ABSTRACT
Stroke remains the leading cause of disability and the third leading cause of death.
Despite advances in treatment, the early and later outcomes remain poor with a high
rate of death and or disability. Strategies for prevention have assumed a central
role. Given the close relationship between advancing age, atrial fibrillation, and
increasing stroke, there is great interest in this large specific population of patients.
Although warfarin has been the cornerstone of therapy for stroke prevention in patients
with atrial fibrillation, it is often not used because of absolute or relative contraindications,
or is ineffective because of poor control of the international normalized ratio (INR).
The relative risk-benefit ratio of stroke prevention versus bleeding hazard plays
a central role in therapeutic decisions. New pharmacologic approaches have been studied,
most recently direct thrombin inhibitors. These drugs may be associated with less
bleeding than warfarin, although there continues to be incremental bleeding risk over
a patient's lifetime. In patients with nonvalvular atrial fibrillation, device strategies
are being tested. These are based upon the information that in such patients, stroke
arises from thrombus in the left atrial appendage in 90% of cases. Left atrial appendage
occlusion has now been tested in a randomized clinical trial. In this trial, device
closure was found to be noninferior to warfarin for prevention of all-cause stroke,
cardiac death, and systemic embolization. There was an early safety hazard typically
related to periprocedural pericardial effusions; however, subsequent experience has
continued to document excellent efficacy and improved safety profiles. New randomized
trials and registries continue to explore the potential for device placement as an
alternative to anticoagulant therapy for stroke prevention in this group of patients.
KEYWORDS
Atrial fibrillation - stroke prevention - left atrial appendage closure
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David R HolmesJr. M.D.
Professor of Medicine, Mayo Clinic
200 First Street SW, Rochester, MN 55905
eMail: holmes.david@mayo.edu
