(837) NT-ProBNP in preeclampsia with severe features as a predictor of adverse maternal cardiac outcomes

Objective: N-terminal brain natriuretic peptide (NT-ProBNP) is secreted by cardiac myocytes when exposed to excess myocardial stretching or ischemia and is predictive of heart failure in non-pregnant adults. We aimed to evaluate the predictive value of NT-ProBNP for adverse maternal cardiac outcomes among patients with preeclampsia with severe features (PreESF).

Study Design: This was a prospective cohort study of singleton pregnant patients diagnosed with PreESF from 1/2022 to 7/2023. Patients with pre-existing cardiac diseases were excluded. NT-ProBNP was drawn at diagnosis and postpartum day one (PPD#1). The primary outcome was a composite of peripartum cardiomyopathy (PPC) or postpartum readmission (PPR) within 6 weeks for a preeclampsia-related complication. Diagnosis and PPD#1 NT-ProBNP levels were analyzed using multivariable logistic regression with backwards selection and receiver operating characteristic curves to evaluate the association and predictive value. Maximum Youden indices were calculated to identify optimal NT-ProBNP cutoffs.

Results: 80 patients were included. Mean maternal age was 31.8±7.1 years and mean gestational age at preeclampsia diagnosis was 34.7±3.2 weeks. Sixty percent identified as Black (n=48) and 15% (n=12) as Hispanic. Ten patients (12.5%) experienced the composite outcome: PPC n=6 and PPR n=4. Multivariable logistic regression identified diagnosis NT-ProBNP (p=0.02) and PPD#1 NT-ProBNP (p=0.04) as associated with the composite outcome. Diagnosis NT-ProBNP and PPD#1 NT-ProBNP were similarly predictive of outcome with an area under the curve (AUC) of 0.796 (p=0.0001, 95% CI [0.63,0.96]) and 0.778 (p=0.0001, 95% CI [0.63,0.92]) respectively. Youden index for diagnosis NT-ProBNP was 274.5 pg/mL (sensitivity 70%, specificity 81.2%, PPV 41.1%, NPV 95.2%) and for PPD#1 NT-ProBNP was 102 pg/mL (sensitivity 90%, specificity 58%, PPV 23.7%, NPV 97.6%).

Conclusion: Elevated NT-ProBNP at diagnosis or after delivery of PreESF is predictive of adverse maternal cardiac outcomes and may be a useful marker to identify patients in need of additional cardiac evaluation and follow-up.