Individualizing Thromboprophylaxis: From Fixed Doses to Targeted Low-Molecular-Weight Heparin Use

Venous thromboembolism (VTE), encompassing deep vein thrombosis and pulmonary embolism, constitutes a significant cause of postoperative morbidity and mortality among surgical patients. Despite the widespread use of low-molecular-weight heparin (LMWH) for thromboprophylaxis, conventional fixed-dose regimens frequently yield subprophylactic anti-factor Xa (anti-Xa) levels, particularly in individuals with obesity, renal impairment, or altered drug pharmacokinetics. These interindividual variations in LMWH pharmacodynamics underscore the need for personalized anticoagulant strategies. Anti-Xa-guided dosing has emerged as a strategy to individualize prophylaxis and optimize outcomes.

To summarize evidence on individualized LMWH thromboprophylaxis, focusing on anti-Xa-guided strategies, their clinical efficacy, and limitations in real-world implementation.

A systematic literature review was conducted to identify studies evaluating fixed-dose, weight-based, and anti-Xa-adjusted LMWH prophylaxis across trauma, surgical, intensive care, and oncology settings.

Across multiple studies, up to 87.7% of patients receiving fixed-dose LMWH were found to have subtherapeutic anti-Xa levels, particularly in surgical and obese cohorts. Dose adjustment based on anti-Xa monitoring was consistently associated with improved attainment of prophylactic levels and lower VTE incidence, without a significant increase in major bleeding events. However, heterogeneity in study design, small sample sizes, and the lack of large randomized trials limit broad clinical adoption.

Evidence supports the potential benefit of individualized LMWH dosing guided by anti-Xa monitoring in selected patient populations. Standardization of testing protocols and prospective validation are needed to enable widespread clinical application.