Maternal cardiac parameters can help in differentiating the clinical profile of preeclampsia and in predicting progression from mild to severe forms

Abstract

Background: A primary role of maternal heart dysfunction in the pathophysiology of preeclampsia had been previously advocated although if contradictory results have been reported.

Objectives: The objectives of the study were to describe maternal hemodynamic parameters according to 2 main preeclampsia phenotypes and to investigate whether cardiac findings may be helpful in characterizing the severity and the progression of the disease.

Study design: This was a prospective cohort study. We used an ultrasonic cardiac output monitor system to compare the hemodynamic parameters of women with preeclampsia with a group of healthy normotensive women enrolled as controls with a ratio of 1:2. Cardiac output, systemic vascular resistance, and stroke volume were compared among controls and preeclamptic women who were grouped in accordance to the following characteristics: early preeclampsia (<34 weeks' gestation) vs late preeclampsia onset (≥34 weeks' gestation); preeclampsia associated with appropriate for gestational age or small-for-gestational-age newborns. Hemodynamic characteristics were also compared between preeclamptic women with a mild form vs those who progressed toward a severe form.

Results: A total of 38 preeclamptic women and 61 normotensive women were included in the study. Both cases of preeclampsia associated with small-for-gestational-age neonates as those with normal-sized ones showed higher systemic vascular resistance compared with the control group (respectively, 1580.6 ± 483.2 vs 1479.1 ± 433.3 vs 1105.3 ± 293.1; P < .0001), while a lower cardiac output was reported only for preeclamptic women with small-for-gestational-age neonates compared with controls (5.7 ± 1.5 vs 6.5 ± 1.3; P = .02). Maternal cardiac parameters were comparable between these 2 groups of preeclamptic women (small-for-gestational-age vs appropriate-for-gestational-age preeclampsia) with the exception of a lower stroke volume in the former one (64.8 ± 24.4 vs 75.2 ± 17.8; P = .04). Similarly, women with both early and late preeclampsia showed higher systemic vascular resistance compared with controls (1559.5 ± 528.3 vs 1488.5 ± 292.9 vs 1105.3 ± 293.1, respectively; P < .001), while a lower cardiac output was noted only in the early-onset group compared with controls (5.5 ± 1.2 P = .02). Maternal cardiac findings were similar between women with early vs late-onset preeclampsia. Hemodynamic parameters are significantly different between those women with mild preeclampsia who remained stable compared with those who progressed toward a severe disease. Cardiac output Z-score, systemic vascular resistance Z-score, and uterine arteries' pulsatility index Z-score showed similar sensitivity (80% vs 75% vs 80%, respectively) and specificity (73% vs. 73% vs 74%, respectively), while the association of systemic vascular resistance Z-score and uterine arteries pulsatility index Z-score showed a sensitivity of 95% and a specificity of 80% (area under the curve, 0.90) in predicting evolution toward severe forms.

Conclusion: Evaluation of maternal cardiovascular system could help clinician in defining a subset of preeclamptic patients with more profound placental impairment and might predict the likelihood of progression toward a severe condition in cases with a mild preeclampsia at clinical onset.

Keywords: cardiac output; fetal growth restriction; maternal hemodynamic; preeclampsia; systemic vascular resistance; ultrasonic cardiac output monitor; uterine arteries.