Cardiovascular remodelling after hypertensive pregnancy: the impact of postpartum blood pressure control

Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of later cardiovascular disease. Whether this relates to how HDP are managed or because HDP merely identify women predisposed to disease is debated. HDP induce significant cardiac remodelling and, several years ago, the researchers I work with proposed a novel hypothesis: that failure of cardiovascular recovery postpartum permanently alters blood pressure (BP) trajectory. In support of this, persistent BP elevation six weeks postpartum, and/or adverse cardiac remodelling predict future hypertensive risk. Furthermore, in a randomised trial [SNAP-HT] investigating feasibility of BP self-management postpartum, diastolic BP was lower 6 months postpartum in the intervention group. I have now tested this hypothesis further using two clinical trials. Firstly, by performing long-term follow up of the SNAP-HT cohort I found that BP differences were sustained for up to four years postpartum, consistent with a permanent alteration in blood pressure trajectory. I then undertook the Physician Optimised Post-partum Hypertension Treatment trial (POP-HT), a prospectively randomised open blinded endpoint study of >200 women, with pre-eclampsia or gestational hypertension, who required anti-hypertensive medication on discharge. The trial was appropriately powered for blood pressure differences with randomisation 1:1 to either physician-optimised postpartum BP self-management or usual care. The trial demonstrated the intervention significantly reduced systolic and diastolic BP 6-9 months postpartum, measured by both clinic and 24hr ambulatory BP. Differences were evident by one week postpartum and the intervention was associated with reduced postnatal readmissions. Echocardiography and cardiovascular magnetic resonance demonstrated BP reductions associated with improved left ventricular systolic and diastolic function, beneficial atrial and ventricular remodelling, and increased aortic compliance. These findings provide significant evidence ...