
Christopher McIntyre
Principal Investigator
Biography
Dr. McIntyre is a nephrologist and Professor of Medicine, Professor of Medical Biophysics, and Professor of Paediatrics at Western University. He also serves as Director of the London Health Sciences Centre Research Institute. He leads a team of multidisciplinary researchers focused largely on understanding and reducing dialysis-associated organ injury. These studies include basic clinical science, natural history studies and the development and application of novel therapeutic strategies into large scale randomized controlled trials. Multimodal imaging plays an important role in these studies including ultrasound, CT, PET and MRI.
Active Clinical Studies
(11)Publications (since 2022)
Updated Nov 13, 2026
Research Profile
Research Areas
Study Types
Methods & Approaches
2026click to view publications
WCN26-6966 EFFECT OF A 12-WEEK INTRADIALYTIC CYCLING INTERVENTION ON HEMODIALYSIS-INDUCED MYOCARDIAL STUNNING: A MULTI-CENTRE RANDOMIZED CONTROLLED TRIAL (TICKERS_HD)
Paul N. Bennett, Jarrin D. Penny, Christopher William McIntyre, Jessica Anne Vanderlinden, Megan S. Borkum, Shilpanjali Jesudason, Mercedeh Kiaii, Justin Presseau, Claudio Rigatto, Mitra Shirazi, Anita Soni, Brett D. Tarca, Stephanie Thompson, Jennifer M. MacRae, Clara J Bohm
Kidney International Reports · 2026
This protocol describes an ongoing multi-centre randomized controlled trial evaluating the effects of a 12-week intradialytic cycling program for patients receiving maintenance hemodialysis. Researchers are investigating whether exercising on a stationary bicycle during dialysis treatments can reduce hemodialysis-induced myocardial stunning, a form of temporary heart injury caused by reduced blood flow. By mitigating this injury, the intervention aims to improve vital organ perfusion, reduce symptom burden, and improve overall cardiovascular outcomes in this high-risk population.
Progressive White Matter Injury Dominates in Patients Receiving Hemodialysis over Peritoneal Dialysis after 1 Year of Dialysis.
Vanderlinden JA, Jain A, McIntyre C
Kidney360 · 2026
Researchers used brain scans and thinking tests to follow 14 people receiving hemodialysis or peritoneal dialysis for one year. Signs of injury to the brain’s connecting tissue worsened in all eight people receiving hemodialysis and one of six receiving peritoneal dialysis, but thinking-test scores did not change significantly.
Peritoneal dialysis patients exhibit cognitive deficits but not ischemic brain injury: A magnetic resonance spectroscopy & diffusion tensor imaging study.
Vanderlinden JA, Wong D, Chiu M, McIntyre C, Jain AK
Perit Dial Int · 2026
This study used advanced brain imaging and cognitive testing to examine how peritoneal dialysis affects the brain compared to the known risks of hemodialysis. Researchers found that while patients on peritoneal dialysis experienced significant increases in brain glucose levels during treatment, they did not show the acute signs of restricted blood flow or brain injury typically seen in hemodialysis patients. Despite this protective effect on brain structure, many participants still demonstrated difficulties with memory, attention, and executive function during cognitive assessments.
Caution in extending SGLT2 inhibitor trials to children with CAKUT: a call for phenotype-specific safety considerations.
Filler G, McIntyre CW
Pediatr Nephrol · 2026
This commentary cautions against directly extending findings from sodium-glucose cotransporter-2 inhibitor trials to children with congenital anomalies of the kidney and urinary tract. The authors highlight the need for phenotype-specific safety considerations in this pediatric population, given their unique anatomical and physiological characteristics. They emphasize that safety profiles established in adults with other forms of chronic kidney disease may not directly translate to children with structural kidney abnormalities.
Randomized Controlled Trial of Intradialytic Cycling as Kidney Exercise Rehabilitation for Cardiac Stunning in Hemodialysis (TICKERS_HD): A Clinical Research Protocol.
Bennett PN, Penny JD, McIntyre CW, Vanderlinden J, Borkum MS, Castillo G, Collister D, Corradetti B, Duhamel TA, Farion H, Ford E, Garcia E, Getachew R, Jesudason S, Kiaii M, Leu RL, Presseau J, Rigatto C, Seitz AK, Shirazi M, Soni A, Stewart K, Tarca B, Tennankore K, Verdin N, Whitlock R, Wilund K, Thompson S, MacRae JM, Bohm C
Can J Kidney Health Dis · 2026
This protocol describes the design of an ongoing multicentre randomized controlled trial evaluating the impact of a 12-week intradialytic cycling program on hemodialysis-induced heart muscle stunning. Researchers will measure changes in regional wall motion abnormalities during dialysis, alongside secondary outcomes like cognitive function, recovery time, and symptom burden. The study aims to determine if exercise during dialysis can mitigate cardiac injury and improve patient-reported symptoms and functional status.
2025
Insult to Injury: Dialysis-Induced Cerebrovascular Reactivity and Cognitive Impairment.
Vanderlinden J, Tamasi T, Dorie J, McIntyre C
Kidney360 · 2025
In 11 people receiving dialysis, researchers measured how well blood vessels in the brain adjusted blood flow before and after treatment and assessed thinking skills. The vessels were less able to adjust blood flow after dialysis, with some recovery by the next session; weaker responses were linked to poorer scores on thinking tests. These findings suggest that dialysis-related strain on brain circulation may be associated with difficulties in thinking.
Fluid Volume Estimation by Bioimpedance: Methodological Caveats and Clinical Interpretation.
Mussnig S, Schneditz D, Keane DF, McIntyre CW, Hecking M
Am J Nephrol · 2025
This review examines the technical challenges and potential errors in using bioimpedance to estimate fluid volumes in patients undergoing hemodialysis. The authors demonstrate through data simulation that standard wrist-to-ankle bioimpedance measurements tend to underestimate extracellular fluid volume as a patient's body fat percentage increases. They suggest that using segmental measurements or incorporating subject-specific body shape corrections, such as those from three-dimensional smartphone scans, can improve the accuracy of these fluid assessments.
Impact of Expanded Hemodialysis on Subjective Experience Using Dynamic Patient-Reported Outcome Measurement Tool.
Penny JD, Gozdzik D, Tamasi T, Dorie J, Koyle K, Lozon ZB, Cesario R, Nesrallah G, McIntyre CW
Kidney Med · 2025
This study examined whether expanded hemodialysis, which uses a specialized filter, could improve quality of life and symptom burden compared to standard hemodialysis. Over 15 months, 47 patients in Ontario, Canada, switched between standard hemodialysis and expanded hemodialysis while tracking their symptoms using a dynamic patient-reported outcomes tool. Expanded hemodialysis led to durable improvements in overall quality of life, energy, sleep, and pain, with symptoms worsening when patients switched back to standard hemodialysis.
The Effect of Dialysate Sodium on Endothelial Injury and Microcirculatory Dysfunction.
Hur L, Zhang Y, Akbari A, Patterson EK, Janssen BGH, McIntyre CW
Kidney360 · 2025
Using an animal model, researchers investigated how different sodium concentrations in dialysis fluid affect blood vessel health and blood flow during hemodialysis. They found that hemodialysis itself causes acute injury to the protective lining of blood vessels and reduces blood flow, but these harmful effects were significantly worsened when a high-sodium dialysis fluid was used. This suggests that exposing patients to high sodium levels during dialysis may aggravate blood vessel damage.
Coronary Artery Disease and Intradialytic Myocardial Ischemia in Hemodialysis: An Exploratory Study Using Intradialytic Imaging.
Hur L, Islam A, Penny JD, Dorie J, McIntyre CW
Kidney Med · 2025
A study of thirteen patients undergoing maintenance hemodialysis used advanced heart imaging to examine how dialysis affects blood flow to the heart muscle. Researchers found that hemodialysis reduced blood flow and caused temporary heart muscle dysfunction even in patients without coronary artery disease. In patients who did have coronary artery disease, these negative effects on heart perfusion and contraction were even more pronounced and persisted after the dialysis session ended.
Studying the effects of digital arts-based interventions on teenagers’ social media usage, brain connectivity, and mental health: study protocol of the SMART project
Lucía Vaquero, Karleigh Groves, Eva Luna Muñoz-Vidal, Kevin James, J. L. Marlor, Christopher William McIntyre, Lorena Ostia, С. А. Сирота, Lindsay Shields, Franziska Degé, Elisa García‐Mingo, Pablo Ripollés
European Journal of Psychotraumatology · 2025
This study protocol describes an ongoing project evaluating whether digital arts-based training, such as music or photography editing, can help teenagers use social media in healthier, more goal-oriented ways. Researchers will compare adolescents participating in a three-month digital arts programme to a control group, measuring changes in social media habits, attention, mood, and brain connectivity using advanced imaging. The goal is to determine if creative digital interventions can mitigate the negative mental health and cognitive effects associated with social media overuse.
Patients receiving maintenance dialysis often experience faster and more severe cognitive decline compared to those with advanced kidney disease who are not on dialysis. This review explores how both hemodialysis and peritoneal dialysis can cause structural and functional brain changes, leading to symptoms ranging from short-term confusion and brain fog to long-term loss of cognitive ability. The authors examine the underlying biological mechanisms of this decline and discuss potential medical interventions to protect brain health in this population.
Dialyzer characteristics are associated with differential effects on intradialytic microvascular tissue perfusion.
Janssen B, Zhang YM, Hur L, Moradshahi M, Akbari A, Mahmoud O, McIntyre CW
Ann Med Surg (Lond) · 2025
Using a rat model of hemodialysis, researchers compared how different types of dialyzer membranes affect blood flow in tiny blood vessels. They found that conventional high-flux polysulfone dialyzers caused a twenty-five percent reduction in microvascular tissue perfusion, whereas newer mid-cut-off dialyzers preserved this blood flow. The conventional dialyzers also showed higher activation of the complement immune pathway, suggesting that dialyzer membrane design plays a key role in preventing tissue-damaging drops in blood flow during treatment.
2024
In vivo assessment of pediatric kidney function using multi-parametric and multi-nuclear functional magnetic resonance imaging: challenges, perspectives, and clinical applications.
De Mul A, Schleef M, Filler G, McIntyre C, Lemoine S
Pediatr Nephrol · 2024
This review explores the potential of advanced functional magnetic resonance imaging techniques, including multi-parametric and multi-nuclear imaging, to assess kidney function in children. These non-invasive methods can evaluate kidney perfusion, tissue oxygenation, and scarring without the need for a biopsy, and can track sodium and phosphate levels to monitor specific kidney disorders. Because these techniques do not use radiation, they are particularly well-suited for safely monitoring pediatric kidney health over time.
Development of a Novel Intraperitoneal Icodextrin/Dextrose Solution for Enhanced Sodium Removal.
Asher JL, Ivey-Miranda JB, Maulion C, Cox ZL, Borges-Vela JA, Mendoza-Zavala GH, Cigarroa-Lopez JA, Silva-Rueda RI, Revilla-Monsalve C, Moreno-Villagomez J, Ramos-Mastache D, Goedje O, Crosbie I, McIntyre C, Finkelstein F, Turner JM, Testani JM, Rao VS
Kidney Med · 2024
Researchers developed and tested a novel, sodium-free intraperitoneal solution containing 30% icodextrin and 10% dextrose to optimize fluid and sodium removal. In animal models and a small study of ten human patients with kidney failure, this new solution removed significantly more water and sodium than standard peritoneal dialysis solutions without causing serious adverse events or tissue damage. These findings suggest the solution could be a highly effective treatment for managing fluid overload in patients with kidney failure or other swelling disorders like heart failure.
Redefining the concept of residual renal function with kidney sodium MRI: a pilot study.
Lemoine S, Akbari A, Brahm G, Dorie J, Tamasi T, Penny J, McIntyre CW
Nephrol Dial Transplant · 2024
This pilot study evaluated the feasibility of using sodium magnetic resonance imaging to assess residual kidney function in patients receiving hemodialysis by measuring the sodium gradient between the inner and outer parts of the kidney. Researchers found that healthy volunteers had a significantly higher sodium gradient than patients on hemodialysis, and this gradient correlated closely with urine concentration. This imaging technique may provide a new way to evaluate remaining kidney tubule function in dialysis patients, which is currently difficult to measure in clinical practice.
Dedicated Patient Optimization Program Improves Lives of Vulnerable Patients
Jarrin D. Penny, Patrik Deleaval, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2024
In a small study of 19 people receiving hemodialysis who had not responded well to usual care, clinicians used detailed monitoring to tailor several parts of dialysis to each person over two weeks. The programme was associated with better quality of life, much shorter recovery times, fewer blood pressure drops, less weight gain between treatments, and less dialysis-related heart injury; three people were later listed for transplantation and two received a transplant. These results suggest that individualized dialysis care may make treatment safer and more tolerable for people who struggle with standard approaches.
Dynamic Patient-Reported Outcome Measures Evaluate Durability of Expanded Hemodialysis on Health-Related Quality of Life (HR-QoL) and Symptom Variability
Jarrin D. Penny, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2024
This 15-month study examined what happened when 47 people receiving in-centre hemodialysis in Ontario switched between expanded hemodialysis and their usual treatment, using repeated questionnaires about quality of life and symptoms. Expanded hemodialysis improved overall quality of life and several symptoms, including low energy, poor sleep, itching, pain, and recovery after treatment; these benefits persisted during treatment and became smaller when usual dialysis resumed.
Initial Evaluation of Sodium-Free Intraperitoneal 30% Icodextrin/10% Dextrose Solution to Test Short-Term Safety, Tolerability, and Preliminary Efficacy
Christopher W. McIntyre, Patrik Deleaval, Jarrin D. Penny, Amy Freeman
Journal of the American Society of Nephrology · 2024
Researchers tested a new salt-free dialysis fluid in 10 adults already receiving peritoneal dialysis. After a single treatment lasting four to six hours, participants had mild to moderate abdominal discomfort but no meaningful changes in blood pressure, heart function, or blood sodium, while removing about five grams of sodium and two litres of fluid. These early findings suggest the solution was tolerated and may improve salt and fluid removal during peritoneal dialysis.
Initial Feasibility Pilot Study of Interdialytic Peritoneal Ultrafiltration to Manage Volume Status in Patients on Hemodialysis (iPUF-HD)
Patrik Deleaval, Jarrin D. Penny, Amy Freeman, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2024
In a small pilot study, five people receiving hemodialysis who had difficult-to-control fluid weight gain received two brief treatments each week that used the abdominal lining to remove extra salt and fluid after dialysis. Their between-treatment weight gain fell over three weeks, and the treatment was generally well tolerated, although blood sodium levels decreased modestly. Blood pressure and other measured markers stayed stable, while heart imaging suggested less dialysis-related heart strain in two of the three patients with usable images.
Intradialytic Microvascular Tissue Perfusion Is Affected by Dialyzer Membrane Characteristics
Barry Janssen, Yanmin Zhang, Lisa Hur, Alireza Akbari, Christopher William McIntyre
Journal of the American Society of Nephrology · 2024
In a rat model of haemodialysis, researchers compared two types of dialysis filters and measured blood flow through small vessels in muscle. The conventional polysulfone filter reduced this blood flow and triggered more activation of part of the immune system, while the newer mid-cut-off filter preserved blood flow without changing the removal of small waste products. These findings suggest that filter materials may affect tissue circulation during dialysis and can be evaluated in animal models before human studies.
Quantification of Muscle Wasting in CKD by Texture Analysis on 1H-Magnetic Resonance Images
Lisa Hur, Nicole Latman, Alireza Akbari, Justin R. Dorie, Tanya Tamasi, Christopher William McIntyre
Journal of the American Society of Nephrology · 2024
Researchers used a non-invasive magnetic resonance imaging technique to measure calf muscle structure in 85 people with chronic kidney disease, including people receiving dialysis and people with both heart and kidney problems. Muscle patterns were more irregular in those receiving dialysis or with both heart and kidney problems than in people with chronic kidney disease who were not receiving dialysis, and the imaging findings were related to blood markers of kidney and mineral health. This approach could offer a way to assess muscle wasting and structural changes without a biopsy.
#1321 Long term outcomes in people with fluctuating criteria for the diagnosis of chronic kidney disease
Maarten W Taal, Bethany Lucas, Natasha Mcintyre, Christopher Mcintyre, Richard Fluck
Nephrology Dialysis Transplantation · 2024
This study followed a group of patients diagnosed with stage 3 chronic kidney disease in primary care over nearly ten years to see how fluctuations in their diagnostic criteria affected long-term outcomes. Researchers found that more than a quarter of the patients experienced periods of "remission," where their kidney function measurements temporarily improved to normal levels. While patients who experienced these periods of remission had a significantly lower risk of death and kidney disease progression compared to those with persistent disease, they still remained at risk and required ongoing monitoring.
#2879 Residual kidney function is more than urinary output alone in PD patients: insights derived from tubular functional Na MRI of the kidney
Sandrine Lemoine, Alireza Akbari, Justin Dorie, Tanya Tamasi, Arsh Jain, Christopher Mcintyre
Nephrology Dialysis Transplantation · 2024
This pilot study used advanced sodium magnetic resonance imaging to evaluate the kidney's tubular function in patients undergoing peritoneal dialysis compared to those on hemodialysis. Although peritoneal dialysis patients typically maintain higher urine volumes, the imaging revealed that both groups had similarly reduced levels of tubular function, specifically in their ability to concentrate urine. These findings suggest that measuring urine volume alone provides an incomplete picture of residual kidney health in dialysis patients.
#443 LEVIL evaluates the impact of HDx on HR-QoL and symptoms, including durability-of-effect and variability
Jarrin Penny, Christopher Mcintyre
Nephrology Dialysis Transplantation · 2024
This study evaluated the impact of expanded hemodialysis, which uses a medium cut-off dialyzer to remove a broader range of toxins, on the quality of life and symptom burden of patients receiving maintenance hemodialysis in Ontario, Canada. Using a specialized patient-reported outcome tool, researchers found that switching to expanded hemodialysis significantly improved general well-being, energy, sleep quality, and pain, with benefits remaining durable over time. These improvements gradually declined when patients were switched back to conventional high-flux hemodialysis.
#536 Dedicated patient optimization program delivers effective complex intervention improving the lives of vulnerable HD patients
Jarrin Penny, Patrik Deleaval, Christopher Mcintyre
Nephrology Dialysis Transplantation · 2024
Researchers evaluated a patient optimization program designed to deliver individualized, complex interventions for vulnerable hemodialysis patients who had poor tolerance to standard treatments. For the thirteen patients who completed the program, the personalized approach led to significant improvements in quality of life, energy levels, and blood pressure, while also reducing post-dialysis recovery time and dialysis-induced heart muscle injury. These findings suggest that tailoring dialysis prescriptions to individual patient physiology can successfully improve both subjective well-being and objective clinical outcomes.
(23)NaMRI Assessed Cyst Sodium Concentration in Polycystic Kidney Disease to Identify Cyst Metabolic Activity: A Proof of Concept Study.
Lemoine S, Akbari A, McIntyre CW
Kidney Med · 2024
This proof-of-concept study evaluated the feasibility of using sodium magnetic resonance imaging to measure the sodium concentration within kidney cysts in four patients with autosomal dominant polycystic kidney disease. The researchers successfully captured sodium images of the kidneys, revealing a wide and previously unappreciated range of sodium content across different cysts. This imaging technique could eventually help clinicians assess the metabolic activity of cysts to improve prognosis and monitor responses to treatment without invasive procedures.
Effect of Intradialytic Exercise on Cardiovascular Outcomes in Maintenance Hemodialysis: A Systematic Review and Meta-Analysis.
Verrelli D, Sharma A, Alexiuk J, Tays Q, Rossum K, Sharma M, Ford E, Iansavitchene A, Al-Jaishi AA, Whitlock R, McIntyre CW, Garg AX, Bohm C
Kidney360 · 2024
This systematic review and meta-analysis evaluated the impact of exercise during hemodialysis sessions on cardiovascular health in adults with kidney failure. Analyzing data from thirty-two studies, researchers found that intradialytic exercise, primarily aerobic, significantly reduced arterial stiffness and improved diastolic blood pressure, heart pumping function, and heart rate variability compared to standard care. These findings suggest that incorporating exercise programs during dialysis treatments can meaningfully improve several physiological measures of cardiovascular health.
Update on Hemodialysis-Induced Multiorgan Ischemia: Brains and Beyond.
McIntyre CW
J Am Soc Nephrol · 2024
This review examines how the circulatory stress of recurrent hemodialysis causes abnormal blood flow and progressive, irreversible damage to vital organs like the brain and heart. It explores the underlying biological mechanisms of this vascular injury and discusses potential therapeutic strategies to protect patients from these complications. Ultimately, addressing these issues is critical to reducing the high rates of cardiovascular disease and premature death in people receiving hemodialysis.
Reassuring Data on the Cardiovascular Risk in Adults With X-linked Hypophosphatemia Receiving Conventional Therapy.
Bouzemane A, Vignot E, Derain Dubourg L, De Mul A, Molin A, Chapurlat R, Fontanges E, Delsart D, Akbari A, Huang SHS, McIntyre CW, Bacchetta J, Lemoine S
J Clin Endocrinol Metab · 2024
Researchers studied whether adults with X-linked hypophosphatemia, a rare genetic condition causing high levels of a hormone called fibroblast growth factor 23, have an increased risk of heart disease or high blood pressure. In a group of twenty-two patients, the study found that most had normal heart structure and blood pressure, with no signs of stiffening in the arteries. These findings suggest that the elevated hormone levels associated with this specific genetic condition may not carry the same cardiovascular risks as seen in patients with chronic kidney disease.
2023
A novel multiplex biomarker panel for profiling human acute and chronic kidney disease.
Van Nynatten LR, Miller MR, Patel MA, Daley M, Filler G, Badrnya S, Miholits M, Webb B, McIntyre CW, Fraser DD
Sci Rep · 2023
Researchers evaluated a new multiplex testing panel that measures 21 different proteins in blood and urine samples from healthy individuals, critically ill patients with acute kidney injury, and patients with chronic or end-stage kidney disease. They identified unique protein profiles that could accurately distinguish patients with kidney injury or disease from healthy controls, with specific markers like TIMP-1 and osteoactivin showing high predictive value. These findings demonstrate the potential of using multi-protein panels to better characterize and profile different stages of kidney dysfunction.
Effects of the pandemic on adolescent and caregiver attitudes towards telemedicine use
Yi Qiu, Subhrata Verma, Christopher William McIntyre, Guido Filler
Clinical Nephrology · 2023
This study compared the attitudes of adolescents with chronic conditions and their caregivers toward telemedicine before and during the COVID-19 pandemic. While caregivers continued to prefer telemedicine over in-person visits for safety and convenience, adolescents shifted their preference toward more in-person visits during the pandemic, placing a higher value on the personal connection, comfort, and communication of face-to-face consultations. Interestingly, pre-pandemic concerns such as technical frustrations and adolescents not taking virtual appointments seriously largely disappeared during the pandemic.
Kidney Sodium MRI: Extending the Concept of Residual Kidney Function in Hemodialysis
Sandrine Lemoine, Alireza Akbari, Jarrin D. Penny, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2023
Researchers tested whether a sodium-sensitive magnetic resonance scan could assess remaining kidney function in people receiving hemodialysis, comparing 17 patients with 21 healthy volunteers. The scan showed a lower sodium signal in the inner kidney among the dialysis patients, and this signal tracked urine concentration but not urine volume, suggesting imaging may capture aspects of remaining kidney tubule function that current measures do not.
Long-Term Outcomes in Persons with Stage 3 CKD Recruited from Primary Care
Maarten W. Taal, Natasha J. McIntyre, Christopher W. McIntyre, Richard J. Fluck
Journal of the American Society of Nephrology · 2023
Researchers followed 1,741 people with moderate chronic kidney disease recruited through primary care for about 10 years. About three in ten had a substantial decline in kidney function, fewer than two in 100 reached the most advanced stage, and about four in ten died. Deaths were more common than progression to kidney failure in this older group, highlighting the importance of considering overall health as well as kidney function.
Peritoneal Dialysis Patients Exhibit Quantifiable Neurocognitive Impairment but Not Acute Ischemic Brain Injury: A Magnetic Resonance Spectroscopy and Diffusion Tensor Imaging Study
Jessica Vanderlinden, Dickson Y. Wong, Michael Chiu, Christopher W. McIntyre, Arsh Jain
Journal of the American Society of Nephrology · 2023
Researchers tested thinking skills and used brain scans in 12 people receiving peritoneal dialysis, before and after a 90-minute period with dialysis fluid in the abdomen. Many participants had difficulties with attention and other thinking skills; scans showed no short-term injury to the brain’s communication pathways, although brain sugar levels increased. The findings suggest no immediate brain injury during this treatment in this small group, but do not show what happens over time.
Does cooled dialysate still have a role in reducing intradialytic stress? Implications of the MyTEMP trial.
Hull KL, McIntyre C, Burton JO
Curr Opin Nephrol Hypertens · 2023
This review examines the practice of cooling dialysis fluid to prevent drop in blood pressure and protect organs like the heart and brain from stress during hemodialysis. While smaller studies previously suggested benefits, a recent large-scale trial found that a center-wide policy of using cooler dialysis fluid did not improve cardiovascular outcomes. The authors discuss why cooler dialysate may still be useful for certain individual patients rather than being completely abandoned.
Non-invasive intradialytic percutaneous perfusion monitoring: a view to the heart through the skin.
Penny JD, Hur L, Salerno FR, Wong D, Jan MH, McIntyre CW
Front Nephrol · 2023
This study evaluated whether non-invasive skin perfusion monitoring using photoplethysmography could detect hemodialysis-induced heart injury in twelve patients. Researchers found that a significant reduction in skin pulse strength during dialysis was associated with both decreased myocardial perfusion and the development of regional heart wall motion abnormalities, which indicate myocardial stunning. The findings suggest that monitoring skin perfusion is a promising, non-invasive way to detect and manage circulatory stress and heart injury during hemodialysis treatments.
Recent Advances in Sodium Magnetic Resonance Imaging and Its Future Role in Kidney Disease.
Akbari A, McIntyre CW
J Clin Med · 2023
This review highlights recent progress in sodium magnetic resonance imaging, a technology used to detect excess sodium accumulation in tissues like the skin, heart, and kidneys. Researchers have linked this tissue sodium buildup to declining kidney function, inflammation, and cardiovascular issues across the entire spectrum of chronic kidney disease. The article discusses how this imaging technique could serve as a valuable tool in future clinical trials and patient care.
Hemodialysis-Related Acute Brain Injury Demonstrated by Application of Intradialytic Magnetic Resonance Imaging and Spectroscopy.
Anazodo UC, Wong DY, Théberge J, Dacey M, Gomes J, Penny JD, van Ginkel M, Poirier SE, McIntyre CW
J Am Soc Nephrol · 2023
Using advanced magnetic resonance imaging and spectroscopy during active hemodialysis sessions, researchers found direct evidence of acute brain injury in patients. The study revealed brain tissue changes consistent with swelling and chemical markers of oxygen deprivation during the period of maximum circulatory stress. These findings suggest that even a single hemodialysis session can cause acute, ischemic brain injury, which may contribute to long-term cognitive decline in this patient population.
Midodrine Is an Effective Therapy for Resistant Intradialytic Hypotension: PRO.
House AA, McIntyre CW
Kidney360 · 2023
This article discusses the clinical utility of midodrine, an oral medication commonly used to prevent and treat low blood pressure during hemodialysis. While small studies show midodrine effectively raises blood pressure and improves symptoms, a large observational study raised safety concerns by linking its use to higher mortality and hospitalizations. However, these observational findings may be biased by confounding, as patients prescribed midodrine are typically sicker and at higher baseline risk for poor outcomes.
2022
Initial evaluation of extracorporeal immunomodulatory therapy for the treatment of critically ill COVID-19 infected patients.
Lemoine S, Penny J, Fraser DD, Salerno FR, Dorie J, Tamasi T, Arntfield R, House A, Slessarev M, McIntyre CW
Sci Rep · 2022
This preliminary study evaluated the safety and feasibility of a novel extracorporeal immunomodulatory therapy designed to regulate white blood cells in critically ill patients with severe COVID-19. In twelve patients requiring mechanical ventilation and blood pressure support, the therapy was found to be safe and was associated with a significant 37 percent reduction in the need for blood pressure-boosting medications. These findings support further evaluation of this blood-filtering approach to manage severe inflammation in critically ill patients.
Personalised cooler dialysate for patients receiving maintenance haemodialysis (MyTEMP): a pragmatic, cluster-randomised trial.
MyTEMP writing committee
Lancet · 2022
This study investigated whether tailoring the temperature of dialysis fluid to each patient's body temperature could reduce cardiovascular problems in people receiving long-term dialysis. Researchers found no significant difference in rates of cardiovascular death or hospital admission between patients receiving personalized cooler dialysis and those receiving standard temperature dialysis. The findings suggest that the widespread adoption of cooler dialysis may need to be re-evaluated, as it did not demonstrate the expected cardiovascular benefits in this large trial.
Does Sodium Magnetic Resonance Imaging Help for Initiation of Incremental Dialysis?
Sandrine Lemoine, Alireza Akbari, Jarrin D. Penny, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2022
Researchers used sodium-based magnetic resonance imaging to compare kidney salt patterns in 10 people receiving haemodialysis and 15 healthy volunteers, exploring whether the scan might help identify people suited to less frequent dialysis. The kidney’s inner-to-outer salt gradient was lower in people receiving haemodialysis than in volunteers and was no longer visible in those with no remaining kidney function; scan measurements also tracked with how concentrated the urine was. These findings show that the imaging can detect differences in kidney salt handling, but do not establish whether it can identify who would benefit from less frequent dialysis.
Intradialytic Exercise on Cardiac Response to Hemodialysis
Lisa Hur, Jarrin D. Penny, Justin R. Dorie, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2022
Researchers compared heart function during hemodialysis with and without cycling exercise in 10 participants, using scans to assess blood flow and heart muscle movement. Cycling did not change the drop in heart blood flow during treatment, but there was a possible reduction in areas of abnormal heart movement afterward, suggesting a protective effect that this small study could not establish.
Sodium-Induced Microcirculatory Dysfunction During Hemodialysis
Lisa Hur, Yanmin Zhang, Barry Janssen, Christopher W. McIntyre
Journal of the American Society of Nephrology · 2022
In eight healthy rats, researchers compared hemodialysis using fluid with a higher or lower sodium concentration and measured blood flow in small vessels and a blood marker of vessel-lining injury. Both groups showed increasing evidence of acute injury to the vessel lining during treatment; the lower-sodium group tended to have poorer small-vessel blood flow, although this difference was not statistically significant. These preliminary findings suggest that the sodium concentration of dialysis fluid may affect small-vessel function even when blood pressure changes are similar.
Choice of the Optimal Dialysate Sodium Concentration
Christopher W. McIntyre
Kidney and Dialysis · 2022
This review examines the challenges of choosing the optimal dialysate sodium concentration for patients undergoing hemodialysis. It discusses how to individualize dialysate sodium choices to better address patient symptoms and improve survival outcomes, highlighting that sodium transport and its clinical consequences are still not fully understood.
Assessment of microcirculatory function during hemodialysis.
Penny JD, Moradshahi M, McIntyre CW
Curr Opin Nephrol Hypertens · 2022
Patients undergoing hemodialysis experience significant circulatory stress that can damage small blood vessels and lead to organ injury, even when their overall blood pressure appears stable. This review examines various non-invasive technologies used to monitor microcirculatory function during dialysis treatments. Incorporating these monitoring tools into clinical practice could help healthcare providers detect tissue stress early and personalize dialysis delivery to improve patient outcomes.
Effects of pediatric chronic kidney disease and its etiology on tissue sodium concentration: a pilot study.
Salerno FR, Akbari A, Lemoine S, Scholl TJ, McIntyre CW, Filler G
Pediatr Nephrol · 2022
Using advanced sodium magnetic resonance imaging, researchers measured tissue sodium levels in the legs of children with chronic kidney disease and compared them to healthy peers and adults. While overall tissue sodium levels did not differ significantly between healthy children and those with kidney disease, differences emerged when looking at the underlying cause of the kidney disease. Children with glomerular diseases showed elevated tissue sodium levels, whereas those with tubular disorders had reduced levels, with these measurements closely linked to protein loss in the urine and low blood albumin.
The Renal Community Photo Initiative
Ruth Skinner, Cindy House, Andrew A House, Christopher McIntyre, Ann Tillmann, Elaine Hayter, Jared McGregor, Pamela Ireland
Canadian Journal of Kidney Health and Disease · 2022
The Renal Community Photo Initiative: A Program Report in Ontario, Canada.
Skinner R, House C, House AA, McIntyre C, Hayter E, Ireland P, McGregor J, Tillmann A
Can J Kidney Health Dis · 2022
The Renal Community Photo Initiative used a participatory photography method called Photovoice to explore resilience and quality of life among adult hemodialysis patients in Ontario, Canada. Participants used various photographic technologies to capture their daily lives and met in focus groups to discuss their experiences and direct how their images should be shared publicly. The project successfully gathered over 1600 images and handwritten logs, establishing a participant-led model to raise public awareness about living with chronic kidney disease.
Growth hormone therapy in HHRH.
Filler G, Schott C, Salerno FR, Ens A, McIntyre CW, Díaz González de Ferris ME, Stein R
Bone Rep · 2022
This study reports on a twelve-year-old male with a rare genetic kidney disorder called hereditary hypophosphatemic rickets with hypercalciuria, which causes bone pain, fractures, and kidney calcification. Standard phosphate and potassium treatments failed to correct these issues, but adding recombinant human growth hormone, fluconazole, and dietary salt restriction successfully improved the patient's growth, bone pain, and calcium levels. Advanced sodium magnetic resonance imaging also showed normal tissue sodium levels, providing a physiological rationale for the salt restriction.
MO645: Does Sodium Magnetic Resonance Imaging Help for Initiation of Incremental Dialysis?
Sandrine Lemoine, Alireza Akbari, Jarrin Penny, Christopher Mcintyre
Nephrology Dialysis Transplantation · 2022
Researchers tested whether a specialised magnetic resonance scan that measures sodium across the kidney could help identify people who might be suitable for starting dialysis twice a week. Among four people receiving dialysis, the scan showed a smaller difference in sodium levels across the kidney than in 15 healthy volunteers, and larger differences were linked with more concentrated urine; it did not distinguish the one person who still produced urine from those who did not. The scan was feasible, but this small study did not establish whether it can guide a less frequent dialysis schedule.
Structure (Epicardial Stenosis) and Function (Microvascular Dysfunction) That Influence Coronary Fractional Flow Reserve Estimation
Jermiah J. Joseph, Clara Sun, Ting‐Yim Lee, Daniel Goldman, Sanjay Kharche, Christopher William McIntyre
Applied Sciences · 2022
This study used a mathematical model of human coronary blood flow to evaluate how narrowing of the large blood vessels and disease of the smaller blood vessels affect heart blood flow and pressure measurements. The simulations showed that while narrowing of the large vessels directly impacts pressure measurements, the presence of small vessel disease also significantly harms overall blood flow. The findings suggest that combining pressure measurements with assessments of small vessel disease is essential for accurate clinical decision-making regarding heart treatments.
Cognitive Impairment Early After Initiating Maintenance Hemodialysis: A Cross Sectional Study.
Schorr M, Zalitach M, House C, Gomes J, Wild CJ, Salerno FR, McIntyre C
Front Neurol · 2022
This study evaluated cognitive function in forty-nine patients who had recently started maintenance hemodialysis, comparing them to age- and sex-matched healthy controls. Researchers found that a high proportion of patients experienced cognitive impairment within their first year of starting dialysis, with the most significant deficits observed in verbal skills and reasoning. These findings suggest that cognitive decline is highly prevalent early in the course of hemodialysis and may be related to the treatment itself.
Addressing feasibility challenges to delivering intradialytic exercise interventions: a theory-informed qualitative study.
Castillo G, Presseau J, Wilson M, Cook C, Field B, Garg AX, McIntyre C, Molnar AO, Hogeterp B, Thornley M, Thompson S, MacRae JM, Bohm C
Nephrol Dial Transplant · 2022
This study explored the barriers and enablers to delivering exercise programs during dialysis treatments by interviewing healthcare providers and patients across twelve hospitals in Ontario, Canada. The researchers identified key challenges, including a lack of staff training, concerns about workload, and uncertainty regarding patient eligibility and safety. To address these issues, they developed a list of practical solutions and a forty-seven-item feasibility checklist to help clinics successfully implement exercise programs in dialysis units.
Atrial Fibrillation and Anterior Cerebral Artery Absence Reduce Cerebral Perfusion: A De Novo Hemodynamic Model
Timothy J. Hunter, Jermiah J. Joseph, Udunna Anazodo, Sanjay Kharche, Christopher William McIntyre, Daniel Goldman
Applied Sciences · 2022
Researchers developed a new computer model of blood flow to study how different anatomical variations in the brain's blood vessels, known as the Circle of Willis, affect brain perfusion during atrial fibrillation. The model showed that missing certain vessel segments significantly increased the risk of low blood flow events, especially at higher heart rates. These findings suggest that individual anatomical differences in brain blood vessels may influence the risk of cognitive decline or dementia in patients with this common heart arrhythmia.
Functional Sodium MRI Helps to Measure Corticomedullary Sodium Content in Normal and Diseased Human Kidneys.
Akbari A, Lemoine S, Salerno F, Marcus TL, Duffy T, Scholl TJ, Filler G, House AA, McIntyre CW
Radiology · 2022
This study evaluated the ability of sodium magnetic resonance imaging to measure the sodium concentration gradient between the inner and outer parts of the kidney, which is a key indicator of kidney function. In healthy volunteers, changes in this gradient measured by the scan closely matched changes in urine concentration after drinking water, and the imaging technique was also shown to be feasible in patients with chronic kidney disease. This non-invasive imaging method could provide a new way to monitor kidney health and function without relying solely on urine tests.
Outcomes and predictors of skin sodium concentration in dialysis patients.
Salerno FR, Akbari A, Lemoine S, Filler G, Scholl TJ, McIntyre CW
Clin Kidney J · 2022
Using advanced sodium magnetic resonance imaging, researchers measured the concentration of sodium in the skin of patients undergoing hemodialysis and peritoneal dialysis. They found that higher levels of skin sodium were strongly linked to a higher risk of death and major cardiovascular events, independent of age, sex, and blood sodium levels. In hemodialysis patients, higher skin sodium was specifically associated with the sodium concentration of the dialysis fluid, low blood albumin, and a history of congestive heart failure.
Electro-anatomical computational cardiology in humans and experimental animal models
Sanjay Kharche, Randa Mudathir, Christopher William McIntyre
Translational Research in Anatomy · 2022
This review examines computational cardiology tools used to study cardiac arrhythmias across different species, including humans, rabbits, and mice. By integrating experimental data into multi-scale electro-anatomical models, researchers can simulate how sub-cellular ion channels and tissue scarring affect electrical propagation and electrocardiogram readings. The work highlights how these computer models can be personalized to improve our understanding of heart rhythm disorders and translate findings from animal models to human treatments.
Intravital microscopic observation of the microvasculature during hemodialysis in healthy rats.
Janssen BGH, Zhang YM, Kosik I, Akbari A, McIntyre CW
Sci Rep · 2022
Using a newly developed small animal model, researchers monitored the microvasculature of healthy rats in real time during hemodialysis. They found that even without fluid removal, the hemodialysis procedure caused significant systemic hemodynamic disturbances and acutely reduced blood flow in skeletal muscle microcirculation. This model demonstrates that hemodialysis itself can directly impair microvascular perfusion, providing a new way to study and prevent dialysis-induced ischemic organ injury.
Cardiac implications of upper-arm arteriovenous fistulas: A case series.
Pucchio A, McIntyre C, Lok C, Moist L
J Vasc Access · 2022
Researchers followed eight patients undergoing hemodialysis through the creation of an upper-arm arteriovenous fistula and tracked changes in their heart structure using magnetic resonance imaging. They found that all patients experienced an increase in the muscle mass of the heart's main pumping chamber, and most experienced a decrease in the chamber’s ability to pump blood effectively within the first year. These changes in heart structure are concerning because increased heart muscle mass is linked to a higher risk of health problems and death in people with kidney disease.