Half-Dose Versus Full-Dose Alteplase for Treatment of Pulmonary Embolism

Recent evidence suggests that half-dose thrombolysis for pulmonary embolism may provide similar efficacy with reduced bleeding risk compared with full-dose therapy, but comparative studies are lacking. We aimed to evaluate the effectiveness and safety of half-dose versus full-dose alteplase for treatment of pulmonary embolism.

A retrospective cohort study comparing outcomes in patients receiving half-dose (50 mg) versus full-dose (100 mg) alteplase for pulmonary embolism. We used propensity score matching and sensitivity analyses to address confounding and hospital-level clustering.

Data from 420 hospitals obtained from the Premier Healthcare Database between January 2010 and December 2014.

Adult critically ill patients with acute pulmonary embolism treated with IV alteplase therapy.

None.

This study included 3,768 patients: 699 (18.6%) in the half-dose and 3,069 (81.4%) in the full-dose group. At baseline, patients receiving half-dose alteplase required vasopressor therapy (23.3% vs 39.4%; p < 0.01) and invasive ventilation (14.3% vs 28.5%; p < 0.01) less often, compared with full dose. After propensity matching (n = 548 per group), half-dose alteplase was associated with increased treatment escalation (53.8% vs 41.4%; p < 0.01), driven mostly by secondary thrombolysis (25.9% vs 7.3%; p < 0.01) and catheter thrombus fragmentation (14.2% vs 3.8%; p < 0.01). Hospital mortality was similar (13% vs 15%; p = 0.3). There was no difference in cerebral hemorrhage (0.5% vs 0.4%; p = 0.67), gastrointestinal bleeding (1.6% vs 1.6%; p = 0.99), acute blood loss anemia (6.9% vs 4.6%; p = 0.11), use of blood products (p > 0.05 for all), or documented fibrinolytic adverse events (2.6% vs 2.8%; p = 0.82).

Compared with full-dose alteplase, half-dose was associated with similar mortality and rates of major bleeding. Treatment escalation occurred more often in half-dose-treated patients. These results question whether half-dose alteplase provides similar efficacy with improved safety, and highlights the need for further study before use of half-dose alteplase therapy can be routinely recommended in patients with pulmonary embolism.