Rates of overtreatment and treatment-related adverse effects among patients with SSPE

Modern computed tomographic pulmonary angiography (CTPA) often picks up on subsegmental pulmonary embolisms (SSPEs), which may represent nothing more than imaging artifact or may be incidental in nature.

Modern computed tomographic pulmonary angiography (CTPA) often picks up on subsegmental pulmonary embolisms (SSPEs), which may represent nothing more than imaging artifact or may be incidental in nature. The overwhelming tendency, however, is to treat them anyway—which researchers at Canada's McGill University say is typically unnecessary and likely harmful. The team performed a retrospective review of all CTPAs during 2014–16 at a single hospital. Of 1,408 scans, 222 came back positive and 79 of those were labeled as subsegmental—including 8 that tested positive for deep vein thrombosis under Doppler ultrasound and 71 diagnosed under emergency department (ED) care. Among the 71 presumed isolated and insignificant SSPEs, 62 were treated with anticoagulation—often in the setting of terminal illness. During followup of 3 months, 26 of those patients experienced adverse events, including drop in hemoglobin levels, blood transfusions, ED visits, hospital readmission for reasons unrelated to venous thromboembolism, and death. The 9 cases disqualified from anticoagulation treatment, meanwhile, were ruled out because of bleeding at diagnosis or poor prognosis. The findings point to common overtreatment of SSPE, which the McGill investigators say should instead be addressed through clinical surveillance. The exceptions include when other emboli are present or when therapy poses risks. In addition, the patient's preference, hospitalization status, and pulmonary reserve should be taken into account.