The CLOSURE-AF trial presented at the American Heart Association's Scientific Sessions 2025 revealed that standard medical care proved more effective than catheter-based left atrial appendage closure for older atrial fibrillation patients facing elevated risks of stroke and bleeding. This study involved more than 900 adults with AFib who were at high risk of stroke and major bleeding, with an average age of 78 years and 39% being women. Participants were enrolled at 42 healthcare sites in Germany from March 2018 to April 2024 and followed for a median of three years, randomly assigned to either standard medical care including anticoagulant blood thinners when eligible, or to the LAA closure procedure that seals off a small pouch in the heart where blood clots typically form.
Researchers compared the frequency of stroke, life-threatening blood clots, cardiovascular or unexplained death, and major bleeding between the two treatment groups. The study aimed to demonstrate that the catheter-based procedure was not inferior to standard medical care, but this goal was not achieved. Standard care, which included medication for those eligible, performed better at preventing stroke, blood clots, cardiovascular or unexplained death, or major bleeding than the minimally invasive procedure. Study lead researcher Ulf Landmesser, M.D., chairman of the department of cardiology at Deutsche Herzzentrum Charité, expressed surprise at the findings, stating they expected catheter-based LAA closure would be comparable to physician-directed standard medical care often using blood thinning anticoagulant medications.
The implications are significant given the prevalence of atrial fibrillation, with an estimated five million people in the U.S. living with AFib and projections indicating more than 12 million people 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 among people with AFib, they can cause severe bleeding in some individuals, prompting researchers to explore alternative treatments like the LAA closure procedure. Landmesser noted that the results might differ for lower-risk patients, and studies investigating this are currently underway, with additional research comparing LAA closure in combination with blood thinning medications in very high-risk patients.
The study authors emphasized that because medical treatments and LAA closure for AFib continue to evolve, these results may not apply to future research, other techniques, or different procedural approaches. The findings reinforce that standard physician-directed medical care, including blood thinners for eligible patients, remains a valid management option for older patients with irregular heartbeat who face very high risk for stroke and bleeding complications. The research abstract is available through the American Heart Association's Scientific Sessions 2025 Online Program Planner at https://professional.heart.org/en/meetings/scientific-sessions.
