Low Dosage of rt-PA in the Treatment of Pulmonary Thromboembolism in China
Condition: Pulmonary Embolism; Thromboembolism
MeSH terms: Pulmonary Embolism; Embolism; Thromboembolism
Study type: Interventional
Phase: Phase 4

Summary: 
      Recombinant tissue plasminogen activator (rt-PA) is currently the most commonly used
      thrombolytic drug in patients with pulmonary thromboembolism (PTE). Optimal dosing with
      maximal benefits and minimal risks is of great importance. Considering the lower body weight
      in general Chinese population, we compared the efficacy and safety of lower dose rt-PA
      50mg/2h regimen with the FDA-approved rt-PA 100mg/2h regimen in selected PTE patients.
    

Detailed description: 
      Pulmonary thromboembolism (PTE) is a severe and common clinical problem with substantial
      morbidity and mortality both in US and in Europe. Used to be considered as a rare disease in
      China, PTE has been increasingly diagnosed in recent years due to the increased awareness and
      the improvement of imaging techniques. PTE is life threatening without proper intervention at
      the early onset. Effective treatment can decrease the mortality and the complication of
      chronic thromboembolic pulmonary hypertension (CTEPH).

      Recombinant tissue-type plasminogen activator (rt-PA) is currently the most commonly used
      drug for PTE thrombolysis. Like most thrombolytic medications, rt-PA carries a risk of
      significant bleeding, which is dose dependent. Thus, optimal dosing that can maximize
      benefits and minimize risks is of great importance. There is substantial controversy and
      debate regarding the optimal rt-PA dosage for thrombolytic therapy and whether the same dose
      should be used in all patients. Low dose of intravenous rt-PA for thrombolysis after acute
      myocardial infarction (AMI) had been suggested by previous studies. Experimental and clinical
      studies have indicated that a lower dose of rt-PA bolus may be potentially safer, and yet
      equally effective then the 2-h 100 mg rt-PA continuous infusion for PTE.

      Considering lower body weight in Chinese population, a lower dose of 50mg rt-PA/2h may
      exhibit similar efficacy and safety as 100mg/2-h rt-PA for treating acute PTE in this
      population. We, therefore, compared these two regimens in a multi-center, randomized,
      controlled trial. The efficacy was assessed by the improvement of the right ventricular
      function on echocardiograms, perfusion defect score of lung V/Q scans or quantitative
      computed tomographic (CT) evaluation, safety was evaluated by incidence of major or minor
      bleeding, death rate, and PTE recurrence on 24h,14d after treatment.

      110 patients will be randomized in the study. The patients included in the study will be
      randomized, in a double blind fashion, to receive rt-PA 100mg 2h (55 patients) or rt-PA50mg
      2h(55 patients).Study treatment should be administered within 72 hours from echocardiography.
      Echocardiography will be repeated at 24 hours and 14 days from rt-PA injection. A Follow-up
      visit at 14 days from randomization will include: clinical history, physical examination and
      ECG and an echocardiographic examination CTPA and V/Q scan.
    

Intervention name(s): rt-PA; rt-PA
Intervention type(s): Drug; Drug
Intervention description(s): rt-PA 100 mg continuous intravenous infusion for 2 hours; rt-PA 50 mg continuous intravenous infusion for 2 hours
Other intervention name(s): Recombinant tissue plasminogen activator; Recombinant tissue plasminogen activator
Intervention MeSH terms: Plasminogen; Tissue Plasminogen Activator
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Thrombolytic therapy; Recombinant tissue plasminogen activator; Efficacy; Safety