Objective To investigate the relation of spinal ventricular septal angle (SVSA) measured by computer tomographic pulmonary angiography (CTPA) and pulmonary vascular resistance (PVR) measured by right heart catheterization in patients with chronic thromboembolic pulmonary hypertension (CTEPH) .Methods Eighty-nine patients with CTEPH (male 57, female 32; 53.08 ±12.43 years) were recruited as a CTEPH group, and 89 patients without pulmonary artery hypertension and pulmonary embolismwere recruited as a control group. The CTEPH patients received CTPA before right-heart catheterization and pulmonary angiography. SVSA and pulmonary artery obstruction indexes including Qanadli Index and Mastora index were evaluated by two radiologists.Results SVSA was 65.13°±12.26°and 39.69°±5.84°in the CTEPH group and the control group respectively, with significant difference between two groups ( t =14.479, P = 0.000) . Qanadli index of the CTEPH patients was( 42.50 ±17.67) % , which had no correlation with SVSA ( r= 0.094, P = 0.552) . Mastora index was ( 30.02 ±15.53) % , which also had no correlation with SVSA ( r=0.025, P =0.873) . SVSA had a moderate positive correlation with PVR ( r =0.529, P =0.000) and a weak positive correlation with right atriumpressure ( r =0.270, P =0.010) . Area under ROC was 0.764 and sensitivity, specificity for PVR≥1000 dyne· s· cm- 5 was 0.714 and 0.778 respectively when SVSA≥67.55°. Conclusion SVSA measured by CTPA can be used as a better predictor for evaluating PVR in CTEPH patients.
