Clinical Outcomes of Intermediate-Risk Pulmonary Embolism Across a Northeastern Health System: A Multi-Center Retrospective Cohort Study

Objective: The role of thrombolytic therapy in the management of intermediate-risk pulmonary embolism is controversial. Our objective was to determine clinical outcomes for a population of patients with intermediate-risk pulmonary embolism receiving anticoagulation with and without thrombolytic therapy in a large Northeastern health system. Design: A retrospective cohort study. Setting: ICU and non-ICU settings in 8 hospitals. Patients: Hemodynamically stable patients with intermediate-risk pulmonary embolism. Interventions: Treatment arms were anticoagulation (AC) alone, AC with low dose intravenous thrombolysis, AC with full-dose intravenous thrombolysis, and AC with ultrasound-assisted, catheter-directed thrombolysis. Measurements and Main Results: In 257 patients, utilizing a Bonferroni corrected P value cutoff of α = 0.003, our data shows no differences in 7 day or 30 day all-cause mortality (α = 0.37 and α = 0.04, respectively) , hospital length of stay (α = 0.31), 7 or 30 readmission rates (α = 0.97 and α = 0.84, respectively), or any major (α = 0.82) or minor bleeding events (α = 0.007) among the four treatment groups. Use of anticoagulation alone was associated with a lower duration of ICU stay (α < 0.001). There was a significant decrease in the secondary outcome of one year all-cause mortality in favor of full dose and catheter-directed thrombolytic treatment (α = 0.003). Pulmonary artery systolic pressure of > 70 mmHg was associated with increased 7-day mortality (OR 7.79, P = 0.048), and systolic blood pressure < 130 (OR 23.0; P = 0.003) and elevated N-terminal pro-B-type natriuretic peptide > 1400 pg/nl (OR 15.33; P = 0.01) were associated with increased 30- day mortality. Conclusions: The use of thrombolytic therapy is not associated with a mortality benefit in the first 30 days compared to anticoagulation alone in this patient population and is associated with increased utilization of intensive care unit resources. We advocate for a conservative approach utilizing initial anticoagulation alone in a patient diagnosed with intermediate-risk pulmonary embolism.