Boston Scientific Watchman shown to cut stroke risk
Transcatheter left atrial appendage occlusion (LAAO) with a Boston Scientific Watchman device was associated with a low rate of stroke at one year — even among older patients with atrial fibrillation (AFib) who faced a high risk for stroke or bleeding based on their previous health history, according to new data presented at ACC.21.
FDA-approved in 2015, the Watchman device blocks a small portion of the heart to help reduce the risk of a dangerous clot formation stroke in patients with AFib and in patients who require an alternative to the long-term use of blood thinners.
After a follow-up period of one year, an estimated 1.53% of patients in the registry suffered an ischemic stroke, 8.52% died and less than 0.7% experienced systemic embolism. The stroke rate was 77% lower than would be predicted by the patients’ CHA2DS2-VASc scores, a measure of stroke risk for patients with AFib. The study focused only on outcomes from LAAO procedures using the Watchman device; future studies are planned to assess clinical efficacy at three and four years.
The study, an analysis of a prospective registry of patients who received a Watchman device via a catheter inserted into a blood vessel in the groin, found that in practice, the rate of ischemic stroke (the study’s primary endpoint) was generally on par with rates seen in clinical trials leading to the device’s approval. The findings offer reassurance that LAAO with the Watchman device is likely effective for the patient population currently receiving it, according to the researchers.
“Based on these data, it seems like we’re doing the right thing,” said lead author Dr. Matthew J. Price, director of the cardiac catheterization laboratory at Scripps Clinic in La Jolla, California, in a news release. “The rate of ischemic stroke was low and supports the clinical effectiveness of transcatheter LAAO as it is currently applied in the U.S.”
The researchers analyzed real-world data from more than 36,000 procedures recorded in the ACC’s National Cardiovascular Data Registry LAAO Registry, a registry that includes almost all LAAO procedures performed in the U.S. The study includes data from patients who received a Watchman device in 2016, 2017 or 2018. It was published in the Journal of the American College of Cardiology.
“I was actually a bit surprised by the relatively low event rates because the patients are substantially higher risk than those studied in clinical trials,” Price said. “However, all-cause mortality, as well as bleeding in the weeks following the procedure, were not infrequent—consistent with the co-morbidities of this patient population. This underscores the need to individualize one’s approach to stroke prevention so that patients reap the clinical benefit of stroke reduction.”