Low-Dose Alteplase for the Treatment of Submassive Pulmonary Embolism: A Case Series.

PURPOSE: Pulmonary embolism (PE) can lead to significant morbidity and mortality. Thrombolytics are currently approved for the treatment of massive PE; however, the CHEST guidelines recommend against systemic thrombolytic use in acute PE patients without hypotension, unless these patients deteriorate on anticoagulation alone. Several studies have demonstrated the effectiveness of thrombolysis in submassive PE; however, the full thrombolytic dose resulted in significantly increased risk of non-intracranial bleeding and hemorrhagic stroke. The MOPETT trial demonstrated that low-dose tissue plasminogen activator (tPA) significantly reduced the risk of pulmonary hypertension and recurrent PE compared to anticoagulation alone in submassive PE patients without any bleeding events. SUMMARY: This case series highlights 5 patient cases utilizing low-dose tPA for submassive PE. All patients had successful resolution of their symptoms and improvement in vitals and laboratory values. Furthermore, no patient had any bleeding during or after tPA administration. Three patients showed improved right ventricle function and reduced or normal right ventricle size on echocardiogram after tPA administration. CONCLUSION: The potential for low-dose tPA as a safe and efficacious treatment option for submassive PE is illustrated by this case series. However, larger, randomized controlled trials are needed to establish low-dose tPA as an accepted treatment modality.