Abstract
Background: Subsegmental pulmonary embolism (SSPE) affect the subsegmental and distal branches of the pulmonary arteries. Clinical equipoise exists in SSPE management, with insufficient evidence of improved mortality or reduced venous thromboembolism (VTE) recurrence with anticoagulation, but a risk of clinically significant bleeding. We aim to investigate SSPE prevalence, risk factors and clinical outcomes.
Method: A retrospective observational study of all consecutive SSPEs diagnosed using CTPA from 2013 to 2018 at 3 UK hospitals. CTPA reports were text mined in R (v3.5.1) for words related to PE. Diagnosis was confirmed by manual review and validated by a second reviewer. Electronic health record data was collected. Comparator groups (no PE (NPE); segmental PE (SPE)) were propensity matched by age, sex and year of CTPA. Outcomes (VTE recurrence, major bleeding, mortality) at 3 months are reported.
Results: 14,300 CTPA’s provided 1929 (13.5%) PE diagnoses, of which 82 (4.3%) were SSPEs. 75 (96.2%) SSPEs, 72 (98.6%) SPEs and 17 (21.8%) NPEs were treated with anticoagulation; DOACs in 57.7%, 57.5% and 7.6% cases respectively. No significant difference in VTE recurrence (p=0.11), major bleeding (p=0.21) and mortality (p=0.78) between SSPE, SPE and NPE groups.
Conclusion: Clinical equipoise remains regarding the treatment of SSPEs given insufficient evidence of improvement of mortality and VTE recurrence. A multicentre randomised controlled trial of 1466 SSPE patients in the UK (STOP-APE: stopping anticoagulation for isolated SSPE (NIHR128073) aims to address the clinical equipoise in SSPE treatment by comparing anticoagulation and no anticoagulation strategies.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3568.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020