197. Markers of maternal cardiac dysfunction in pre-eclampsia and superimposed pre-eclampsia

Abstract

Introduction Women who experience hypertensive disorders of pregnancy have an increased risk of developing cardiovascular disease in later life. The mechanism underlying this association unknown. Objectives To determine whether elevated glycogen phosphorylase isoenzyme B (GPBB) and/or brain natriuretic peptide (BNP) concentrations suggestive of cardiac dysfunction are observed in pre-eclampsia and superimposed pre-eclampsia (SPE). Method Four groups of women were selected from an existing cohort study: healthy controls (n = 21), pre-eclampsia (n = 19), pre-existing chronic hypertension (CHT) and/or chronic kidney disease (CKD) without (n = 20), or with SPE (n = 19). Plasma samples taken in the third trimester or at time of disease were assayed using Diagenics Dianeonatal® Glycogen phosphorylase Isoenzyme BB (GP-BB)-ELISA in vitro diagnostic device kits and Alere Triage © CardioRenal assays (BNP). Log transformed GPBB and BNP concentrations were compared using interval regression as ratios of the geometric means with 95% confidence intervals. Results No difference was observed in GPBB plasma concentrations between the control and pre-eclampsia groups (mean [95% C.I.]: 4.72 [2.49–8.94] ng/mL vs 4.98 [2.52–9.84] ng/mL; N = 40, p = 0.91), or between CHT and/or CKD and SPET groups (mean [95% C.I.]: 9.49 [4.93–18.25] ng/mL vs 10.24 [5.27–19.92] ng/mL; N = 39, p = 0.87). BNP plasma concentrations were significantly raised in the pre-eclampsia group compared to the control group (mean [95% C.I.]: 31.75 [19.21–52.49] pg/mL vs 11.31 [7.00–18.25] pg/mL; N = 40, p = 0.004), but did not reach statistical significance between the SPET and CHT and/or CKD groups (GM [95% C.I.]: 20.66 [12.40–34.44] pg/mL vs 16.06 [9.83–26.23] pg/mL; N = 39, p = 0.486). Discussion There was no difference in GPBB concentration between groups. BNP concentrations were elevated in cases of pre-eclampsia compared to controls. This suggests cardiac dysfunction at the time of pre-eclampsia but through a mechanism other than cardiac ischaemia, and little role for the use of GPBB as a biomarker in hypertensive disorders of pregnancy.