Scoliosis Surgery Normalizes Cardiac Function in Adolescent Idiopathic Scoliosis Patients

Study Design. Single-center retrospective chart review with minimum 2-year follow up. Objective. To determine incidence of pulmonary hypertension in adolescent idiopathic scoliosis patients and to determine the effect of scoliosis surgery on pulmonary hypertension. Summary of Background Data. Spinal deformity in adolescent idiopathic scoliosis can increase right atrial and ventricular pressures secondary to restrictive lung disease. Pulmonary hypertension leading to cor pulmonale is the most feared outcome, however mild pulmonary hypertension in adolescent idiopathic scoliosis (AIS) patients has been reported. No study has previously examined changes in the improvement of right heart function following scoliosis surgery. Methods. Cobb angle, 2D-echo signs of structural heart disease, aortic root dimensions, tricuspid regurgitant jet velocity (TRV), pulmonary function tests (PFTs), arterial blood gas (ABG), and patient demographics reviewed. Right ventricular systolic pressure (RVSP) estimated using Bernoulli equation (4[TRV](2)) and right atrial pressure. RVSP >= 36mmHg is a surrogate marker for pulmonary hypertension. All echocardiograms were read by board certified Pediatric Cardiologists. Logistic regression used to assess for differences in TRV between groups. Results. Mean preoperative RVSP was significantly elevated in AIS patients (26.9 +/- 0.49; P< 0.001) compared with controls (17.25+0.88). Only 47 (21%) Group 1 patients had elevated preoperative TRV (>= 2.8 m/s) versus none in Group 2 (P< 0.001). Additionally, logistic regression showed AIS patients have odds ratio of 3.29 for elevated TRV (P= 0.007)-an indirect measure of pulmonary hypertension. In all Group 3 patients, the cardiac function normalized postoperatively (mean TRV = 2.09+0.23; P< 0.001). No association found between Cobb angle, aortic root parameters, or pulmonary function tests. Conclusion. This study found 13.9% of patients with adolescent idiopathic scoliosis had elevated TRV while controls had no TRV abnormalities. Additionally, RVSP measurements demonstrated mild pulmonary hypertension in AIS patients. These abnormal values normalized postoperatively, indicating the benefits of scoliosis surgery on cardiac function in adolescent idiopathic scoliosis.