Abstract:
Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe but potentially
treatable complication of pulmonary embolism (PE). SPECT CT has emerged as a non-invasive
modality capable of detecting residual perfusion defects, potentially improving early risk stratification.
Current guidelines rely on echocardiographic and hemodynamic assessment for CTEPH diagnosis, but
these methods may lack sensitivity in early-stage disease.
Objective: To investigate the predictive value of RV echocardiographic findings and SPECT CT in
identifying PE survivors at risk of developing CTEPH and to assess its role in guiding therapeutic
interventions.
Methods: It is a prospective study that enrolled PE survivors who had completed standard
anticoagulation period (3-6 months). Patients underwent structured follow-up, including clinical
assessment (dyspnea score, 6-minute walk test), echocardiography, biochemical markers (NTproBNP), and SPECT CT imaging. Correlations between SPECT CT findings, right ventricular
dysfunction, and pulmonary hemodynamics were analyzed using multivariate logistic regression on
SPSS program.
Results: Among 86 enrolled patients, 30 underwent complete imaging workup, revealing persistent
perfusion defects in 60% of symptomatic individuals. Of these, 43% exhibited echocardiographic
markers suggestive of chronic thromboembolic pulmonary hypertension (CTEPH), with significant
associations between perfusion abnormalities and elevated NT-proBNP levels (p<0.001).
Echocardiographic findings suggest a strong correlation between TAPSE/PSAP rapport and the
NTproBNP test (p<0,001), RV strain changes (p<0,02) and high probability of pulmonary
hypertension (p<0,001). The severity of perfusion defects on SPECT CT correlated strongly with
thoracic pain (p<0,03) and high probability of pulmonary hypertension (p<0.03). No statistical
significant correlation found between SPECT CT changes and RV strain (p<0,9), 3D RVEF results
(p<0,1) or TAPSE/PSAP rapport (p<0,08).
Conclusions: SPECT CT may represent a valuable imaging modality in early detection of post-PE
sequelae, identifying patients with high probability of pulmonary hypertension who may benefit from
more diagnostic tests or/and interventional and improving long-term cardiovascular
outcomes. However, additional prospective scientific studies are required to draw definitive
conclusions regarding its clinical utility and optimal integration into post-PE management.
