Effect of half-dose thrombolysis on hypoxemia duration in intermediate risk pulmonary embolism

In intermediate high-risk pulmonary embolism (PE), the role of thrombolysis remains debated with a disagreement between European and American guidelines. Expected benefits are counterbalanced by increased hemorrhagic events with full-dose fibrinolysis. In these patients, half-dose thrombolysis may have similar effects with less complications. We have hypothesized that half-dose thrombolysis compared to anticoagulation alone may reduce hypoxemia duration and hospital length of stay. We have performed a 6 years' retrospective study in 2 Emergency Departments of French hospitals. One practiced fibrinolysis in intermediate risk PE (tPA 50 mg/2 h) and the other did not. We used logistic regression and propensity score matching to assess the effect of a thrombolysis strategy. 473 patients had a diagnosis of acute PE during the study period. 110 (23%) patients with intermediate risk PE met the inclusion criteria. After propensity score matching, 30 patients with thrombolysis therapy were compared to 30 control patients. The duration of oxygen therapy was shorter in the thrombolysis group (3 days, interquartile range 2 to 4) than in the control group (8 days, interquartile range 3 to 11; p = 0.0003). There was no significant difference between groups regarding pulmonary, cardiac, and hemorrhagic complications. The rates of treatment failure, defined by death or persistent hypotension requiring vasopressors, were not significantly different between the 2 groups (2% vs. 6%). Compared to anticoagulation alone, half-dose thrombolysis in intermediate risk PE is associated with a significantly shorter duration of hypoxemia.