A new study from UHN, featured on the cover of Nature Medicine, shows that wearable technologies such as Apple Watch can help monitor heart failure by providing early signs of deteriorating health where medical attention may be needed.
Heart failure—when the heart does not pump blood adequately to meet the body’s needs—is a global health crisis that leads to hospitalizations, increased use of health care services, and reduced life expectancy. Despite recent medical advances, patients with heart failure still face a high risk of poor outcomes. This highlights the need to improve risk assessment and better guide timely interventions.
“For patients with heart failure, periods of stability are often interspersed with flare-ups of symptoms such as shortness of breath or fatigue. These episodes may require medical attention to prevent hospitalization and improve quality of life,” says Dr. Heather Ross, Clinician Investigator at UHN and co-senior author of the study. “However, risk assessments for heart failure patients often rely on scheduled clinical visits or evaluation tools that take measurements at only one point in time. They don’t account for the changing, episodic nature of heart failure.”
Therefore, doctors and clinicians need to find better ways of monitoring heart failure symptoms and predicting when medical intervention may be needed. Wearable technology, such as Apple Watch, can continuously track important health and fitness measures, such as heart rate and blood oxygen levels, making it an excellent candidate for monitoring. However, until recently, it has been unclear how these measurements might be used to understand day-to-day changes in people living with heart failure.
To investigate this, the research team, led by researchers at UHN’s Peter Munk Cardiac Centre and the Ted Rogers Centre for Heart Research, initiated the Ted Rogers Understanding Exacerbations of Heart Failure study (TRUE-HF) in collaboration with Apple in the fall of 2020. The study examined whether biometric data from Apple Watch could be used to predict peak oxygen uptake (pVO2) in patients with heart failure in their daily lives for a three-month period. PVO2 is the highest amount of oxygen the body uses during intense exercise, serving as a key indicator of cardiorespiratory fitness. It is typically measured in a clinical setting using Cardiopulmonary Exercise Testing (CPET), where patients are evaluated while exercising to maximal capacity.
“We created an AI model, called TRUE-HF, trained on data from 154 patients and then validated on 63 patients, to estimate individuals' daily peak oxygen uptake using measurements from Apple Watch,” says Dr. Chris McIntosh, Senior Scientist at UHN and co-senior author of the study. “We found that when participants went about their daily routines while wearing an Apple Watch, our smartwatch-based pVO2 estimates strongly correlated with lab-derived ones from CPET.”
What’s more, they found that each 10% drop in the TRUE-HF–estimated fitness measure (pVO2) was linked to a more than threefold higher risk of an unplanned medical event. These events typically occurred approximately a week after the drop first appeared. A modified version of the model also predicted unplanned use of medical services around 21 days after the first drop in predicted pVO2. These results were further validated in a public cross-platform FitBit dataset from the National Institutes of Health (NIH) All of Us Research Program.
These results suggest that daily smartwatch measurements can provide early warning signs of worsening health and help predict when unplanned medical care may be needed for people living with heart failure. Identifying real-time changes in health through wearable technology, without requiring additional tests or added effort from patients, could enable faster, better care.
Yuan Gao is a doctoral candidate at UHN and co-first author of the study.
Dr. Yas Moayedi is a Clinician Investigator at UHN and co-first author of the study.
Dr. Christopher McIntosh, Senior Scientist at UHN and Dr. Heather Ross, Clinician Investigator at UHN, are co-senior authors of the study. Dr. McIntosh is an Assistant Professor in the Department of Medical Biophysics at the University of Toronto (U of T). Dr. Heather Ross is a Professor at the Institute of Medical Sciences at U of T.
Other study authors from UHN include Farid Foroutan, Bhavish Verma, Ben Kim, Enza De Luca, Margaret Brum, Darshan H. Bhrambhatt, Joe Duhamel, and Anne Simard.
This work was supported by the Ted Rogers Centre for Heart Research, the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Institutes of Health Research (CIHR), the University of Toronto, and UHN Foundation.
Dr. Ross is the Loretta Rogers Chair in Heart Function.
Apple Incorporated provided 200 iPhones and Apple Watch devices for the study, provided feedback on the manuscript, and collaborated with all authors to build the study-specific mobile application. All authors are investigating patenting the TRUE-HF model described in the manuscript.
Many people diagnosed with breast cancer rely on health information to understand their diagnosis and make decisions about their treatment. A new study from The Institute for Education Research at UHN shows that patients and caregivers often feel overwhelmed by the amount and complexity of health information and face persistent gaps in timely, inclusive, and tailored resources.
The research team interviewed 16 patients with breast cancer and caregivers to understand their experiences with accessing, evaluating, and using health information during diagnosis, treatment, and follow-up. Despite high education levels and digital literacy, many participants said they felt unprepared and overwhelmed by the volume and complexity of information presented to them. During the interviews, participants highlighted three main challenges:
● Mixed feelings about guidance from health care providers: Some participants felt reassured when clinicians cautioned against independent online research. Others, however, felt it limited their ability to actively participate in decision-making about their care.
● Information overload: Participants described difficulty navigating large amounts of information and finding resources that were timely, relevant, and appropriate for their specific stage of care.
● Need for more tailored and inclusive resources: Participants noted gaps in information, especially for male patients and people from racialized or cultural minority groups, who often could not find materials that reflected their experiences.
Participants emphasized the importance of connecting with other patients and caregivers. They also expressed strong support for a curated digital library that would bring trustworthy information together in one easy-to-access place.
These findings highlight opportunities for health care systems to strengthen information and resources available to support informed decision-making, promote patient participation, and create more equitable cancer care. Future research should explore the needs of patients who face additional barriers to accessing health information, including those with lower health literacy or limited support networks.
Mohamed Ugas, first author of the study, is a research analyst at the Princess Margaret Cancer Health Literacy Research Centre.
Dr. Janet Papadakos, senior author of the study, is a Scientist at The Institute for Education Research at UHN and the Co-Director of the Princess Margaret Cancer Health Literacy Research Centre. At the University of Toronto, Dr. Papadakos is an Assistant Professor at the Institute of Health Policy, Management, and Evaluation.
This work was supported by The Princess Margaret Cancer Foundation, with operational support provided by UHN Foundation.
Ugas M, Giannopoulos E, Tan J, Cil TD, Croke J, Forbes R, Giuliani ME, Koch A, Papadakos T, Quartey NK, Snow M, Westergard S, Papadakos J. Exploring the information needs of breast cancer patients and families in a large, urban, academic hospital: perceived barriers and facilitators to finding relevant and credible information. Support Care Cancer. 2026 Jan 23. doi: 10.1007/s00520-026-10344-3.
Treatment options for liver diseases, including hepatitis B, remain limited, and many patients ultimately require a liver transplant. New ways to study the liver are critical for developing therapeutic interventions and filling this treatment gap. Researchers at UHN have created the first comprehensive atlas of liver and immune cells in a widely used preclinical model of chronic Hepatitis B Virus (HBV) infection—a development that could accelerate research into the disease and its progression to liver cancer.
The liver is a vital organ that regulates chemicals in the blood. HBV is a virus that can cause a lifelong (chronic) infection that leads to serious illnesses such as liver scarring and liver cancer (hepatocellular carcinoma, HCC). In end-stage liver disease, the liver can no longer regenerate after injury, making transplantation the primary treatment option.
Studying HBV infection, including disease progression and treatment, remains challenging because there are few experimental models and limited human tissue availability. To address this, researchers sought to characterize a commonly used preclinical model of HBV at a cellular level.
The team generated an atlas of single-cell gene expression data that also includes information on which genes are expressed in which parts of the liver. This atlas captures how tens of thousands of liver and immune cells behave in both healthy conditions and during chronic viral infection in the HBV model.
Using this atlas, the researchers found that the cell population in this preclinical model is comparable to human livers and the immune cells trigger the same kinds of inflammatory responses. The liver atlas also showed that HBV infections in this model lead to gene expression and cellular changes similar to those in the human liver. HBV infections in both the model and in humans activate certain immune cells, called dendritic cells, in the same area of the liver, and T cells become “worn out” over time.
This study highlights that HBV infection affects this well-known preclinical model in similar ways to humans, confirming the model’s importance in liver disease research. This atlas, therefore, offers a powerful new tool for understanding HBV and developing better treatments.
Zoe Clarke, Jawairia Atif, and Xinle Wang are co-first authors of the study. Zoe Clarke is a PhD Candidate at the University of Toronto (U of T), Dr. Jawairia Atif is a PhD graduate at UHN, and Xinle Wang is a former research student at UHN and a current medical student at U of T.
Dr. Ian McGilvary, Senior Scientist at UHN and Dr. Gary Bader, Affiliate Scientist at Princess Margaret Cancer Centre are co-senior authors of the study. Dr. McGilvary is also a Professor in the Department of Surgery at U of T. Dr. Bader is also a Professor in the Department of Molecular Genetics at U of T.
Dr. Sonya MacParland, a Senior Scientist at UHN, the Research Director of the Ajmera Transplant Centre, and a Professor in the Department of Laboratory Medicine and Pathobiology at U of T, is the co-senior and corresponding author of the study.
This work was supported by the University of Toronto McLaughlin Centre, Canadian Liver Foundation, the Natural Sciences and Engineering Research Council, the Canadian Institutes for Health Research, and UHN Foundation.
Sonya MacParland is a Tier 2 Canada Research Chair in Liver Immunobiology.
Clarke ZA, Atif J, Wang X, Liu LY, Wood L, Camat D, Liu Y, Shiwram A, Hyduk SJ, Chung S, Ma XZ, Manuel J, Lok S, Lau TNH, Thoeni C, Michalak TI, McGilvray ID, Bader GD, MacParland SA. A single-cell atlas of the woodchuck liver reveals cellular programs conserved in human HBV infection. J Hepatol. 2026 Jan 22:S0168-8278(26)00019-X. doi: 10.1016/j.jhep.2025.12.030. Epub ahead of print.
Co-first authors of the study (L to R): Zoe Clarke, a PhD Candidate at the University of Toronto, Dr. Jawairia Atif, a PhD graduate at UHN, and Xinle Wang, a former research student at UHN and a current medical student at U of T.
Disturbances in sleep and daily activity patterns can lead to safety risks and declining well-being for people living with dementia. However, clinicians lack practical tools to monitor these changes over time. Researchers at UHN’s KITE Research Institute (KITE) found that routinely collecting safety data from wearable, real-time location systems (RTLS) can be used to monitor daily activity and sleep to support people living with dementia.
In this study, led by KITE graduate student Yasser Karam, 47 residents of a specialized dementia care unit wore RTLS bracelets that tracked their movements for an average of nine weeks. The research team analyzed this data to calculate how much participants moved, how regular their daily activity was, and how much time they spent in bed. These digital markers were then analyzed by machine learning models to group participants into six distinct categories, ranging from well-regulated daily activity to severe disturbances.
The researchers confirmed that higher nighttime movement and less regular daily activity were linked to greater sleep difficulties and increased motor agitation, such as restlessness or fidgeting, which can indicate distress. Participants with more disrupted activity were found to be older with more severe cognitive impairment, reduced independence in daily activities, and more mood-related symptoms than those with fewer activity disruptions.
These findings suggest that RTLS can be used as a continuous monitoring tool for sleep and activity disturbances. By identifying meaningful patterns in daily behaviour, this approach could help clinicians detect emerging problems earlier and develop more personalized care plans to support better sleep, mood, and overall wellbeing for people living with dementia.
At the time of the study, first author, Yasser Karam, was a Master’s student co-supervised by Drs. Andrea Iaboni and Shehroz Khan at UHN’s KITE Research Institute. This work was completed as part of his Master’s thesis.
Dr. Andrea Iaboni, co-senior author of the study, is currently a Scientist at UHN’s KITE Research Institute. At the University of Toronto, Dr. Iaboni is an Associate Professor in the Department of Psychiatry and a Faculty Member of the Rehabilitation Sciences Institute.
At the time of the study, Dr. Shehroz Khan, co-senior author of the study, was a Scientist at UHN’s KITE Research Institute. He is currently an Assistant Professor at the College of Engineering and Technology, American University of the Middle East, Kuwait.
This work was supported by UHN Foundation, AGE-WELL, Toronto Dementia Research Alliance, Canadian Institutes of Health Research, and the Walter & Maria Schroeder Institute for Brain Innovation and Recovery.
Karam Y, Shum LC, Faruk T, Arora T, McArthur C, Chu CH, McGilton KS, Flint AJ, Lim A, Khan SS, Iaboni A. Digital markers and phenotypes of rest-activity rhythms in people with advanced dementia using real-time location data. J Gerontol A Biol Sci Med Sci. 2026 Feb 5. doi: 10.1093/gerona/glaf288.
A new study from researchers at UHN’s Donald K. Johnson Eye Institute (DKJEI) found that a non‑surgical approach can effectively manage corneal damage and thinning, helping reduce the risk of vision loss. The findings clarify how different treatment options compare and underscore the importance of careful clinical assessment to avoid unnecessary invasive procedures.
The integrity of the cornea—the transparent tissue covering the front of the eye—is vital for vision and overall eye health. Perforations (holes) or thinning of the cornea require urgent treatment to prevent vision loss, or in severe cases, loss of the eye itself.
Cyanoacrylate tissue adhesive (CTA), a specialized medical glue, is commonly used as a first-line treatment for corneal thinning or perforation. If CTA alone is insufficient to restore the cornea's integrity, some patients subsequently undergo a corneal transplant, called penetrating keratoplasty (PKP). Previous studies, however, have not clearly established whether outcomes differ between patients who receive PKP and those treated with CTA alone.
To determine whether PKP offers additional benefits, Dr. Clara Chan, a Clinician Investigator at DKJEI, and her team evaluated 189 cases of corneal thinning or perforation. Of these, 125 received CTA alone and 64 received CTA followed by PKP.
The researchers found that post-treatment vision outcomes were similar between groups, even though individuals who underwent PKP had more advanced disease at baseline. Patients requiring PKP were more likely to have a condition that impaired healing or caused inflammation, such as a viral infection. They also found that individuals who ultimately underwent PKP had typically received multiple CTA applications, suggesting that the number of applications may signal the need for surgical intervention.
Overall, the study reinforces CTA as an effective first‑line treatment for corneal perforation and thinning. This is particularly valuable for centres without the capacity to perform PKP. The findings also highlight the importance of tailoring treatment to each patient’s needs—whether CTA alone or CTA followed by PKP—to ensure effective care while minimizing unnecessary surgical risks.
The first author of this study is Ryan Huang, a Doctor of Medicine candidate at the University of Toronto’s Temerty Faculty of Medicine.
Dr. Clara Chan is the senior author of this study. Dr. Chan is a Clinician Investigator at UHN’s Donald K. Johnson Eye Institute, an Associate Professor of Ophthalmology and Vision Sciences at the University of Toronto’s Temerty Faculty of Medicine, and the Medical Director of the Ontario Division of The Eye Bank of Canada.
This work was supported by the UHN Foundation.
Dr. Clara Chan has previously received funds as a consultant from several companies including Abbvie, Bausch & Lomb, Johnson & Johnson Vision, and Labtician Ophthalmics Inc. She has also received research grant support from Aurion, Corneat, and Claris Bio. For a complete list of competing interests, please see the publication.
Huang RS, Agarwal M, Mimouni M, Chan CC. Comparative effectiveness of penetrating keratoplasty and conservative cyanoacrylate tissue adhesive application for corneal perforation and thinning. Eye (Lond). 2026 Jan 8. doi: 10.1038/s41433-025-04201-6. Epub ahead of print.
New results from a clinical trial at UHN’s Princess Margaret Cancer Centre shed light on why some targeted cancer therapies are not effective for tumours with specific BRAF gene mutations.
The BRAF gene, which is mutated in many human cancers, encodes a protein that is important for the growth and division of cells. The BRAF protein sends signals to cells through a pathway called the MAPK/ERK pathway—a set of proteins that work together to control important cell behaviours like growth and survival.
Some types of BRAF mutations (class 1 mutations) can be targeted for cancer therapies, while others (class 2 and 3 mutations) have no current targeted therapies. Class 2 and 3 BRAF mutations account for 30% of all solid tumours with BRAF mutations.
Inhibiting the BRAF protein and a protein from the MAPK pathway—called MEK—at the same time is an effective treatment for most cancer types with class 1 BRAF mutations. Despite this, the approach has not previously been used for tumours with class 2 and 3 BRAF mutations. The research team, therefore, wanted to determine the efficacy of BRAF and MEK inhibitors in patients with this type of advanced cancer.
In a clinical trial evaluating the efficacy of Binimetinib (MEK inhibitor) and Encorafenib (BRAF inhibitor), the researchers found that these drugs had minimal efficacy against advanced tumours with class 2 or 3 BRAF mutations.
However, the team was still able to establish the safety of this therapeutic regimen and decided to dig deeper in order to understand why the response to these drugs was weak.
By analyzing genetic data from patient tumours, patient-derived tumour models, and other sources, the team discovered several mechanisms that are used by tumours with class 2 and 3 BRAF mutations to resist treatments targeting BRAF and MEK. These mechanisms include the development of new mutations that enable the MAPK signalling pathway to be reactivated and drive tumour growth, and new mutations that drive tumour growth independently of MAPK signalling.
Two other drivers of drug resistance stood out: CDK4/6 and SHP2—proteins that regulate cell growth even when BRAF and MEK are inhibited. Importantly, the researchers found that adding CDK4/6 or SHP2 inhibitors to BRAF/MEK therapy made cancer models more responsive.
The study suggests that simply blocking BRAF and MEK is insufficient to treat most cancers with class 2 and 3 BRAF mutation but targeting a broader range of proteins could overcome tumour resistance and make these treatments more effective. These findings open the door to future combination treatments that could finally offer targeted options for patients with these rare mutations.
Dr. April Rose is first and co-corresponding author of the study. She is a clinician-scientist and Assistant Professor in the Department of Oncology at McGill University.
Dr. Anna Spreafico is the co-corresponding author of the study. She is a Clinician Investigator at Princess Margaret Cancer Centre and an Associate Professor in the Department of Medicine at the University of Toronto.
The BEAVER clinical trial was sponsored by the Cancer Genomics Program of the Princess Margaret Cancer Centre. This investigator-initiated trial was supported by Pfizer. Exploratory objectives and preclinical experiments were funded by the Conquer Cancer Foundation, Canadian Cancer Society, Canadian Institutes of Health Research, TransMedTech Institute, the Government of Canada, the Jewish General Hospital Foundation, the Canada Foundation for Innovation, the Province of Quebec, and The Princess Margaret Cancer Foundation.
Dr. Rose has provided consultation for Advanced Accelerator Applications/Novartis, EMD Serrono, Merck, and Pfizer. Dr. Rose reports research funding from AstraZeneca (Inst), Novartis (Inst), Merck (Inst), Seattle Genetics (Inst), Pfizer (Inst), and Essa Pharma (Inst). Dr. Spreafico reported a consulting advisory role with Merck, Bristol-Myers Squibb, and Alents and grant/ research funding from Novartis, Bristol-Myers Squibb, Symphogen, AstraZeneca/Medimmune, Merck, Bayer, Surface Oncology, Northern Biologics, Janssen Oncology/Johnson & Johnson, Roche, Regeneron, Alkermes, Array Biopharma/Pfizer, GSK, NuBiyota, Oncorus, Treadwell, Amgen, ALX Oncology, Nubiyota, Genentech, Seagen, Servier, Incyte, and Alentis.
For a full list of competing interests, see the manuscript.
Rose AAN, Maxwell J, Rousselle E, Mukonoweshuro CL, Elkholi IE, Riaud M, Biondini M, Cianfarano E, Soria-Bretones I, Tobin C, McGuire M, Law RWY, Elia AJ, Wang BX, King I, Zhang T, Pugh TJ, Kamil ZS, Butler M, Shepherd FA, Leighl NB, Razak AA, Hansen A, Saibil SD, Bedard PL, Siegel PM, Siu LL, Cescon DW, Spreafico A. Binimetinib and encorafenib for the treatment of advanced solid tumors with non-V600E BRAF mutations: results from the Phase II BEAVER trial. Nat Commun. 2026 Jan 3;17(1):1323. doi: 10.1038/s41467-025-68076-7.
Cancer touches nearly every family in Canada. It is the leading cause of death in the country and a disease that continues to affect lives across generations. Despite this, research shows that up to 40% of cancer cases could be prevented through changes in lifestyle, environment, and earlier detection—highlighting the urgent need for research that gives people more tools to protect their health before cancer can develop.
On February 26, 2026, the Honourable Marjorie Michel, Minister of Health, visited UHN’s Princess Margaret Cancer Centre (PM) to announce a $41-million national investment in cancer prevention and early diagnosis research. The initiative, led by the Canadian Institutes of Health Research (CIHR) in partnership with five national and international organizations, will support 19 research teams across the country, including two teams at UHN.
“Preventing cancer saves lives and eases the burden on patients, families, and our health care system,” said Minister Michel. “That’s why we’re proud to partner nationally and internationally to support exceptional Canadian researchers working to reduce cancer across the country.”
The announcement underscored growing momentum in prevention research, driven by advances in understanding how biology, behaviour, genetics, and aging intersect to influence cancer risk. This investment aims to accelerate discovery in these evolving areas and create practical, accessible pathways for earlier detection and risk reduction.
Dr. Brad Wouters, Executive Vice President of Science and Research at UHN, highlighted the impact of this coordinated approach. “Research that identifies risk early creates both the time and opportunity to intercept and prevent cancer before it impacts health. This investment allows teams at UHN and across Canada to build shared knowledge and real solutions for patients,” he said.
Dr. Faiyaz Notta, Senior and Allan Slaight Scientist at PM, received $5.3 million to lead the ELDER Study, a Canada–Japan collaboration investigating how aging biology contributes to early‑onset colorectal and pancreatic cancers—diseases that are increasingly diagnosed in younger adults. “By studying the microbiome, genetic mutations, and age‑related epigenetic changes, we aim to understand why the rates of these cancers are rising and how to detect them sooner,” said Dr. Notta.
Dr. Steven Chan, Senior and Allan Slaight Scientist at PM, received nearly $2 million to explore whether GLP‑1 receptor agonists—commonly prescribed for diabetes and weight management—can reduce the risk of blood cancers. “Inflammation and metabolism shape how mutant blood stem cells grow and expand. If GLP‑1 medications can interrupt this process, we may have a safe and widely available way to lower blood cancer risk,” said Dr. Chan.
Former Princess Margaret patient Melissa Tobros also spoke at the event, sharing how genetic testing has shaped her family’s understanding of inherited cancer risk and underscoring the human importance of prevention research.
As Canada deepens its investment in prevention-focused science, UHN researchers will continue contributing discovery, collaboration, and leadership—moving closer to a future where fewer people face a cancer diagnosis.
See the full list of the awarded projects here.
Research at UHN takes place across its research institutes, clinical programs, and collaborative centres. Each of these has specific areas of focus in human health and disease, and work together to advance shared areas of research interest. UHN's research spans the full breadth of the research pipeline, including basic, translational, clinical, policy, and education.
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