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Abstract

Introduction: In patients with massive and submassive pulmonary embolism (PE), alteplase administration enhances the rate of clot resolution and improves hemodynamics, but increases the risk for bleeding. Factors available to clinicians at the time alteplase is administered, such as product package insert-noted contraindications and warnings (CI/W) for alteplase administration and body weight, may be associated with bleeding. Hypothesis: Lower body weight is independently associated with a higher risk for bleeding compared to higher body weight. Methods: This retrospective, case-control study included adult patients who received alteplase 100 mg over 2 hours for the treatment of PE. Bleeding was defined as any of the following within 72 hours post-alteplase: death from bleeding, radiographic evidence of hemorrhage, procedure to treat bleeding, transfusion of two or more units of packed red blood cells, or a reduction in hemoglobin of 2 g/dL or more during each 24 hour period. The primary objective was to compare body weight between cases (patients meeting bleeding criteria) and controls (non-bleeding patients). Secondarily, the influence of risk factors for bleeding was evaluated with logistic regression. Results: Ninety nine patients were screened from January 2000 to August 2011, with 62 patients included. At baseline, 45% of patients had massive PE, while 53% had submassive PE. Overall, 28 patients (45%) experienced bleeding. There was no difference in median body weight between cases and controls (95 vs. 101 kg; p=0.098). However, significantly more case patients had at least one CI/W for alteplase administration (61% vs. 24%, p=0.003) and massive PE (61% vs. 32%, p=0.04). On multivariate logistic regression, presence of CI/W for alteplase administration (OR 5.2, 95% CI 1.6-17.5, p=0.007) and body weight (OR 0.84 per 10 kg, 95% CI 0.72-0.98, p=0.023) were independently associated with bleeding. Conclusions: Bleeding occurred relatively frequently in this cohort of patients receiving alteplase for PE. Lower body weight was associated with a higher bleeding risk on multivariate analysis.