Extended DVT Prophylaxis after Hospital Discharge in Patients with Elective Hip Arthroplasty

A systematic review 1 included 6 studies on patients discharged after elective hip arthroplasty. Duration of thromboprophylaxis after discharge ranged from 18 to 29 days. Compared with placebo, extended out-of-hospital prophylaxis decreased the frequency of all episodes of deep venous thrombosis (DVT) (RR 0.41, 95% CI 0.32 to 0.54), proximal venous thrombosis (RR 0.31, 95% CI 0.20 to 0.47), and symptomatic venous thromboembolism (RR 0.36, 95% CI 0.20 to 0.67). In placebo group, rate for any DVT was 22.5%, proximal venous thrombosis 11.2%, and symptomatic venous thromboembolism 4.2%. Major bleeding was rare, occurring in only one patient in the placebo group.

A systematic review2 included 9 studies (n=3 999) comparing extended-duration thromboprophylaxis (8 studies used LMWH and 1 study unfractionated heparin) with placebo or untreated control in patients undergoing elective total hip or knee replacement. Seven studies included only patients undergoing total hipreplacement and 2 included both total hip andknee replacements. All patients received in-hospital thromboprophylaxis. Extended-duration prophylaxis for 30-42 days reduced symptomatic venous thromboembolism (VTE) (1.3% vs 3.3%; OR 0.38, 95% CI 0.24 to 0.61, NNT=50). There was a greater risk reduction in patients undergoing hip replacement (1.4% vs 4.3%, OR 0.33, 95% CI 0.19 to 0.56, NNT=34) compared with knee replacement (1.0% vs 1.4%; OR 0.74, 95% CI 0.26 to 2.15, NNT=250). A significant reduction in symptomless venographic deep vein thrombosis was also observed (9.6% vs 19.6%; OR 0.48, 95% CI 0.36 to 0.63, NNT=10). There was no increase in major bleeding but extended-duration prophylaxis was associated with excess minor bleeding (3.7% vs 2.5%; OR 1.56, 95% CI 1.08 to 2.26, NNH=83).

A systematic review 3 included 8 studies (n=2 917), and compared prolonged (≥21 days) with standard-duration (7 to 10 days) thromboprophylaxis (with fondaparinux, warfarin, enoxaparin, or dalteparin) after major orthopedic surgery (total hip replacement 6 studies, total knee or total hip replacement 1 study, surgery for hip fracture 1 study) in adults. Prolonged prophylaxis resulted in fewer cases of pulmonary embolism (PE) (OR 0.14, 95% CI 0.04 to 0.47; 5 studies) and symptomatic DVT (OR 0.36, 95% CI 0.16 to 0.81; 4 studies). There were fewer symptomatic objectively confirmed episodes of venous thromboembolism (RR 0.38, 95% CI 0.19 to 0.77; 4 studies), nonfatal PE (OR 0.13, 95% CI 0.03 to 0.54; 4 studies), and DVT (RR 0.37, 95% CI 0.21 to 0.64; 7 studies) with prolonged prophylaxis. There was more minor bleeding events with prolonged prophylaxis (OR 2.44, 95% CI 1.41 to 4.20), and 1 study on hip fracture surgery suggested more surgical-site bleeding events (OR 7.55, 95% CI 1.51 to 37.64) with prolonged prophylaxis.

The following decision support rules contain links to this evidence summary:

• Extended thromboprophylaxis in patients with elective hip arthroplasty http://www.ebmeds.org/ebmeds/ebmeds_home.asp?mode=scripts&submode=view&id=scr00483&country=UK

References

• Hull RD, Pineo GF, Stein PD, Mah AF, MacIsaac SM, Dahl OE, Butcher M, Brant RF, Ghali WA, Bergqvist D, Raskob GE. Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review. Ann Intern Med 2001 Nov 20;135(10):858-69. [PubMed]
• Eikelboom JW, Quinlan DJ, Douketis JD. Extended-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of the randomised trials. Lancet 2001;358(9275):9-15. [PubMed]
• Sobieraj DM, Lee S, Coleman CI et al. Prolonged versus standard-duration venous thromboprophylaxis in major orthopedic surgery: a systematic review. Ann Intern Med 2012;156(10):720-7. [PubMed][DARE]