WASHINGTON – Left atrial appendage closure can be performed safely and effectively in older patients, those with end-stage renal disease, and likely others not included in the pivotal clinical trials, according to a series of new studies, including a late-breaker, presented on the both older and newer Watchman devices at the Cardiovascular Research Technologies conference.
In the case of the late-breaking clinical trial report, which included more than 60,000 patients, the goal was to look at the safety of the Watchman FLX, which is the newest of the devices in real-world practice, according to Samir R. Kapadia, MD, chairman of the department of cardiovascular medicine at the Cleveland Clinic.
In the SURPASS registry, the number of patients discharged on the Watchman FLX climbed from zero in August 2020, when data accrual began, to 66,894 by March 2022. For the current analysis, 45-day follow-up was available for 61,963 patients and 1-year follow-up was available for 18,233.
Based on this number of patients treated by more than 2,300 clinicians at more than 740 sites, the SURPASS registry establishes that Watchman FLX “can be accomplished safely with clinical outcomes similar to pivotal trials at 45 days and 1 year,” Dr. Kapadia reported.
No surprises found in real-world outcome
At 7 days or hospital discharge (whichever came last), the rate of all-cause death was 0.18%, the rate of ischemic stroke was 0.13%, and there were no systemic emboli. By 45 days, the rate of all-cause death (0.84%) and stroke of any kind (0.32%) remained less than 1% and there were still no systemic emboli. Major bleeding events, of which about one-third occurred during hospitalization, had reached 3.34% by day 45.
By 1 year, all-cause mortality had risen to 8.3%, the stroke rate was 1.6%, and major bleeding reached 6.7%. The rate of systemic emboli remained very low (0.1%). The rates of death and stroke rose at a slow but steady rate throughout the 1-year follow-up. In contrast, major bleeding events rose steeply in the first 90 days and were followed by a much slower accrual subsequently.
At 1 year, 84.4% of patients had a complete seal. Leaks ≤ 3 mm were observed in 12.1%. The remaining leaks were larger, but just 0.7% had a leak > 5 mm.
Relative to the first-generation Watchman, the Watchman FLX has numerous design changes, including a shorter profile, more struts, and a reduced metal exposure. Most of these changes were performed to make the device easier to deploy.
When the SURPASS data are compared to the pivotal trials with Watchman FLX or to the Ewolution and National Cardiovascular Data (NCD) registries, which were created to monitor efficacy and safety with the earlier generation Watchman, the outcomes are similar or, in many cases, numerically favorable for such outcomes as bleeding and rates of stroke.
In addition to providing reassurance for the real-world safety of Watchman FLX, Dr. Kapadia said that these data establish reasonable benchmarks for centers tracking in-hospital and 1-year outcomes.
Dr. Kapadia also reported that outcomes overall in SURPASS were similar in women and men with the exception of major bleeding, a finding common to other interventional studies.
The late-breaker panelists generally agreed that SURPASS provides a robust set of data by which to be reassured, but David J. Cohen, MD, director of Clinical and Outcomes Research at the Cardiovascular Research Foundation in New York, said that he thinks the rate of bleeding is unnecessarily high.
“You really need to figure out a way to get the rate of bleeding at 45 days down,” Dr. Cohen said. He called for studies of anticoagulation in the post-procedural period that offer a better benefit-to-risk ratio.