TCT: Abbott's Amulet, Boston Scientific's Watchman heart occluders show similar performance after one year in randomized study

A head-to-head, randomized study of the two leading heart implants worldwide for reducing the risk of stroke among people with an irregular pulse found there was little difference between their safety and performance after more than one year.

The trial, presented as a late-breaking study at the Transcatheter Cardiovascular Therapeutics conference in San Francisco, evaluated the 13-month clinical outcomes of left atrial appendage closure devices—specifically Boston Scientific’s Watchman line and Abbott’s Amplatzer Amulet. 

Both are designed to expand and seal off a small pocket within the inside of the heart wall through a minimally invasive procedure. In patients with atrial fibrillation, the arrhythmia can force blood to pool within the appendage and form clots, which can ultimately lodge themselves in the brain. The study, dubbed SWISS-APERO, split up participants whose heart anatomies made them candidates to receive either implant.

Not only did subsequent CT angiography of the heart show comparable appendage seals after 45 days, scans showed about the same rates of patency after 13 months, along with similar leak profiles. 

Both the Amulet and the Watchman—including the first-generation Watchman 2.5 and its successor, the Watchman FLX—also had similar rates of definite or possible device-related blood clots, at 2.4% and 3.8%, or two versus three cases, respectively.

Clinically, a composite measurement that combined the rates of cardiovascular death, stroke and embolism was comparable between the two cohorts, at 9.5% and 10.2%, as were the numbers of cerebrovascular and bleeding events, according to the study, which was also published in the American Heart Association journal Circulation.

Abbott’s Amplatzer Amulet was approved by the FDA in August 2021 after first receiving a CE mark in Europe in 2013. Earlier this year, the agency issued a Class I label to a recall of the Amplatzer Amulet sheath used during implantation procedures due to a risk of introducing an air embolism. The recall did not affect the occluder implant itself.

Meanwhile, Boston Scientific’s Watchman implant was first approved in 2015. Its latest version, the FLX Pro, received an FDA green light this past September. The upgraded device features a new polymer coating that the company says assists in the natural healing process following the closure procedure in addition to larger size options. Boston Scientific previously scored a Watchman approval in September 2022 that expanded the range of blood thinning drug regimens that can be used after implantation.