心房細動における脳梗塞の予防

The Prevention of Brain Infarction in Patients with Atrial Fibrillation

はじめに

　心房細動は心原性脳塞栓症の塞栓源として重要である。心房細動の基礎疾患として，リウマチ性弁膜症が減少し，代わって高齢者に多い非弁膜性心房細動（non-valvular atrial fibrillation: NVAF）が増加している^1）。NVAFは心原性脳塞栓における塞栓源の主座を占め，近年，特に高齢者の脳梗塞の原因として注目されている^2，3）。本稿ではNVAFからの脳梗塞の予防を中心に概説する。

Abstract

　The patients with cardioembolic stroke sometimes suffer from severe neurological deficit and from recurrent strokes. Since atrial fibrillation, especially non-valvular atrial fibrillation (NVAF) is associated with over half of the cardioembolic strokes, the prevention of cardioembolic stroke in patients with NVAF is important. There have been some reports about how to prevent stroke. They have indicated that the best medication for preventing from stroke was anticoagulation by warfarin. Therefore, the guidelines recommended the patients with NVAF to take warfarin. In case with the older patients under 70 years, prothrombin international normalized ratio (PT-INR) should be kept from 2.0 to 3.0. On the other hand, if the patients with NVAF are over 70 years,PT-INR has to be controlled from 1.6 to 2.6. Before extraction of a tooth, anticoagulation should not be call off.