Impact of Blood Pressure Self-Management on Vascular Remodeling After Hypertensive Pregnancy

Abstract

Background: Hypertensive pregnancy disorders are associated with long-term adverse cardiac and vascular remodeling post index pregnancy. The POP-HT trial (Physician Optimised Postpartum Hypertension Treatment) demonstrated that improved puerperal blood pressure control leads to reduced blood pressure and beneficial cardiac remodeling during the first year postpartum. This study describes the impact on postpartum vascular remodeling.

Methods: A prospective, randomized, open-label, blinded end point trial in a single UK hospital where 220 women were assigned 1:1 to intervention (self-management via physician-guided antihypertensive titration) or control (usual postnatal care via primary care doctor±midwife). Eligible participants were ≥18 years, with preeclampsia or gestational hypertension and requiring antihypertensives on discharge. Prespecified secondary vascular outcomes included aortic blood pressure and pulse wave velocity measured by Vicorder at baseline and 9 months postpartum, and additional cardiovascular magnetic resonance measures of aortic distensibility were performed.

Results: There were no baseline differences in aortic blood pressure or pulse wave velocity but by 9 months postpartum, aortic diastolic blood pressure was -5.2 mm Hg lower ([95% CI, -8.0 to -2.2]; P<0.001), and pulse wave velocity was -0.71 m/s lower ([95% CI, -1.42 to -0.06]; P=0.048) in the intervention arm compared with the control arm, which corresponded with greater aortic distensibility by 0.78×10^-3 mm Hg^-1 ([95% CI, 0.01 to 1.55]; P=0.046).

Conclusions: Postpartum blood pressure self-monitoring combined with physician-guided medication titration is associated with reduced central arterial stiffness during the first year after a hypertensive pregnancy, in addition to the previously demonstrated effects on blood pressure and cardiac remodeling.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04273854.

Keywords: hypertension; postpartum period; pre-eclampsia; pregnancy; vascular remodeling.

Figure 1.

Flow diagram of study visits from baseline visit (visit 1 [V1]) to final study visit (visit 4 [V4]). V1/baseline visit took place on postnatal ward at D1−D5 postpartum and included transthoracic echocardiogram, Vicorder assessment of aortic blood pressure, pulse wave velocity and augmentation index, peripheral blood pressure measurement, and anthropometric measures, as well as documentation of relevant obstetric and medical history, medications, and blood and urine results. Visit 2 took place at week 1±5 days postpartum and included an update of the medical and obstetric history, medication doses and any side effects, any new investigations/admissions, and measurement of peripheral blood pressure using a validated, calibrated monitor. Visit 3 took place at week 6±5 days postpartum and included an update of the medical and obstetric history, medication doses and any side-effects, any new investigations/admissions, and measurement of peripheral blood pressure using a validated, calibrated monitor, and a 24-hour ambulatory blood pressure monitoring was fitted and posted back to the study site for analysis. V4/Final study visit took place at ≈9 months postpartum (249.8 days [14.6] in intervention arm vs 247.9 days [17.1] in the control arm) and included all measures performed at V1 plus magnetic resonance imaging of brain, heart, kidneys and aorta, retinal imaging, repeated blood sampling for lipid and sugar metabolism and assessment of renal function and a cardiopulmonary exercise test and bicycle exercise echocardiogram. Created in BioRender. Leeson, P. (2025) https://BioRender.com/4d0xcpu.

Figure 2.

Aortic systolic and diastolic blood pressure (BP), aortic pulse wave velocity, and aortic distensibility at ≈9 months postpartum by randomization group. A, Aortic systolic BP at ≈9 months postpartum adjusted for baseline differences. B, Aortic diastolic BP at ≈9 months postpartum adjusted for baseline differences. C, Aortic pulse wave velocity (m/s) adjusted for aortic diastolic BP at time of the visit 4 (V4) assessment. D, Aortic distensibility at ≈9 months postpartum. Violin plots with overlaid box plots. Tukey box plots represent median and interquartile range (IQR), whiskers represent largest value within 1.5× IQR above 75th percentile and smallest value within 1.5× IQR below 25th percentile, and data points beyond the whiskers represent values >1.5× and <3× the IQR. Adjusted mean difference, 95% CI, and P values are provided above each plot, representing the significance between control and intervention groups at 9 months. Linear regression models on the Vicorder data were performed on Vicorder measures from V4 with measures from the baseline visit/visit 1 (V1) and baseline mean diastolic BP included in the model as per the original study Statistical Analysis Plan. For pulse wave velocity, data were adjusted for aortic diastolic BP at the time of V4 and baseline Vicorder measures. Aortic distensibility is adjusted for body surface area (calculated by Mosteller equation) and age at the time of final study visit. Aortic distensibility (10⁻³ mm Hg⁻¹) was calculated as follows: (A_max–A_min)/A_min×(P_max–P_min), where A_max and A_min represent the maximal and minimal cross-sectional area of the aorta on cine cardiovascular magnetic resonance images, and P_max and P_min represent the V4 24-hour averaged systolic and diastolic BP (in millimeters of mercury), respectively.