Is the Watchman device effective for stroke prevention in atrial fibrillation patients with a left ventricular ejection fraction (LVEF) of 35%?

Watchman Device Efficacy in Patients with LVEF 35%

The Watchman device can be effective for stroke prevention in atrial fibrillation patients with LVEF of 35%, but oral anticoagulation remains the preferred first-line therapy unless absolute contraindications exist. 1

Evidence for Efficacy

The Watchman device has demonstrated non-inferiority to warfarin for stroke prevention in atrial fibrillation patients, with specific benefits in reducing hemorrhagic stroke and cardiovascular death. 2 The PROTECT-AF trial showed superiority for the composite endpoint of stroke, systemic embolism, and cardiovascular/unexplained death at 3.8 years follow-up. 2 A patient-level meta-analysis confirmed comparable rates of the composite primary efficacy outcome with significantly lower hemorrhagic stroke and cardiovascular death compared to warfarin. 2, 1

Critical Limitation: No Data Specific to Reduced LVEF

None of the available guidelines or studies specifically address the efficacy or safety of the Watchman device in patients with LVEF ≤35%. The major trials (PROTECT-AF and PREVAIL) did not stratify outcomes by ejection fraction, and current guidelines do not provide LVEF-specific recommendations for left atrial appendage occlusion. 2, 1

However, patients with LVEF ≤35% are at increased stroke risk and typically have strong indications for anticoagulation. 2 Guidelines recommend oral anticoagulation (INR 2.0-3.0) for patients with heart failure and LVEF <35%. 2

Current Guideline Recommendations for Device Use

The 2024 ESC Guidelines state that percutaneous LAA occlusion may be considered (Class IIb) only in patients with AF and contraindications for long-term anticoagulant treatment. 2 This represents a weak recommendation with the device positioned as a second-line option. 1

The American College of Cardiology/American Heart Association/Heart Rhythm Society (2019) similarly recommends percutaneous LAA occlusion may be considered in patients with AF at increased risk of stroke who have contraindications to long-term anticoagulation (Class IIb, Level of Evidence B-NR). 1

Important Caveats for Reduced LVEF Patients

Patients with LVEF ≤35% require careful hemodynamic monitoring during any cardiovascular intervention. 3 The procedural risks of Watchman implantation include:

• Serious periprocedural complications in approximately 6-7% of cases, including pericardial effusion requiring drainage, device embolization, and major bleeding. 1
• Device-related thrombus formation occurs in up to 7.2% per year and is associated with increased ischemic stroke risk. 1, 4
• The procedure requires at least 45 days of warfarin plus aspirin post-implantation, followed by dual antiplatelet therapy until 6 months. 4 This exposes patients to bleeding risk during a vulnerable period.

Critical Evidence Gap

No randomized trials have compared the Watchman device with direct oral anticoagulants (DOACs), which have better safety profiles than warfarin. 2, 1 Since the device trials used warfarin as the comparator, and DOACs now demonstrate similar bleeding rates to aspirin, the role of Watchman in current practice is unclear. 2

Clinical Algorithm for Decision-Making

For AF patients with LVEF 35%:

1. First-line: Prescribe oral anticoagulation (DOAC preferred, or warfarin INR 2.0-3.0) unless absolute contraindications exist. 2, 1

2. Consider Watchman only if: Patient has absolute contraindications to all oral anticoagulants (both warfarin and DOACs) AND can tolerate at least 45 days of post-procedural anticoagulation AND the procedure is performed at a center with low complication rates. 2, 1

3. Avoid Watchman if: Patient cannot tolerate any post-procedural anticoagulation, has severe hemodynamic instability, or lacks access to experienced operators. 2, 1

Post-Implantation Monitoring Requirements

If Watchman is implanted, mandatory surveillance includes:

• TEE at 45 days and 1 year to evaluate for device-related thrombus and peridevice leak before discontinuing anticoagulation. 4
• Any peridevice leak detected by TEE is associated with increased thromboembolism risk. 4
• Deep device implantation (>10 mm from pulmonary vein limbus) increases device-related thrombus risk (OR 2.41). 4