Background: Congenital heart defects (CHDs) affect 40 000 US births per year, half of which require surgical intervention. Individual differences in surgical outcomes including mortality and complications are not well understood but may be due to genetic variability. We hypothesized that polygenic risk scores (PRSs) for blood pressure in adults are associated with treatments and postsurgical outcomes in children with CHD, as CHD survivors are at higher risk of negative cardiometabolic disease.
Methods: We used imputed genotype data from pediatric participants requiring surgery for CHD (median age at surgery, 201 days; nmax=2498). Base data for the systolic and diastolic blood pressure PRSs (nmax=760 226) came from published genome-wide association study. The blood pressure PRSs were tested for association with postsurgical outcomes. All effects presented are per SD increase in PRS and adjusted for age, sex, body mass index, surgical complexity score, and first 10 principal components of ancestry.
Results: A higher diastolic blood pressure PRS was associated with decreased in-hospital mortality risk (odds ratio, 0.57 [0.39-0.82]; P=0.0022). Additional analyses suggest an interaction between diastolic blood pressure PRS and vasopressor dose. Those with a diastolic blood pressure PRS 1 SD above the mean, receiving a vasopressor dose in the top tertile, were estimated to have 52% (32%-66%) lower risk of in-hospital mortality compared with those with a vasopressor dose in the bottom tertile.
Conclusions: These results suggest a genetically determined postsurgical survival advantage for CHD patients with blood pressure increasing alleles. Further study may reveal novel mechanisms contributing to postoperative morbidity and mortality, and this approach may assist in early identification of children at risk for adverse postoperative outcomes.
Keywords: CHD; adult; blood pressure; child; humans; prospective studies.