Clinically Proven Outcomes

Clinically Proven Results

The WATCHMAN Implant is a one-time, minimally invasive procedure designed to reduce the risk of strokes that originate in the left atrial appendage (LAA). With over 150,000 patients implanted globally, almost 20 years of clinical-trial and real-world experience—including over 10 clinical trials—WATCHMAN is the most studied left atrial appendage closure (LAAC) device.

Long-term Results

Long-term results from PROTECT AF and PREVAIL demonstrated WATCHMAN reduced risk of disabling stroke, bleeding post procedure, and mortality vs. warfarin. 1, 2

55 percent

Relative Risk Reduction

In Disabling and Fatal Strokes1

72 percent

Relative Risk Reduction

In Major Bleeding 6-months Post Implant2

27 percent

Relative Risk Reduction

In All-Cause Mortality1

WATCHMAN is the Only FDA-Approved Device Proven to Reduce Stroke Risk in Patients with Non-Valvular Atrial Fibrillation (NVAF)

Five-year meta-analysis of Protect AF and Prevail data showed comparable primary efficacy results to wafarin1

  • Long-term results from a patient-level meta-analysis of the PROTECT AF (2,717 pt yrs) and PREVAIL (1,626 pt yrs) trials demonstrated that WATCHMAN offered1:
    • Comparable primary efficacy and all-cause stroke reduction
    • Statistically significant reductions in disabling and fatal stroke (largely driven by reduction in hemorrhagic stroke), as well as mortality
    • Notably, WATCHMAN has now demonstrated ischemic stroke reduction similar to that observed with warfarin in both the PROTECT AF and PREVAIL trials, as well as four additional registries, when accounting for differences in CHA2DS2-VASc score  

**Two strokes in PREVAIL are excluded because baseline MRS unavailable.
* Cardiovascular death is defined as a death from a cardiovascular event including sudden death, MI, cardiac arrhythmia, and heart failure. In addition, any death caused by an undetermined etiology will be cardiovascular.

WATCHMAN Comparable to Warfarin For Ischemic Stroke Risk Reduction4

Across seven studies WATCHMAN consistently demonstrated ischemic stroke risk reduction in line with warfarin and better than no therapy. 

Ischemic Stroke Risk (Events per 100 PT-Years)1, 4-9

WATCHMAN Is Proven To Reduce Risk of Disabling Strokes

At 5 years, WATCHMAN patients had a 55% lower relative risk of disabling or fatal strokes compared to patients treated with warfarin. 

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A meta-analysis revealed that WATCHMAN reduced relative risk of hemorrhagic stroke by 80%, which are often disabling or fatal.

80 percent

Relative Risk Reduction in Hemorrhagic Stroke


Reduced Risk of Major Bleeding*

WATCHMAN has showed significant reductions in the risk of stroke in NVAF patients without the bleeding risks that come with a lifetime of anticoagulant use.

NOTE: Data are from five-year results from PROTECT AF and 2 year results from PREVAIL.

Freedom of Major Bleeding Over Three Adjunctive Pharmacotherapy Intervals2


major bleeds graph

* Major bleeding defined as adverse event that was assigned one of several bleeding codes and was adjudicated by an independent Clinical Events Committee as significant (life-threatening or resulting in hospitalization, prolongation of hospitalization, substantial disability, or death).

NOTE: Data are from five-year results from PROTECT AF and 2 year results from PREVAIL.

Reduced Mortality

At 5 years, WATCHMAN showed a 27% relative risk reduction in all-cause mortality versus warfarin.1

reduced mortality graph

Discontinued Use of OACs3

WATCHMAN enables patients to discontinue oral anticoagulant (OAC) medications.

92 percent graph

of patients were able to discontinue warfarin after 45 days

99 percent graph

of patients were able to discontinue warfarin after 1 year



  1. Reddy VY, Doshi SK, Kar S, et al. 5-year outcomes after left atrial appendage closure. J Am Coll Cardiol. 2017;70(24):2964-2975.
  2. Price MJ, Reddy VY, Valderrábano M, et al. Bleeding outcomes after left atrial appendage closure compared with long-term warfarin: a pooled, patient-level analysis of the WATCHMAN randomized trial experience. JACC Cardiovasc Interv. 2015;8(15):1925-1932. 
  3. Holmes DR Jr, Kar S, Price MJ, et al. Prospective randomized evaluation of the Watchman Left Atrial Appendage Closure device in patients with atrial fibrillation versus long-term warfarin therapy: the PREVAIL trial. J Am Coll Cardiol. 2014;64(1):1-12. 
  4. Friberg. Eur Heart J (2012);
  5. Reddy VY, et al. JACC 2017; 70(24): 2964-2975. 
  6. NICE UK (2014). 
  7. Phillips K, et al. ILC Heart & Vasculature 2019; 23(100358). 
  8. Boersma LVA, et al. Circ Arrhy Electrophysiol. 2019; 12e006841. 
  9. Sharma D, et al. JACC 2016; 67(18): 2190-2192.



CAUTION: Federal law (USA) restricts this device to sale by or on the order of a physician. Rx only. Prior to use, please see the complete “Instructions for Use” for more information on Indications, Contraindications, Warnings, Precautions, Adverse Events, and Operator’s Instructions.


The WATCHMAN FLX Device is indicated to reduce the risk of thromboembolism from the left atrial appendage in patients with non-valvular atrial fibrillation who:

  • Are at increased risk for stroke and systemic embolism based on CHADS2 or CHA2DS2-VASc scores and are recommended for anticoagulation therapy;
  • Are deemed by their physicians to be suitable for anticoagulation therapy; and
  • Have an appropriate rationale to seek a non-pharmacologic alternative to anticoagulation therapy, taking into account the safety and effectiveness of the device compared to anticoagulation therapy.


Do not use the WATCHMAN FLX Device if:

  • Intracardiac thrombus is present.
  • An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present.
  • The LAA anatomy will not accommodate a Closure Device (see Table 45 of the eIFU).
  • The patient has a known hypersensitivity to any portion of the device material or the individual components (see Device Description section of the eIFU) such that the use of the WATCHMAN FLX Device is contraindicated.
  • Any of the customary contraindications for other percutaneous catheterization procedure (e.g., patient size too small to accommodate TEE probe or required catheters) or conditions (e.g., active infection, bleeding disorder) are present.
  • There are contraindications to the use of anticoagulation therapy, aspirin, or P2Y12 inhibitor.


Implantation of the WATCHMAN FLX Device should only be performed by interventional cardiologists and/ or electrophysiologists who are trained in percutaneous and transseptal procedures and who have completed the WATCHMAN FLX Physician Training program.

  • This device has not been studied in pregnant or breastfeeding women. Careful consideration should be given to use of the Closure Device in pregnant and/ or breastfeeding women due to the risk of significant exposure to x-rays and the use of anticoagulation medication.
  • Device selection should be based on accurate LAA measurements obtained using echocardiographic imaging guidance in multiple views (TEE recommended in multiple angles [e.g., 0°, 45°, 90°, 135°]) to avoid improper Closure Device sizing.
  • Do not release (i.e., unscrew) the WATCHMAN FLX Device from the core wire unless all release criteria are satisfied to avoid suboptimal results.
  • Potential for Closure Device embolization exists with cardioversion < 30 days following Closure Device implantation; verify Closure Device position after cardioversion during this period.
  • Appropriate post-procedure drug therapy should be followed. See Post-Procedure Information section (of the eIFU) for further detail.


  • The safety and effectiveness (and benefit-risk profile) of the WATCHMAN FLX Device has not been established in patients for whom long-term anticoagulation is determined to be contraindicated.
  • The LAA is a thin-walled structure. Use caution when accessing the LAA, and deploying, recapturing, and repositioning the Closure Device.
  • Use caution when introducing a WATCHMAN Access System to prevent damage to cardiac structures.
  • Use caution when introducing the Delivery System to prevent damage to cardiac structures.
  • To prevent damage to the Delivery Catheter or Closure Device, do not allow the WATCHMAN FLX Device to protrude beyond the distal tip of the Delivery Catheter when inserting the Delivery System into the Access Sheath.
  • If using a power injector, the maximum pressure should not exceed 100 psi.


In considering the use of the WATCHMAN FLX Device, the rationale for seeking an alternative to long-term anticoagulation therapy and the safety and effectiveness of the device compared to anticoagulation should be taken into account.

  • The presence of indication(s) for long-term anticoagulation therapy, other than non-valvular atrial fibrillation (e.g. mechanical heart valve, hypercoagulable states, recurrent deep venous thrombosis).

Details regarding the indications, contraindications, warnings, and precautions for oral anticoagulants approved for patients with non-valvular atrial fibrillation are provided in their respective Instructions for Use. Of note:

  • The safety and effectiveness (and benefit-risk profile) of the WATCHMAN FLX Device has not been established in patients for whom long-term anticoagulation is determined to be contraindicated.

Factors that need to be considered for the WATCHMAN FLX Device and implantation procedure include the following:

  • Overall medical status, including conditions which might preclude the safety of a percutaneous, transcatheter procedure.
  • Suitability for percutaneous, transseptal procedures, including considerations of:
    • Cardiac anatomy relating to the LAA size and shape.
    • Vascular access anatomy (e.g., femoral vein size, thrombus, or tortuosity).
    • Ability of the patient to tolerate general or local anesthesia.
    • Ability of the patient to undergo required imaging.
    • Ability to comply with the recommended post-WATCHMAN FLX Device implant pharmacologic regimen (see Post-Procedure Information section) especially for patients at high risk for bleeding.


Potential adverse events (in alphabetical order) which may be associated with the use of a left atrial appendage closure device or implantation procedure include but are not limited to:

  • Air embolism
  • Airway trauma
  • Allergic reaction to the contrast media, anesthetic, WATCHMAN Implant material, or medications
  • Altered mental status
  • Anemia requiring transfusion
  • Anesthesia risks
  • Angina
  • Anoxic encephalopathy
  • Arrhythmias
  • Atrial septal defect
  • Bruising, hematoma, or seroma near the catheter insertion site
  • Cardiac perforation
  • Chest pain discomfort
  • Confusion post procedure
  • Congestive heart failure
  • Contrast related nephropathy
  • Cranial bleed
  • Death
  • Decreased hemoglobin
  • Deep vein thrombosis
  • Device embolism
  • Device fracture
  • Device thrombosis
  • Edema
  • Embolism
  • Excessive bleeding
  • Fever
  • Fistula
  • Groin pain
  • Groin puncture bleed
  • Hematuria puncture
  • Hemoptysis
  • Hypotension
  • Hypoxia
  • Improper wound healing
  • Inability to reposition, recapture, or retrieve the device
  • Infection/pneumonia
  • Interatrial septum thrombus
  • Intratracheal bleeding
  • Major bleeding requiring transfusion
  • Misplacement of the device/improper seal of the appendage/movement of device from appendage wall
  • Myocardial erosion
  • Nausea
  • Oral bleeding
  • Pericardial effusion/tamponade
  • Pleural effusion
  • Prolonged bleeding from a laceration
  • Pseudoaneurysm
  • Pulmonary edema
  • Renal failure
  • Respiratory insufficiency/failure
  • Stroke - Hemorrhagic
  • Stroke - Ischemic
  • Surgical removal of the device
  • TEE complications (e.g., throat pain, bleeding, esophageal trauma)
  • Thrombocytopenia
  • Thrombosis
  • Transient ischemic attack (TIA)
  • Valvular or vascular damage
  • Vasovagal reactions

There may be other potential adverse events that are unforeseen at this time.

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