What are the risks associated with a Watchman (Left Atrial Appendage Closure) device?

From the Guidelines

The Watchman device is generally considered safe, but it does carry some risks, and its use should be carefully considered based on the latest evidence from 2025, which highlights the importance of proper device placement and patient selection to minimize complications. The procedure-related risks include bleeding at the insertion site, infection, device migration, blood clots forming on the device, stroke during implantation, and cardiac perforation. However, these complications are relatively rare, occurring in less than 5% of cases, as reported in studies such as 1. Most patients can discontinue blood thinners 45 days after implantation following confirmation of proper device placement and sealing via transesophageal echocardiogram.

Key Considerations

• The device works by permanently closing off the left atrial appendage where most stroke-causing blood clots form in atrial fibrillation patients.
• For most eligible patients, the long-term benefit of stroke prevention outweighs the short-term procedural risks, especially when compared to the bleeding risks associated with lifelong anticoagulation therapy, as discussed in 2 and 3.
• Recovery typically takes a few days, with most patients returning to normal activities within a week.
• The latest evidence from 2025 1 emphasizes the need for careful patient selection and proper device placement to minimize the risk of device-related thrombus and other complications.

Risks and Benefits

• The Watchman device has been compared with warfarin in patients with atrial fibrillation at increased risk of stroke in several randomized controlled trials, including the PROTECT AF and PREVAIL trials, as mentioned in 4 and 5.
• A meta-analysis combining data from these trials demonstrated that patients receiving the device had significantly fewer hemorrhagic strokes than those receiving warfarin, but there was an increase in ischemic strokes in the device group, as reported in 2 and 3.
• However, when periprocedural events were excluded, the difference in ischemic strokes was not significant, highlighting the importance of proper device placement and patient selection.

Latest Evidence

• The 2025 study 1 provides the most recent and highest-quality evidence on the safety and efficacy of the Watchman device, emphasizing the need for careful patient selection and proper device placement to minimize complications.
• This study highlights the importance of considering the risk factors for device-related thrombus, including non-paroxysmal AF, renal insufficiency, hypercoagulable disorders, pericardial effusion, deep device implantation, and older age.

From the Research

Risks Associated with the Watchman Device

• The Watchman device is efficacious and safe in preventing stroke and systemic embolization, but it carries risks such as device-related thrombosis 6.
• Antithrombotic therapy with aspirin and clopidogrel for six months followed by daily aspirin indefinitely may be feasible for patients with an absolute contraindication to oral anticoagulation 6.
• There is a low risk of Watchman device-related infection, even in the setting of a bloodstream infection 7.
• Device-related thrombosis is an important complication of left atrial appendage closure, and the use of direct-acting oral anticoagulants may be preferential to warfarin for prevention and treatment of this complication 8.
• The Watchman device has more complications compared to warfarin, including procedure-related complications 9.
• The overall complication rate for Watchman device implantation is low, with an in-hospital mortality rate of 0.29% and a pericardial effusion rate of 0.68% 10.

Comparison to Other Treatments

• Novel oral anticoagulants are superior to warfarin for stroke prevention in nonvalvular atrial fibrillation, but the Watchman device is a reasonable noninferior alternative to warfarin for stroke prevention 9.
• The Watchman device confers a significant reduction in life-threatening bleeding compared to oral anticoagulation 8.
• Direct-acting oral anticoagulants may be more convenient to use than warfarin, and limited evidence suggests that they are not inferior following implantation of the Watchman device 6.

Patient Populations

• Left atrial appendage closure may be preferable to direct-acting oral anticoagulants in patients with contraindications to oral anticoagulation, end-stage renal disease, prior intracranial hemorrhage, recurrent gastrointestinal bleeding, and patients undergoing transcatheter aortic valve replacement or left atrial electrical isolation 8.
• The Watchman device is a suitable option for patients with atrial fibrillation who have an increased bleeding risk 7.