Standard Medical Care Outperforms Catheter Procedure for High-Risk Atrial Fibrillation Patients

The CLOSURE-AF trial, conducted across 42 healthcare sites in Germany from March 2018 to April 2024, revealed that standard medical care including anticoagulant blood thinners when appropriate provided better outcomes than catheter-based left atrial appendage closure for older atrial fibrillation patients at high risk of stroke and bleeding. The study followed more than 900 adults with an average age of 78 years, 39% of whom were women, for a median of three years, comparing the frequency of stroke, life-threatening blood clots, cardiovascular or unexplained death, and major bleeding between the two treatment approaches.

Atrial fibrillation affects an estimated five million people in the United States, with projections indicating this number will exceed 12 million by 2030 according to the American Heart Association's 2025 Heart Disease and Stroke Statistics report. While blood thinners effectively reduce stroke risk in AFib patients, they can cause severe bleeding in some individuals, prompting researchers to explore alternative treatments like left atrial appendage closure procedures. This minimally invasive technique seals the left atrial appendage, a small heart pouch where most blood clots form in AFib patients, potentially allowing patients to discontinue blood thinners for clot prevention.

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 noted. "However, this was not the case in this trial of older patients at very high risk of bleeding and stroke." The research aimed to demonstrate non-inferiority for the catheter procedure regarding combined risk of stroke, systemic embolism, cardiovascular or unexplained death, or major bleeding, but this endpoint was not achieved.

The implications of these findings are significant for clinical practice and patient care decisions. Landmesser emphasized 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." However, he clarified that the results may differ for lower-risk patients, with studies currently investigating this population. Additional research is also examining LAA closure in combination with blood thinning medications for very high-risk patients.

It is important to note that the study findings, presented as a research abstract at the American Heart Association's Scientific Sessions 2025, are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal. The abstract and additional meeting information are available through the American Heart Association's Scientific Sessions 2025 Online Program Planner. As medical treatments and LAA closure techniques for atrial fibrillation continue to evolve, the results of this specific study may not apply to future research, alternative techniques, or different procedural approaches.