Introduction:  Obesity is a risk factor for venous thromboembolism, but studies evaluating its association with pulmonary embolism (PE) in patients with suspected PE are lacking.

Objectives:  To evaluate whether body mass index (BMI) and obesity (i.e., BMI ≥30 kg/m²) are associated with confirmed PE in patients with suspected PE and to assess the efficiency and safety of the age-adjusted D-dimer strategy in obese patients.

Methods:  We conducted a secondary analysis of a multinational, prospective study, in which patients with suspected PE were managed according to the age-adjusted D-dimer strategy and followed for 3 months. Outcomes were objectively confirmed PE at initial presentation, and efficiency and failure rate of the diagnostic strategy. Associations between BMI and obesity, and PE were examined using a log-binomial model that was adjusted for clinical probability and hypoxia.

Results:  We included 1,593 patients (median age: 59 years; 56% women; 22% obese). BMI and obesity were not associated with confirmed PE. The use of the age-adjusted instead of the conventional D-dimer cut-off increased the proportion of obese patients in whom PE was considered ruled out without imaging from 28 to 38%. The 3-month failure rate in obese patients who were left untreated based on a negative age-adjusted D-dimer cut-off test was 0.0% (95% confidence interval: 0.0-2.9%).

Conclusion:  BMI on a continuous linear scale and obesity were not predictors of confirmed PE among patients presenting with a clinical suspicion of PE. The age-adjusted D-dimer strategy appeared safe in ruling out PE in obese patients with suspected PE.