Watchman device migration and embolization: A report from the NCDR LAAO Registry

Introduction: Incomplete anchoring of the Watchman left atrial appendage closure (LAAO) device can result in substantial device migration or device embolization (DME) requiring percutaneous or surgical retrieval.

Methods: We performed a retrospective analysis of Watchman procedures (January 2016 through March 2021) reported to the National Cardiovascular Data Registry LAAO Registry. We excluded patients with prior LAAO interventions, no device released, and missing device information. In-hospital events were assessed among all patients and postdischarge events were assessed among patients with 45-day follow-up.

Results: Of 120 278 Watchman procedures, the in-hospital DME rate was 0.07% (n = 84) and surgery was commonly performed (n = 39). In-hospital mortality rate was 14% among patients with DME and 20.5% among patients who underwent surgery. In-hospital DME was more common: at hospitals with a lower median annual procedure volume (24 vs. 41 procedures, p < .0001), with Watchman 2.5 versus Watchman FLX devices (0.08% vs. 0.04%, p = .0048), with larger LAA ostia (median 23 vs. 21 mm, p = .004), and with a smaller difference between device and LAA ostial size (median difference 4 vs. 5 mm, p = .04). Of 98 147 patients with 45-day follow-up, postdischarge DME occurred in 0.06% (n = 54) patients and cardiac surgery was performed in 7.4% (n = 4) of cases. The 45-day mortality rate was 3.7% (n = 2) among patients with postdischarge DME. Postdischarge DME was more common among men (79.7% of events but 58.9% of all procedures, p = .0019), taller patients (177.9 vs. 172 cm, p = .0005), and those with greater body mass (99.9 vs. 85.5 kg, p = .0055). The rhythm at implant was less frequently AF among patients with DME compared to those without (38.9% vs. 46.9%, p = .0098).

Conclusion: While Watchman DME is rare, it is associated with high mortality and frequently requires surgical retrieval, and a substantial proportion of events occur after discharge. Due to the severity of DME events, risk mitigation strategies and on-site cardiac surgical back-up are of paramount importance.