Warfarin for non-rheumatic atrial fibrillation: five year experience in a district general hospital

Abstract

Objectives: To assess the long term efficacy of and risks associated with computer aided oral anticoagulation for non-rheumatic atrial fibrillation (NRAF) in a district hospital setting. Design: Retrospective, age stratified, event driven clinical database analysis. Setting: District general hospital. Participants: 739 patients receiving warfarin for NRAF between 1996 and 2001. Patients were selected from an anticoagulation database through appropriate filter settings. Main outcome measures: Anticoagulation control (international normalised ratio (INR)) and hospitalisations for bleeding complications, thromboembolic events, and stroke. Results: Over 1484 patient-years, computer assisted anticoagulation was uncontrolled in 38.3% of patients (INR , 2.0 or . 3.0). No significant differences in INR control were observed with respect to patient age (, 65, 65-75, and . 75 years), although to achieve adequate control of anticoagulation, the frequency of testing increased significantly with age. Annual risks of bleeding complications, thromboembolism, and stroke were 0.76%, 0.35%, and 0.84%, respectively. No significant differences in these events were observed between the three age groups studied. Patients who had thromboembolic events and haemorrhagic complications were significantly more likely to have been under-anticoagulated (INR , 2.0) and over-anticoagulated (INR . 3.0), respectively, at the time of their clinical event.Conclusions: Computerised long term oral anticoagulation for NRAF in a community setting of elderly and diverse patients is safe and effective. Anticoagulation control, bleeding events, thromboembolic episodes, and stroke rates are directly comparable with those reported in major clinical trials. The authors therefore support the strategy of rate control with long term oral anticoagulation for NRAF in general clinical practice.

Adherence and Quality of Oral Anticoagulation in Cerebrovascular Disease Patients with Atrial Fibrillation

“…The quality of OAC at follow-up was moderate, and more than half of all patients reported at least one coagulation parameter outside the therapeutic window at some time during the preceding 3 months. Although this rate is within the range reported in previous hospital-based studies [7, 20, 21], it still raises concern about the effectiveness of OAC in daily routine. Nevertheless, the rate of recurrent stroke was about 2% and comparable to a nonrandomized as well as large randomized studies in patients with AF [22, 23], while the rate of intracranial hemorrhage is of limited value due to only 2 observations (1 subdural and 1 intracranial) leading to wide confidence intervals.…”

Quality of Wafarin Control Affects the Incidence of Stroke in Elderly Patients with Atrial Fibrillation

“…Connolly et al reported that the benefit of anticoagulation was demonstrated only at medical centers where the average TTR for the standard range (2.0-3.0) of PT-INR was above 65% in the ACTIVE W trial, and the estimated minimum TTR threshold to distinguish the centers was 58% (16). In addition, it was suggested that TTR was about 50% in clinical practice (17)(18)(19).…”

Age and the Risk of Warfarin‐Associated Hemorrhage: The Anticoagulation and Risk Factors In Atrial Fibrillation Study

“…Rates ranged from 0.76% per year 19 to approximately 10% per year in a study of patients aged 75 and older. 20 Prior studies have also provided conflicting data on whether older age is a risk factor for warfarin-associated hemorrhage.…”