Clinical significance and management of subsegmental pulmonary embolism

Computed tomographic pulmonary angiography (CTPA) has a high sensitivity for diagnosing filling defects in subsegmental pulmonary arteries. The adoption of CTPA as the prefered diagnostic modality for the diagnosis of pulmonary embolism (PE) has led to an increased rate of PE diagnosis. However, the case fatality rate is lower and the mortality rate of PE has remained unchanged despite this rise in PE diagnosis suggesting that the disease is of lesser severity. There continues to be clinical equipoise on whether patients diagnosed with isolated subsegmental PE (SSPE) require anticoagulation or can be managed conservatively if the presence of deep vein thrombosis (DVT) has been excluded. Recent recommendations from the European Society of Cardiology suggest an individualized approach for the management of patients with newly diagnosed SSPE based on the risk/benefit ratio of anticoagulation and the presence of lower limb DVT. Prospective data evaluating the safety and efficacy of management strategies for SSPE is needed in order to determine the optimal management of these patients.