March 25, 2010 – The FDA this week granted permission for a conditional investigational device exemption (IDE) to evaluate the safety and efficacy of a transcatheter plug to seal the left atrial appendage (LAA). The appendage is frequently the source of stroke-causing clots in atrial fibrillation patients.
The study will evaluate the Amplatzer Cardiac Plug, or ACP. The trial is designed to demonstrate efficacy in preventing stroke in atrial fibrillation patients who are eligible to receive warfarin, as well as safety of the device and the procedure.
The ACP clinical study will be a multicenter trial with a two-to-one randomization between the ACP and medical management, warfarin, the current standard of care. The study design is based on a statistical method referred to as a Bayesian adaptive design with interim analyses that use observed efficacy and safety event rate data to predict the final sample size, probabilities for trial success and when the trial should be stopped. Interim analyses will be performed after the first 400 patients are enrolled and at predetermined periodic intervals thereafter, until a possible maximum of 2,000 patients are enrolled. These interval analyses will determine when the trial has achieved its endpoints and if AGA Medical is able to conclude the trial prior to enrolling 2,000 patients.
The trial design includes a feasibility phase to be followed by a pivotal phase. The results of the feasibility phase, which consists of the first 30 patients to receive the ACP, will serve to further validate safety conclusions demonstrated through preclinical testing. These patients will be followed for 45 days after the procedure and evaluated for adverse events. The 45-day feasibility data will be reviewed by an independent data safety monitoring board prior to FDA review. Additional subjects will be enrolled in the pivotal phase of the trial after the FDA has completed its review.
Scientific data have demonstrated that patients with atrial fibrillation face a five-fold higher incidence of stroke. Clinical research has further demonstrated that a stroke in these patients is linked to the LAA, a small structure, shaped like a pouch, off the left atrium. Atrial fibrillation can cause blood to pool in the LAA, increasing the chance of clots that may travel to the brain. The current standard of medical care is to treat these patients with anticoagulants, which are difficult to tolerate for many people and carry a risk of complications, such as bleeding.
The Amplatzer Cardiac Plug received European CE mark approval in December 2008, and is currently sold in Europe, South America and parts of the Pacific Rim.
For more information: www.amplatzer.com