JOA - 2026-08-24 - Journal Article
Delayed Initiation of Low-Molecular-Weight Heparin Chemoprophylaxis Is Associated with Higher Risk of In-Hospital Screen-Detected Distal Deep Vein Thrombosis Following Hip Fracture Arthroplasty.
Hou W, Han Z, Kong J, Dong Q, Zhang Y, Feng X
Topics
Key Takeaway
In 2,639 hip fracture arthroplasty patients, LMWH initiation delayed ≥19 hours from admission increased screen-detected in-hospital VTE risk by 22.8% (aHR 1.228, 95% CI 1.036–1.456), with each additional hour of delay conferring a 0.3% incremental VTE risk increase.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This retrospective cohort study examined whether door-to-prophylaxis (DTP) time for LMWH independently predicts postoperative in-hospital VTE in hip fracture arthroplasty patients. Using restricted cubic splines and multivariable Cox regression, delayed DTP (≥19 hours, based on median split) was associated with a 22.8% higher VTE risk versus early DTP, with a linear dose-response of 0.3% increased risk per hour of delay. The association was driven entirely by screen-detected distal DVT; no significant association was found for proximal DVT or PE.
Key Limitation
The primary outcome is screen-detected distal DVT, which has uncertain clinical significance and does not translate to a demonstrated reduction in symptomatic proximal DVT or PE—the endpoints that drive morbidity and mortality in this population.
Original Abstract
BACKGROUND
This study aimed to determine the impact of the time from admission to initiation of low-molecular-weight heparin (LMWH) chemoprophylaxis on postoperative in-hospital venous thromboembolism (VTE) in patients who underwent hip fracture arthroplasty.
METHODS
This retrospective cohort study included 2,639 patients who a mean age of 72 years (range, 55 to 99) who underwent arthroplasty for hip fracture and received perioperative LMWH chemoprophylaxis. The primary exposure was door-to-prophylaxis (DTP) time. The primary outcome was screen-detected postoperative in-hospital VTE. The key secondary endpoint was postoperative in-hospital proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Patients were categorized as early or delayed DTP based on median values (18.9 hours; interquartile range, 13.6 to 43.7). Restricted cubic splines and Cox proportional hazards regressions were used to analyze the relationship between DTP time and VTE risk.
RESULTS
A significant linear correlation was identified between DTP time and postoperative in-hospital VTE. On multivariable Cox analyses, delayed DTP (≥ 19 hours) was independently associated with increased VTE risk by 22.8% versus early DTP (less than 19 hours) (adjusted hazard ratio [HR], 1.228; 95% confidence interval [CI], 1.036 to 1.456; P = 0.018). This association persisted across types and dosing regimens of LMWH (adjusted HR, 1.248; 95% CI, 1.041 to 1.497; P = 0.017). Similarly, for every 1-hour delay in DTP, the likelihood of VTE increased by 0.3% (adjusted HR, 1.003; 95% CI, 1.000 to 1.006; P = 0.030). There was no association detected between DTP and proximal DVT and/or PE, with imprecise estimates (all P > 0.05).
CONCLUSION
The DTP time was linearly associated with the occurrence of screen-detected postoperative in-hospital VTE in hip fracture arthroplasty. Notably, DTP delayed to 19 hours or later was associated with a higher risk of screen-detected distal DVT, whereas no robust association was observed for proximal DVT and/or PE.