Frontiers of anticoagulation therapy for atrial fibrillation.

In the management of atrial fibrillation (AF), stroke prevention has been proved to play a pivotal role in addition to therapy for concomitant diseases. And, hitherto, anticoagulation by warfarin has been the only effective choice that is known to decrease the stroke rate with ∼70% risk reduction. Although the evidence has been rigid, there are many barriers not to make warfarin therapy pervasive. However, the principle of "KISS (keep it short and simple)" seems to alter our situations. Changing the complex pharmacology with warfarin into the simple pharmacology with new anticoagulants would lead us to a new paradigm, where the old book is now rewritten by a new language.