Associação entre sinal da veia pulmonar e diagnóstico de tromboembolismo pulmonar agudo

Abstract

Introduction: Pulmonary thromboembolism (PE) is the third leading cause of mortality among acute cardiovascular diseases, after myocardial infarction and stroke. Computed Tomography Pulmonary angiography (CTPA) is the gold standard for diagnosing PE, making it possible to identify filling defects in the pulmonary veins in areas adjacent to the PE. Objective: Considering that pulmonary arterial obstruction decreases venous flow, we have hypothesized that filling defects in pulmonary veins can be identified in areas adjacent to pulmonary embolism (PE); this sign has been called “pulmonary vein sign” (PVS), therefore, we evaluated its prevalence and performance for PE diagnosis in CTPA. Casuistic and Method: This retrospective study enrolled consecutive patients with clinical suspicion of PE who underwent CTPA scan. The PVS was defined by the following criteria: (a) presence of a homogeneous filling defect of at least 2 cm in a pulmonary vein; (b) attenuation of the left atrium [160 Hounsfield units. Using the cases that presented PE on CTPA as reference, sensitivity, specificity, and positive and negative predictive values were calculated for PVS. Results: In total, 119 patients (73 female; mean age, 62 years) were included in this study. PE was diagnosed in 44 (35.8%) patients. The PVS was present in 16 out of the 44 patients with PE. Sensitivity was 36.36% (95% confidence interval (CI) 22.83-52.26%); specificity, was 98.67% (95% CI 91.79-99.93%); positive predictive value, 94.12% (95% CI 69.24-99.69%); negative predictive value, 72.55% (95% CI 62.67-80.70%). The Kappa Index for the PVS was good (0.801; 95% CI 0.645-0.957). PVS was correlated with lobar and segmental pulmonary embolism (p 1 0.01). Conclusions: Despite a low sensitivity; the presence of the pulmonary vein sign was highly specific for PE, with good agreement between readers. This sign could contribute to PE diagnosis in CTPA studies.