BEYOND DIAGNOSIS: PROGNOSTIC UTILITY OF B-NATRIURETIC PEPTIDE IN PREGNANT PATIENTS PRESENTING TO ARKANSAS’ HIGH-RISK CARDIO-OBSTETRICS PROGRAM

Therapeutic Area

ASCVD/CVD Risk Assessment

Background

B-natriuretic peptide (BNP) is used as a screening biomarker for patients in cardio-obstetric programs. In nonpregnant females, obesity falsely lowers BNP, but its accuracy in the obese pregnant population is less known. We studied the diagnostic and prognostic utility of BNP in a predominantly obese, high-risk obstetric population in Arkansas.

Methods

We established a retrospective registry of pregnant patients who had undergone a BNP and echocardiographic assessment (within 30 days of each other) at the University of Arkansas Medical Center between January 1, 1995, to October 30, 2022. We assessed the relationship between BNP levels and left ventricular ejection fraction (LVEF) using Pearson correlation coefficients. We used receiver operating curves to identify an optimal BNP cutoff for predicting a reduced LVEF (<50%), and cox regression analysis to determine a prognostic cutoff value. A p-value of <0.05 indicated statistical significance. Analyses are performed using MedCalc software (Ostend, Belgium).

Results

We studied a total of n=315 pregnant patients with a median ±SD age of 29.8 years old (25-34) and BMI of 34 kg/m2 (34-41). In patients with a BMI of ≥ 35, there was no correlation between BNP and LVEF [-0.05 (-0.21 to 0.09, P = 0.47)] (Figure 1b). Of all variables examined, only LVEF of <50% was predictive of maternal mortality with a 95% confidence interval of 1.1 to 25.1 and a P value of 0.04. Significant cutoff values for BMI and BNP are listed in Figure 1c-d.

Conclusions

BNP based screening in high-risk obstetric patients requires consideration of BMI in interpretation of test, paralleling the effect obesity has on BNP in a non-pregnant population. In conclusion, we recommend considering an echocardiography in obese, pregnant patients with a clinical suspicion of new or worsening heart failure, regardless of BNP level.