Data are limited on clinical presentation and outcomes in elderly patients with acute symptomatic isolated subsegmental pulmonary embolism (SSPE). We compared clinical presentation, risk factors, processes of care, and outcomes between elderly patients with SSPE and patients with more proximal pulmonary embolism (PE).
We prospectively followed 578 patients aged ≥65 years with acute symptomatic isolated SSPE or proximal PE in a multicentre Swiss cohort study. We compared quality of life at three months using the PEmb-QoL, and examined the independent association between localization of PE and clinical outcomes (recurrent venous thromboembolism [VTE], overall mortality) using regression models with adjustment for potential confounders.
Overall, 11% of patients had isolated SSPE. Patients with SSPE were less likely to have a pulse ≥110/min (3% vs. 13%), but more likely to have active cancer (28% vs. 15%) and to receive outpatient care (11% vs. 4%) than patients with proximal PE. Virtually all patients (98%) with SSPE received anticoagulants. Quality of life did not differ between the groups at 3 months. No patient with SSPE vs. seven patients with proximal PE died from the index PE event. No significant difference was observed for the 3-year cumulative incidence of recurrent VTE (7% vs. 12%) and death (29% vs. 20%). After adjustment, SSPE was not associated with a lower risk of clinical outcomes than proximal PE.
Clinical presentation and incidences of adverse outcomes did not differ significantly between elderly patients with SSPE or proximal PE, although the power to detect differences might have been limited given the small number of events. Thus, our study does not provide evidence that unselected, elderly patients with SSPE have a more benign clinical course.