Stroke Protection Holds Up Long-term After LAA Closure: NCDR/Medicare Data

Medicare patients with nonvalvular atrial fibrillation who underwent left atrial appendage occlusion (LAAO) with Watchman (Boston Scientific) in the first few years after the device arrived on the US market experienced “low and durably consistent” stroke rates over the long term, results from the National Cardiovascular Data Registry (NCDR) show.

Yet more than four in 10 of these patients—who received LAAO between 2016 and 2019—died within 5 years, Angela Y. Higgins, MD (Maine Medical Center, Portland), and colleagues report in a paper published earlier this month in the Journal of the American Heart Association. The persistently high all-cause mortality rates “underscore the importance of incorporating patient values and preferences when considering LAAO,” they stress.

Speaking with TCTMD, Higgins pointed out that this study represents the longest follow-up to date available on “real clinical use as opposed to a trial” and captures a “nationally representative cohort of patients.” Thus, she said, there was a need to see if outcomes diverged between research and clinical settings, especially given that real-world patients tend to be higher risk and have less tightly controlled medication regimens.

In this population, their study confirmed that LAAO in fact “works as well as it did in the trials” for stroke prevention, Higgins said.

While the news is good for stroke, it’s less so for all-cause death. Real-world LAAO patients have “a lot of comorbidities, and their risk of mortality is proportional,” she explained. “So even though we can protect them from stroke, we can’t really protect them from [that background risk].”

Knowledge of what to expect over 5 years “helps with the informed decision-making for patients. You can try to paint the picture for patients, so that they have realistic expectations for left atrial appendage occlusion and try to kind of get across what those risks and benefits truly are. . . . It’s not likely to lengthen their life necessarily,” said Higgins.

Still, she noted, LAAO stands to add “significant convenience” and improve quality of life for patients by eliminating their need to take  long-term anticoagulation, the monitoring this therapy can require, and the bleeding that can accompany the medication.

You can try to paint the picture for patients, so that they have realistic expectations. Angela Y. Higgins

Andrew Goldsweig, MD (University of Massachusetts-Baystate, Springfield), writing chair for the recently released LAAO guidelines, pointed out that the new report may not be entirely relevant to today’s practice, however.

“It’s a little out of date,” he commented to TCTMD. “The patients who had LAAO from 2016 to 2019 don’t look like the patients who have LAAO today, and you can see that reflected in the mortality rate . . . . In the early days of the procedure, [it] was only offered to people who were really high risk—if somebody came into the hospital with a GI bleed and they were otherwise healthy, you’d put them back on anticoagulation and it would only be their second or third bleed, I believe, that would prompt a procedure.”

That said, this study is revealing, he added. “ The best news that I see in this is that the LAAO registry is linked to Medicare data, so that we can continue to get longer-term follow-up on more contemporary patients.” The NCDR only tracks LAAO patients for a limited time, but Higgins et al were able to continue tracking outcomes through Medicare claims.

The investigators rightfully emphasize patient selection, Goldsweig agreed, pointing out that the new guideline recommendations advise that patients should have at least 1 year of quality life expectancy to be considered for LAAO.  Both prognosis and preference are key, he said.

Despite Stroke Reduction, Death Still Rose

The Food and Drug Administration approved Watchman in 2015 on the basis of the PREVAIL and PROTECT-AF trials, both of which enrolled patients with nonvalvular atrial fibrillation who were candidates for long-term anticoagulation. Yet the Centers for Medicare & Medicaid Services decided to reimburse for LAAO only if patients were able to take short-term anticoagulation, not if longer-term therapy was contraindicated—the latter group, most often due to higher bleeding risk, accounts for the “majority of patients undergoing LAAO in real-world practice,” the paper notes.

Delving into the FDA-mandated NCDR LAAO Registry, the researchers identified 34,975 fee-for-service Medicare beneficiaries who underwent LAAO with a Watchman device between 2016 and 2019. They used Medicare inpatient claims data to track outcomes beyond the 1-year mark. Median CHA₂DS₂–VASc score at baseline was 4.7, and median follow-up was 2.8 years.

The study’s primary outcomes were any stroke and all-cause mortality. While stroke rates—both any and ischemic—rose by an absolute rate of about 4% between 1 and 5 years, death rates increased by nearly 36%.

LAAO Outcomes, 2016-2019: NCDR

For Higgins, “the biggest take-home from this is just that left atrial appendage occlusion does provide stable, long-term protection from stroke for patients. So, in a real-world population, it works, and it works well, and we would expect it to be even better with the newer devices.” Newer iterations of Watchman have higher procedural success, shorter procedure times, and lower risks of device-related thrombus, she noted. The Amplatzer Amulet (Abbott), another LAAO device, is now on the market as well.