Study led by LIMR’s Gray demonstrates feasibility of stroke-prevention device

A pre-clinical study co-authored by William A. Gray, MD, a nationally recognized interventional cardiologist from the Lankenau Institute for Medical Research (LIMR), part of Main Line Health, supports the safety and feasibility of a left atrial appendage closure device that can be implanted to reduce stroke risk in patients who have atrial fibrillation.

Based on the promising results of the pre-clinical study, Gray - also System Chief of the Division of Cardiovascular Disease at Main Line Health and co-director of Lankenau Heart Institute - led the early feasibility, first-in-human study (results soon to be published). He will serve as co-principal investigator of the upcoming Phase III clinical pivotal trial seeking to gain FDA approval for the device.

Stroke is a serious risk for patients with atrial fibrillation. Patients with the condition have an irregular and often rapid heart rate caused by a disruption of normal regular electrical signals. Static blood flow can result in the atrium, increasing the chances of clots, which can trigger a stroke if are released into the body's circulation.

Most patients are placed on oral blood thinners to reduce the risk of clots, but not everyone can take them. Since clots from atrial fibrillation form more than 90% of the time in the left atrial appendage (LAA), a small sac-shaped outgrowth in the muscular wall of the left atrium, an alternative nonsurgical catheter-based treatment is to seal it off with a procedure called LAA occlusion. Implanting these devices involves delivering it through a catheter inserted into a leg vein.

The new study was underpinned by preclinical (non-human) evaluations of the second-generation Conformal Left Atrial Appendage Seal (CLAAS), which comes in two sizes (regular and large) and is made of a foam matrix designed to stretch and conform to the patient's anatomy. Gray said the results were highly encouraging.

'First-generation devices require more exact sizing and strategic delivery approaches, both of which require extensive imaging,' Gray said. 'The CLAAS device appears to be simpler to use, and its material appears to work as intended by conforming with the patient's anatomy for a precise, reliable seal..'

'This is truly groundbreaking work,' said George Prendergast, LIMR president and CEO. 'Bill has served as principal investigator for more than 50 clinical trials of coronary, endovascular, and structural heart interventions and continues to be a leader in his field. We're fortunate to have physicians who not only deliver such important advances in research but translate them into improved patient treatment and outcomes.'

The study, 'Preclinical Assessment of a Novel Conformable Foam-Based Left Atrial Appendage Closure Device,' was published in BioMed Research International.

Lankenau Institute for Medical Research (LIMR) is a nonprofit biomedical research institute located on the campus of Lankenau Medical Center and is part of Main Line Health. Founded in 1927, LIMR's mission is to improve human health and well-being. Faculty and staff are devoted to advancing innovative new approaches to formidable medical challenges, including cancer, cardiovascular disease, gastrointestinal disorders and autoimmune diseases, such as diabetes and arthritis. LIMR's principal investigators conduct basic, preclinical and translational research, using their findings to explore ways to improve disease detection, diagnosis, treatment and prevention. They are committed to extending the boundaries of human health through technology transfer and training of the next generation of scientists and physicians.