Can Aspirin be Used for VTE Prophylaxis after Knee or Hip Surgery?

BACKGROUND AND PURPOSE:

  • Aspirin may be effective for prevention of venous thromboembolism after total hip or total knee arthroplasty
  • Anderson et al. (N Engl J Med 2018) compared aspirin with direct oral anticoagulants for prophylaxis beyond hospital discharge

METHODS:

  • Multicenter, double-blind, randomized, controlled trial
  • Participants: Patients undergoing total hip or knee arthroplasty
  • Patients received once-daily oral rivaroxaban (10 mg) until postoperative day 5
  • Patients were then randomized into the following groups
    • Continue rivaroxaban (10 mg)
    • Switch over to Aspirin (81 mg daily)
  • Medication was continued an additional 9 days for knee arthroplasty and 30 days for hip arthroplasty
  • Primary effectiveness outcome
    • Symptomatic proximal DVT or PE within 90 days post treatment (confirmed with objective testing)
  • Primary safety outcome
    • Bleeding complications, including major or clinically relevant nonmajor bleeding

RESULTS:

  • Data was collected from 3,424 patients
    • 1,804 undergoing total hip arthroplasty
    • 1,620 undergoing total knee arthroplasty
  • VTE was not significantly different between groups (P<0.001 for noninferiority and P=0.84 for superiority)
    • 0.64% in the aspirin group
    • 70% in the rivaroxaban group
  • Major bleeding complications were not significantly different between groups (P=0.42)
    • 0.47% in the aspirin group
    • 0.29% in the rivaroxiban group
  • Clinically important bleeding was also similar between groups (P=0.43)
    • 1.29% in the aspirin group
    • 0.99% in the rivaroxaban group

CONCLUSION:

  • Authors of this study found no difference between inexpensive aspirin and rivaroxaban to prevent symptomatic VTE following hip and knee surgery

Learn More – Primary Sources:

Aspirin or Rivaroxaban for VTE Prophylaxis after Hip or Knee Arthroplasty

Patient with Stable CVD: Rivaroxaban, Aspirin or Both to Prevent Recurrent Events?

BACKGROUND AND PURPOSE:

  • Aspirin reduces risk of major CV events by 19% and CV death by 9% in those with CVD
    • 5 to 10% of patients will still have recurrent CV events
  • Eikelboom et al. (NEJM, 2017) assessed whether rivaroxaban, aspirin or both is most effective for secondary cardiovascular event prevention in those with stable atherosclerotic vascular disease

METHODS:

  • Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial
  • 602 centers in 33 countries
  • Double-blind randomized controlled (RCT) trial
  • Inclusion criteria: Coronary artery disease, peripheral arterial disease, or both
  • Participants were randomly assigned to 1 of 3 cohorts
    • rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily)
    • rivaroxaban (5 mg twice daily)
    • aspirin (100 mg once daily)
  • Primary outcome
    • Composite of cardiovascular death, stroke, or myocardial infarction
  • The study was stopped short at 23 month follow-up, due to superiority of the rivaroxaban and aspirin group

RESULTS:

  • Comparing to aspirin-alone group, the rivaroxaban-plus-aspirin group had
    • Fewer patients (4.1% vs 5.4%) with adverse cardiovascular events (hazard ratio [HR] 0.76; 95% CI 0.66 – 0.86; P<0.001)
    • More major bleeding events occurred (3.1% vs 1.9% HR 1.70; 95% CI 1.40 to 2.05; P<0.001)
  • Most major bleeding was into the gastrointestinal tract
  • There was no significant difference in intracranial bleeding, fatal bleeding or bleeding into a critical organ
  • There were 313 deaths (3.4%) in the rivaroxaban-plus-aspirin group as compared with 378 (4.1%) in the aspirin-alone group ([HR] 0.82; 95% CI 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025)
  • When comparing rivaroxaban-alone group than in the aspirin-alone group, there was no significant difference in primary outcome but there were more major bleeding events

CONCLUSION:

  • Rivaroxaban-plus-aspirin had better cardiovascular outcomes compared to aspirin alone
  • Rivaroxaban alone did not impact outcomes

Learn More – Primary Sources:

Rivaroxaban with or without Aspirin in Stable Cardiovascular Disease