Publications by authors named "Thomas Hiemstra"

Article Synopsis
  • Traditional diagnostic tools may not accurately represent cardiovascular issues in patients with chronic kidney disease (CKD), prompting this study to explore if exercise response patterns can detect these abnormalities in mild-to-moderate CKD.
  • The study analyzed data from 3,075 participants in the Framingham Heart Study and 451 from the Massachusetts General Hospital Exercise Study, focusing on measurements like peak oxygen uptake (VO2 Peak) and minute ventilation to carbon dioxide production ratio (VE/VCO2) across different eGFR groups.
  • Results indicated that both VO2 Peak and VO2 at anaerobic threshold were significantly lower with decreasing kidney function in all analyses, highlighting a concerning connection between cardiovascular fitness and CKD status.
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Background: Metformin has been used in the management of diabetes for decades. It is an effective, low-cost intervention with a well-established safety profile. Emerging evidence suggests that metformin targets a number of pathways that lead to chronic kidney damage, and long-term use may, therefore, slow the rate of kidney function decline and chronic kidney disease (CKD) progression.

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Article Synopsis
  • Patients with chronic kidney disease (CKD) are at a higher risk of being hospitalized for heart failure, especially when treated with daprodustat compared to the conventional drug darbepoetin, although the difference isn't statistically significant.
  • The study analyzed data from two trials, ASCEND-D and ASCEND-ND, focusing on how daprodustat impacts heart failure hospitalization rates among CKD patients with and without dialysis.
  • Key risk factors for heart failure hospitalizations included a history of heart failure, diabetes, and higher blood pressure, but the increase in hospitalizations attributed to daprodustat compared to conventional treatments wasn't statistically conclusive.
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Background: 25-hydroxyvitamin D can undergo C-3 epimerization to produce 3-epi-25(OH)D3. 3-epi-25(OH)D3 levels decline in chronic kidney disease (CKD), but its role in regulating the cardiovascular system is unknown. Herein, we examined the relationship between 3-epi-25(OH)D3, and cardiovascular functional and structural endpoints in patients with CKD.

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In anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), hematuria and proteinuria are biomarkers reflecting kidney involvement at diagnosis. Yet, the prognostic value of their persistence after immunosuppressive induction therapy, reflecting kidney damage or persistent disease, remains uncertain. To study this, our post hoc analysis included participants of five European randomized clinical trials on AAV (MAINRITSAN, MAINRITSAN2, RITUXVAS, MYCYC, IMPROVE).

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Article Synopsis
  • There is a continued need for pre-exposure prophylactic treatments against SARS-CoV-2, especially for vulnerable groups such as organ transplant recipients and those with certain health conditions.
  • The PROTECT-V trial is evaluating multiple preventive agents in these populations while allowing for flexibility to add new treatments over time.
  • The trial aims to measure symptomatic SARS-CoV-2 infections, currently testing approved agents like niclosamide, ciclesonide, and sotrovimab.
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Background: Fibroblast growth factor 23 (FGF23) is a bone-derived phosphatonin that is elevated in chronic kidney disease (CKD) and has been implicated in the development of cardiovascular disease. It is unknown whether elevated FGF23 in CKD is associated with impaired cardiovascular functional capacity, as assessed by maximum exercise oxygen consumption (VOMax). We sought to determine whether FGF23 is associated with cardiovascular functional capacity in patients with advanced CKD and after improvement of VOMax by kidney transplantation.

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Background The transition to dialysis period carries a substantial increased cardiovascular risk in patients with chronic kidney disease. Despite this, alterations in cardiovascular functional capacity during this transition are largely unknown. The present study therefore sought to assess ventilatory exercise response measures in patients within 1 year of initiating dialysis.

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Background The myocardial cytoskeleton functions as the fundamental framework critical for organelle function, bioenergetics and myocardial remodeling. To date, impairment of the myocardial cytoskeleton occurring in the failing heart in patients with advanced chronic kidney disease has been largely undescribed. Methods and Results We conducted a 3-arm cross-sectional cohort study of explanted human heart tissues from patients who are dependent on hemodialysis (n=19), hypertension (n=10) with preserved renal function, and healthy controls (n=21).

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Background: Users of guideline-recommended renin-angiotensin-aldosterone system (RAAS) inhibitors may experience disruptions to their treatment, e.g. due to hyperkalaemia, hypotension or acute kidney injury.

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Background: Pain affects 60% of the autosomal dominant polycystic kidney disease (ADPKD) population. Despite being an early and debilitating symptom, it is poorly characterized and management is suboptimal. This study aimed to develop an ADPKD-specific pain assessment tool (APAT) to facilitate pain research.

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Background: Hyperkalaemia occurs in up to 10% of hospital admissions but its treatment in the emergency setting is inconsistent.

Objectives: To describe the emergency management of hyperkalaemia in adults with insulin-dextrose (IDex) and to explore clinical outcomes associated with IDex treatment.

Design And Setting: Cohort study using comprehensive electronic health records of all emergency admissions to a large university hospital in the United Kingdom between April 2015 and August 2018.

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Background And Objectives: In a randomized double-blind, placebo-controlled trial, treatment with spironolactone in early-stage CKD reduced left ventricular mass and arterial stiffness compared with placebo. It is not known if these effects were due to BP reduction or specific vascular and myocardial effects of spironolactone.

Design, Setting, Participants, & Measurements: A prospective, randomized, open-label, blinded end point study conducted in four UK centers (Birmingham, Cambridge, Edinburgh, and London) comparing spironolactone 25 mg to chlorthalidone 25 mg once daily for 40 weeks in 154 participants with nondiabetic stage 2 and 3 CKD (eGFR 30-89 ml/min per 1.

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Introduction: In pivotal trials of patients with autosomal dominant polycystic kidney disease at risk of rapid progression, tolvaptan slowed estimated glomerular filtration rate (eGFR) decline in early-to-moderate (TEMPO 3:4 [NCT00428948]) and moderate- to late-stage (REPRISE [NCT02160145]) chronic kidney disease (CKD). Discontinuation was less frequent in REPRISE (15.0%) than TEMPO 3:4 (23.

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Introduction: Classification of acute kidney injury (AKI) requires a premorbid baseline creatinine, often unavailable in studies in acute infection.

Methods: We evaluated commonly used surrogate and imputed baseline creatinine values against a "reference" creatinine measured during follow-up in an adult clinical trial cohort. Known AKI incidence (Kidney Disease: Improving Global Outcomes [KDIGO] criteria) was compared with AKI incidence classified by (1) back-calculation using the Modification of Diet in Renal Disease (MDRD) equation with and without a Chinese ethnicity correction coefficient; (2) back-calculation using the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation; (3) assigning glomerular filtration rate (GFR) from age and sex-standardized reference tables; and (4) lowest measured creatinine during admission.

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Conflicting data exists as to whether vitamin D receptor agonists (VDRa) are protective of arterial calcification. Confounding this, is the inherent physiological differences between human and animal experimental models and our current fragmented understanding of arterial vitamin D metabolism, their alterations in disease states and responses to VDRa's. Herein, the study aims to address these problems by leveraging frontiers in human arterial organ culture models.

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Kidney donation results in reductions in kidney function and lasting perturbations in phosphate homeostasis, which may lead to adverse cardiovascular sequelae. However, the acute effects of kidney donation on bone mineral parameters including regulators of calcium and phosphate metabolism are unknown. We conducted a prospective observational controlled study to determine the acute effects of kidney donation on mineral metabolism and skeletal health.

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Ring chromosome 20 syndrome (r(20)) is an ultra-rare disease characterized by drug-refractory epilepsy, cognitive impairment, and behavioral problems. Nonpharmacological treatments alongside antiepileptic drugs early after diagnosis may help reduce seizure frequency and preserve cognition. Ketogenic dietary therapy (KDT) has benefitted children with complex, refractory epilepsies, but its efficacy in r(20) is unknown.

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Importance: Restitution of kidney function by transplant confers a survival benefit in patients with end-stage renal disease. Investigations of mechanisms involved in improved cardiovascular survival have relied heavily on static measures from echocardiography or cardiac magnetic resonance imaging and have provided conflicting results to date.

Objectives: To evaluate cardiovascular functional reserve in patients with end-stage renal disease before and after kidney transplant and to assess functional and morphologic alterations of structural-functional dynamics in this population.

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Background: The progress of electronic health technologies and biobanks holds enormous promise for efficient research. Evidence shows that studies based on sharing and secondary use of data/samples have the potential to significantly advance medical knowledge. However, sharing of such resources for international collaboration is hampered by the lack of clarity about ethical and legal requirements for transfer of data and samples across international borders.

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Purpose Of Review: This review describes recent developments in the management of serum phosphate in dialysis patients, with a focus on the development of recent trials which randomize patients to different levels of control.

Recent Findings: We review the uncertainties around clinical benefits of serum phosphate control and alternative approaches to current management, as well as a multinational attempt to conduct randomized controlled trials in this area. We discuss novel methods of limiting oral phosphate absorption.

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Context: A large body of experimental and observational data has implicated vitamin D deficiency in the development of cardiovascular disease. However, evidence to support routine vitamin D supplementation to prevent or treat cardiovascular disease is lacking.

Design And Results: A comprehensive literature review was performed using PubMed and other literature search engines.

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