Geographic Distribution of Congenital Heart Disease: A Single Surgical Center Experience

Abstract

To determine presence of spatial clustering or dispersion of pre and postnatally detected hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (TGA) cases. This retrospective study examined all patients with a prenatal or postnatal diagnosis of HLHS or TGA who had an initial visit or hospitalization at our tertiary care center over a 5-year period from 2012 to 2016 (n=105). Using geographic information systems software, the nearest neighbor ratio (NNR) tool was used to determine whether statistically significant clustering or dispersion occurred. Geographic clustering was observed among prenatally diagnosed pooled cases of HLHS and TGA and all total cases (NNR=0.73 and 0.66, respectively), but not postnatally detected cases (NNR=1.08). Notably, there was significant dispersion of postnatally detected TGA cases (NNR=1.22) There was no pattern for prenatally detected TGA or HLHS when analyzed individually. The spatial distribution of HLHS and TGA is not random; these conditions occur in geographic clusters. Clustering of all patients in the study population and dispersion of postnatal diagnosis of TGA represent opportunities for improved delivery of fetal cardiac care.