Differences in the clinical course of acute massive and submassive pulmonary embolism

Acute massive or submassive pulmonary embolism (PE) has high mortality, but the clinical course according to the location of onset (ie, in-hospital or out-of-hospital) is unknown.

In the present study 56 consecutive patients with acute massive or submassive PE were studied retrospectively and a comparison made of the clinical characteristics, and outcomes between in-hospital onset (Group A) and out-of-hospital onset (Group B). Patients in Group A (n=28) had more frequent comorbidities with hemodynamic instability (54% vs 4%, p<0.0001) and temporary risk factors (93% vs 11%, p<0.0001), whereas patients in Group B (n=28) had a longer duration of symptoms (median: 5.5 days vs 0.5 day; p<0.0001), and had higher systolic pulmonary artery pressure (63+/-17 mmHg vs 46+/-12 mmHg, p=0.0006). Although in-hospital mortality did not differ between the 2 groups, the recurrence rate was higher in Group B (23% vs 0%, p=0.03).

Patients who had in-hospital onset of PE had mostly temporary risk factors, unstable hemodynamics and a lower recurrence rate compared with the cases of out-of-hospital onset. In cases of in-hospital onset, prompt diagnosis and suitable treatment is needed to prevent fatalities and cases of out-of-hospital onset should be followed carefully for recurrence.