Low utility of pre-operative cardiology referrals in adolescent idiopathic scoliosis using a cutoff of Cobb > 70 degrees

Background: Severe adolescent idiopathic scoliosis (AIS) may be associated with cardiopulmonary issues, including previously undiagnosed congenital cardiac anomalies, valvular disease, and pulmonary hypertension. Many centers routinely refer patients with coronal Cobb angles ≥ 70° for pre-operative cardiology evaluation prior to posterior spinal fusion (PSF). The clinical utility of this practice remains uncertain. Methods: A retrospective review was conducted of AIS patients undergoing PSF at a single pediatric orthopedic center from 2017 to 2024. All patients received pre-operative anesthesia evaluations including history, auscultation, and electrocardiogram (EKG). Cardiology referral was made for patients with Cobb angles ≥ 70° or for those with cardiac symptoms, murmurs, or EKG abnormalities. Data collected included cardiology referral status, echocardiogram (TTE) findings, need for intervention or follow-up, surgical delays, and perioperative cardiac complications. Comparative analysis was performed between patients with Cobb angles ≥ 70° and < 70°. Results: Of 151 patients (mean age 14.5 years [range 11–20] 75% female), 51 had Cobb angles ≥ 70°. These patients were more likely to report cardiac symptoms (20% vs. 3%, p = 0.0012) and have murmurs (10% vs. 1%, p = 0.017). 35 patients with Cobb ≥ 70° patients were referred to cardiology, and 17 underwent TTE. Nine had abnormal but largely benign findings; only three required follow-ups. No patient in either group experienced surgical delays or perioperative cardiac complications. Conclusions: Although AIS patients with Cobb angles ≥ 70° demonstrate higher rates of symptoms and murmurs, routine cardiology referral based on Cobb angle alone rarely uncovers clinically significant findings or impacts surgical timing. A targeted referral strategy incorporating symptoms, exam findings, and EKG abnormalities may optimize patient safety while reducing unnecessary testing and cost.