title: Rivaroxaban vs dabigatran for thromboprophylaxis after joint-replacement surgery: exploratory indirect comparison based on meta-analysis of pivotal clinical trials.
abstract: OBJECTIVE
  To indirectly compare rivaroxaban and dabigatran for prevention of venous thromboembolism (VTE) after total hip or knee arthroplasty (THA, TKA) based on their pivotal efficacy/safety trials embracing a total of 20618 patients.
  
  
  METHODS
  Pooled risk differences (RD) for rivaroxaban vs enoxaparin and dabigatran vs enoxaparin obtained from separate meta-analyses of two sets of trials were used to indirectly estimate RDs for rivaroxaban vs dabigatran.
  
  
  RESULTS
  Primary efficacy (any VTE+all-cause mortality) and safety (major bleeding) outcomes in enoxaparin arms largely differed across similarly designed rivaroxaban and dabigatran trials (differences in venography adjudication and bleeding events definitions). However, incidence of symptomatic VTE and incidence of major/non-major clinically relevant bleeding (including surgical site) were consistent in this respect. RDs (as percentages) for symptomatic VTE were: rivaroxaban-enoxaparin=-0.4% (95% confidence interval [CI], -0.9 to 0.05); dabigatran-enoxaparin=-0.09% (95% CI, -1.0 to 0.8); rivaroxaban-dabigatran=-0.3% (95% CI, -1.3 to 0.7; P=0.275). RDs for major/clinically relevant bleeding were rivaroxaban-enoxaparin=0.99% (95%CI, 0.29 to 1.69); dabigatran-enoxaparin=0.02% (95% CI, -1.0 to 1.0); rivaroxaban-dabigatran=0.97 (95% CI, -0.43 to 2.37; P=0.085). Mortality rates (all-cause, VTE-related, bleeding-related) were very low not indicating differences between any two of the three treatments.
  
  
  CONCLUSIONS
  Methodological differences disable indirect comparisons of rivaroxaban vs dabigatran that would be based on major efficacy/safety outcomes of their pivotal trials. The two drugs do not seem to differ regarding incidence of symptomatic VTE. Risk of a relevant bleeding is higher with rivaroxaban than with enoxaparin and the same tendency exists also vs dabigatran. Direct rivaroxaban vs dabigatran comparisons in this setting are needed.
authors.affiliation: Department of Pharmacology, Zagreb University School of Medicine, Salata 11, 10000 Zagreb, Croatia. vtrkulja@mef.hr
authors.forename: Vladimir
authors.initials: V
authors.lastname: Trkulja
authors.forename: Robert
authors.initials: R
authors.lastname: Kolundzic
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D001562:Benzimidazoles / Q000009:adverse effects / Q000627:therapeutic use*; D000069604:Dabigatran; D017984:Enoxaparin / Q000009:adverse effects / Q000627:therapeutic use; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D009025:Morpholines / Q000009:adverse effects / Q000627:therapeutic use*; D011182:Postoperative Care; D011725:Pyridines / Q000009:adverse effects / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D000069552:Rivaroxaban; D012449:Safety; D016019:Survival Analysis; D013876:Thiophenes / Q000009:adverse effects / Q000627:therapeutic use*; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D001562:Benzimidazoles; D017984:Enoxaparin; D009025:Morpholines; D011725:Pyridines; D013876:Thiophenes; D000069552:Rivaroxaban; D000069604:Dabigatran
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