Postpartum cardiovascular function in patients with hypertensive disorders of pregnancy: a longitudinal study

Abstract

Women with a history of hypertensive disorders of pregnancy (HDP) are at increased risk of cardiovascular diseases that are usually mediated by the development of cardiovascular risk factors, such as chronic hypertension, metabolic syndrome or subclinical myocardial dysfunction. Increasing evidence has been showing that little time elapses between the end of pregnancy and the development of these cardiovascular risk factors. To assess the persistence of hypertension and myocardial dysfunction at four months postpartum in a cohort of women with HDP and to compare the echocardiographic parameters between the peripartum and the postpartum period. In a longitudinal prospective study, a cohort of women with preterm or term HDP and an unmatched group of women with term normotensive pregnancy were recruited. Women with pre-existing chronic hypertension (n=29) were included in the HDP cohort. All participants underwent two cardiovascular assessments: the first was conducted either before or within one week of delivery (V1: peripartum assessment), and the second was between three and 12 months following giving birth (V2: postpartum assessment). The cardiovascular evaluation included blood pressure profile, maternal transthoracic echocardiography (left ventricular mass index (LVMI), relative wall thickness (RWT), left atrial volume index (LAVI), E/A, E/e', peak velocity of tricuspid regurgitation (TR), ejection fraction (EF), and LV global longitudinal strain (GLS) and twist) and metabolic assessment (fasting glycemia, insulin, lipid profile and waist measurement). Echocardiographic data were compared between V1 and V2 using paired t-test or McNemar test in HDP and in the control groups. Among 260 patients with pregnancies complicated by HDP and 33 patients with normotensive pregnancies, 219 (84.2%) and 30 (90.9%) attended postpartum follow-up, respectively. Patients were evaluated at a median (IQR) of 124 (103-145) days after delivery. Paired comparisons of echocardiographic findings demonstrated significant improvements in cardiac remodeling rates (left ventricular mass index (g/m2) 63.4±14.4 vs 78.9±16.2, p<0.0001; relative wall thickness 0.35±0.1 vs 0.42±0.1, p<0.0001), most diastolic indices (E/E' 6.3±1.6 vs 7.4±1.9, p<0.0001), ejection fraction (EF<55%: 9 (4.1%) vs 28 (13.0%), p<0.0001) and global longitudinal strain (-17.3±2.6% vs -16.2±2.4%, p<0.0001) in the postpartum period compared to the peripartum. The same improvements in cardiac indices were observed in the normotensive group. However, at the postnatal assessment, 153/219 (69.9%) had either hypertension (76/219, 34.7%) or an abnormal global longitudinal strain (125/219, 57.1%), 13/67 (19.4%) had metabolic syndrome and 18/67 (26.9%) exhibited insulin resistance. Although persistent postpartum cardiovascular impairment was evident in a substantial proportion of these patients since more than two-thirds had either hypertension or myocardial dysfunction postpartum, cardiac modifications due to pregnancy-related overload and hypertension were significantly more pronounced in the peripartum than in the postpartum periods.