Pulmonary embolism: a retrospective comparative study between patients with atypical vs typical clinical presentation

Natural history and outcomes of patients with pulmonary embolism (PE) without typical symptoms (atypical PE) remain unclear. The aim of the study is to compare the clinical characteristics and the prognosis between typical PE and atypical PE.

We retrospectively analyzed data from consecutive patients admitted to the Emergency Department (ED) because of a diagnosis of PE and classified them in two groups: typical PE and atypical PE. We defined PE to be typical in presence of almost one of the following symptoms or signs: dyspnea, chest pain, hemoptysis or signs of deep vein thrombosis.

Of the 191 patients with PE, 154 (81%) had typical PE and 37 (19%) had atypical PE. Patients with atypical and typical PE seemed to had similar prognostic factor such as high risk sPESI (73% vs 65%, p=0.3), right ventricular dysfunction (30% vs 26%, p=0.6) and central PE at chest CT scan (38% vs 36%, p=0.8). The rate of 30 day mortality was 7% in the typical group and 8% in the atypical group (p=0.8). The length of stay in hospital was the same in the two groups (6 days; p=0.2).

We found that atypical and typical PE seem to be related diseases with a similar short term prognosis. Therefore, we could speculate that a missed diagnosis of PE in ED could expose the patients to a worsen prognosis. Further perspective studies are required for better investigate this diagnostic challenge.