This clinical trial is focused on studying a condition known as intermediate-high-risk acute pulmonary embolism. This is a serious condition where a blood clot blocks the blood vessels in the lungs, which can lead to severe health issues. The treatment being tested in this study is a medication called ACTILYSE, which contains the active substance alteplase. This medication is used to help dissolve blood clots and is administered through an injection or infusion into the veins. The study also involves a comparison with a placebo, which is a substance with no active medication.

The purpose of the study is to evaluate the effectiveness of a reduced dose of this thrombolytic therapy, which is a treatment that helps break down blood clots, in patients with this type of pulmonary embolism. Participants in the study will receive either the reduced dose of ACTILYSE or a placebo. The study will monitor the participants over a period of 30 days to assess the outcomes, which include the risk of death from any cause, the occurrence of hemodynamic decompensation (a condition where the heart cannot maintain adequate blood flow), or the recurrence of pulmonary embolism.

Throughout the study, researchers will also observe any severe or life-threatening bleeding events and evaluate the overall clinical benefits of the treatment. The study aims to provide valuable insights into whether a lower dose of the medication can effectively treat the condition while minimizing potential side effects. This research is important for improving treatment options for patients with intermediate-high-risk acute pulmonary embolism.