Persistence of symptoms and discomfort after pulmonary embolism (PE) is frequent and poorly understood.

To identify patients who remained symptomatic 6 months after an acute PE, and to determine factors associated with a 6-months functional impairment.

One hundred and fifty-three patients with acute symptomatic PE were prospectively included from February 2015 to January 2017 at the University hospital of Toulouse, France. Clinical and paraclinical data were evaluated at inclusion and after 6 months of follow-up. Six-month follow-up included clinical evaluation, psychiatric survey, echocardiography and functional cardiopulmonary test. Symptomatic patients (i.e. patients with dyspnea and/or chest discomfort) underwent a ventilation-perfusion scintigraphy scan.

Sixty (39%) patients remained symptomatic 6 months after the acute PE. After multivariate analysis, only an initial history of deep vein thrombosis (DVT) was predictive of 6-months symptoms (OR 3.35, 95% CI [1.19–9.39], P=0.022), while initial use of low molecular weight heparin (LMWH) was protective (OR 0.36, 95% CI [0.13–0.96], P=0.041). The six-month functional test appears to be related to symptoms. There was no difference in clinical, laboratory or echocardiographic parameters between symptomatic and asymptomatic patients. No pathological defect was found on ventilation-perfusion scintigraphy for 27 (52%) of symptomatic patients.

Persistence of symptoms at six months of PE is frequent and is associated with a history of DVT and less frequent with initial LMWH therapy. Pathophysiology of post-pulmonary embolism syndrome is complex and not related to the initial PE severity nor the parameters of echocardiography.