22 - Intrapartum trends of NT-proBNP and hs-TnT in patients with severe features of preeclampsia

Friday, February 10, 2023

9:15 AM – 9:30 AM

Location: Room 3009, Moscone West, Level 3

Objective: Because preeclampsia with severe features (SPE) is a multisystem disorder associated with long-term cardiac morbidity, our aim was to examine two analytes in patients with SPE during labor. NT-proBNP and high sensitivity troponin-T (hs-TnT) are sensitive markers of cardiac stretch and ischemia, respectively. We hypothesized that patients with SPE would have increased levels of these analytes as compared with normal laboring patients.

Study Design: This was a prospective cohort study at a single academic center. Patients with intrapartum SPE and normal controls were recruited for inclusion on admission to the labor unit. Patients with chronic hypertension, heart disease, renal disease, BMI >45kg/m², pregestational diabetes, and medication-treated gestational diabetes were excluded. Venous blood was collected for NT-proBNP and hs-TnT measurement at three time points: 0-2 hours, 4 hours, and 12 hours after admission. A mixed random effects regression model was used to compare analyte levels at each time point and to compare trends over time. Power analysis yielded a goal sample of 25 patients with a 12 hour and at least 1 other sample in each arm.

Results: Of 78 patients recruited, 36 had SPE and 42 were normal controls with 25 in each arm having collection at all time points. Demographics between the SPE and normal laboring patients were similar (Table). Although there were no differences in hs-TnT trends or levels at the three time points (all 3 timepoints for hs-TnT P >0.05), the NT-proBNP trends were significantly different between the two cohorts (P < 0.001, Figure). After adjustment for multiple comparisons, the NT-proBNP mean was elevated in the SPE group at 0-2 and 4 hours, but not at 12 hours (Figure).

Conclusion:

When measured during the intrapartum period, levels of NT-proBNP were almost doubled in patients with SPE when compared to normal controls with most pronounced differences noted during early labor. These findings suggest cardiac dysfunction with SPE may precede admission to labor and delivery and offer future insights to strategies to reduce maternal cardiac morbidity and mortality.

Primary & Presenting Author(s)

Joseph Fixler, MD

Fellow
University of Texas Southwestern
Farmers Branch, TX, United States

Slides

Coauthor(s)

GC

Gary Cunningham, MD

UT Southwestern Medical Center
Dallas, Texas, United States
JB

John J. Byrne, MD, MPH

Physician
UT Health Sciences Center at San Antonio
San Antonio, Texas, United States
David B. Nelson, MD

Associate Professor
University of Texas Southwestern Medical Center
Dallas, Texas, United States