Risk Factors, Clinical Profile, and Management Outcome of Patients with Isolated Subsegmental Pulmonary Embolism: A Single-Center Experience from North India

Background and Objective: The clinical profile of patients with isolated subsegmental pulmonary embolism (SSPE) remains understudied and underreported. To describe the clinical particulars of patients with SSPE, we aimed to compare clinical signs and symptoms, risk factors, lab parameters, and short-term mortality between patients with isolated SSPE and those with proximal pulmonary embolism (PE). Materials and Methods: We prospectively studied all patients with objectively confirmed PE over 4 years. Depending on the location of the most proximal pulmonary artery in which emboli were detected, patients were divided into two groups: (a) isolated SSPE and (b) proximal PE. Different clinical and laboratory parameters were compared between the two groups. Results: One hundred and fifty patients were enrolled during the 4-year study. Twenty-three (15.3%) patients were diagnosed with isolated SSPE. Compared to proximal PE, patients with SSPE are younger, are more likely to have active malignancy, less likely to have dyspnea, and more likely to have chest pain, are hemodynamically stable with a lesser prevalence of hypoxemia and hypocapnia. Patients with isolated SSPE have shorter hospital stays and lower 30-day mortality compared to proximal PE. Conclusion: Patients with isolated SSPE have a mild clinical presentation, lesser laboratory abnormalities, and a favorable short-term outcome compared to patients with proximal PE.