ISTH 2019

Developments in prognostic risk stratification and the availability of orally administered anticoagulants have made home treatment of acute pulmonary embolism (PE) both safe and feasible - in 30-55% of patients, as shown by previous studies. Home treatment can improve quality of life and can substantially reduce healthcare costs.¹

"Detailed data from day-to-day clinical practice are largely unavailable, therefore we aimed to evaluate current practice patterns and outcomes of home treatment in PE patients throughout the Netherlands," explained Dr Stephan Hendriks, Leiden University Medical Center, Department of Thrombosis and Hemostasis, the Netherlands.

His team analysed data post hoc from YEARS, a prospective, diagnostic management study across 12 hospitals. The analysis looked at 456 adult patients with suspected acute PE, excluding those who were pregnant, had a contraindication for CT pulmonary angiography, were not available for follow-up, or had received anticoagulation of ≥24 hours. Twelve patients were excluded as they were diagnosed with PE during hospitalisation.

The primary outcomes included the proportion of PE patients treated at home and the reasons for admission (if treated in hospital), and secondary outcomes included the 3-month incidence of PE-related re-admissions in the two groups. Hestia criteria were used to assess risk.

"Of all 444 patients included in this experiment, 191 were treated at home. So, 43% [95% CI: 38-48] of all patients were discharged from hospital within 24 hours. Those patients tended to be younger than those who were hospitalised, and also had less signs of renal dysfunction."

Mean age was 56 (SD: 16) versus 62 (SD: 16) and CrCl <60 mL/min was 12% (n=23) versus 22% (n=54) in the home treatment versus hospitalised group.

For the 253 (53%) patients who were hospitalised, the main reasons were: for oxygen administration (frequency: 78; 32% of patients) and/or medical or social reasons (frequency: 100; 41%).

Commenting on secondary outcomes of the analysis, Dr Hendriks continued, “the 3-month cumulative incidence of any adverse event was 3.7% in those treated at home, consisting of two recurrent VTEs, three major bleeds and two deaths. This is important, because recurrent VTEs and the major bleeds did not turn out to be fatal. Also, the two deaths were not adjudicated to be associated with VTE.” These deaths were attributed to progressive lung carcinoma and non-specific interstitial pneumonia.

In the hospitalised group, 3-month incidence of any adverse event was 9.5% (three cases of recurrent VTE, six major bleeding events and 14 deaths).

PE-related re-admission rate was 9.4% in outpatients versus 7.9% in hospitalised patients, resulting in a non-significant hazard ratio of 1.22 (95% CI: 0.64-2.3).

"Of course, this analysis has limitations… you've got the post-hoc design," explained Dr Hendriks, adding "there could be an under-representation of high-risk subgroups. For example, all pregnant patients were excluded." The primary outcomes could therefore be overestimated.

"However, as the YEARS criteria were implemented as standard diagnostic care in the participating centres, the vast majority of all potential PE patients were included in this study."

"[In] conclusion, 43% of all outpatients were treated at home, the rates of adverse events were low, and PE-related re-admission rates did not differ between patients treated at home or in hospital," he summarised. The findings provide a valuable contribution to our limited knowledge of inpatient versus outpatient treatment for acute PE.