Aspirin or Rivaroxaban for VTE Prophylaxis after Hip or Knee Arthroplasty.

Background: Clinical trials and meta-analyses have suggested that aspirin may be effective for the prevention of venous thromboembolism (proximal deep-vein thrombosis or pulmonary embolism) after total hip or total knee arthroplasty, but comparisons with direct oral anticoagulants are lacking for prophylaxis beyond hospital discharge.

Methods: We performed a multicenter, double-blind, randomized, controlled trial involving patients who were undergoing total hip or knee arthroplasty. All the patients received once-daily oral rivaroxaban (10 mg) until postoperative day 5 and then were randomly assigned to continue rivaroxaban or switch to aspirin (81 mg daily) for an additional 9 days after total knee arthroplasty or for 30 days after total hip arthroplasty.

Aspirin versus low-molecular-weight heparin for extended venous thromboembolism prophylaxis after total hip arthroplasty: a randomized trial.

Background: The role of aspirin in thromboprophylaxis after total hip arthroplasty (THA) is controversial.

Objective: To compare extended prophylaxis with aspirin and dalteparin for prevention of symptomatic venous thromboembolism (VTE) after THA.

Design: Multicenter randomized, controlled trial with a noninferiority design based on a minimal clinically important difference of 2.

Computed tomographic pulmonary angiography vs ventilation-perfusion lung scanning in patients with suspected pulmonary embolism: a randomized controlled trial.

Context: Ventilation-perfusion (V(dot)Q(dot) lung scanning and computed tomographic pulmonary angiography (CTPA) are widely used imaging procedures for the evaluation of patients with suspected pulmonary embolism. Ventilation-perfusion scanning has been largely replaced by CTPA in many centers despite limited comparative formal evaluations and concerns about CTPA's low sensitivity (ie, chance of missing clinically important pulmonary embuli).

Objectives: To determine whether CTPA may be relied upon as a safe alternative to V(dot)Q(dot scanning as the initial pulmonary imaging procedure for excluding the diagnosis of pulmonary embolism in acutely symptomatic patients.

Use of spiral computed tomography contrast angiography and ultrasonography to exclude the diagnosis of pulmonary embolism in the emergency department.

Spiral computed tomography (CT) contrast angiography is a promising imaging modality for the diagnosis of pulmonary embolism but the negative predictive value of this test remains controversial. We performed a multi-center prospective cohort study to determine the safety of relying on a negative spiral CT contrast angiography scan to exclude pulmonary embolism. Patients presenting to the Emergency Departments of three tertiary care institutions with clinically suspected pulmonary embolism were potentially eligible for the study.