Atrial Fibrillation (AFib) is an irregular heart rhythm that significantly increases the risk of blood clot formation in the heart and thereby posing an elevated risk of ischemic (blockage-type) strokes through dislodging of such blood clots from the heart to brain vessels. Carefully conducted studies since 1990s established the role of anticoagulants in decreasing the risk of blood clot formation, therefore lowering ischemic stroke risk. Warfarin, dabigatran, rivaroxaban, apixaban, and edoxaban are approved by FDA to decrease stroke risk in patients with atrial fibrillation not related to significant heart valve problems. This type called non-valvular atrial fibrillation is common, affecting 2.7–6.1 million people in the United States. The most feared complication of these anticoagulants is brain bleeding, this fear limits the use of these important drugs.
In patients with non-valvular atrial fibrillation who can tolerate anticoagulant use for 6 weeks or longer in whom there is an increased risk of bleeding, a new FDA-approved procedure, namely left atrial appendage closure (LAAC) using WATCHMAN device can eliminate the need for life-long anticoagulation while decreasing the risk of ischemic strokes. As any other interventional procedure, the qualifications and skills of the operator and their team matter for successful implantation of the device without complications. This device is placed in a small unused annex of the left atrium of the heart, ie the left atrial appendage. The left atrial appendage is unused after the birth but its connection to the circulation and its anatomy make it the most common site of blood clot formation in patients with non-valvular atrial fibrillation. Research showed that more than 90% of blood clots are formed in left atrial appendage among patients with non-valvular atrial fibrillation. Clinical studies suggested that closing the left atrial appendage can relieve the patient from using warfarin and dual antiplatelet medications about 6 months after a successfully performed procedure in carefully selected patients. LAAC indeed requires an interventional procedure with some potential risks including damaging the vessels, the heart and its surroundings (~1%) as well as other small but serious risks of dislodgment of the device (0.24%), stroke (0.08%) or death (0.08%) but this approach does not require surgery. The small WATCHMAN device is pushed through a catheter advanced to the heart from a vessel in the groin. After going from the right atrium to the left atrium through what is called septal puncture, this device is placed in the left atrial appendage to seal it off from the left atrium. An advanced and somehow invasive imaging method called transesophageal echocardiography (TEE) is used during the procedure in order to make sure that the catheter and device are correctly manipulated and the device is placed where it needs to go. The device may not be able to be implanted in up to 5% of procedures if the anatomy of the left atrial appendage is not suitable. Typically the patient uses warfarin (with target INR 2-3) and aspirin for about 6 weeks after the procedure. If a TEE performed around 6 weeks after the procedure shows "good seal" defined as either no communication between the left atrial appendage and left atrium or a very small communication (jet) less than 5mm in diameter, than warfarin is stopped and patient uses a combination of aspirin and clopidogrel antiplatelets for 4.5 months. If everything goes well at the end of this period (about 6 months after the procedure), the patient is kept on aspirin only, stopping clopidogrel as well.
As summarized above, the left atrial appendage closure with WATCHMAN device is only indicated for patients with atrial fibrillation who do not have significant heart valve disease (non-valvular AFib) or heart failure. There are other exclusion criteria. There still is a need to use anticoagulation for few weeks and patient needs to take aspirin life-long but that indeed might be better than life-long use of a stronger blood thinner (anticoagulant) for patients at higher baseline brain bleeding risk. Discussing he risks and benefits of different management approaches with experts not only in Cardiology but also Stroke Neurology would be beneficial in order to select the best management approach. Use of warfarin or the newer anticoagulants are options, especially in patients at lower bleeding risk. The newer anticoagulants were associated with a significantly lower brain bleeding risk in a general population but their safety in patients with a high baseline brain bleeding risk is unknown. The problem with these medical therapies is that they need to be used lifelong making them a potential constant risk factor for bleeding while missing few doses might increase the risk of ischemic (blockage-type) strokes as well. The potential advantages (no need for life-long anticoagulation with its known risks) and disadvantages (possibility of procedural complications, less well known long-term results) of the left atrial appendage closure procedures should be carefully discussed.
It should be remembered that there is no medication or procedure that can zero the risk of ischemic or bleeding type stroke in atrial fibrillation or any other stroke-related condition. Physicians try to minimize these risks by encouraging the most appropriate treatments for individual patients but the risks always exist. There might be other risks or benefits than from what is discussed on this website by using medical or interventional treatments.
Management of the atrial fibrillation patient with a high baseline brain bleeding risk requires close collaboration between the patient/family and a multidisciplinary group of expert physicians. Shared decision making approaches that aim to answer patient/family's questions using the highest level of available scientific data and placing the patient's wishes to the center stage are very important. The Centers for Medicare & Medicaid Services (CMS) mandates a formal shared decision making interaction with an independent non-interventional physician to discuss alternatives including but not limited to WATCHMAN procedure and life-long anticoagulant use before a decision to perform left atrial appendage closure can be taken. Details can be accessed from the following link to CMS' website