Impact of a Pharmacist-Directed Anticoagulation Service on the Quality and Safety of Heparin-Induced Thrombocytopenia Management

BACKGROUND: The use of anticoagulant medications is complex and prone to error in the inpatient setting. Patients with heparin-induced thrombocytopenia (HIT) must receive treatment with alternative anticoagulant agents to ensure optimal patient outcomes. OBJECTIVE: To evaluate the impact of an inpatient pharmacist-directed anticoagulation service (PDAS) on the safety and efficiency of direct thrombin inhibitor use in patients with HIT. METHODS: This was a quasi-experimental pre/postintervention study comparing patients with HIT managed with usual care to patients managed with a focused inpatient anticoagulation service. The primary endpoints of the study were the percent of time that the activated partial thromboplastin time (aPTT) remained within the therapeutic range and time to achievement of a therapeutic aPTT. Bleeding and appropriateness of warfarin initiation were evaluated as secondary endpoints. RESULTS: A total of 193 patients were included in the study. Percent of time that aPTT was in the therapeutic range was 32% higher with the PDAS (p < 0.001) and time to therapeutic aPTT was shortened by approximately 12.5 hours in patients managed by the PDAS (p < 0.001). There was a trend for more bleeding events, regardless of severity, among control patients (p = 0.130). Rate of TIMI (Thrombolysis in Myocardial Infarction) major bleeding was lower in the PDAS group (p = 0.006), but there was no significant difference between groups in GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) moderate/severe bleeding (p = 0.679). Appropriateness of warfarin initiation was also similar between groups. CONCLUSIONS: Implementation of a focused inpatient PDAS was associated with improved efficiency of dosing, improved monitoring, and low bleeding risk.