He Vigilant The left atrial appendix (LAA) closure device (Boston Scientific) is associated with low stroke rates for one year, despite being used commercially in older and sicker patients than those observed in basic clinical trials, suggest new data.
Among more than 36,000 patients with atrial fibrillation (AF), the estimated Kaplan-Meier rate ischemic stroke at 1 year it was 1.53% (95% CI, 1.40% – 1.66%).
This represents a 77% reduction in the relative risk of ischemic stroke with the device than expected based on patients’ CHA.2DS2-VASc score if not treated (6.64% vs 1.53%).
The cumulative rate of ischemic stroke was 1.40 per 100 person-years (95% CI: 1.27 – 1.53).
“Thromboembolic events at 1 year are uncommon among patients undergoing a commercial implantation of Watchman, which supports early-term clinical efficacy as it is currently being used in the United States,” said Dr. Faculty of Cardiology (ACC) Scientific session of 2021.
The Watchman device was approved in 2015 for the stroke prevention in high-risk patients with non-valvular atrial fibrillation (AF) and is presented as an alternative to lifelong oral anticoagulation. The latest version, the Watchman FLX, won approval in 2020.
This study was based on 36,681 patients from the LAA Occlusion Registry (LAAO) of the National Cardiovascular Data Registry (NCDR) implanted with a Watchman device from January 2016 to December 2018. Participation in the registry is required by the Food and Drug Administration of the U.S. as part of its post-marketing surveillance and is mandatory for reimbursement from Medicare and Medicaid (CMS) service centers.
First procedural results reported last year ACC meeting show a higher implant success rate and a substantially lower hospital complication rate in the real world than can be seen in the pivot PROTECT-AF i PREVALA essays.
However, there is little data on long-term safety and efficacy of the Watchman device in contemporary practice, noted Price, director of the cardiac catheterization lab at Scripps Clinic, La Jolla, California. The population of the randomized trials that led to Watchman’s approval also differs substantially from that indicated in the CMS coverage decision.
CMS covers patients with CHADS2 score equal to or greater than 2 or CHA2DS2-Basque score of 3 or higher that are suitable for the short term warfarin but is considered incapable of taking long-term oral anticoagulation. In contrast, trial participants had a lower thromboembolic risk (CHADS2 score ≥ 1 for PROTECT-AF and CHADS2 score ≥ 2 or CHADS2 score ≥ 1 with PREVAIL conditions) and were eligible for long-term warfarin.
LAAO-registered patients were, on average, 76 years old, compared with 71.7 years of PROTECT-AF and 74 years of PREVAIL, and had a higher mean CHA2DS2-VASc score (4.6 vs 3.4 vs 3.8, respectively). A quarter had previously had a stroke or transient ischemic attack (29.8% vs. 17.7% vs. 27.5%) and 69.4% previously had clinically relevant hemorrhages (no trial data available). The mean follow-up was 373 days (interquartile range, 208 to 425 days).
At 1 year, the estimated mortality rate was 8.52%, with 32.6% of cases for cardiovascular mortality, 60.3% for non-cardiovascular death, and 7.1% unspecified. The cumulative mortality rate for all causes was 7.58 per 100 person-years.
The estimated rate of bleeding greater than 1 year was 6.2% (cumulative rate, 7.08 / 100 years-person).
“The incidence of mortality at 1 year is not uncommon, mainly due to non-cardiovascular death, and the risk of bleeding, especially at the beginning of the first 6 weeks, is higher than that seen in randomized trials. these balance risks.when considering the Watchman device for a patient, “Price said theheart.org | Cardiology Medscape.
Although 93.6% of patients in the registry had at least one follow-up visit after discharge, the percentage of patients with follow-up fell to 78% at 180 days and 71% at 365 days.
However, there were no differences between patients with or without follow-up of thromboembolic risk (ACC2DS2-VASc, both 4.8) or bleeding risk based on HAS-BLED score (both 3.0) or clinically relevant previous bleeding (69.4% vs 70.2%; Pg = .39), indicated price. The AF classification was also similar (paroxysmal AF, 52.4% vs 52.2%; Pg = .82).
“This is an impressive response when it comes to comparing real-world data with what we have in studies,” panelist and electrophysiologist Jodie Hurwitz, MD, Medical City Hospital, Dallas, Texas said during a discussion of the results. .
Hurwitz asked whether information on the use of warfarin and antiplatelet therapy would be given among registered patients. Price noted that the first results published last year included these data in about 32,000 45-day patients.
“Relatively low stroke events cannot be attributed solely to LAAO because patients take a short period of post-procedure pharmacotherapy,” he said. “But certainly given the risk to the population, the results are reassuring about how we are practicing medicine now in the United States with the Watchman, and the use of these pharmacotherapies then translates into a low rate. of thromboembolic events “.
Price said upcoming analyzes will examine hospital complication rates based on hospital volume. “It will be important to understand the relationship between hospital volume, physician experience, and outcomes.”
Asked whether the results in these “incredibly ill” patients may be sufficient to strengthen the recommendation of mild IIb for LAAO in clinical guidelines, Price said missing random data from this population. The randomized ASAP-TOO trial in patients not eligible for oral anticoagulation was stopped due to low enrollment, although randomized trials comparing the Watchman with new oral anticoagulants in patients who are good candidates for OAC will help inform the guidelines.
“It would be nice to see a consensus document, so that more people can access it,” Hurwitz said. “That’s very impressive.”
Price communicated consultant fees / fees Abbott Vascular, Accutus, AstraZeneca, Baylis Medical, Boston Scientific, InnovHeart, Johnson & Johnson, MEDTRONIC and WL Gore; participation of the Office of Speakers for Abbott Vascular and AstraZeneca; and stock in Indian Wells. Hurwitz reported that he had been an officer, director, administrator, or other trustee of Medical City Dallas; have a major ownership interest / partnership / function with Baylor Plano Heart Hospital; and serving the Medtronic speaker office.
Scientific Session of the American College of Cardiology (ACC) 2021. Abstract 403-11. Filed May 15, 2021.
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