Impact of an Inpatient Anticoagulation Management Service on Clinical Outcomes

Abstract

Background: Antithrombotic medications require careful management to avoid thrombotic or hemorrhagic complications. The benefits of specialized anticoagulation management services (AMS) in the outpatient setting are well established; less evidence of benefit in the hospital setting is available. Objective: To evaluate the clinical benefits of an inpatient AMS to cardiac surgery patients requiring warfarin anticoagulation therapy. Methods: After obtaining institutional review board approval, we conducted a retrospective, single-center, cohort study of consecutive cardiac surgery patients treated before (January 2003–May 2005) and after (June–December 2005) establishment of an inpatient AMS. Demographic and clinical characteristics as well as laboratory and clinical data were retrieved from institutional electronic databases and compared between the 2 patient cohorts. Comparisons between study groups were conducted using a χ2 or Fisher's Exact test for categorical variables and a Student's t-test for continuous variables. Analysis of rare event data was conducted using Poisson regression analysis. Results: Of 1919 patients admitted during the study interval, 826 received warfarin (674 pre-AMS, 152 post-AMS). The number of patients with postsurgical panic international normalized ratio (INR) values declined after initiation of the AMS (pre-AMS 90/674 [13.4%] vs post-AMS 11/152 [7.2%]; p = 0.036). There was a trend toward fewer clinically significant postoperative bleeding events (pre-AMS 21/674 [3.1%] vs post-AMS 2/152 [1.3%]; p = 0.22) and fewer repeat surgeries for late postoperative bleeding (pre-AMS 8/674 [1.2%) vs post-AMS 0/152 [0%]; p = 0.08). AMS intervention was associated with a 17% decrease in the average postsurgical length of stay (13.9 days vs 11.6 days; p = 0.015). Conclusions: A multidisciplinary AMS can improve anticoagulation management, leading to fewer panic INR values and a reduced length of hospital stay.