Pulmonary artery obstruction index, pulmonary artery diameter and right ventricle strain as prognostic CT findings in patient with acute pulmonary embolism

Abstract

OBJECTIVE: This study was designed to determine predictors of pulmonary hypertension and signs of right heart dysfunction caused by pulmonary embolism (PE) that may lead to early detection of high-risk patients. So the predictive value of pulmonary artery obstruction index (PAOI), measured by pulmonary CT angiography (PCTA) in the acute setting, in predicting the patients susceptible to PE cardiac complications was evaluated. Also two other PCTA indices, pulmonary artery diameter (PAD), and right ventricle (RV) strain, in these patients were investigated and their predictive value for cardiac complications on follow up echocardiography were demonstrated. MATERIALS AND METHODS: In the study 120 patients with a definite diagnosis of PE were included. The PAOI, PAD and RV strain were measured using PCTA at the time of the initial diagnosis. Transthoracic echocardiography was done 6 months after the diagnosis of PE and RV echocardiographic indices were measured. Pearson correlation was used to investigate correlation between PAOI, PAD, RV strain and signs of right heart dysfunction. RESULTS: PAOI was strongly correlated with systolic pulmonary artery pressure (SPAP) (r=0.83), RV systolic pressure (r=0.78) and RV wall thickness (r=0.61) in long-term follow up echocardiography. A higher rate of RV dysfunction and RV dilation was detected among the patients with higher PAOI (P<0.001). PAOI≥18 was strongly predictive for development of RV dysfunction. Also developments of pulmonary hypertension, RV systolic hypertension, RV dilation, RV dysfunction, and RV hypertrophy were significantly more common among patients with higher PAD and RV strain (P<0.001). CONCLUSIONS: PAOI, PAD and RV strain are sensitive and specific PCTA indices that can predict the development of long-term complications such as pulmonary hypertension and right heart dysfunction, at the time of initial PE diagnosis.