The Interesting Saga of the Left Atrial Appendage Closure Device

(Posted Sept. 29, 2026, on LinkedIn)

Devices for closure of the left atrial appendage (LAA) have a fascinating history to say the least. These devices have undoubtedly thwarted a large number of strokes in patients with non-valvular atrial fibrillation, but the pharmaceutical industry has moved on from legacy oral anticoagulants, which in turn has applied significant pressure on these devices.

The latest development in connection with LAA devices is a recent meta-analysis of LAA closure devices that keyed in on six randomized, controlled trials. These trials enrolled more than 7,000 patients, and the authors concluded that there is a numerically greater incidence of ischemic stroke for LAA closure devices relative to pharmacological therapy. That difference in ischemic stroke seems to be offset by a lower rate of hemorrhagic stroke, however. Nonetheless, device therapy is recommended by several medical societies, so the question is: How did we get here?

LAA closure devices began to take shape in the 1990s, but the first human implant apparently didn’t take place until the 2000s. AtriCure was one of the first companies to make it to market with an FDA-approved device, but the AtriClip device is inserted during conventional surgery. Other companies, such as Boston Scientific, came up with designs that allow the closure device to be delivered via a catheter, but Boston Sci had to endure three FDA advisory hearings before winning a PMA for the first generation of the Watchman device.

Clinicians also wary of closure early on

While it was quite difficult to get the first generation of transcatheter LAA closure devices through the FDA premarket approval gauntlet, proponents of LAA closure devices faced a real slog where clinician acceptance was concerned as well. I recall both FDA advisory hearings and medical society meetings during which a lot of the clinical audience seemed resistant to the idea of inserting a device into the appendage despite all the well-known problems with warfarin. Still, the data eventually won out. The transcatheter versions of these devices then wrapped up the to-market voyage with a Medicare coverage memo from February 2016, seven years after the first FDA advisory hearing for the Watchman.

At the time during which pivotal trials for many of these devices were underway, anticoagulation was provided primarily – and in many cases entirely – by legacy prescription drugs such as warfarin. Warfarin of course presents a high risk of bleeding, but the pharmaceutical industry responded with direct oral anticoagulation (DOAC) products, which provide a similar benefit of reduced intracranial coagulation while lowering the risk of bleeding events. DOACs also are far less likely than warfarin to interact with other pharmaceutical agents and with foods that might exert anticoagulative effects of their own.

But here we are with a September 2026 analysis which claims that closure of the LAA carries an incident rate ratio (IRR) of 1.34 for ischemic stroke relative to oral anticoagulation. The IRR for stroke of any kind (any-stroke) falls to 1.09 for LAA closure, thanks to these devices’ performance in the realm of hemorrhagic stroke. However, the authors stated that the benefit of device therapy on hemorrhagic stroke was more conspicuous when warfarin, rather than a DOAC, was used as the pharmaceutical comparator.

As I’m sure we all can relate, patients with afib are not particularly keen to engage in any kind of anti-thrombotic medication for the remainder of their lives, regardless of whether the prescription is for a DOAC or warfarin. The authors pointed out that even DOACs carry a 2-4% annual major bleeding risk. Real-world data seems to back the notion that patients are wary of DOACs, given data that suggest a discontinuation rate of 30-40% at a mere two years. One can only imagine the discontinuation rate at five or 10 years. But once the LAA closure device is in there, it’s in there for the vast majority of patients as seen in a long-term device removal rate of 0.58%.

The problem for device manufacturers at this point is that this meta-analysis is not the first to call into question whether device therapy is legitimately a better choice than DOACs for the non-valvular subset of afib patients. And Boston Scientific is not the only company with some exposure here. Medtronic has the Penditure, which is designed to be placed during cardiac surgeries. Abbott has of course the Amplatzer Amulet, which like the Watchman is designed for transcatheter delivery.

J&J bails on Laminar, but former managers still on board

Interestingly, Johnson & Johnson has spun off the company’s LAA product division to a group of former employees and an investment firm. J&J picked up Laminar Inc. in 2023 for about $400 million, but the Laminar approach is apparently to eliminate the left atrial appendage altogether with a rotating device. J&J suspended the pivotal trial for this device last year, but perhaps one should expect setbacks when introducing an entirely new approach to a tricky clinical problem in a confined volume of space.

Depending on whom one asks, the global market for LAA closure devices is poised to reach $9.4 billion by 2033, which would represent an annual compound growth rate of nearly 19% relative to 2025. This forecast is from this past January, so it arrived after news of the middling results of LAA closure devices as seen in the CLOSURE-AF study. On the other hand, CLOSURE-AF studied patients deemed at high risk of stroke, precisely the population some believe are less than ideal candidates for device therapy.

These latest developments don’t constitute a complete setback for these devices, although there is an emerging signal that patient selection is going to be front and center for the next few years. Conversely, device makers are always looking to improve on their products, and some of the questions about device performance in high-risk patients may soon be answered to the satisfaction of cardiologists and patients alike. For cardiologists, investors and patients, this is a space that bears watching as the next generation of LAA closure devices emerges.