Physician optimized postpartum hypertension treatment (POP-HT) randomized trial

News - Nov. 20, 2023

Presented at the AHA Scientific Sessions 2023 by: Jamie Kitt, MD, PhD - Oxford, UK

Introduction and methods

Approximately 1 in 10 women develop high BP during pregnancy, and approximately one-third of these women develop chronic hypertension within 10 years after a hypertensive pregnancy, usually early in their 30s and 40s.This early onset is associated with a significant higher risk of heart attack and stroke later in life.

The heart and blood vessels remodel during pregnancy to cope with the hemodynamic demand of pregnancy. After delivery, remodeling should occur to restore the pre-pregnancy state. In women affected by pregnancy hypertension, cardiac and vascular remodeling can be more severe and problematic. Observational data suggest that women who have persistent changes at week 6 postpartum have a high risk of developing subsequent CVD. The aim of the POP-HT trial was to determine whether improving BP control immediately after delivery may help the heart to recover, and reduce long-term CVD risk.

The POP-HT trial was a randomized trial in which 220 women with pregnancy hypertension who still required anti-hypertensive medication at discharge were randomized to an intervention arm or usual care arm. Participants in the intervention arm self-monitored their BP via an app, and were advised by physicians in the research team to make adjustments to their anti-hypertensive medications to better control their BP during the first 6 weeks postpartum. Participants in the usual care arm received standard care, which in the UK involves review by primary care physician or midwife at week 1 and at week 6-8. All participants in the study had a visit at baseline that involved measurements of the heart and blood vessels and BP measurements (visit 1), and subsequent visits at week 1 (visit 2) and week 6 (visit 3) with BP measurements. All participants had a final visit (visit 4) at month 6-9, with a detailed set of measurements which included all previous measurements, as well as cardiac MRI, exercise tolerance test, and blood tests.

The primary outcome was 24-h mean diastolic BP (DBP) as measured with ambulatory BP-monitoring at visit 4, adjusted for baseline DBP.

Main results

• Participants in the intervention group had lower mean 24-h average DBP compared with the control group (difference in mean 24 hr average DBP was -5.8 mmHg; 95%CI: -7.4 to -4.2).
• Mean 24-h average systolic BP (SBP) was also reduced in the intervention group compared with the control group (difference was -6.5 mmHg; 95%CI: -8.8 to -4.2).
• The intervention strategy reduced the risk of postnatal readmission compared with the usual care strategy (absolute risk reduction: 20%; relative risk reduction: 73.5%; number needed to treat: 5).
• Participants in the intervention group had reduced left ventricular mass, improved systolic and diastolic function, and reduced left arterial size at month 9 compared with the control group. These changes were all consistent with beneficial cardiac remodeling effects.

Conclusion

In the POP-HT trial, an intervention strategy of self-monitoring of BP and physician-guided medication adjustment during the first 6 weeks postpartum led to improvements in BP up to 9 months postpartum after hypertensive pregnancy. Moreover, the intervention strategy had beneficial effects on cardiac remodeling compared with usual care. These results indicate that what happens immediately postpartum may have long term effects.

- Our reporting is based on the information provided at the AHA Scientific Session 2023 –

The primary outcome results of this study were simultaneously published in JAMAThe cardiac imaging results of this study were simultaneously published in Circulation