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HelixTalk Episode #62 - Devices not drugs: stroke risk reduction in atrial fibrillation

Date posted: June 13, 2017, 6:00 am

In this episode, we discuss the pathophysiology of embolic stroke in patients with atrial fibrillation and review the use of left atrial occlusion devices, such as the WATCHMAN device, to reduce the risk of stroke in patients with atrial fibrillation without the use of anticoagulants like warfarin.


Key Concepts

  1. Patients with atrial fibrillation are at risk for embolic stroke because blood clots can form in the left atrial appendage (LAA) and travel to the brain, causing a stroke.
  2. In patients with a CHADS2-VASC score of 1 to 2 or more, anticoagulation with warfarin or direct oral anticoagulants (DOACs) is the primary method of reducing the risk of stroke.
  3. For patients who are not good candidates for anticoagulation, the WATCHMAN device (and other LAA occlusion devices) may reduce the risk of stroke similarly to full anticoagulation.
  4. The implantation procedure does carry some risk (primarily pericardial effusion), but the lack of long-term anticoagulation if the device is successful confers a reduced risk of hemorrhage versus traditional long-term anticoagulation. 


  1. PROTECT AF study: Holmes DR, Reddy VY, Turi ZG, et al. Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: a randomized non-inferiority trial. Lancet. 2009 Aug 15;374(9689):534-42. doi: 10.1016/S0140-6736(09)61343-X. PubMed link.
  2. PREVAIL study: 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 Jul 8;64(1):1-12. doi: 10.1016/j.jacc.2014.04.029. PubMed link.