Scientific Poster Session III - Original Research

Abstract

Research Question or Hypothesis: Compare the rates of venous thromboembolism (VTE) and major or clinically relevant non-major bleeding in underweight hospitalized patients on standard-dose UFH and LWMH versus low-dose.

Study Design: Retrospective, single-center, cohort study

Methods: Adult underweight (BMI < 18.5 or weight < 50 kilograms) patients from 2020-2022 receiving UFH or LMWH thromboprophylaxis for >/= 48 hours were included. Patients were excluded for CrCl < 30 mL/min, COVID-19 treatment, or admission for trauma, VTE, or major bleed. Low-dose thromboprophylaxis was defined as subcutaneous UFH < 15,000 units/day or LMWH < 40 milligrams/day. Patients were matched 1:1 to standard-dose thromboprophylaxis patients, defined as UFH 5,000 units TID or LMWH 40 mg daily. Descriptive statistics were performed via Stata/MP v17 followed by use of t-tests, Mann-Whitney U, Fisher’s exact or Pearson chi-squared tests to compare appropriate data points. Statistical significance threshold was set at ?<0.05.

Results: 280 patients were included for analysis: 140 patients in each group. The low-dose group had a higher rate of previous VTE (p=0.036). Four VTE events occurred, 3 in the low-dose group and 1 in the standard-dose group(p = 0.622). Five bleeding events occurred; 1 in the low-dose group and 4 in the standard-dose group (p = 0.370). Of the bleeding events, 3 were major bleeds in the standard-dose group.

Conclusion: The utilization of low-dose UFH and LMWH in underweight hospitalized patients resulted in lower rates of bleeding, but higher rates of thrombosis. Given the numerical differences in major bleeding, risks and benefits of an empiric low-dose thromboprophylaxis strategy should be carefully considered.

Presenting Author

Authors