B-type Natriuretic Peptide in Pregnant Women with Cardiac Disease

  • Dr David Tanous, Australia
  • Dr Samuel Siu, University Health Network and Mount Sinai Hospital, Toronto, Canada
  • Jennifer Mason, University Health Network and Mount Sinai Hospital, Toronto, Canada
  • Dr Matthias Greutmann, University Health Network and Mount Sinai Hospital, Toronto, Canada
  • Dr Rachel Wald, University Health Network and Mount Sinai Hospital, Toronto, Canada
  • Dr Mathew Sermer, University Health Network and Mount Sinai Hospital, Toronto, Canada
  • Dr Jack Colman, University Health Network and Mount Sinai Hospital, Toronto, Canada
  • Dr Candice Silversides, University of Toronto Pregnancy and Heart Disease Research Program, University Health Network and Mount Sinai Hospital, Toronto, Canada

    • Background:
    B-type natriuretic peptide (BNP) release occurs with hemodynamic stress. Although pregnancy can impose stress on the heart in women with heart disease, BNP levels during pregnancy in this group of women has not been studied. The objective of this study was to examine the neurohormonal response to pregnancy in women with heart disease.

    Methods:
    We prospectively enrolled 66 women with structural heart disease (age 31±5 years) and 12 healthy pregnant controls. Clinical data, echocardiographic data and plasma BNP levels during the 1st trimester, 3rd trimester and post-partum (>6 weeks) were obtained.

    Results:
    The most common cardiac diagnoses were congenital cardiac lesions (74%). Plasma BNP concentrations were significantly higher in women with cardiac disease (1st trimester 98±203 vs. 28±14, 3rd trimester 82±82 vs. 24±13, postpartum 102±144pg/mL vs. 24±8pg/mL, p<0.05 all time-points) compared to controls. Adverse cardiac events occurred in 8 patients (death n=1, need for cardiac surgery n=1, sustained arrhythmia n=3; heart failure n=3). Women with events had higher BNP levels (518±442 vs. 89±58 pg/mL, p<0.001), lower LVEF (54±4 vs.62±7, p=0.006) and more commonly had a history of cardiac events before pregnancy (63% vs.11%, p=0.003). A maximum BNP >100 pg/mL was present in 100% (8/8) of patients with adverse events. Thirty-three percent (8/24) of patients with a BNP>100 pg/mL had an adverse event.

    Conclusions:
    Pregnant women with heart disease have increased BNP levels during pregnancy compared to pregnant women without heart disease. Elevated BNP levels during pregnancy and early postpartum are associated with increased risk of adverse cardiac events.