Conformal CLAAS System’s Thrombogenicity Evaluated in Comparative Study

March 19, 2024—Conformal Medical, Inc. recently announced that findings from an in vitro study comparing the relative thrombogenicity of the company’s CLAAS left atrial appendage occlusion (LAAO) implant to the Watchman FLX device (Boston Scientific).

The CLAAS system, which aims to reduce the risk of stroke without the need for anticoagulants in patients with atrial fibrillation, is an investigational device limited by federal law in the United States to investigational use.

According to the company, the CLAAS features a foam cup with an embedded nitinol skeleton with an expanded polytetrafluoroethylene (ePTFE) cover. The nitinol frame of the Watchman FLX is covered by polyethylene terephthalate.

In the study, three of each device (n = 3) were inserted into an acute radiolabeled in vitro blood loop system. After 90-120 minutes of exposure, the implants were visually assessed and the radiolabels were measured.

Compared to the Watchman FLX, the CLAAS device demonstrated incomplete coverage with seemingly thinner thrombus and 44% lower platelet deposition.

The study, titled “Comparative Acute Thrombogenicity of the CLAAS Foam Implant and Watchman FLX in an In Vitro Blood Loop Model,” was presented by William Gray, MD, in a Best Abstracts session at CRT 2024, the Cardiovascular Research Technologies annual meeting held March 9-12 in Washington, DC. Additionally, Dr. Gray et al recently published the study online in JACC: Cardiovascular Interventions.

“These results are very encouraging, indicating the CLAAS implant appeared less thrombotic than the Watchman FLX in this in vitro blood loop model,” commented Dr. Gray in Conformal Medical’s press release.

Dr. Gray continued, “Device-related thrombus (DRT) remains a concern in left atrial appendage closure and advances in device design may help mitigate this in the clinical setting. The ePTFE fluoropolymer component in the CLAAS device appears to be less thrombogenic, which may reduce DRT; still, more studies are required to further validate these initial results.”

Conformal Medical is actively enrolling patients in the CONFORM pivotal trial, which is evaluating the safety and efficacy of the CLAAS system compared to other commercially available LAAO devices. The prospective, multicenter, randomized controlled study will enroll approximately 1,600 patients. The company announced the commencement of enrollment in CONFORM in June 2022.