Abstract Body (Do not enter title and authors here): Background: Infants with hypoplastic left heart syndrome (HLHS) have the highest risk of morbidity and mortality during the interstage period. Brain natriuretic peptide (BNP) is frequently measured during the Stage I palliation (S1P) hospitalization. However, there is limited data on the association of BNP with interstage morbidity and mortality. In this context, we sought to examine the association between maximum BNP during the S1P hospitalization and last BNP prior to S1P discharge with days alive and out of hospital (DAOH) during the interstage period. We hypothesized that patients with higher BNPs during their S1P hospitalization would have fewer DAOH during the interstage period.
Methods: We performed a single-center retrospective cohort study of infants with HLHS who underwent S1P at our institution between December 1, 2010 and December 31, 2022. Subjects were categorized based on maximum BNP and pre-discharge BNP tertiles. DAOH was calculated by subtracting the number of days hospitalized from the number of days alive during the interstage period. Multivariable zero-truncated negative binomial regression models were used to examine whether there was an association between BNP and DAOH. Models were adjusted for demographic, operative, and discharge characteristics and included an offset for interstage duration.
Results: Of 251 infants, 221 (88%) had at least one BNP measured during their S1P hospitalization. The median maximum BNP was 529 (289-944) pg/mL, pre-discharge BNP was 346 (216-589) pg/mL, and DAOH was 97 (89-100) per 100 interstage days. The median maximum BNP in patients who remained admitted during the interstage period (n=32) was 1,027 (446-1,968) pg/mL which was significantly higher than the study cohort (p<0.001). Patients in the maximum BNP upper tertile were more likely to have moderate to severe atrioventricular valve regurgitation (p=0.04) and had higher pre-discharge and pre-Stage 2 palliation BNPs (p<0.001). There was no association between either maximum BNP or pre-discharge BNP with DAOH. Patients in the maximum BNP upper tertile had significantly more BNPs collected during their S1P hospitalization and interstage period.
Conclusions: BNP during the S1P hospitalization is not predictive of interstage DAOH. In patients deemed candidates for discharge after S1P, repeated BNP measurements may have limited utility. Further work is needed to assess the association between BNP measured in the interstage period and longer-term outcomes.