170. Scoliosis surgery normalizes cardiac function in AIS patients

Abstract

<h3>BACKGROUND CONTEXT</h3> Spinal deformity in AIS 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 AIS patients has been reported in the past. No study has examined these changes including the improvement of right heart function following scoliosis surgery. <h3>PURPOSE</h3> To study if scoliosis repair resolves cardiac functional abnormalities. <h3>STUDY DESIGN/SETTING</h3> Retrospective review. <h3>PATIENT SAMPLE</h3> Group 1, 202 AIS patients undergoing PSF from 2009-2013 at a single institution. Group 2 control patients, 179 healthy, age-matched adolescents. <h3>OUTCOME MEASURES</h3> Cobb angle, 2D-echo signs of structural heart disease, aortic root dimensions, tricuspid regurgitant jet velocity (TRV), PFTs, ABG and patient demographics reviewed. Right ventricular systolic pressure (RVSP) was estimated using Bernoulli's equation (4[TRV]2) and right atrial pressure. RVSP ≥ 36mmHg is a surrogate marker for pulmonary hypertension. <h3>METHODS</h3> All echocardiograms were read by board certified pediatric cardiologists. Group 3, 47 AIS patients from group 1 with elevated preoperative TRV underwent corrective PSF. Logistic regression was used to assess for differences in TRV between groups. <h3>Results</h3> Mean preoperative RVSP was significantly elevated in AIS patients (26.9 ± 0.49; p<0.001) compared to controls (17.25 ± 0.88). Forty-seven (21%) group 1 patients had elevated preoperative TRV (≥ 2.8 m/s) vs no group 2 patients (p<0.001). Additionally, logistic regression showed AIS patients have an odds ratio of 3.29 for elevated TRV (p value=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 was found in Cobb angle, aortic root parameters or PFTs. <h3>Conclusions</h3> This study found that 21% of patients with AIS had elevated TRV while age-matched 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 AIS. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.