Compliance, frequency of target INR achievement and complications in patients on long term oral anticoagulant therapy

ABSTRACT

To assess compliance and achievement of target international normalized ratio [INR] in patients with a broad range of indications for long term oral anticoagulant therapy [OAT] with warfarin. Case-review of 50 patients on long term OAT. Department of Cardiology, Shifa International Hospital, July 2004-Dec 2004. Medical records of 50 patients on long term OAT for at least six months and being followed in the cardiology outpatient department [OPD] were reviewed. Data was collected and analyzed for indication for OAT, frequency of INR check, target INR achievement and subsequent complications. Descriptive statistics were used to detect frequencies. Out of a total of 50 patients, 30 [60%] were male and 20 [40%] were female. Majority of the patients [61%] belonged to the cities of Islamabad and Rawalpindi. 40.9% of the patients were getting their INR checked every 1-2 months. 20.5% were getting it checked every 2-4 months and a third [38.6%] was having their INR checked more than 4 months apart. Commonest indications for OAT were atrial fibrillation alone [25%], prosthetic heart valve alone [29.5%] or both [20%]. Average INR values were between 1-2 in 17 [38.6%], between 2-3 in 22 [50%] and more than 3 in 5 [11.4%] patients. Major complications occurred in 2 [4.6%] patients only. Majority of the patients on long term OAT were getting their INR checked latter than recommended with a third of the patients with INR checks more than 4 months apart. More than a third of the patients did not achieve their target INR. However, despite these suboptimal results, major complications occurred very infrequently