Background:
Although practice guidelines recommend outpatient care for selected, haemodynamically stable patients with pulmonary embolism, most treatment is presently inpatient based. we aimed to assess non-inferiority of outpatient care compared with inpatient care.
Methods:
We undertook an open-label, randomised non-inferiority trial at 19 emergency departments in switzerland, france, belgium, and the usa. we randomly assigned patients with acute, symptomatic pulmonary embolism and a low risk of death (pulmonary embolism severity index risk classes i or ii) with a computer-generated randomisation sequence (blocks of 2-4) in a 1:1 ratio to initial outpatient (ie, discharged from hospital ≤24 h after randomisation) or inpatient treatment with subcutaneous enoxaparin (≥5 days) followed by oral anticoagulation (≥90 days). the primary outcome was symptomatic, recurrent venous thromboembolism within 90 days; safety outcomes included major bleeding within 14 or 90 days and mortality within 90 days. we used a non-inferiority margin of 4% for a difference between inpatient and outpatient groups. we included all enrolled patients in the primary analysis, excluding those lost to follow-up. this trial is registered with clinicaltrials.gov, number nct00425542.
Findings:
Between february, 2007, and june, 2010, we enrolled 344 eligible patients. in the primary analysis, one (0·6%) of 171 outpatients developed recurrent venous thromboembolism within 90 days compared with none of 168 inpatients (95% upper confidence limit [ucl] 2·7%; p=0·011). only one (0·6%) patient in each treatment group died within 90 days (95% ucl 2·1%; p=0·005), and two (1·2%) of 171 outpatients and no inpatients had major bleeding within 14 days (95% ucl 3·6%; p=0·031). by 90 days, three (1·8%) outpatients but no inpatients had developed major bleeding (95% ucl 4·5%; p=0·086). mean length of stay was 0·5 days (sd 1·0) for outpatients and 3·9 days (sd 3·1) for inpatients.
Interpretation:
In selected low-risk patients with pulmonary embolism, outpatient care can safely and effectively be used in place of inpatient care.
Funding:
Swiss national science foundation, programme hospitalier de recherche clinique, and the us national heart, lung, and blood institute. sanofi-aventis provided free drug supply in the participating european centres.