84 m/s for device-embedded, MATLAB-based, and numerical simulation analyses, respectively. Intersession coefficients of variation were 7.0% ± 4.9% and 3.2% ± 1.9% (

Purpose/Background/Objective: We have previously shown that restoration of kidney function through kidney transplantation (KTx) is associated with improved aortic stiffness. In this study, we aim to examine whether this change in aortic stiffness translates into improvement of radial artery systolic-diastolic pulse transit time. Methods: Before and three months after KTx, we obtained radial pressure waveforms using applanation tonometry, in a group of 61 patients with restored renal function (eGFR > 45 ml/min/1,73 m2). Radial waveforms were recorded over a 10 seconds period and ensemble-averaged (using in house-MATLAB program) to obtain a single waveform and then modelled using two Gaussian functions, was then determined as the transit time between the first systolic peak T1 and the early diastolic peak T2. Results: 61 patients (66% male, mean age: 48 ± 14 years, mean eGFR 3 months after Ktx: 66.0 ± 17.1) were assessed. After KTx, there was a significant reduction in central systolic (125,266 ± 21,848 to 108,994 ± 14,407, p < 0.001) and diastolic BP (84,718 11,679 to 74,092 9,774, p < 0.001), carotid-femoral PWV (11,444 2,626 to 10,235 1,890, p < 0.001) and carotid-radial PWV (9,350 1,485 to 8,831 1,291, p = 0,003). While T1 declined (0.184 [0.173–0.198] to 0.180 [0.168–0.194], p = 0.018), there were no significant changes in T2 (0.322 [0.295–0.360] to 0.318 [0.283–0.355], p = 0.169) and in dT1-2 (0.135 [0.119–0.161] to 0.134 [0.117–0.167], p = 0.457). Conclusions: Contrary to our expectation, three months after KTx, we did not observe a significant change in radial systolic-diastolic pulse transit time after kidney transplantation, despite an improvement of BP, aortic and brachial stiffness.

BACKGROUND: Kidney failure is associated with a high burden of morbidity and mortality. Previous studies have raised the possibility that arteriovenous fistula (AVF) creation may attenuate eGFR decline. This study aimed to compare eGFR decline in predialysis patients with an AVF, matched to patients oriented toward peritoneal dialysis (PD). METHODS: Predialysis patients with an AVF and those oriented toward PD were retrospectively matched using a propensity score. Time zero was defined as the “AVF creation date” for the AVF group and the “date when eGFR was closest to the matched patient’s eGFR at AVF creation” for the PD group. Crude and predicted eGFR decline in AVF and PD groups were compared before and after time zero using mixed-effect linear regressions. RESULTS: In total, 61 pairs were matched. Crude annual eGFR decline before AVF creation/time zero was −4.1 ml/min per m(2) per year in the AVF group versus −5.3 ml/min per m(2) per year in the PD group (P=0.75) and after time zero, −2.5 ml/min per m(2) per year in the AVF group versus −4.5 ml/min per m(2) per year in the PD group (P=0.02). The predicted annual decline decreased from −5.1 ml/min per m(2) per year in the AVF group before AVF creation to −2.8 ml/min per m(2) per year after (P

Key Points Question Is glomerular hyperfiltration associated with future cardiovascular events in healthy individuals? Findings In this cohort study of 9515 patients with health information accessed through the CARTaGENE research platform, glomerular hyperfiltration was shown to be associated with increased risk of cardiovascular events in middle-aged healthy individuals. Meaning This study found an increased cardiovascular disease risk associated with glomerular hyperfiltration in middle-aged healthy individuals, suggesting that glomerular hyperfiltration could be a useful cardiovascular biomarker in this population., This population-based cohort study examines whether glomerular hyperfiltration is associated with a higher risk of cardiovascular events in healthy middle-aged individuals., Importance Glomerular hyperfiltration is associated with increased risk of cardiovascular disease in high-risk conditions, but its significance in low-risk individuals is uncertain. Objective To determine whether glomerular hyperfiltration is associated with increased cardiovascular risk in healthy individuals. Design, Setting, and Participants This was a prospective population-based cohort study, for which enrollment took place from August 2009 to October 2010, with follow-up available through March 31, 2016. Analysis of the data took place in October 2019. The cohort was composed of 9515 healthy individuals, defined as individuals without hypertension, diabetes, cardiovascular disease, estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2, or statin and/or aspirin use, identified among 20 004 patients aged 40 to 69 years with health information accessed through the CARTaGENE research platform. Exposures Individuals with glomerular hyperfiltration (eGFR >95th percentile after stratification for sex and age) were compared with individuals with normal filtration rate (eGFR 25th-75th percentiles). Main Outcomes and Measures Adverse cardiovascular events were defined as a composite of cardiovascular mortality, myocardial infarction, unstable angina, heart failure, stroke, and transient ischemic attack. Risk of adverse cardiovascular events was assessed using Cox and fractional polynomial regressions and propensity score matching. Results From the 20 004 CARTaGENE participants, 9515 healthy participants (4050 [42.6%] male; median [interquartile range] age, 50.4 [45.9-55.6] years) were identified. Among these, 473 had glomerular hyperfiltration (median [interquartile range] eGFR, 112 [107-115] mL/min/1.73 m2) and 4761 had a normal filtration rate (median [interquartile range] eGFR, 92 [87-97] mL/min/1.73 m2). Compared with the normal filtration rate, glomerular hyperfiltration was associated with an increased cardiovascular risk (hazard ratio, 1.88; 95% CI, 1.30-2.74; P = .001). Findings were similar with propensity score matching. The fractional polynomial regression showed that only the highest eGFR percentiles were associated with increased cardiovascular risk. The cardiovascular risk of individuals with glomerular hyperfiltration was similar to that of the 597 participants with an eGFR between 45 and 60 mL/min/1.73 m2 (hazard ratio, 0.90; 95% CI, 0.56-1.42; P = .64). Conclusions and Relevance These findings suggest that glomerular hyperfiltration is independently associated with increased cardiovascular risk in middle-aged healthy individuals. This risk profile appears to be similar to stage 3a chronic kidney disease.

In this report we examine the differences between the 2017 Hypertension Canada and 2017 American College of Cardiology and American Heart Association (ACC/AHA) blood pressure (BP) guidelines regarding the proportions of individuals with a diagnosis of hypertension, BP above thresholds for treatment initiation, and BP below targets using the CARTaGENE cohort. Compared with the 2017 Canadian guidelines, the 2017 ACC/AHA guidelines would result in increases of 8.7% in hypertension diagnosis and 3.4% of individuals needing treatment, with 17.2% having a different BP target. In conclusion, implementing the 2017 ACC/AHA hypertension guidelines in Canada could result in major effects for millions of Canadians.

Objective During the COVID-19 pandemic, social distancing and self-isolation called for innovative, readily implementable, and effective short-term health solutions. The objective of this study was to assess the feasibility of self-assessment of vital signs and symptoms with electronic transmission of results, by self-isolating individuals with positive SARS-CoV-2 polymerase chain reaction (PCR) test. The secondary objective was to describe the association between the presence of abnormal vital signs and severe symptoms as well as their evolution over time. Method Participants with positive SARS-CoV-2 PCR test were asked to perform twice daily standardized vital signs measurements and self-assessment of symptoms for 14 consecutive days. All data were transmitted electronically through a mobile application and a web-based platform. Participants were provided with decision support tools based on the severity of their condition and a weekly nurse practitioner telephone follow-up. Abnormal values for vital signs and severe symptoms were determined. Per participant and per days, proportions of abnormal vital signs and severe symptoms were calculated. Results Data from 46 participants (mean age 54.1 ± 6.9 years, 54% male) were available for analysis. On average, participants performed the standardized self-assessment for 12.3 ± 3.4 days (89% performed at least 7 measurement days and 61% completed all 14 days). The highest proportions abnormal values for vital signs were for oximetry (20.1%) and respiratory rate (12.1%). The highest proportions of severe symptoms were for fatigue (16.9%) and myalgia. (10.2%). The combined proportion of abnormal vital signs and severe symptoms was maximal on day 1 with 20.3% of total measurements, with a linear decrease to 3.5% on day 14. Conclusion Remote initiation of home measurements of vital signs and symptoms, self-management of these measures, accompanied by a decision support tool and supported by preplanned nurse follow-up are feasible. This could allow to opening up new insight for the care of sick individuals.

Background Missing preadmission serum creatinine (SCr) values are a common obstacle to assess acute kidney injury (AKI) diagnosis and outcomes. The Kidney Disease Improving Global Outcomes (KDIGO) guidelines suggest using a SCr computed from the Modification of Diet in Renal Disease (MDRD) with an estimated glomerular filtration rate of 75 ml/min/1.73 m2. We aimed to identify the best surrogate method for baseline SCr to assess AKI diagnosis and outcomes. Methods We compared the use of 1) first SCr at hospital admission 2) minimal SCr over 2 weeks after intensive care unit admission 3) MDRD computed SCr and 4) Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) computed SCr to assess AKI diagnosis and outcomes. We then performed multilinear regression models to predict preadmission SCr and imputation strategies to assess AKI diagnosis. Results Our one-year retrospective cohort study included 1001 critically ill adults; 498 of them had preadmission SCr values. In these patients, AKI incidence was 25.1% using preadmission SCr. First SCr had the best agreement for AKI diagnosis (22.5%; kappa = 0.90) and staging (kappa = 0.81). MDRD, CKD-EPI and minimal SCr overestimated AKI diagnosis (26.7%, 27.1% and 43.2%;kappa = 0.86, 0.86 and 0.60, respectively). However, MDRD and CKD-EPI computed SCr had a better sensitivity than first SCr for AKI (93% and 94% vs. 87%). Eighty-eight percent of patients experienced renal recovery at least 3 months after hospital discharge. All methods except the first SCr significantly underestimated the percentage of renal recovery. In a multivariate model, age, male gender, hypertension, heart failure, undergoing surgery and log first SCr best predicted preadmission SCr (adjusted R2 = 0.56). Imputation methods with first SCr increased AKI incidence to 23.9% (kappa = 0.92) but not with MDRD computed SCr (26.7%;kappa = 0.89). Conclusion In our cohort, first SCr performed better for AKI diagnosis and staging, as well as for renal recovery after hospital discharge than MDRD, CKD-EPI or minimal SCr. However, MDRD SCr and CKD-EPI SCr improved AKI diagnosis sensitivity. Imputation methods minimally increased agreement for AKI diagnosis. Electronic supplementary material The online version of this article (doi:10.1186/s12882-017-0552-3) contains supplementary material, which is available to authorized users.

Background Reservoir‐wave approach is an alternative model of arterial hemodynamics based on the assumption that measured arterial pressure is composed of volume‐related (reservoir pressure) and wave‐related components (excess pressure). However, the clinical utility of reservoir‐wave approach remains debatable. Methods and Results In a single‐center cohort of 260 dialysis patients, we examined whether carotid and radial reservoir‐wave parameters were associated with all‐cause and cardiovascular mortality. Central pulse pressure and augmentation index at 75 beats per minute were determined by radial arterial tonometry through generalized transfer function. Carotid and radial reservoir‐wave analysis were performed to determine reservoir pressure and excess pressure integral. After a median follow‐up of 32 months, 171 (66%) deaths and 88 (34%) cardiovascular deaths occurred. In Cox regression analysis, carotid excess pressure integral was associated with a hazard ratio of 1.33 (95% CI , 1.14–1.54; P CI : 1.18–1.75; P CI : 1.08–1.54; P =0.004) and cardiovascular mortality (hazard ratio per 1 SD, 1.31; 95% CI : 1.04–1.63; P =0.019). Conversely, there were no significant associations between radial reservoir‐wave parameters, central pulse pressure, augmentation index at 75 beats per minute, pressure forward, pressure backward and reflection magnitude, and all‐cause or cardiovascular mortality after adjustment for comorbidities. Conclusions These observations support the clinical value of reservoir‐wave approach parameters of large central elastic vessels in end‐stage renal disease.

BACKGROUND: In chronic kidney disease, the enhanced aortic stiffness increases risk of cardiovascular events. Kidney transplantation (KTx) may improve aortic stiffness; however, it is unclear whether the improvement of aortic stiffness is merely the outcome of the reduction of blood pressure (BP) post-KTx. Furthermore, the long-term trajectory of aortic stiffness remains uncertain, as activation of the immune system may have a negative long-term impact on arterial wall property.METHOD: Using aortic stiffness β0 as a BP-independent stiffness parameter, and a statistical adjustment for BP, we aimed to examine the early vs. late changes in aortic stiffness, and to define the characteristics of patients with favourable and unfavourable long-term trajectories of aortic stiffness. In this longitudinal study, aortic stiffness was assessed before, 3, 6 and 24 months after KTx in 79 individuals. Aortic stiffness was determined by carotid-femoral pulse wave velocity (cf-PWV), and aortic stiffness index β0 was obtained by applying the stiffness parameter β0 theory to cf-PWV based on Bramwell-Hill's equation using a reference pressure.RESULTS: There was an early reduction of β0 3 months after KTx (29.0 ± 2.0 to 25.8 ± 1.2, P = 0.033) followed by a gradual increase at 6 (28.0 ± 1.4, P = 0.005 vs. 3 months) and 24 months (28.3 ± 1.3, P = 0.003 vs. 3 months). A late increase in β0 was associated with higher levels of the interleukin-6 (P = 0.029) even after adjustment for potential cofounders. Using statistical adjustments for BP showed similar results.CONCLUSION: Reduction of aortic stiffness index β0 3 months after KTx suggests that KTx leads to an early de-stiffening of the intrinsic mechanical properties of aorta. However, this improvement is followed by a later stiffening, which is associated with increased interleukin-6, suggesting that activation of the immune system may be involved in arterial wall remodelling in kidney recipients.

Purpose/Background/Objective: According to reservoir-wave approach (RWA) arterial pressure is the sum of a reservoir pressure (RP) accounting for dynamic storage and release of blood from arteries, and an excess pressure (XSP) analogous to flow. RP is the minimal left ventricular work required to generate aortic flow, while XSP corresponds to surplus cardiac workload. We have previously shown that kidney transplantation (KTx) improves aortic stiffness [1], however, by adding renal vessels to existing vascular network, KTx may increase cardiac output. Thus, we aimed to examine whether XSP increases after KTx. Methods: Before and 3 months after KTx, carotid pressure waves were recorded using arterial tonometry, calibrated using brachial diastolic and mean blood pressure. Using pressure only approach, reservoir-wave analysis was used to derive RP, XSP and their integrals (RPI, XSPI). RWA parameters were compared with Wilcoxon non-parametric test using SPSS 26.0. Results: 75 patients (69% male, mean age 51 ± 13 years) were assessed. Three months after KTx, both carotid RP (121.2 ± 20.7 vs 103.5 ± 15.7, p < 0.001) and RPI (11192.52 ± 2763.11 vs 9531 ± 1978, p < 0.001) decreased significantly, but carotid XSP and XSPI remained unchanged. Carotid systolic (131.0 ± 23.2 vs 114.1 ± 15.5, p < 0.001) and diastolic (83.4 ± 11.9 vs 72.8 ± 9.93, p < 0.001) blood pressures were also reduced. Conclusion: KTx decreased reservoir pressure, suggesting a decrease in minimal cardiac workload. However, we did not see an increase in excess pressure or its integral, suggesting that addition of a donor renal artery does not significantly alter cardiac outflow and excess workload 3 months after KTx.

Purpose/Background/Objectives: According to reservoir-wave theory, excess pressure (XSP) is analogous to flow and related to excess cardiac workload. In end-stage renal disease (ESRD) patients, we have shown that XSPI is associated with increased mortality and is higher in patients with arteriovenous fistula (AVF). Recently AVF has been proposed treatment for treatment of resistant hypertension. However, this benefit may be mitigated through an increase in cardiac output. Therefore, we examine whether XSPI increases after creation of an AVF in ESRD patients. Methods: Hemodynamic assessments were performed within 1 month before and 6 months after creation of AVF in ESRD patients. Carotid pressure waves were recorded using arterial tonometry, calibrated using brachial diastolic and mean arterial pressure. Using pressure only approach, reservoir-wave analysis was used to derive reservoir pressure (RP), XSP and their integrals (RPI, XSPI). Results: 38 patients (63% male, mean age 59 ± 15 years) were assessed 3.9 ± 1.2 months Post-AVF. Carotid RP decreased slightly (115 ± 18 vs 109 ± 24, p = 0.060), due to the reduction of diastolic BP (79 ± 10 vs 73 ± 12 mm Hg, p = 0.003). While, carotid systolic BP (123 ± 20 vs 119 ± 27 mm Hg, p = 0.380) remained unchanged, XSP and XSPI increased (XSP: 14 [12–19] to 17 [12–22] mmHg, p = 0.031; XSPI: 275 [212–335] to 334 [241–349] kPa.s, p = 0.015). Conclusion: While AVF creation reduced diastolic BP, it resulted in higher XSPI, which has been associated with increased mortality. Therefore, the long-term efficacy of AVF in reducing clinical outcomes should be specifically addressed.