The Prevalence of Pulmonary Embolism in Patients With Interstitial Lung Disease: A Cross-Sectional Retrospective Study

Objective: Interstitial lung disease (ILD) can be complicated by comorbidities, particularly pulmonary embolism (PE). We aimed to assess the prevalence of PE in ILD patients. Methods: Our study is a cross-sectional retrospective study conducted on ILD cases diagnosed between January 1, 2010, and June 30, 2021. Out of the total ILD cases (n = 153), we enrolled for analysis only those who underwent a computed tomography pulmonary angiography (CTPA) (n = 48). We recorded the number of patients who had a PE event on CTPA, gender, age at PE and ILD diagnoses, a chronology of PE with ILD diagnosis, PE characteristics, PE therapy, type of ILD, radiographic progression of ILD, presence of pulmonary hypertension, and mortality. Results: Seven patients out of 48, had PE (14.6%). The mean age at the time of PE diagnosis was 70 ± 9.73 years. No statistical difference existed between the PE and non-PE groups regarding gender predominance or the age at ILD diagnosis. All of the identified PE events (n = 7) were segmental (100%), one was saddle PE (14.3%) and one was recurrent (14.3%). No PE events were diagnosed prior to ILD diagnosis, three patients (42.9%) had a simultaneous diagnosis of PE and ILD, and four patients (57.1%) were diagnosed with a PE after ILD diagnosis by a mean time of eight months. No difference in ILD radiographic progression, pulmonary hypertension, or mortality between the two groups was found. Conclusion: PE is not uncommon in ILD and needs to be ruled out, especially in patients with worsening respiratory status.