Study Finds Standard Medication Outperforms Heart Procedure for High-Risk Atrial Fibrillation Patients

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 assumptions about the benefits of catheter-based left atrial appendage closure for this specific patient population.

The CLOSURE-AF trial compared catheter-based left atrial appendage closure with physician-directed standard medical care in patients with atrial fibrillation at high risk for stroke and bleeding. Researchers found that standard care, which included anticoagulant blood thinners when eligible, performed better at preventing stroke, systemic embolism, cardiovascular or unexplained death, or major bleeding than the procedure that seals off the left atrial appendage where blood clots typically form.

Study lead researcher Ulf Landmesser, M.D., chairman of the department of cardiology at Deutsche Herzzentrum Charité, expressed surprise at the results. "We expected that catheter-based LAA closure would be comparable to physician-directed standard medical care often using blood thinning anticoagulant medications," Landmesser said. "However, this was not the case in this trial of older patients at very high risk of bleeding and stroke."

The study involved more than 900 adults with atrial fibrillation whose average age was 78 years, with 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. They were randomly assigned to either standard medical care or the LAA closure procedure.

Atrial fibrillation affects an estimated five million people in the U.S., 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 in AFib patients, they can cause severe bleeding in some individuals, prompting research into alternative treatments like LAA closure.

The left atrial appendage closure procedure seals a small pouch in the heart where blood clots typically form in people with irregular heartbeat. Closing this pouch reduces stroke risk and potentially allows patients to stop taking blood thinners. However, the study failed to demonstrate non-inferiority for the procedure compared to standard care in this high-risk population.

Landmesser noted that the results may differ for lower-risk patients, with studies currently investigating this distinction. Additional research is comparing LAA closure in combination with blood thinners in very high-risk patients. The study abstract is available at https://www.ahajournals.org/doi/abs/10.1161/circ.152.suppl_1.12545.

These findings are particularly significant given the aging population and increasing prevalence of atrial fibrillation. The research provides crucial guidance for physicians treating older patients with multiple risk factors, suggesting that established medical therapies may offer superior protection against serious complications compared to newer procedural interventions in this specific demographic.

The study represents an important contribution to the ongoing evolution of atrial fibrillation management strategies. As medical treatments and LAA closure techniques continue to develop, this research highlights the need for careful patient selection and underscores that procedural interventions may not always provide superior outcomes compared to optimized medical therapy, even when targeting the anatomical source of clot formation.