2026 Southeastern Residency Conference

Comparing Safety and Efficacy of Subcutaneous Unfractionated Heparin Dosing Frequencies for Venous Thromboembolism Prophylaxis in a Community Hospital
Authors: Jonathan Johnson, Adam Harnden, Madison Sanders, M. Trey Dailey, Nancy Bailey, Matthew Hadley
Background: Venous thromboembolism (VTE) is a major cause of in-hospital morbidity and mortality with an estimated 375,000 new cases and approximately 100,000 deaths annually in the United States. Patients in the hospital are at a higher risk of developing VTE due to underlying conditions and acute illness. Using unfractionated heparin (UFH) to prevent VTE is an appropriate choice of therapy to decrease the risk of VTE events and death; however, there is not a consensus on administration frequencies. This study aimed to assess the safety and efficacy between dosing strategies in patients that were admitted to a community hospital.
Methods: This retrospective, institutional review board approved study, was conducted at a 344-bed community hospital in Montgomery, Alabama. A clinical decision support tool was utilized to identify patients receiving UFH 5,000 units subcutaneously twice daily (BID) or three times daily (TID) between January 1, 2024 to December 31, 2024. Patients included in the study were at least 19 years old, non-surgical, and received prophylactic UFH 5,000 units for at least 48 hours dosed either BID or TID. Patient populations excluded were pregnant patients, trauma patients, those on continuous renal replacement therapy, those who had a major bleed upon admission, therapeutic anticoagulation doses for more than 12 hours, received low molecular weight heparin or fondaparinux, or if patients received both UFH dosing schedules for at least 48 hours. Patients were separated into two cohorts of UFH dosing: BID or TID. The primary endpoint of this study was the incidence of VTE events. Secondary endpoints included incidence of the individual components of VTE: deep vein thrombosis and pulmonary embolism. Other secondary endpoints included major and minor bleeding, heparin-induced thrombocytopenia, hospital length of stay (LOS), hospital re-admission, and in-hospital mortality. Data for the study were collected from an on-site secure electronic medical record where patient information was reviewed. Power was calculated through an open-access statistical analysis software such that 120 patients were required to reach 90% power. Appropriate statistical tests were applied to analyze data as well as appropriate use of descriptive statistics.
Results: A total of 140 patients were included in this study with 70 patients in each arm, meeting protocol. A total of 156 patients were excluded with the majority due to not receiving doses for at least 48 hours.  The primary outcome, incidence of VTE, occurred in 1/70 (1%) patients in the TID dosing group compared to no incidence of VTE in the BID group (P=1). The incidence of VTE that occurred in the TID group was due to a deep vein thrombosis. Major bleeding occurred in 1/70 (1%) patients in the TID group and minor bleeding occurred in 1/70 patients (1%) of both the BID and TID groups. Re-admission rates occurred in 35 patients in the BID group compared to 23 patients in the TID group (P=0.06). Incidence of in-hospital mortality occurred in 3 patients in the BID group compared to 10 patients in the TID group (P=0.08). Mean number of days for LOS was 7.94 for the BID group and 10.57 for the TID group (P=0.13).
Conclusion: In this study, patients receiving UFH 5,000 units for VTE prophylaxis had similar safety and efficacy endpoints when comparing BID and TID dosing. Limitations of this study include being a single center study that relied on medical record documentation and having difficulty in extrapolating the results due to the prevalence of hospital acquired VTE.