Novel Anticoagulants Eliminate the Need for Left Atrial Appendage Exclusion Devices

The justification for implanting a left atrial appendage (LAA) exclusion device is based on the assumption that the pathogenesis of stroke in every patient with atrial fibrillation (AF) is the embolism of clot from the LAA to the brain. This hypothesis, although true in some patients, is a simplistic view of a more complex disease. What is well established is that AF is often accompanied by hypertension, diabetes mellitus, systolic left ventricular dysfunction, vascular disease, and previous stroke, conditions that are independent risk factors for stroke.1 In an individual patient it is often impossible to determine which among these factors is responsible for a stroke. Of interest, AF may be the underlying cause of an ischemic stroke but may also go undetected, and lead to the erroneous diagnosis of cryptogenic stroke.2,3 The common pathogenesis of ischemic stroke is thrombosis, and anticoagulation is a highly effective preventative measure particularly when AF is present.4–8 Noteworthy, warfarin, against which the novel anticoagulants and Watchman device have been compared, is very effective for stroke prevention in patients with AF, with a reduction of up to 81% against placebo in open-label trials and 79% in the only completed double-blind trial.5,7 The novel anticoagulants (dabigatran, rivaroxaban, apixaban, and edoxaban) were developed primarily to obviate the difficulties of using warfarin. The expectation was to show noninferiority for both efficacy and safety compared with warfarin.9–12 In definitive clinical trials these agents have either exceeded or met expectations against warfarin. Dabigatran 150 mg twice daily (BID) and apixaban (5 mg BID down-titrated to 2.5 mg BID for age ≥80 years, body weight ≤60 kg, and serum creatinine ≥1.5 mg/dL) were superior in efficacy to well-controlled warfarin.13,14 Rivaroxaban (20 mg down-titrated to 15 mg …