The use of oversized devices for patients receiving the first-generation Watchman device while undergoing left atrial appendage occlusion (LAAO) has increased over time, according to a study published Dec. 6, 2022, in Circulation: Cardiovascular Interventions. The practice was associated with less risk of significant leak or device embolization and no greater risk of other adverse events.

Using data from ACC’s LAAO Registry, Amneet Sandhu, MD, FACC, et al., assessed 68,456 patients undergoing LAAO with implantation of the Watchman 2.5 device from Jan. 1, 2016 to June 30, 2020. After stratifying patients based on left atrial appendage orifice size, researchers found that 10.5% of patients received undersized devices, 26.0% received a device size according to manufacturer recommendations, and 64.4% received an oversized device. Use of oversized devices increased significantly over the four-year study period, from 60.3% in 2016 to 66.0% in 2020 (p<0.001).

The study authors found no increased odds of pericardial effusion when comparing manufacturer recommended sizing to either undersized (1.048, 95% CI‚ 0.801-1.372, p=0.733) or oversized (1.101, 95% CI‚ 0.933-1.298, p=0.254) devices. When investigating the odds of a composite outcome of device migration or embolization and significant peridevice leak at 45 days, researchers found a similar risk between manufacturer recommended sizing and undersized devices (1.030, 95% CI‚ 0.735-1.444, p=0.863) and less risk associated with oversized devices (0.701,95% CI‚ 0.561-0.876, p=0.002), mainly due to lower odds of leak.

“Intuitively, the risk-benefit tradeoff of appropriate device sizing weighs an increased risk of pericardial effusion with oversizing against an increase in device embolism or significant (>5 mm) leak with undersizing,” state the authors. “However, relative to manufacturer recommendations, we found no association between rates of adverse events and oversized devices.”

Sandhu, et al., conclude that given the lower odds of device migration, device embolism or significant leak and no observed increase in pericardial effusion with oversized devices, the device selection made by operators in these cases was “safe and clinically sound.”

Clinical Topics: Pericardial Disease

Keywords: Atrial Appendage, Registries, Risk Assessment, Embolism, Pericardial Effusion, LAAO Registry, National Cardiovascular Data Registries

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