Pulmonary Embolism Thrombolysis a Double-Edged Sword

A new study has found that thrombolytic therapy (TT) nearly halved mortality in patients with pulmonary embolism (PE), but at the cost of a higher risk of major bleeding.

Researchers at St. Luke's-Roosevelt Hospital Center (New York, NY, USA), Thomas Jefferson University Hospital (Philadelphia, PA, USA), and other institutions conducted a meta-analysis of studies to determine mortality benefits and bleeding risks associated with TT compared with anticoagulation in acute PE. In all, 16 eligible trials comprising 2,115 individuals were identified over the past four decades. The primary outcomes were all-cause mortality and major bleeding; secondary outcomes were risk of recurrent embolism and intracranial hemorrhage (ICH).

The results showed that TT was associated with a 47% reduction in mortality, and a 2.7-fold increase in major bleeding compared with standard anticoagulant therapy. Major bleeding was not significantly increased in patients younger than age 65, but a subgroup analysis of patients over the age of 65 revealed a threefold increase in risk of major bleeding. Only one small study evaluated the use of catheter-directed TT, which limited the study’s generalizability beyond patients receiving systemic treatment. The study was published in the June 18, 2014, issue of the Journal of the American Medical Association (JAMA).

“Among patients with pulmonary embolism, including those who were hemodynamically stable with right ventricular dysfunction, thrombolytic therapy was associated with lower rates of all-cause mortality and increased risks of major bleeding and ICH,” concluded lead author Saurav Chatterjee, MD, of St. Luke's-Roosevelt, and colleagues. “However, findings may not apply to patients with pulmonary embolism who are hemodynamically stable without right ventricular dysfunction.”

PE is most often caused by a blood clot migrating to the lungs, with the most common source being a deep vein thrombosis (DVT); less common causes include air bubbles, fat droplets, amniotic fluid, or clumps of parasites or tumor cells. Risk factors include burns, cancer, childbirth, a family history of blood clots, fractures of the hips or thigh bone, heart attack or heart surgery, long-term bed rest, severe injury, stroke, surgery, use of birth control pills or estrogen therapy.

Related Links:
St. Luke's-Roosevelt Hospital Center
Thomas Jefferson University Hospital