Anticoagulant treatment for subsegmental pulmonary embolism

Acute pulmonary embolism (PE) is a common cause of death, accounting for 50,000 to 200,000 deaths annually. It is the third most common cause of mortality among the cardiovascular diseases, after coronary artery disease and stroke. The advent of multi-detector computed tomographic pulmonary angiography (CTPA) has allowed better assessment of PE regarding visualisation of the peripheral pulmonary arteries, increasing its rate of diagnosis. More cases of peripheral PEs, such as isolated subsegmental PE (SSPE) and incidental PE, have thereby been identified. These two conditions are usually found in patients with few or no classic symptoms such as coughing (including coughing up blood), chest or upper back pain, acute shortness of breath, or general or specific failure of the circulation that is either cardiac or peripheral in nature. However, in patients with an impaired cardiac and pulmonary condition the classic PE symptoms can be found with isolated SSPEs. Incidental SSPE is found casually in asymptomatic patients, usually by diagnostic imaging performed for other reasons (for example routine computed tomography (CT) for cancer staging in oncologic patients). Patients with isolated SSPE or incidental PE may have a more benign clinical presentation compared with those with proximal PEs. However, the clinical significance and prognosis in these patients has to be studied to evaluate whether anticoagulation therapy is required. No studies met the inclusion criteria of the review. There is no randomised controlled trial evidence for the effectiveness and safety of anticoagulation therapy versus no intervention in patients with isolated subsegmental pulmonary embolism (SSPE) or incidental SSPE and, therefore, we can not draw any conclusions. Well-conducted research is required before informed practice decisions can be made.