Objective: To explore the relationship of spinal ventricular septal angle (SVSA) measured by computer tomographic pulmonary angiography (CTPA) and right cardiac functions, N-terminal brain natriuretic peptide (NT-proBNP) in the patients with chronic thromboembolic pulmonary hypertension (CTEPH).
Methods: Forty-four CTEPH patients, 26 males and 18 females aged (52 ± 12) years old on average, at our hospital from January 2008 to January 2010 were retrospectively reviewed. SVSA and such pulmonary artery obstruction indices as Qanadli and Mastora indices were evaluated by two independent radiologists. The parameters of right heart functions were evaluated by echocardiography and right-heart catheterization. The level of NT-proBNP was measured by enzyme linked immunosorbent assay (ELISA).
Results: SVSA was (63 ± 11)° in CTEPH and (40 ± 7)° in the control group. The differences were significant (t = 12.320, P = 0.000). SVSA had a moderately positive correlation with the level of NT-proBNP (r = 0.704, P = 0.000). A positive correlation existed between SVSA and right atrium transverse diameter (r = 0.381, P = 0.002), right atrium long axis diameter (r = 0.437, P = 0.000) and right ventricular transverse diameter (r = 0.449, P = 0.000) on echocardiography. But there was no correlation between SVSA and right ventricular ejection fraction (r = -0.175, P = 0.365, n = 24). Also there was a negative correlation between SVSA and cardiac output (r = -0.337, P = 0.025), cardiac index (r = -0.351, P = 0.020), right cardiac work (r = -0.307, P = 0.043) and right ventricular stroke work (r = -0.384, P = 0.010).
Conclusion: Spinal ventricular septal angle measured on CTPA may serve as a better predictor for evaluating the level of NT-proBNP and right cardiac functions in CTEPH.