Follow-up imaging after left atrial appendage closure.

Area of Science:

• Cardiology
• Medical Devices
• Interventional Cardiology

Background:

• Device-related thrombus (DRT) after Watchman left atrial appendage closure is linked to poor outcomes.
• Current guidelines recommend surveillance transesophageal echocardiography (TEE) at 45 days and 1 year.
• Early TEE at 45 days may miss DRT due to concurrent oral anticoagulant use and subsequent aspirin monotherapy.

Purpose of the Study:

• To assess an alternative surveillance strategy using initial TEE or CT imaging at 4 months post-Watchman implantation.
• To evaluate the safety and efficacy of this delayed imaging approach.

Main Methods:

• A cohort of 530 patients received Watchman implantation and followed a truncated drug regimen.
• The regimen included 6 weeks of oral anticoagulant/clopidogrel plus aspirin, followed by 6 weeks of dual antiplatelet therapy, and then aspirin monotherapy.
• Patients underwent TEE or CT imaging at 4 months and 1 year.

Main Results:

• 16 ischemic strokes (ISs), 8 transient ischemic attacks (TIAs), and 1 systemic embolization occurred over a median 12-month follow-up.
• Crucially, no ISs occurred between 45 days and 4 months, the period of interest for this strategy.
• Device-related thrombus (DRT) was detected in 2.4% at 4 months and 0.9% at 1 year, with no associated ISs after DRT detection.

Conclusions:

• A 4-month delay for the first imaging post-Watchman implantation is associated with no ischemic strokes during this "vulnerable" period.
• This strategy appears safe and may allow for earlier detection of DRT after antiplatelet therapy has transitioned to monotherapy.