cardiac structure and function six months after normal and hypertensive pregnancies – the P4 study

Mikhail Sarofim , George Mangos, George Youssef, Lily Xu, Lynne Roberts, Amanda Henry, Gregory Davis, Caroline Homer, Franziska Pettit, Mark Brown

Introduction: Hypertensive disorders of pregnancy (HDP) are associated with increased post-partum cardiovascular risk compared to normal pregnancy (NP); however the association between cardiac structural/functional changes following an HDP and cardiovascular risk is not clear. Echocardiography is a non-invasive tool useful in detecting early systolic/diastolic dysfunction.

Objectives: To assess cardiac structure/function by 2D-echocardiogram in women, six-months after NP or pregnancy complicated by gestational hypertension or pre-eclampsia (HDP group).

Methods: A prospective cohort was recruited to the ongoing P4 (Postpartum Physiology, Psychology, and Paediatric follow-up) study at St George Hospital, Sydney. Two-dimensional-echocardiography was performed six-months after either NP or HDP. Cardiac sonographers were blinded to a NP or an HDP. All studies were performed on the Phillips-iE33 and Epic machines at St George Hospital. Women with chronic hypertension were excluded. Statistical analysis was completed using independent t-tests.

Results: Forty-eight women have been recruited to date (n=22 NP, n=26 HDP). The HDP group showed subtle evidence of structural change with trend to increased 2D ventricular septal thickness (8.9±1.3 v 8.3±0.9mm, HDP v NP, p=0.08), increased posterior wall thickness (8.8±1.1 v 7.8±0.7mm, HDP v NP, p<0.01) and increased relative wall thickness (0.39±0.06 v 0.35±0.04, HDP v NP, p<0.01 (nr<0.42)). Functionally, the HDP group had slower ventricular diastolic filling (E/A ratio 1.4±0.4 v 1.7±0.4, HDP v NP, p<0.05), trending towards diastolic dysfunction (E/A NR>1.0). Systolic function was similar between groups, measured by ejection fraction (63±4 v 62±15, HDP v NP, p=n.s.) and global longitudinal strain (-19.3±1.6 v -19.8±5.3, HDP v NP, p=n.s.).

Conclusion: Six-months post-partum, women with HDP had early structural and functional changes compared to NP. There was no systolic dysfunction or strain but rather subtle features of increased ventricular mass and diastolic dysfunction. The cardiac changes, although within (current) normal ranges, may be useful in future if included in CV risk algorithms.