B-Type Natriuretic Peptide As A Predictor Of Hypertensive Disease Of Pregnancy In Maternal Cardiac Disease

To investigate changes in B-type natriuretic peptide (BNP) during pregnancy in women with congenital heart disease (CHD) and evaluate its utility as a predictor of adverse outcomes. Retrospective cohort study of singleton gestations with maternal CHD that delivered at a tertiary care center from March 2013 to August 2020 with at least one pregnancy BNP value. The primary outcomes were development of a composite adverse cardiovascular (CV) outcome, diagnosis of hypertensive (HTN) disease of pregnancy, and endorsement of CV symptoms. BNP values were categorized as less than or equal to or greater than 100 pg/mL, the threshold predictive of heart failure outside of pregnancy. Given lack of an established diagnostic threshold value in pregnancy, median, maximum, and trend of BNP values were obtained. Only BNP measurements collected prior to the development of an adverse outcome were evaluated. BNP values were compared with Chi-squared and Wilcoxon rank sum tests among those who did and did not develop an adverse outcome. 81 pregnancies with maternal CHD had at least one BNP measurement. 30 (37.0%) had a composite adverse CV outcome, 16 (19.8%) developed HTN disease of pregnancy, and 52 (64.2%) endorsed CV symptoms. BNP was not different for those who developed an adverse CV outcome (p=0.76) or endorsed CV symptoms (p=0.40). A BNP measurement above 100 pg/mL was associated with the development of HTN disease of pregnancy (p=0.01). The difference between minimum and maximum BNP values throughout pregnancy was higher with the development of HTN disease of pregnancy (p=0.03). A BNP less than or equal to 100 pg/mL has a negative predictive value of 96.1% for HTN disease of pregnancy in participants. In pregnancies complicated by maternal CHD, BNP greater than 100 pg/ml and increasing BNP over gestation is associated with the development of HTN disease of pregnancy but not adverse CV outcomes. Evaluation of BNP may be of clinical utility in the antepartum surveillance of pregnant women with cardiac disease, specifically when evaluating for HTN disease of pregnancy.