Correction, Depression, Cardiac Compression and Haller Indices Fail to Correlate with Cardiopulmonary Impairment in Pectus Excavatum

Abstract

Background: Pectus excavatum (PE), the most common congenital chest wall deformity in children, is the posterior intrusion of the anterior chest wall. The standard for determining disease severity is the Haller Index (HI), which has been shown to poorly correlate with physiologic impairment. Recently, more novel indices have been introduced in an effort to more accurately reflect burden of disease but limited evidence demonstrates a correlation between the indices and physiologic impairment. Data confirming such a correlation would provide a means to measure both the severity of deformity and changes in functional disability in patients with PE. Methods: This is a retrospective study of 71 children who underwent evaluation for corrective surgery for pectus excavatum with preoperative cardiopulmonary exercise testing and endexpiratory chest computed tomography or magnetic resonance imaging at a regional children’s hospital. Regression models were performed to predict VO2 max or O2 pulse predicted. Results: The regression models were not significant at predicting VO2 max or O2 pulse predicted. Additionally, when evaluating the either VO2 max or O2 pulse predicted along with the indexes independently in the linear regression model, there was no statistically significant relationship identified. Conclusions: We found that when assessing for a correlation between the HI, correction index, depression index, or cardiac compression index at end-expiration together and independently with cardiopulmonary impairment, both the linear and multiple regression models failed to identify a statistically significant relationship. While it would be highly advantageous for a PE severity index to correlate with objective physiologic impairment, our data suggest that the currently defined indices calculated at end-expiration fail to do so.