What does this research mean for the field?

Device-related thrombus was detected in 2.3% of patients by TEE and 1.9% by CT at the first follow-up after WATCHMAN implantation. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

What question did this study set out to answer?

This study aims to evaluate the incidence of device-related thrombus (DRT) post-WATCHMAN implantation through follow-up evaluations using TEE and CT.

February 8, 2026

Device-related thrombus post WATCHMAN implantation in the real world: lessons from a prospective multicenter registry of high-volume operators in the US

Key Result

Device-related thrombus occurred in 2.3% by TEE and 1.9% by CT within 90 days post WATCHMAN implantation, confirming low DRT rates in real-world use.

Key Points

This study aims to evaluate the incidence of device-related thrombus (DRT) post-WATCHMAN implantation through follow-up evaluations using TEE and CT.
Conducted a prospective registry for patients undergoing WATCHMAN FLX or WATCHMAN FLX Pro device implantation.
Patients were followed without interference from study leadership, adhering to local care standards.
Evaluated procedural success and complications, including rates of leak and thrombus using a central imaging core lab.
Detected DRT in 2.3% of patients (21/916) at TEE within 90 days post-implantation.
Detected DRT in 1.9% of patients (13/676) at CT within the same follow-up period.
Findings confirm that DRT incidence remains low post-WATCHMAN implant, consistent with controlled clinical studies.

Structured PICO

Population

Patients scheduled to undergo implantation with a WATCHMAN FLX or WATCHMAN FLX Pro device (n=916 for TEE follow-up, n=676 for CT follow-up).

Intervention

WATCHMAN FLX or WATCHMAN FLX Pro device implantation followed per local standard of care.

Outcome

Incidence of device-related thrombus (DRT) at follow-up (up to 90 days) as detected by transesophageal echo (TEE) and CT, adjudicated by a central core lab.surrogate

In a real-world US registry, device-related thrombus rates following WATCHMAN FLX/FLX Pro implantation remained low (around 2%) at 90 days, supporting the modern practice of using CT as an alternative to TEE for follow-up imaging.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Abstract Background The FDA approved the WATCHMAN device in March 2015 with the caveat follow-up transesophageal echo (TEE) at 45 days and 1 year post implant to assess peri-device leak (PDL) and device-related thrombus formation (DRT) as an important step before interruption of anticoagulation. However, our understanding of these PDLs and DRTs relies on well designed and published clinical trials. The real-world experience regarding these issues is lacking. We sought to evaluate the DRT incidence at follow-up by TEE and CT to one year as adjudicated by a central core lab to minimize variability in reporting. Methods Patients were eligible for enrollment in this prospective registry if they were scheduled to undergo implantation with a WATCHMAN FLX or WATCHMAN FLX Pro device. Enrolled patients were implanted with a WATCHMAN device and followed per local standard of care without interference from the central core lab or study leadership. There were no pre-specified endpoints, but analyses include procedural success, procedural complications, and leak and thrombus rates as adjudicated by a central imaging core lab. Results At the time of the first follow-up, up to 90 days, 2.3% (21/916) of patients had a DRT as detected by TEE and 1.9% (13/676) of patients had a DRT as detected by CT (Figure 1). Conclusion As observed in well-controlled clinical studies, DRTs remain low post WATCHMAN implant both on TEE and CT. This experience expands our understanding of visualization of DRT beyond TEE to incorporate the modern practice of using CT for follow-up in patients post WATCHMAN implant.

Bookmark