Next-generation LAA closure device lowers risk for in-hospital major adverse events
Patients who underwent left atrial appendage closure with a next-generation device were significantly less likely to experience in-hospital major adverse events, including pericardial effusion, compared with an earlier-generation device.
In a real-world analysis of registry data, researchers also found that the Watchman FLX device (Boston Scientific) was associated with consistently higher rates of implant, device and procedural success for patients who received a Watchman FLX compared with the first-generation Watchman 2.5 device, James V. Freeman, MD, MPH, MS, associate professor of medicine and director of the Atrial Fibrillation Program at Yale School of Medicine, said during a presentation at Heart Rhythm 2022.
The Watchman FLX, launched in August 2020, was redesigned to allow the device to be repositioned and recaptured multiple times, with additional struts to allow the device to better conform to the left atrial appendage (LAA), Freeman said.
“That allows for, potentially, a decrease in trauma related to placement of the device and a decrease in pericardial effusion, and the opportunity to optimize positioning and improve location of the device within the left atrial appendage,” Freeman said during a press conference. “What we wanted to do in this study is assess if they were successful in improving the safety profile of the procedure and potentially the success rate of the procedure as well.”
Assessing registry data
Freeman and colleagues assessed observational data from 27,103 patients who received a Watchman FLX device and 27,103 patients who received a Watchman 2.5 device from 611 sites participating in the National Cardiovascular Data Registry (NCDR) Left Atrial Appendage Occlusion Registry (LAAO Registry). The mean age of patients was 76 years; 59% were men; mean CHA2DS2-VASc score was 4.8.
Researchers compared the safety and acute procedural success of the first-generation device compared the Watchman FLX. The primary endpoint was a composite of death, cardiac arrest, stroke, major bleeding, major vascular complication, MI, pericardial effusion requiring intervention and device embolization. Secondary endpoints included implant success (device deployed and released), device success (device deployed and released without a residual leak > 5 mm) and procedural success (device deployed and released without a peridevice leak > 5 mm and no in-hospital major adverse events).
Compared with the Watchman 2.5 device, patients who received the Watchman FLX were 43% less likely to experience any in-hospital major adverse event, with an adjusted OR of 0.57 (95% CI, 0.5-0.65; P < .001). Assessing individual component endpoints, risk for death was 41% lower for patients who received the Watchman FLX vs. the Watchman 2.5 (aOR = 0.59; 95% CI, 0.38-0.91; P = .016) and rates for pericardial effusion requiring intervention, cardiac arrest and major bleeding fell by 66% (aOR = 0.34; 95% CI, 0.28-0.42; P < .001), 41% (aOR = 0.59; 95% CI, 0.39-0.89; P = .012) and 47% (aOR = 0.53; 95% CI, 0.46-0.62; P < .001), respectively, compared with Watchman 2.5.
“The rate of major adverse events dropped from 2.4% with the original device to 1.4%,” Freeman said. “In particular, the rate of pericardial effusion, which is the main reason this device was redesigned, dropped from 1.2% down to 0.4%, a marked decrease. That resulted in rates of major bleeding being lower, rates of death dropped from two in 1,000 down to one in 1,000, cardiac arrest was also statistically significantly lower. A lot of the downstream consequences of pericardial effusion, including death, were also decreased.”
Procedural success metrics
Assessing acute procedural success metrics, researchers found rates of implant success (97.8% vs. 96.8%;), device success (97.4% vs. 96.6%) and procedural success (96.1% vs. 94.6%) were greater for the Watchman FLX vs. the Watchman 2.5 (P for all < .001)
Researchers also found procedure duration was a mean 3.8 minutes shorter (mean, 83 minutes vs. 86.8 minutes; P < .001) and incidence of peridevice leak greater than 5 mm was lower (0.03% vs. 0.06%; P = .234) for the next-generation Watchman vs. Watchman 2.5.
“All of this shows that Boston Scientific was successful in terms of redesigning this device to address ... pericardial effusion and to help improve the optimal positioning and acute procedural success,” Freeman said. “It appears they were successful; they markedly improved the safety profile with the new device, improved acute procedural success and shortened the length of the procedure.”
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Freeman JV, et al. Late Breaking Clinical Trials: Late Breaking Science. Presented at: Heart Rhythm 2022; April 29-May 1, 2022; San Francisco (hybrid meeting).