New study shows more efficient way to rule out blood clots in older adults
Health care is always evolving to meet patients’ needs, whether through personalized care plans or new scientific advancements.
An international team recognized the need to adapt care when diagnosing deep vein thrombosis (DVT) in older adults. For years, the standard practice was to use a blood test to check for D-dimer, with high levels potentially signaling a blood clot. But the results aren’t always accurate: D-dimer levels naturally rise with age, even when no clot is present, leading to unnecessary treatment.
The team led an international study to test an age-adjusted D-dimer cutoff, designed to make the test more accurate for older adults and reduce unnecessary procedures. Published in JAMA, the study included 3,205 participants with suspected leg DVT across Belgium, Canada, France, and Switzerland. Instead of using a single, standard cutoff, researchers adjusted the threshold based on age to account for naturally higher D-dimer levels in older adults. Patients whose results fell within the healthy range for their age avoided unnecessary treatments, including leg ultrasounds and blood thinners.
"Our goal was to make diagnosis more efficient, especially for older adults,” said Dr. Grégoire Le Gal.
In the three-month follow-up, the team found that the approach was accurate: the risk of recurring venous thromboembolic events for participants within the age-adjusted ranges was very low. Older adults saw the greatest benefits, with the number who did not require treatment tripling compared to the standard method.
“Our goal was to make diagnosis more efficient, especially for older adults,” said study lead Dr. Grégoire Le Gal, senior scientist, physician and Program Director of the Inflammation and Chronic Disease Program at The Ottawa Hospital and professor at the University of Ottawa. “Since many hospitals don’t have ongoing access to ultrasound machines, patients who have high D-dimer levels must start anticoagulants, then return another day for their ultrasound. By adjusting the D-dimer threshold for age, we can reduce unnecessary tests and treatments without compromising patient safety — a big win for both patients and busy emergency departments.”
Authors:
Grégoire Le Gal, Helia Robert-Ebadi, Venkatesh Thiruganasambandamoorthy, Fares Moustafa, Andrea Penaloza, Judith Catella, Marie Chevallier Grenot, Shaun Visser, Lucia Mazzolai, Alain Plumacker, Stefano Barco, Eddy Lang, Vicky Tagalakis, Claire Deroche, Meghan Garnett, Jennifer Hulme, Pierre-Marie Roy, Alexandre Ghuysen, Francis Couturaud, Rolf Engelberger, Dominique El Kouri, Drahomir Aujesky, Marc Righini
Funding:
The Swiss National Research Foundation, The Heart and Stroke Foundation of Canada, The Forum pour la Recherche Thrombo-Embolique aux Urgences, The INVENT network, The Clermont-Ferrand University Hospital, Center of Clinical Research (Geneva University Hospital) and The Canadian Venous Thromboembolism Research Network (CanVECTOR).
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The Ottawa Hospital is a leading academic health, research and learning hospital proudly affiliated with the University of Ottawa and supported by The Ottawa Hospital Foundation.
