The left atrial appendage (LAA) is a common site in the heart for blood clot formations that lead to a stroke in patients who have atrial fibrillation. Typically, physicians recommend blood-thinner medications for patients with atrial fibrillation who are susceptible to stroke, but a small subset of patients have contraindications to blood thinners. Therefore, this subset of patients are good candidates for left atrial appendage occlusion (LAAO), a surgical or minimally invasive procedure that closes off the LAA.
A common minimally invasive procedure that seals off the LAA is the transcatheter implantation of parachute-shaped, self-expanding devices known as ‘occluders’. Historically, the first-generation Watchman device (Boston Scientific ) was the only FDA-approved device for LAAO since its release in 2015. Then, in 2020, the FDA approved the second-generation Watchman, the Watchman FLX (Boston Scientific), and a year later, the FDA approved the Amplatzer Amulet (Abbott ). This wave of new devices contributes to the forecast compound annual growth rate of 24.7% by 2024 in the medical device industry.
The Lariat device (Atricure) is another LAAO device but, unlike the previous three devices, which are occluders implanted in the heart, the Lariat is almost like a zip-tie that externally ligates the LAA. Additionally, the Lariat did not receive FDA approval, but rather, it received FDA 510(k) clearance for soft tissue ligation. An FDA-cleared product breaks into the market a lot faster than an FDA-approved product. When a product is FDA-cleared, it can enter the US market without any clinical testing, though the manufacturers must still demonstrate that the product is similar to an already marketed FDA-approved or -cleared product.
While the FDA rigorously evaluates premarket submissions, FDA approval or clearance of a product does not guarantee patient safety. In 2015, despite receiving the 510(k) clearance, approximately 45 patients who received LAAO with the Lariat device experienced severe adverse events. It is important to note that the Lariat device was cleared for soft tissue ligation, meaning it did not go through the necessary clinical testing specifically for LAA ligation.
The FDA simply decides to approve or clear a product by weighing the benefits with the risks based on the results of the company that made the product. A newer and faster-released product does not always mean better outcomes; there is always an increased risk when trying out a newly released medical device.