Standard medical care including blood thinners proved more effective than a minimally invasive heart procedure for older patients with irregular heart rhythms who face high risks of stroke and bleeding, according to research presented at the American Heart Association's Scientific Sessions 2025. The findings challenge previous assumptions about the benefits of the catheter-based procedure for this specific patient population and highlight the continued importance of physician-directed medical management.
The CLOSURE-AF trial compared catheter-based left atrial appendage closure with standard medical care in more than 900 adults with atrial fibrillation at high risk for stroke and bleeding. Participants averaged 78 years of age, with 39% being women, and were followed for a median of three years after enrollment at 42 German healthcare sites between March 2018 and April 2024. The study aimed to demonstrate that the procedure was at least as effective as medical therapy in preventing stroke, systemic embolism, cardiovascular death, or major bleeding, but this goal was not achieved.
"We expected that catheter-based LAA closure would be comparable to physician-directed standard medical care often using blood thinning anticoagulant medications," said study lead researcher Ulf Landmesser, M.D., chairman of the department of cardiology at Deutsche Herzzentrum Charité. "However, this was not the case in this trial of older patients at very high risk of bleeding and stroke." The procedure involves sealing off the left atrial appendage, a small pouch in the heart where most blood clots form in people with atrial fibrillation.
Atrial fibrillation affects an estimated five million people in the United States, with projections indicating more than 12 million will have the condition by 2030 according to the Association's 2025 Heart Disease and Stroke Statistics report available at https://www.heart.org/en/statistics. While blood thinners effectively reduce stroke risk, they can cause severe bleeding in some patients, leading researchers to explore alternative treatments like LAA closure that might allow patients to stop taking blood thinners.
The study's findings are particularly significant given the aging population and increasing prevalence of atrial fibrillation. Landmesser noted that while the results favor standard care for high-risk older patients, the outcomes may differ for lower-risk populations, with studies currently investigating this distinction. Additional research is also examining LAA closure in combination with blood thinners for very high-risk patients. The abstract for this study can be found through the American Heart Association's Scientific Sessions 2025 Online Program Planner at https://professional.heart.org/en/meetings/scientific-sessions.
These preliminary findings, presented as a research abstract at the association's scientific meeting, await full publication in a peer-reviewed journal. The results underscore the complexity of treating atrial fibrillation in high-risk elderly patients and emphasize that standard medical care remains a valid management option for this vulnerable population despite advances in procedural interventions.
