Female-specific reference values for blood pressure and its relationship with subclinical echocardiographic findings in women with a history of preeclampsia: the Queen of Hearts study
Authors: Janssen E , Spaanderman M E A , Van 'T Hof A W J , Ghossein-Doha C 
Published: October 2022

Abstract

Introduction
Hypertension is the most crucial modifiable risk factor for cardiovascular disease (CVD). Sex differences in what is considered optimal blood pressure (BP) might deviate from current sex-blinded guidelines for hypertension. In women, an obstetric history of preeclampsia relates to postpartum hypertension and substantially increases the risk of premature CVD.

Purpose
To establish female-specific reference values for BP in relatively young women and assess its association with subclinical aberrant echocardiographic findings in a high-risk female population.

Methods
Data was used from the Queen of Hearts study; a cross-sectional cohort study on early detection of heart failure among young women with a history of preeclampsia and a control group of low-risk healthy women with a history of uncomplicated pregnancy. The control group was used to non-parametrically establish reference values for BP (95th percentile). The association between the derived reference values and the risk of subclinical aberrant echocardiographic findings was evaluated in the former preeclamptic group using logistic regression. All women were admitted to a standardized cardiovascular assessment including transthoracic echocardiography and 30-minutes BP measurement. Subclinical echocardiographic findings included left ventricular (LV) hypertrophy (LVH), LV concentric remodelling (LCVR), diastolic dysfunction (DD) and impaired LV ejection fraction (LVEF, &lt;55%).

Results
A total of 429 women in the healthy control group and 856 in the former preeclamptic group were included (44±8 and 38±8 years, respectively). In the healthy control group, 97.7% and 99.8% of women had a systolic (SBP) and diastolic BP (DBP) value below the European Society of Cardiology (ESC) guidelines for hypertension. Overall, the derived reference value for SBP and DBP in our control group was 133 and 82 mmHg, respectively. Age-specific reference curves are presented in Figure 1 and 2. In the subgroup of former preeclamptic women 10.4% and 14.6% had SBP and DBP levels above 133 mmHg and 82mmHg, respectively. In this group, the Odds Ratio (OR) for subclinical aberrant echocardiographic findings when having SBP ≥133mmHg was 5.3 (95% CI 2.3–12.3) for LVH, 1.4 (95% CI 0.6–3.2) for LVCR, 5.9 (95% CI 3.3–10.7) for DD and 1.3 (95% CI 0.3–6.0) for impaired LVEF. For DBP ≥82mmHg, the OR for LVH was 3.5 (95% CI 1.5–8.0), LVCR 1.3 (95% CI 0.6–2.7), DD 3.4 (95% CI 1.9–6.0) and impaired LVEF 1.5 (95% CI 0.4–5.3).

Conclusions
Upper limits for SBP and DBP values in current guidelines correspond with the value of less than 2% of women in our healthy (no pre-eclampsia) population. We derived new reference values with the upper limit corresponding with the upper 5th centile. Values above this level, even below decision limits for hypertension, are associated with abnormal subclinical cardiac function and geometry in a high-risk young female population.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Dutch Heart Foundation