The Evidence Speaks Series is a recurring feature highlighting the latest in Advancing Health research. This series features summaries of select publications and is designed to keep media and the research community up to date with the Centre’s current research results in the health outcomes field.
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High potassium levels are associated with higher mortality rates after cardiac arrest
Byrne C, Krogager M, Kragholm K, Pareek M, Mohr G, Ringgren K, Wissenberg M, Riddersholm,S Wolder M, Folke F, Gislason G, Køber L, Hassager C, Kjærgaard J, Fordyce C, Torp-Pedersen C, Lip Y, Barcella C. The association between arrival potassium and 30-day survival following resuscitation from out-of-hospital cardiac arrest: a retrospective cohort study. Scand J Trauma Resusc Emerg Med. 2025
Cardiac arrests happen when a malfunction in the heart’s electrical system causes it to abruptly stop beating. They are very dangerous, particularly when they occur out-of-hospital, due to the delay in receiving medical care. Even after the heart restarts beating on its own, over half of out-of-hospital cardiac arrest patients remain in a comatose state by the time they arrive at the hospital. These comatose patients have a mortality rate of up to 50 per cent.
Prognostic biomarker tests would help identify particularly at-risk cardiac arrest patients and give them additional support, but currently no such tests exist. Given that potassium plays a major role in maintaining heart rhythm, a team of researchers Advancing Health scientist Dr. Christopher Fordyce joined a group of researchers in Denmark to see if there was any association between potassium level and patient survival. They analysed data collected from 4,894 Danish patients admitted for out-of-hospital cardiac arrests between 2001–2019. Patients were sorted into seven groups based on their blood serum potassium level at admission and compared the 30-day mortality rate for all these groups.
The researchers found that low levels of potassium had no impact on patient survival. However, high levels of potassium (4.7 mmol/L or higher) were found to correspond with lower survival rates compared to normal levels of potassium. This association was found even when controlling for other factors, such as age, sex, and other medical conditions. While further research is needed on long-term survival, impact on neurological function, and to understand the underlying cause for this correlation, this association could help identify particularly high-risk cardiac arrest patients and give them the additional care they need.
Measuring duration of viral DNA presence in the body could be key to improving treatment for CMV infections
Dobrer S, Sherwood KR, Davis K, Lan JH, Gill J, Matic N, Keown PA. Impact of viral load kinetics and recurrent cytomegalovirus infection in kidney transplantation. Front Immunol. 2025.
Post-transplant viral infections, including cytomegalovirus (CMV), remain a major risk to transplant success. When the CMV virus reactivates, it can cause tissue invasion, superinfection, breakthrough rejection, and graft loss, often negating any benefits of the transplant. Current treatment for CMV is using antiviral medications, which can kill the virus, and can even be used pre-emptively before symptoms even develop. However, they are only partially effective and are toxic, so they must be used thoughtfully. Previous research had investigated the levels of CMV DNA in the body over time. Called viral load kinetics, they found that the levels during the first CMV infection episode after transplantation were particularly key predictors of transplant failure. They wanted to conduct a more thorough analysis of viral load kinetics so that they could better predict which patients were most at risk and would require a more proactive treatment with antivirals.
A group of researchers, including Advancing Health scientist Dr. John Gill, examined the relationship between CMV reinfection and viral load kinetics on graft loss and patient survival. They conducted a retrospective study on 2,464 patients aged 2–80 years who received kidney transplants between 2008 and 2018. Patients were treated according to a standard protocol and monitored for up to 13 years. The study found that 434 patients (17.6 per cent) developed CMV infections, with 367 (84.6 per cent) experiencing a single episode, and 67 (15.4 per cent) experiencing 150 episodes of recurrent infection. Throughout the study, they tracked viral load kinetics, measuring both the volume of viral DNA in the blood and the duration during which the DNA was detectable. While both elements had an impact on health outcomes, duration had much more negative consequences than volume of DNA. This means that a series of many re-infections, or long, drawn-out infections, were larger threats than a smaller number of intense infections.
The researchers found that if during their initial CMV episode, a patient had a viral load higher than 10,000 IU/ml that remained present for over 15 days, they were at a much higher risk of transplant failure. The risk is worsened by recurrent CMV infections, especially if they last longer than 60 days, and they developed a risk profile for such patients, considering factors such as older age, non- Caucasian race, diabetes, use of anti-rejection therapy, and delayed graft function. Taken all together, this will help high-risk patients be identified and receive timely treatments. Treating these patients remains challenging due to the ineffectiveness and toxicities of existing anti-viral therapies. However, along with two new anti-viral therapies recently approved and expanding opportunities for care, these new insights could help maximize transplant success.
Only one-third of COPD patients in British Columbia receive the medications they need
Yin Y, Mehareen J, Sadatsafavi M, Brigham E, Vera M, Duan K, Johnson K. Factors associated with guideline-concordant maintenance inhaled medication for COPD: a population-based, longitudinal cohort study. Thorax. 2025.
Chronic obstructive pulmonary disease (COPD) is a lung condition marked by symptoms such as intense coughing and shortness of breath that become progressively worse over time. There are a wide variety of different inhaled medications available to patients to help manage conditions, but to be effective, they must be taken daily over the long term according to a strict regimen. Previous research in the US and Canada found that patients struggle to receive or persist in taking their medications, although no study has investigated this in a large number of patients over an extended period.
To fill that gap, a team of scientists in Vancouver, including Advancing Health’s Mary De Vera, looked at data from new COPD patients in British Columbia from 2011 to 2022. This anonymized information was taken from the databases of PharmaNet, Medical Services Plan (MSP) registration, MSP Payment File, hospital discharges, and the National Ambulatory Care Reported System. They analysed data from 71,996 patients who were sorted into either high risk or low risk categories depending on their recent medical history. The patients were followed until they either left the BC health system, died, or came to the end of the reporting period.
Only one-third of the COPD patients enrolled in this study were found to have ever received medications following the recommended guidelines. Only a further third of that group continued with the regimen for the remainder of the reporting period. While it was found that high-risk patients were seven times more likely to receive treatment and five times more likely to continue it, this data nonetheless uncovers a major gap in care for COPD patients. Further research is needed to understand how to bridge this gap, but the team recommends improved access to pulmonologist care and outpatient visits as a key starting point.
