18 May 2021
As long as surgeons have a patient under anesthesia for one heart procedure, they may as well make it two—and according to a new study, the benefits in preventing future strokes could last a lifetime.
Researchers examined whether making a quick detour during surgery to close off the left atrial appendage—a small pouch in the wall of the heart muscle, where it’s believed blood can pool and form dangerous clots—could help reduce the overall risk of stroke in patients with atrial fibrillation that isn’t caused by a heart valve.
They found that taking less than 10 minutes to seal that appendage with sutures, staples or other surgical devices could reduce the number of ischemic strokes by at least a third—or by up to 42% over the long term, after the initial 30 days following the procedure.
This benefit would come on top of commonly used prescription blood thinners, with no evidence of additional side effects seen in the randomized study, which was halted early due to the procedure’s observed progress.
“We were ecstatic to see these results,” said the study’s lead author, Richard Whitlock, a cardiac surgeon at McMaster University in Canada, who described them as confirmation of a new paradigm in stroke prevention. The late-breaking data were presented during the annual scientific sessions of the American College of Cardiology and published in the New England Journal of Medicine.
“This trial opens a new option for treatment of these patients by layering a mechanical approach—occlusion—on top of a medical approach,” Whitlock said. “Instead of a tension between anticoagulation and occlusion, we need to start thinking about using these as additive approaches when patients are at high risk for stroke.”
The study only examined approaches taken during open surgery for another heart condition, rather than transcatheter devices used to obstruct the appendage’s opening—such as Boston Scientific’s Watchman or Abbott’s Amplatzer Amulet—which can be delivered separately in a minimally invasive procedure.
It enrolled more than 4,800 participants in 27 countries, with about two-thirds undergoing procedures to treat their heart valves and about 20% receiving coronary artery bypass grafts. All had documented atrial fibrillation and high risks of stroke, and all received a standard course of blood thinners after surgery.
After a median follow-up of nearly four years, 4.8% of patients who received occlusion had suffered a stroke, compared with 7% of patients who had not received the additional procedure. The overall rates of death, including 30-day mortality, and hospitalizations for heart failure remained similar between the two groups.
“This is a procedure that’s done once, and it keeps giving a benefit over time,” Whitlock said. “This is going to prevent thousands of strokes.”
Abbott is currently putting its Amplatzer device up against a newer generation of blood thinners in a head-to-head study, to see if it can serve as an alternative to a lifelong medication regimen.
The randomized trial is expected to collect at least two years of data on non-vitamin K antagonist oral anticoagulants, or NOACs, such as the blockbuster drugs Eliquis, Xarelto and Pradaxa, among patients with atrial fibrillation. The Amplatzer, meanwhile, is threaded into the heart through a cut in the thigh, before expanding to seal the gaps formed by the appendage.
Previously, a 2015 study of Boston Scientific’s Watchman found that the device became more effective and less costly than warfarin after 10 years, and outpaced the category of newer blood thinners after five years.
In a separate late-breaking Watchman study also presented this year at ACC, real-world data showed Boston Scientific’s implant led to stroke rates 77% lower than typically expected among older people with atrial fibrillation and high risk scores.
However, the registry also demonstrated all-cause mortality and bleeding were consistent with the co-morbidities in the elderly, underlining “the need to individualize one’s approach to stroke prevention so that patients reap the clinical benefit of stroke reduction,” said lead author Matthew Price, director of the cardiac cath lab at Scripps Clinic.Print
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