Correlation between severity of adolescent idiopathic scoliosis and pulmonary artery systolic pressure: a study of 338 patients.

Purpose: Study of patients with adolescent idiopathic scoliosis.
Objective: To examine the correlation between pulmonary arterial pressure and coronal Cobb angle of idiopathic scoliosis.
Methods: A total of 338 patients (82.8 % female) with idiopathic scoliosis (average age 15.6 years; range 14-20 years) were included. Preoperatively, the coronal Cobb angle of curvature and the apex location and direction were determined from radiographic records. Tricuspid regurgitation velocity (TRV) and inferior vena cava diameter were also measured using Doppler echocardiography. Pulmonary arterial systolic pressure (sPAP) was calculated from the TRV according to the modified Bernoulli equation and correlations between sPAP and the features of scoliosis were identified by statistical analysis.
Results: Among the 338 patients, there were 305 thoracic curves, 276 (90.5 %) of which were right curves, and 265 thoracolumbar/lumbar curves. sPAP varied from 5.0 to 37.6 mmHg. Pulmonary hypertension could not be excluded in the case of one patient. A mild correlation (Spearman test, correlation coefficient = 0.187, P = 0.001) between sPAP and coronal Cobb angle of the main thoracic (MT) curves was identified. Correlations between sPAP and the degree of other curves were not significant. Patients with sPAP >20 mmHg also had larger thoracic curve angles (mean MT 42.16° vs. 52.45°; U test, P = 0.002). There were no differences in sPAP levels between patients with right and left thoracic curves.
Conclusions: A mild positive correlation was identified between sPAP and the coronal Cobb angle of the MT curves. There was no relationship between sPAP and the direction of the curvature.