Even though advanced age is associated with an increase in the incidence and overall mortality of PE [19–22], to our knowledge, no study has specifically examined the association between CTPA findings and mortality in elderly patients. Given that co-morbid conditions are more frequent in elderly patients and cardiac dimensions alter with increasing age even without underlying diseases , risk stratification by CTPA findings may differ for elderly patients. We therefore aimed to (1) prospectively evaluate the prognostic performance of the CTOI and the RV/LV diameter ratio in a multicenter cohort of elderly patients with acute PE and (2) to compare the prognostic accuracy of the CTOI, the RV/LV diameter ratio, and the Pulmonary Embolism Severity Index (PESI), a validated clinical prognostic score for acute PE .