Standard Medical Care Outperforms Minimally Invasive Procedure for High-Risk Atrial Fibrillation Patients
New research presented at the American Heart Association's Scientific Sessions 2025 found that standard medical care, including blood thinners when appropriate, proved more effective than a catheter-based procedure for preventing stroke and other complications in older atrial fibrillation patients at high risk of bleeding and stroke.
The CLOSURE-AF trial, presented as preliminary research at the American Heart Association's Scientific Sessions 2025, revealed that standard medical care outperformed a promising catheter-based procedure for older patients with atrial fibrillation who face high risks of both stroke and bleeding. The study compared catheter-based left atrial appendage closure with physician-directed standard medical care, including anticoagulant blood thinners when eligible, in patients with irregular heart rhythms at elevated risk for both stroke and bleeding complications.
Researchers found that standard care, which included medication for eligible patients, demonstrated superior outcomes in preventing stroke, blood clots, cardiovascular or unexplained death, or major bleeding compared to the minimally invasive procedure. The procedure, which seals off a small pouch of heart tissue called the left atrial appendage where most blood clots form in people with atrial fibrillation, had been considered a promising alternative to blood thinners. However, in this specific high-risk population, medical therapy proved more effective.
Study lead researcher Ulf Landmesser, M.D., chairman of the department of cardiology at Deutsche Herzzentrum Charité, expressed surprise at the findings. "We expected that catheter-based LAA closure would be comparable to physician-directed standard medical care often using blood thinning anticoagulant medications," Landmesser stated. "However, this was not the case in this trial of older patients at very high risk of bleeding and stroke."
The clinical implications are significant given the growing prevalence of atrial fibrillation. According to the Association's 2025 Heart Disease and Stroke Statistics report available at https://www.heart.org/en/statistics, an estimated five million people in the U.S. currently live with AFib, with projections indicating more than 12 million affected by 2030. While blood thinners effectively reduce stroke risk, they can cause severe bleeding in some patients, prompting the search for alternative treatments like the left atrial appendage closure procedure.
The CLOSURE-AF study involved more than 900 adults with atrial fibrillation who were at high risk of stroke and major bleeding. Participants averaged 78 years of age, with 39% being women, and were enrolled at 42 healthcare sites in Germany from March 2018 to April 2024. Researchers followed participants for a median of three years, randomly assigning them to either standard medical care or the LAA closure procedure.
Landmesser emphasized that the study results specifically apply to older patients at very high risk and noted that outcomes might differ for lower-risk populations. "Our findings indicate that standard physician-directed medical care, including blood thinners for eligible patients, remains a valid management option for those older patients with irregular heartbeat who are at very high risk for stroke and bleeding," he concluded. Additional study details and background information are available in the abstract at https://www.abstractsonline.com/pp8/#!/2025.
The research findings carry particular importance for clinical decision-making in managing atrial fibrillation among elderly patients with multiple risk factors. As medical treatments and LAA closure procedures for AFib continue to evolve, this study provides crucial evidence supporting the continued use of standard medical care in specific high-risk populations, though researchers caution that results may not apply to future techniques or procedures currently under investigation.