The role of Q-SPECT CT in identifying post-pulmonary embolism sequelae

Abstract Background Pulmonary embolism (PE) remains a major global health issue, often leading to chronic complications despite optimal anticoagulant therapy. Over 50% of PE survivors continue to experience persistent symptoms, with a subset developing chronic thromboembolic pulmonary hypertension (CTEPH). Early identification of patients at risk for post-PE sequelae is crucial for optimizing management strategies. Single Photon Emission Computed Tomography with integrated Computed Tomography - Perfusion (Q-SPECT CT) has emerged as a promising tool for detecting residual perfusion defects, potentially refining risk stratification and guiding therapeutic decisions. Objective This study aims to evaluate the role of Q-SPECT CT in assessing pulmonary perfusion abnormalities in symptomatic PE survivors and to determine its utility in predicting long-term cardiovascular outcomes. Methods A prospective study enrolling PE survivors who had completed the standard anticoagulation period (3-6 months). Patients underwent a comprehensive evaluation, including clinical assessment (NYHA classification, 6-minute walk test), biochemical markers (NT-proBNP), echocardiography, and Q-SPECT CT imaging. Statistical analysis was performed using Spearman’s test in SPSS to correlate perfusion defects with functional status, hemodynamic parameters, and clinical outcomes. Results Preliminary data from 60 patients indicate that 83,3% of symptomatic individuals exhibit persistent dyspnea, with Q-SPECT CT revealing perfusion abnormalities in 60% of cases. Echocardiographic findings suggest a strong correlation between TAPSE/PSAP rapport and the NTproBNP test (p0,001), RV strain changes (p0,02) and high probability of pulmonary hypertension (p0,001). The severity of perfusion defects on Q-SPECT CT correlated strongly with thoracic pain (p0,03) and high probability of pulmonary hypertension (p0.03). No statistical significant correlation found between Q-SPECT CT changes and RV strain (p0,9), 3D RVEF results (p0,1) or TAPSE/PSAP rapport (p0,08). Conclusions Preliminary data sugests that Q-SPECT CT may represents a valuable imaging modality for post-PE risk stratification, identifying patients with high probability of pulmonary hypertension who may benefit from more diagnostic tests or/and interventional therapies. More studies needed.