Perfusion defects common following PE
MedWire News: Almost a third of patients show pulmonary perfusion defects 1 year after pulmonary embolism (PE), say French researchers who identified key clinical risk factors for this outcome.
The team from Hôpital Européen Georges Pompidou in Paris also found that these residual effects of PE are associated with increased pulmonary artery pressure (PAP) and poorer patient function during exercise.
Olivier Sanchez and co-workers followed-up 254 patients a median of 12 months after acute PE and after receiving a median of 6 months’ anticoagulation. The patients underwent a ventilation/perfusion lung scan, echocardiography, and a 6-minute walk test, and were examined for thrombophilia and hemostatic markers.
Overall, 29% of patients showed perfusion defects. Patients with perfusion defects were more likely than those without to have dyspnea (60% vs 36%), and had a significantly higher systolic PAP (39 vs 31 mmHg). Defects were also associated with a shorter 6-minute walk distance (374 vs 427 m).
In multivariate analysis, perfusion defects were significantly and independently predicted by age at PE diagnosis (odds ratio [OR]=1.35 per 10-year increase), time interval between symptom onset and diagnosis (OR=1.17 per 10-day increase), percentage pulmonary vascular obstruction at PE onset (OR=1.34 per 10% increase), and prior venous thromboembolism (OR=2.06).
Tissue factor pathway inhibitor level was also associated with perfusion defects, with an OR of 1.25 per 10 ng/ml increase, but no link was found between risk for defects and hereditary thrombophilia or antiphospholipid antibodies.
“Although persistent perfusion defects were associated with some degree of pulmonary hypertension and functional limitation, our study did not allow assessment of the long-term clinical significance of residual defects for the occurrence of chronic thromboembolic pulmonary hypertension or recurrent PE,” Sanchez et al comment in the Journal of Thrombosis and Haemostasis.
“Long-term follow-up of this cohort is currently underway to clarify these issues,” they say.
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By Lynda Williams