Morphofunctional cardiac changes in pregnant women: associations with biomarkers

Abstract

Objective: This longitudinal study was performed to determine changes in echocardiography parameters in association with various biomarker levels in pregnancy/postpartum.

Methods: Fifty-one healthy pregnant women underwent echocardiography with simultaneous determination of blood levels of five biomarkers at each of the first, second and third trimesters of pregnancy, immediately postpartum within 1 week after childbirth and approximately 1 month postpartum. Data on 255 echocardiography scans (five times per woman) and biomarkers were analysed.

Results: Left ventricular end-diastolic dimension, left atrial (LA) volume index and left ventricular (LV) mass index increased with advancing gestation and reached the maximum immediately postpartum concomitant with the highest brain natriuretic peptide (BNP), N-terminal pro B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin I (hs-TnI) and creatine kinase MB levels. The inferior vena cava diameter was significantly reduced in the third trimester compared with that in the first trimester and the peak occurred immediately after childbirth. In 255 paired measurements, hs-TnI level was significantly positively correlated with LA volume index and LV mass index; BNP and NT-proBNP were significantly positively correlated with LA volume index and estimated glomerular filtration rate (eGFR) was significantly positively correlated with the average of early diastolic septal and lateral mitral annular velocity (e').

Conclusions: Maximal cardiac changes in morphology occurred postpartum within 1 week after childbirth, not during pregnancy. BNP/NT-proBNP, hs-TnI and eGFR reflected cardiac changes in pregnancy.

Keywords: echocardiography; heart failure; obstetrics.

Figure 1

Changes in eight representative echocardiographic measurements during pregnancy/postpartum. *P<0.05 vs baseline value determined during the first trimester. Vertical bars indicate ±SE. IVC, inferior vena cava; LA, left atrial; LV, left ventricle; LVDd, left ventricular end-diastolic dimension.

Figure 2

Changes in levels of blood biomarkers during pregnancy/postpartum. *P<0.05 vs baseline value determined during the first trimester. Vertical bars indicate 25th–75th percentile values (see table 2 for median (5th–95th) value). Data on BNP were determined in a limited number of women (see footnote for table 2). BNP, brain natriuretic peptide; CK-MB, creatine kinase MB; eGFR, estimated glomerular filtration rate; hs-TnI, high-sensitivity troponin I; NT-proBNP, N-terminal pro B-type natriuretic peptide.

Figure 3

Comparison of peripartum changes in LA volume index, IVC diameter, E/e′, NT-proBNP and hs-TnI between women with Caesarean section and vaginal delivery. *P<0.05 vs value determined during the third trimester. †P<0.05 between two groups. Vertical bars indicate ±SE. hs-TnI, high-sensitivity troponin I; IVC, inferior vena cava; LA, left atrial; NT-proBNP, N-terminal pro B-type natriuretic peptide.

Figure 4

Standardised regression coefficients between blood variable levels and echocardiographic measurements. β, standardised regression coefficient. Regression line was drawn for β>0.25 or <–0.25. When hs-TnI level was below the limit of detection (0.1 pg/mL), we assumed that hs-TnI was present at a serum concentration of 0.1 pg/mL. BNP, B-type natriuretic peptide; CK-MB, creatine kinase MB; eGFR, estimated glomerular filtration rate; hs-TnI, high-sensitivity troponin I; IVC, inferior vena cava; LA, left atrial; LV, left ventricle; LVDd, left ventricular end-diastolic dimension; LVEF, LV ejection fraction; NT-proBNP, N-terminal pro B-type natriuretic peptide.