Characterization of pulmonary embolism events in patients with suspected pneumonia.

Pneumonia and pulmonary embolism (PE) share similar clinical presentations, posing a significant diagnostic challenge. We investigated whether available diagnostic modalities could identify distinct characteristics in patients suspected of pneumonia later diagnosed with PE. Patients who underwent a CT pulmonary angiography (CTPA) scan on admission were retrospectively screened for suspected pneumonia, defined as a chest X-ray infiltrate accompanied by clinical or laboratory evidence of infection. Patients with COVID-19, pregnancy, and thrombophilia were excluded. Comorbidities, clinical presentation, electrocardiograms, laboratory tests, and outcomes were compared between patients with and without PE. Among 5,522 CTPA scans, 846 patients had suspected pneumonia. 106 (12.5%) had PE. Patients with PE had a higher rate of prior venous thromboembolism (14.2% vs. 7.7%, P = 0.03). However, other risk factors and baseline anticoagulation therapy were comparable between groups. Most clinical and laboratory parameters, including CRP and D-dimer levels, were similar, as were the Wells criteria and Geneva scores. New-onset atrial fibrillation was more frequent in PE patients (11.1% vs. 5.4%, P = 0.009). Prolonged expiration and wheezing were more common in those without PE (17.9% vs. 5.7%, P = 0.0015) and remained the only discriminative parameter in a multivariate analysis (OR = 0.29, 95%CI: 0.09-0.74, P = 0.021). Notably, the presence of PE did not impact mortality rates. PE is prevalent in patients with suspected pneumonia undergoing CTPA. Clinical presentation, laboratory findings, and commonly used diagnostic tools, including the Wells criteria and the Geneva score, perform poorly in this setting. These findings underscore the need for new diagnostic approaches.