Verinder S Sidhu1,2, Thu-Lan Kelly3, Nicole Pratt3, Stephen E Graves4, Rachelle Buchbinder5,6, Sam Adie7, Kara Cashman8, Ilana Ackerman5,6, Durga Bastiras4, Roger Brighton9,10, Alexander W R Burns11, Beng Hock Chong12,13, Ornella Clavisi14, Maggie Cripps1,2, Mark Dekkers15, Richard de Steiger16, Michael Dixon17, Andrew Ellis18,19, Elizabeth C Griffith8, David Hale20, Amber Hansen1,2, Anthony Harris21, Raphael Hau16,22, Mark Horsley23, Dugal James24, Omar Khorshid25, Leonard Kuo26, Peter Lewis27, David Lieu28, Michelle Lorimer8, Samuel MacDessi7,29, Peter McCombe30, Catherine McDougall31, Jonathan Mulford32, Justine Maree Naylor1,2, Richard S Page33, John Radovanovic34, Michael Solomon35, Rami Sorial36, Peter Summersell37, Phong Tran38, William L Walter18,19,39, Steve Webb5, Chris Wilson40,41, David Wysocki42, Ian A Harris1,2,43. 1. School of Clinical Medicine, UNSW Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia. 2. Whitlam Orthopaedic Research Centre, Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia. 3. Clinical and Health Sciences, Quality Use of Medicines Pharmacy Research Centre, University of South Australia, Adelaide, South Australia, Australia. 4. Australian Orthopaedic Association National Joint Replacement Registry, Adelaide, South Australia, Australia. 5. Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia. 6. Monash-Cabrini Department of Musculoskeletal Health and Clinical Epidemiology, Cabrini Health, Melbourne, Victoria, Australia. 7. School of Clinical Medicine, UNSW Medicine and Health, St George and Sutherland Clinical Campuses, Faculty of Medicine and Health, UNSW Sydney, New South Wales, Australia. 8. South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia. 9. Orthopaedic Department, Westmead Private Hospital, Westmead, Sydney, New South Wales, Australia. 10. Orthopaedic Department, Lakeview Private Hospital, Baulkham Hills, Sydney, New South Wales, Australia. 11. Orthopaedic Department, Calvary John James Hospital, Deakin, Canberra, Australian Capital Territory, Australia. 12. Department of Medicine, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia. 13. Department of Hematology, New South Wales Pathology, Kogarah Campus, Sydney, New South Wales, Australia. 14. Musculoskeletal Australia, Melbourne, Victoria, Australia. 15. Orthopaedic Department, Greenslopes Private Hospital, Greenslopes, Brisbane, Queensland, Australia. 16. Department of Surgery, Epworth Healthcare, University of Melbourne, Melbourne, Victoria, Australia. 17. Orthopaedic Department, Kareena Private Hospital, Sutherland, Sydney, New South Wales, Australia. 18. Orthopaedic Department, Royal North Shore Hospital, St Leonard's, Sydney, New South Wales, Australia. 19. Sydney Musculoskeletal Health Flagship Centre of the University of Sydney and Royal North Shore Hospital, St Leonard's, Sydney, New South Wales, Australia. 20. Orthopaedic Department, Hornsby and Kuringai Hospital, Hornsby, Sydney, New South Wales, Australia. 21. Centre for Health Economics, Monash Business School, Monash University, Melbourne, Victoria, Australia. 22. Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia. 23. Orthopaedic Department, Royal Prince Alfred Hospital, Camperdown, Sydney, New South Wales, Australia. 24. Bendigo Healthcare Group, Bendigo Hospital, Bendigo, Victoria, Australia. 25. Orthopaedic Department, Fremantle Hospital, Fremantle, Western Australia, Australia. 26. Orthopaedic Department, Canterbury Hospital, Canterbury, Sydney, New South Wales, Australia. 27. Orthopaedic Department, Calvary Hospital, Adelaide, South Australia, Australia. 28. Orthopaedic Department, Fairfield Hospital, Fairfield, Sydney, New South Wales, Australia. 29. Orthopaedic Department, St George Private Hospital, Kogarah, Sydney, New South Wales, Australia. 30. Orthopaedic Department, Frankston Hospital, Frankston, Melbourne, Victoria, Australia. 31. Orthopaedic Department, The Prince Charles Hospital, Chermside, Brisbane, Queensland, Australia. 32. Orthopaedic Department, Launceston General Hospital, Launceston, Tasmania, Australia. 33. School of Medicine, St John of God Hospital and Barwon Health, Deakin University, Geelong, Victoria, Australia. 34. Orthopaedic Department, Mater Hospital, Raymond Terrace, Brisbane, Queensland, Australia. 35. Orthopaedic Department, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia. 36. Orthopaedic Department, Nepean Hospital, Nepean, Sydney, New South Wales, Australia. 37. Orthopaedic Department, Coffs Harbour Base Hospital, Coffs Harbour, New South Wales, Australia. 38. Orthopaedic Department, Western Health, Melbourne, Victoria, Australia. 39. The Kolling Institute, Faculty of Medicine and Health, The University of Sydney and the Northern Sydney Local Health District, Sydney, New South Wales, Australia. 40. Orthopaedic Department, Flinders Medical Centre, Bedford Park, Adelaide, South Australia, Australia. 41. Department of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia. 42. Orthopaedic Department, Sir Charles Gardiner Hospital, Perth, Western Australia, Australia. 43. Institute of Musculoskeletal Health, School of Public Health, The University of Sydney, Sydney, New South Wales, Australia.
Abstract
Importance: There remains a lack of randomized trials investigating aspirin monotherapy for symptomatic venous thromboembolism (VTE) prophylaxis following total hip arthroplasty (THA) or total knee arthroplasty (TKA). Objective: To determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE after THA or TKA. Design, Setting, and Participants: Cluster-randomized, crossover, registry-nested trial across 31 hospitals in Australia. Clusters were hospitals performing greater than 250 THA or TKA procedures annually. Patients (aged ≥18 years) undergoing hip or knee arthroplasty procedures were enrolled at each hospital. Patients receiving preoperative anticoagulation or who had a medical contraindication to either study drug were excluded. A total of 9711 eligible patients were enrolled (5675 in the aspirin group and 4036 in the enoxaparin group) between April 20, 2019, and December 18, 2020. Final follow-up occurred on August 14, 2021. Interventions: Hospitals were randomized to administer aspirin (100 mg/d) or enoxaparin (40 mg/d) for 35 days after THA and for 14 days after TKA. Crossover occurred after the patient enrollment target had been met for the first group. All 31 hospitals were initially randomized and 16 crossed over prior to trial cessation. Main Outcomes and Measures: The primary outcome was symptomatic VTE within 90 days, including pulmonary embolism and deep venous thrombosis (DVT) (above or below the knee). The noninferiority margin was 1%. Six secondary outcomes are reported, including death and major bleeding within 90 days. Analyses were performed by randomization group. Results: Enrollment was stopped after an interim analysis determined the stopping rule was met, with 9711 patients (median age, 68 years; 56.8% female) of the prespecified 15 562 enrolled (62%). Of these, 9203 (95%) completed the trial. Within 90 days of surgery, symptomatic VTE occurred in 256 patients, including pulmonary embolism (79 cases), above-knee DVT (18 cases), and below-knee DVT (174 cases). The symptomatic VTE rate in the aspirin group was 3.45% and in the enoxaparin group was 1.82% (estimated difference, 1.97%; 95% CI, 0.54%-3.41%). This failed to meet the criterion for noninferiority for aspirin and was significantly superior for enoxaparin (P = .007). Of 6 secondary outcomes, none were significantly better in the enoxaparin group compared with the aspirin group. Conclusions and Relevance: Among patients undergoing hip or knee arthroplasty for osteoarthritis, aspirin compared with enoxaparin resulted in a significantly higher rate of symptomatic VTE within 90 days, defined as below- or above-knee DVT or pulmonary embolism. These findings may be informed by a cost-effectiveness analysis. Trial Registration: ANZCTR Identifier: ACTRN12618001879257.
Importance: There remains a lack of randomized trials investigating aspirin monotherapy for symptomatic venous thromboembolism (VTE) prophylaxis following total hip arthroplasty (THA) or total knee arthroplasty (TKA). Objective: To determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE after THA or TKA. Design, Setting, and Participants: Cluster-randomized, crossover, registry-nested trial across 31 hospitals in Australia. Clusters were hospitals performing greater than 250 THA or TKA procedures annually. Patients (aged ≥18 years) undergoing hip or knee arthroplasty procedures were enrolled at each hospital. Patients receiving preoperative anticoagulation or who had a medical contraindication to either study drug were excluded. A total of 9711 eligible patients were enrolled (5675 in the aspirin group and 4036 in the enoxaparin group) between April 20, 2019, and December 18, 2020. Final follow-up occurred on August 14, 2021. Interventions: Hospitals were randomized to administer aspirin (100 mg/d) or enoxaparin (40 mg/d) for 35 days after THA and for 14 days after TKA. Crossover occurred after the patient enrollment target had been met for the first group. All 31 hospitals were initially randomized and 16 crossed over prior to trial cessation. Main Outcomes and Measures: The primary outcome was symptomatic VTE within 90 days, including pulmonary embolism and deep venous thrombosis (DVT) (above or below the knee). The noninferiority margin was 1%. Six secondary outcomes are reported, including death and major bleeding within 90 days. Analyses were performed by randomization group. Results: Enrollment was stopped after an interim analysis determined the stopping rule was met, with 9711 patients (median age, 68 years; 56.8% female) of the prespecified 15 562 enrolled (62%). Of these, 9203 (95%) completed the trial. Within 90 days of surgery, symptomatic VTE occurred in 256 patients, including pulmonary embolism (79 cases), above-knee DVT (18 cases), and below-knee DVT (174 cases). The symptomatic VTE rate in the aspirin group was 3.45% and in the enoxaparin group was 1.82% (estimated difference, 1.97%; 95% CI, 0.54%-3.41%). This failed to meet the criterion for noninferiority for aspirin and was significantly superior for enoxaparin (P = .007). Of 6 secondary outcomes, none were significantly better in the enoxaparin group compared with the aspirin group. Conclusions and Relevance: Among patients undergoing hip or knee arthroplasty for osteoarthritis, aspirin compared with enoxaparin resulted in a significantly higher rate of symptomatic VTE within 90 days, defined as below- or above-knee DVT or pulmonary embolism. These findings may be informed by a cost-effectiveness analysis. Trial Registration: ANZCTR Identifier: ACTRN12618001879257.
Authors: David R Anderson; Michael Dunbar; John Murnaghan; Susan R Kahn; Peter Gross; Michael Forsythe; Stephane Pelet; William Fisher; Etienne Belzile; Sean Dolan; Mark Crowther; Eric Bohm; Steven J MacDonald; Wade Gofton; Paul Kim; David Zukor; Susan Pleasance; Pantelis Andreou; Steve Doucette; Chris Theriault; Abongnwen Abianui; Marc Carrier; Michael J Kovacs; Marc A Rodger; Doug Coyle; Philip S Wells; Pascal-Andre Vendittoli Journal: N Engl J Med Date: 2018-02-22 Impact factor: 91.245
Authors: John E Farey; Vincent V G An; Verinder Sidhu; Sascha Karunaratne; Ian A Harris Journal: Orthop Traumatol Surg Res Date: 2020-07-04 Impact factor: 2.256
Authors: Verinder Singh Sidhu; Steven E Graves; Rachelle Buchbinder; Justine Maree Naylor; Nicole L Pratt; Richard S de Steiger; Beng H Chong; Ilana N Ackerman; Sam Adie; Anthony Harris; Amber Hansen; Maggie Cripps; Michelle Lorimer; Steve Webb; Ornella Clavisi; Elizabeth C Griffith; Durga Anandan; Grace O'Donohue; Thu-Lan Kelly; Ian A Harris Journal: BMJ Open Date: 2019-11-06 Impact factor: 2.692
Authors: R Peto; M C Pike; P Armitage; N E Breslow; D R Cox; S V Howard; N Mantel; K McPherson; J Peto; P G Smith Journal: Br J Cancer Date: 1976-12 Impact factor: 7.640