Bleeding complications to long-term oral anticoagulant therapy

Abstract

Objective: To evaluate the incidence of bleeding complications in recent randomized trials on oral anticoagetlant treatment for prevention of arterial thromboembolism. Data sources: International publications on studies of prevention. of arterial thromboembolism by oral anticoagulant therapy. Study selection and data extraction: Randomized trials an oral anticoagulant therapy in patients with atrial fibrillation, recent myocardial infarction, and prosthetic heart valves were selected. For comparison older nonrandomized studies were studied. Background: Oral anticoagulant drugs are recommended for primary prevention of thromboembolic events in patients with chronic atrial fibrillation, recent myocardial infarction, and prosthetic heart valves. Still many physicians hesitate to prescribe anticoagulant drugs, presumably for fear of bleeding complications. Results: In six recent trials of warfarin in patients with atrial fibrillation, the highest annual incidence of fatal and major bleeding was 0.8% and 2.0%, respectively. In patients treated with warfarin after a recent myocardial infarction, the incidence of fatal and major bleeding was 0.2% and 0.5% per year, respectively. The annual incidence of fatal and major bleeding in patients with prosthetic heart valves on warfarin treatment was found to be 1.4% and 5.2%, respectively. The mean incidence of fatal and major bleeding in patients on warfarin in these eight trials was 0.5% and 1.7% per year, respectively. The mean incidence of fatal and major bleeds in patients on placebo was 0.1% and 0.7% per year, respectively. In three randomized trials evaluating aspirin versus warfarin, the respective mean incidences of fatal and major bleeding during aspirin treatment were 0.2% and 0.8% per year. A remarkable decrease in the incidence of major bleeding complications to oral anticoagulant therapy is revealed by these trials as compared to previous studies. Reasons for this decline may be less intensive anticoagulant regimes, better control of anticoagulant therapy due to the introduction of the international normalized ratio, and careful pretreatment evaluation of risk factors for bleeding. In alI prospective trials of oral anticoagulation, the risk of bleeding was more than over-weighed by the beneficial effect on the incidence of stroke and peripheral thromboemboli.

All-Cause and Bleeding-Related Health Care Costs in Warfarin-Treated Patients with Atrial Fibrillation

“…25,26 However, the prevalence rates of major GI or IC bleeding events in the present study sample were slightly higher than those observed in previously published clinical trials. In a recent meta-analysis of the efficacy and safety of antithrombotic therapy in AF, the incidence rates for IC and major extracranial hemorrhage for patients receiving adjusteddose warfarin therapy were 0.2% and 1.0%, 27 compared with 0.4% and 1.9% in the present study.…”

The effects of aspirin and warfarin therapy on haemorrhage in vitreoretinal surgery

“…In a review of trials to evaluate haemorrhaging during warfarin therapy, the mean incidence of fatal and major haemorrhaging was 0.5% and 1.7% per year, respectively (Gullov et al 1994). Therefore, it is not surprising that surgeons worry about the possibility of sight-threatening complications due to intra or postoperative haemorrhaging.…”

Determination of Plasma Warfarin Concentrations in Korean Patients and Its Potential for Clinical Application

“…•이경훈 2 •손기호 3 •조현정 5 •온영근 4 •김준수 4 •이수연 1,3 성균관대학교 의과대학 삼성서울병원 진단검사의학교실 1 •분자세포생물학교실 2 •내과 4 •임상약리학, 임상시험센터 3 , 건양대학교 의과대학 진단검사의학교실 5 …”

“…Inadequate or excessive anticoagulation may result in substantial morbidity and mortality due to thromboembolic complications or bleeding [3,4]. Life-threatening bleeding episodes after initiation of warfarin therapy have been reported in approximately 12% of patients; furthermore, elderly patients are especially vulnerable to such events, and there is also a substantial risk of developing warfarin resistance [5][6][7][8][9].…”