SLR - June 2018 - Nooreen Ibrahim

Aspirin or Rivaroxaban for VTE Prophylaxis After Hip or Knee Arthroplasty

Reference: Anderson D.R, Dunbar M, Murnaghan J, Kahn S.R., Gross P, Forsythe M, Pelet S, Fisher W, Belzile E, Dolan S, Crowther M, Bohm E, MacDonald SJ, Gofton W, Kim P, Zuukor D, Pleasance S, Andreou P, Doucetter S, Theriault C, Abianui A, Carrier M, Kovacs MJ, Rodger MA, Coyle D, Wells PS, Vendittoli PA. Aspirin or Rivaroxaban for VTE Prophylaxis after Hip or Knee Arthroplasty. New England Journal of Medicine. 2018 Feb 22; 378(8) 699–707.

Scientific Literature Review

Reviewed By: Nooreen Ibrahim, DPM
Residency Program: Wheaton Franciscan Healthcare, St. Joseph Hospital, Milwaukee, WI

Podiatric Relevance: A postoperative complication surgeons must evaluate for is a VTE and bleeding complications. VTE prophylaxis is something that varies from surgeon to surgeon and is patient and procedure dependent. This study is a trial with patients who underwent total hip arthroplasty or total knee arthroplasty. All patients received once daily rivaroxaban until postoperative day five and then were randomly assigned to continue rivaroxaban or switched to aspirin. This study found that aspirin and rivaroxaban are similarly effective for preventing VTE after either total hip or total knee arthroplasty. This can be applied to podiatric surgery as well and can support a surgeon’s decision to use aspirin as a postoperative prophylaxis for potential bleeding complication and VTE.

Method: This study is a multicenter, double-blinded, randomized, controlled trial involving patients who were undergoing total hip or knee arthroplasty. A total of 3,424 patients were enrolled in the trial. Of the 3,424 patients, 1,804 were undergoing a total hip arthroplasty and 1,620 were undergoing total knee arthroplasty. All patients were started on 10 mg of rivaroxaban until postoperative day five. They were then randomly assigned to continue rivaroxaban or begin 81 mg of aspirin for an additional nine days after total knee arthroplasty or for 30 days after total hip arthroplasty. Patients who had been taking daily low-dose aspirin before the trial took aspirin at a dose less than 100 mg per day in addition to the trial regimen. Patients were then followed for 90 days for symptomatic venous thromboembolism and bleeding complications.

Results: From the 3,424 patients, 1,707 were in the aspirin group, and 1,717 were in the rivaroxaban group. A venous thromboembolism occurred in 11 of the 1,707 patients in the aspirin group and in 12 of the 1,717 patients in the rivaroxaban group. Major bleeding complications occurred in eight patients in the aspirin group and in five in the rivaroxaban group. Clinically important bleeding occurred in 22 patients in the aspirin group and in 17 of the rivaroxaban group. All bleeding events were hemorrhage at the surgical site, and most events took place within 10 days after randomization. Calf DVTs occurred in eight patients in the aspirin group and in five patients in the rivaroxaban group. There was no statistical significance between the two groups in terms of rates of thromboembolic events or major or clinical bleeding complications.

Conclusion: It was found that use of aspirin was not significantly different from rivaroxaban in preventing VTE. The patients had low and very similar rates of symptomatic thromboembolic complications. Rates of clinically important bleeding complications were less than 1.5 percent and did not differ significantly between the two groups. Aspirin and rivaroxaban are similarly effective for preventing VTE after either total hip or total knee arthroplasty. One of the limitations of the study is that patients were recruited postoperatively so the population did not consist of a cohort that was treated using a standardized protocol. However, the findings still provide clear evidence that aspirin and rivaroxaban are safe and effective for postoperative prophylaxis. 

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