AN OUTCOME STUDY OF BLEEDING COMPLICATIONS IN PATIENTS TREATED WITH WARFARIN FOR PULMONARY EMBOLUS AND OTHER CONDITIONS
D.M. Howarth*, L. Lan, P.A. Thomas, L.W. Allen, J.W. Leitch.
Departments of Nuclear Medicine and Cardiology, John Hunter Hospital, Newcastle, New South Wales.
Although the adverse effects of warfarin over dosage are well documented, there is an assumption that bleeding complications occur in the minority of treated patients. The aim of this descriptive study was to determine the incidence and nature of bleeding complications in patients treated with oral warfarin.
Seven hundred and seventeen patients referred for lung scintigraphy were followed for 18 to 30 months to determine clinical outcome. A total of 231 patients received warfarin for at least a three month period. One hundred and thirty-nine patients were treated for pulmonary embolus, 59 for deep vein thrombosis , 12 for ventricular thrombus, 8 for valvular heart disease, 6 for peripheral vascular disease, 5 for chronic arrhythmia and 3 for cerebrovascular disease. All mortality and morbidity data was determined by local physician contact, hospital case records, post-mortem data or information from the NSW registry of births, deaths and marriages.
The median patient age was 67 years (range 16-96 years). Fifty-seven percent of patients were female. Six patients (2.6%) died of haemorrhage directly attributed to anti-coagulation, 13 patients (5.6%) had serious but non-fatal bleeding, 13 patients (5.6%) had minor bleeding and two patients developed heparin-induced thromocytopaenia thrombosis syndrome prior to warfarin therapy. A significantly greater proportion of warfarin treated patients (n = 231) died of bleeding complications compared to non-anticoagulated patients (n = 486) (p=0.005, relative deviate test).
Bleeding complications were observed in a total of 32 patients (13.8%) and serious bleeding complications in 19 patients (8.2%). The risks associated with warfarin treatment are considerable.
