接受香豆素治療的台灣病患其治療範圍內之時間

The Time in Therapeutic Range (TTR) in Patients Receiving Warfarin Therapy in Taiwan

治療範圍內時間(time in therapeutic range, TTR)是對於接受香豆素治療的病患以維持國際標準化比值(international normalized ratio, INR)在目標範圍內一種不可缺少的工具。好的TTR可預防接受香豆素治療的病人因不適當的藥物劑量而導致併發症事件發生。故本研究之目的是評估在台灣病患中的一般TTR數值為何。我們蒐集自2013年1月至2014年12月接受香豆素治療並有定期回診的門診病患臨床資料與其凝血酶原時間／INR資料，並依照病患診斷的疾病以心房震顫、心臟瓣膜置換術、二尖瓣狹窄、血栓栓塞疾病以及其他疾病等將之分類以計算個別的TTR。此外，併發症事件也藉由電子病歷審視被記錄。結果顯示，在目標INR範圍1.5至2.5時，整體TTR中位數值約為52%，當TTR小於60%時，發生出血併發症事件的風險會增加，發生血栓栓塞併發事件的風險則無顯著改變。據我們所知，這是在台灣有關以不同需要以香豆素治療的疾病其個別TTR值的第一份報告。醫師可以建立一個治療策略並與藥劑師以及醫檢師建立良好溝通，使接受香豆素治療的病患能夠達到更好的TTR值。

The time in therapeutic range (TTR) was an indispensible tool to maintain a target international normalized ratio (INR) range for patients under warfarin treatment. A good TTR prevented patients from complication events according to inappropriate warfarin dosage. The aim of this study was to evaluate the generalized TTR in Taiwanese patients. All prothrombin time/ INR test requests for patients receiving warfarin therapy at outpatient clinics from January 2013 to December 2014 were collected. The diagnosed diseases were categorized by atrial fibrillation, heart valve replacement, mitral stenosis, thromboembolic disorders, and miscellaneous. The individual TTR values were calculated. Events of complications were also reviewed via the electronic chart review. The results revealed that general median TTR value was about 52% at a target INR of 1.5 to 2.5 in the Taiwanese patients. A TTR of 60% and less was associated with the risk of developing bleeding events rather than thromboembolic complications. To our best knowledge, this is the first report of TTR in perspective of diseases necessitated by warfarin treatment in the Taiwanese patients. Physician may establish a therapeutic strategy and communicate intensively with pharmacist and medical technologist for patients receiving warfarin therapy to approach better TTR values.