Medical Devices Seek to Prevent Strokes, Still Pose Risks

The pursuit of a safe way to prevent blood clots that lead to deadly strokes has produced two medical devices, each taking two dramatically different routes to approval.

While Boston Scientific’s Watchman waded through a decade of safety testing before finally being approved by the U.S. Food and Drug Administration (FDA) last March, the SentreHEART’s LARIAT went through the FDA’s 510(k) process, which requires far less clinical testing and is now associated with six patient deaths, according to a July 13 FDA alert.

What is the LARIAT?

The LARIAT Suture Delivery Device is a surgical tool designed to deliver a pre-tied surgical stitch (suture) to help close the left atrial appendage (LAA) during surgery in patients with irregular heart rhythm, or atrial fibrillation, to prevent stroke. The left atrial appendage is a pouch-like region of the left atrium of the heart.

Some patients with atrial fibrillation have difficulty taking blood thinners because of the risk of uncontrollable bleeding and other side effects, and LAA closure has been performed as an alternative method to reduce the risk of stroke by preventing a blood clot that might form in the LAA.

The FDA conducted a search of the Manufacturer and User Facility Device Experience database and identified 45 adverse events associated with the use of the LARIAT Suture Delivery Device through June 30, 2015, prompting the alert. The patient deaths and other complications reported included:

• Laceration and/or perforation of the heart
• Complete LAA detachment from the heart
• Hemorrhage
• Low blood pressure
• Fluid collection around the heart
• Cardiac tamponade
• Fluid collection around the lung

Of the 45 adverse events, approximately 75 percent resulted in the need for emergency heart surgery.

According to a recent report in the Minneapolis Star Tribune, the July 13 FDA advisory has dramatically cut down on the use of the Lariat, perhaps creating an opportunity for Boston Scientific, which has spent years testing and marketing Lariat’s competitor, the Watchman. Instead of suturing the LAA as the Lariat does, the Watchman acts as a sort of plug for the appendage that becomes permanent over time, as scar tissue forms over the device inside the heart.