Tak-Yeung Chan1, Ka-Ying Miu. 1. Department of Medicine and Geriatrics, Kwong Wah Hospital, Koweloon, Hong Kong, PROC. mty_chan@yahoo.com
Abstract
BACKGROUND: Oral anticoagulants have an expanding role in cardiovascular and thrombotic disorders. Few data are available describing their safety among Chinese patients. We aim to evaluate the incidence of major and minor bleeding complications among Chinese patients receiving long term anti coagulants in community practice. METHODS: A retrospective cohort study was undertaken in a regional hospital. All patients who were initiated on warfarin from January 1, 1998 to December 31, 1998 were enrolled. Out-patient medical charts were reviewed for demographic data, clinical characteristics and adequacy of anticoagulation. Major and minor bleeding complications were documented. RESULTS: A total of 131 patients were identified. The mean age was 67.8 (SD 11.9) years and 52.6% were women. The mean duration of follow-up was 2.2 years (SD 1.1). Major indications for warfarin were: non-valvular atrial fibrillation (60%), venous thrombosis (17%) and rheumatic heart disease (16%). The subjects spent 50% of their total time within target international normalized ratio range. The average annual rates for major and minor bleeding events were 1.8% (95% confidence interval 0.6 to 4.1%) and 18.5% (95% confidence interval 13.9 to 24.2%), respectively. The cumulative incidences of first major and minor bleeding events at 1, 2 and 3 years were 3%, 4%, 5% and 15%, 24% and 37%, respectively. Intensity of anticoagulation was the only predictive factor identified to be associated with bleeding complications. CONCLUSIONS: Among Chinese patients receiving long-term warfarin, major hemorrhage occurred at an acceptable range in clinical practice, while considerable minor bleeding was observed. Utilization of oral anticoagulants in Chinese patients appears safe and should be advocated in situations with appropriate indications.
BACKGROUND: Oral anticoagulants have an expanding role in cardiovascular and thrombotic disorders. Few data are available describing their safety among Chinese patients. We aim to evaluate the incidence of major and minor bleeding complications among Chinese patients receiving long term anti coagulants in community practice. METHODS: A retrospective cohort study was undertaken in a regional hospital. All patients who were initiated on warfarin from January 1, 1998 to December 31, 1998 were enrolled. Out-patient medical charts were reviewed for demographic data, clinical characteristics and adequacy of anticoagulation. Major and minor bleeding complications were documented. RESULTS: A total of 131 patients were identified. The mean age was 67.8 (SD 11.9) years and 52.6% were women. The mean duration of follow-up was 2.2 years (SD 1.1). Major indications for warfarin were: non-valvular atrial fibrillation (60%), venous thrombosis (17%) and rheumatic heart disease (16%). The subjects spent 50% of their total time within target international normalized ratio range. The average annual rates for major and minor bleeding events were 1.8% (95% confidence interval 0.6 to 4.1%) and 18.5% (95% confidence interval 13.9 to 24.2%), respectively. The cumulative incidences of first major and minor bleeding events at 1, 2 and 3 years were 3%, 4%, 5% and 15%, 24% and 37%, respectively. Intensity of anticoagulation was the only predictive factor identified to be associated with bleeding complications. CONCLUSIONS: Among Chinese patients receiving long-term warfarin, major hemorrhage occurred at an acceptable range in clinical practice, while considerable minor bleeding was observed. Utilization of oral anticoagulants in Chinese patients appears safe and should be advocated in situations with appropriate indications.