LAUSR

BACKGROUND Preeclampsia complicates approximately 5% of all pregnancies. When pulmonary edema occurs, it accounts for 50% of preeclampsia related mortality. Currently, there is no consensus on the degree to which left ventricular systolic dysfunction contributes to the development of pulmonary edema. OBJECTIVES To use cardiac MRI to detect subtle changes in left ventricular systolic function and evidence of acute left ventricular dysfunction (through tissue characterisation) in women with preeclampsia complicated by pulmonary edema when compared to both preeclamptic and normotensive controls. STUDY DESIGN Cases were postpartum women 18 years or older presenting with preeclampsia complicated by pulmonary edema. Two control groups were recruited: women with preeclampsia without pulmonary edema and women with normotensive pregnancies. All women underwent echocardiography and 1,5T cardiac MRI with native T1 and T2 mapping. Gadolinium contrast was administered to cases only. Due to small sample sizes, non-parametric test (Kruskal-Wallis) with pairwise post hoc analysis using Bonferroni correction was used to compare the differences between groups. Cardiac MRIs were interpreted by two independent reporters. The intraclass correlation coefficient was calculated to assess inter observer reliability. RESULTS Twenty women with preeclampsia complicated by pulmonary edema, thirteen women with preeclampsia (five with severe features and eight without), and six normotensive controls were recruited. There were no significant differences in the baseline characteristics between groups apart from the expected differences in blood pressure. Left atrial sizes were similar across all groups. Women with preeclampsia complicated by pulmonary edema had increased left ventricular mass (p=0,01) but normal systolic function when compared to the normotensive controls. They also had elevated native T1 values (p=0,025) and a trend toward elevated T2 values (p=0,07) in the absence of late gadolinium enhancement consistent with myocardial edema. Myocardial edema was also present in all women with eclampsia or HELLP syndrome. Women with preeclampsia without severe features had similar findings to the normotensive controls. All cardiac MRI measurements showed a very high level of inter observer correlation. CONCLUSION To our knowledge, this is the first Cardiac MRI study in women with preeclampsia complicated by pulmonary edema, eclampsia and HELLP syndrome. We have demonstrated normal systolic function with myocardial edema, in women with preeclampsia with these severe features. These findings implicate an acute myocardial process as part of this clinical syndrome. The pathogenesis of the myocardial edema and its relationship to pulmonary edema requires further elucidation. With normal left atrial sizes any haemodynamic component must be acute.