Physiological Reduction in Left Ventricular Contractile Function in Healthy Postpartum Women: Potential Overlap with Peripartum Cardiomyopathy

Abstract

Aims: Peripartum cardiomyopathy is a potentially life-threatening cause of heart failure, commoner in Afro-Caribbean than Caucasian women. Its diagnosis can be challenging due to physiological changes in cardiac function that also occur in healthy women during the early postpartum period. This study aimed to (i) establish the overlap between normal cardiac physiology in the immediate postpartum period and pathological changes in peripartum cardiomyopathy ii) identify any ethnicity-specific changes in cardiac function and cardiac biomarkers in healthy postpartum women.

Methods and results: We conducted a cross-sectional study of 58 healthy postpartum women within 48 hours of delivery and 18 matched non-pregnant controls. Participants underwent cardiac assessment by echocardiography and strain analysis, including 3D echocardiography in 40 postpartum women. Results were compared with 12 retrospectively studied peripartum cardiomyopathy patients. Healthy postpartum women had significantly higher left ventricular volumes and mass, and lower ejection fraction and global longitudinal strain than non-pregnant controls. These parameters were significantly more impaired in peripartum cardiomyopathy patients but with overlapping ranges of values. Healthy postpartum women had higher levels of adrenomedullin, placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt1) compared to controls. The postpartum state, adrenomedullin, sFlt1 and the sFlt1:PlGF ratio were independent predictors of LV remodelling and function in healthy postpartum women.

Conclusion: Healthy postpartum women demonstrate several echocardiographic indicators of left ventricular remodelling and reduced function, which are associated with altered levels of angiogenic and cardiac biomarkers.

Fig 1. Echocardiographic indices in control, healthy postpartum and postpartum cardiomyopathy groups.

a) LV volumes and mass, b) sphericity index, c) 3D ejection fraction, d) 3D ejection fraction vs. stroke work, e) global longitudinal strain, and f) diastolic function. LVEDV, LV end-diastolic volume; LVESV, LV end-systolic volume. *p<0.05, **p<0.01, ***p<0.001.

Fig 2. Serum levels of cardiac biomarkers and markers of oxidative stress in control vs. healthy postpartum women.

a) adrenomedullin, b) NT-pro-BNP, c) hsCRP, d) ox-LDL, e) sFLT-1, f) PlGF, g) sFlt1:PlGF. hsCRP, high sensitivity C-reactive protein; NT-pro-BNP, N-terminal pro-brain natriuretic peptide; ox-LDL, oxidised LDL; PlGF, placental growth factor; sFlt1, soluble fms-like tyrosine kinase.