Outpatient treatment proves safe, effective for low-risk patients with pulmonary embolism, study suggests

"This is the most rigorous study to date to compare inpatient and outpatient care for a selected group of stable patients with pulmonary embolism," said Donald M. Yealy, M.D., senior author of the study and chairman of the Department of Emergency Medicine at the University of Pittsburgh School of Medicine. "Our findings support a shift in clinical management of PE for a substantial portion of low-risk patients, which may reduce hospitalizations and costs."

Pulmonary embolism is a blockage of the main artery of the lung or one of its branches. Most are due to pelvic and upper leg blood clots that grow in the vein before detaching and traveling to the lungs. The most common symptoms include unexplained shortness of breath or chest pain while breathing. On average, 650,000 PEs occur annually, and it is the third-leading cause of hospital death.

In the Outpatient Treatment of Pulmonary Embolism (OPTE) trial, researchers looked at more than 300 patients at 19 emergency departments in Switzerland, Belgium, France and the U.S. who had been randomly assigned to inpatient or outpatient care between February 2007 and June 2010. These patients were judged to have a low risk of death, based on a validated clinical prognostic model. Of those screened, 30 percent met the eligibility criteria, suggesting that a shift in the clinical management of such patients may have a broad effect.

Patients assigned to outpatient treatment received standardized teaching from a study nurse about self-injection with enoxaparin, an anti-coagulant, and were to be discharged from the emergency department within 24 hours. Patients assigned to inpatient treatment were admitted to the hospital and received the same enoxaparin regimen. In both groups, the study protocol recommended early initiation of oral anticoagulation medications and continuation for a minimum of 90 days.

Patient outcomes for outpatient care showed that it was as safe and effective as inpatient care. For instance, researchers found that one of 171 outpatients developed recurrent venous thromboembolism, or blood clots forming within the veins, within 90 days compared with none of 168 inpatients. One patient in each group died within 90 days. Two of the outpatients and no inpatients had major bleeding within 14 days.

Patient satisfaction regarding care exceeded 90 percent for both groups, and both had essentially the same numbers of hospital readmissions, emergency department visits and outpatient visits to a doctor's office within 90 days. But researchers found that cost savings from reductions in hospital stays might be partially offset by an increased frequency in home-nursing visits.

"Our findings are consistent with previous non-randomized studies and systematic reviews that outpatient care of PE is associated with low rates of recurrent venous thromboembolism, major bleeding and death," said Dr. Yealy. "Patients with PE prefer outpatient treatment, and these reassuring trial results should prompt physicians to consider such care more often for low-risk patients."

Co-authors of the study include lead author Drahomir Aujesky, M.D., Bern University Hospital, Switzerland; Pierre-Marie Roy, M.D., LUNAM University and University of Angers, France; Franck Verschuren, M.D., University of Louvain, Belgium; Marc Righini, M.D., and Arnaud Perrier, M.D., University of Geneva, Switzerland; Joseph Osterwalder, M.D., Cantonal Hospital of St. Gallen, Switzerland; Michael Egloff, M.D., and Hans-Jűrg Beer, M.D., Cantonal Hospital of Baden, Switzerland; Bertrand Renaud, M.D., and Alfred N'gako, M.D., University Hospital Henri Mondor, France; Peter Verhamme, M.D., University of Leuven, Belgium; Michael J. Fine, M.D., VA Center for Health Equity Research and Promotion and Pitt School of Medicine; Roslyn A. Stone, Ph.D., and Nathan A. Pugh, B.S., University of Pittsburgh; Catherine Legall, M.D., University of Argenteuil, France; Olivier Sanchez, M.D., Hôpital Européen Georges Pompidou, France; Jacques Cornuz, M.D., and Olivier Hugli, M.D., University of Lausanne, Switzerland.

The study was supported by grants from the Swiss National Science Foundation, the Programme Hospitalier de Recherche Clinique 2007, and the U.S. National Heart, Lung, and Blood Institute. Sanofi-Aventis provided free drug supply in the participating European centers.