Pulse pressure and adverse perinatal outcomes in patients with mild chronic hypertension during pregnancy

Abstract

Pulse pressure (PP) – the difference between systolic and diastolic blood pressure (BP) – is significantly associated with cardiovascular events including death. However, the relationship between PP and pregnancy outcomes is unknown. We evaluated the association between PP and maternal and perinatal outcomes in women with mild chronic hypertension (cHTN). Secondary analysis of The CHAP Trial – an open-label randomized controlled trial of antihypertensives (vs. none) for mild cHTN (BP< 160/105 mmHg). Participants without PP information or outcomes were excluded. Visit count and average PP per patient in active treatment and control groups were compared. The primary analysis evaluated the association between PP during post-randomization clinic visits (5mmHg increments), CHAP primary composite outcome, and small for gestational age (SGA). Logistic regression models were adjusted for randomization assignment. Of 2,325 eligible participants, 50.3% (n=1170) were randomized to active treatment and 49.7% (n=1155) to control. Participants in the active group had marginally more BP assessments per patient (7.4 ± 3.0 vs 7.1 ± 2.9, p = 0.02). Average PP per patient was lower in the active compared to control group (49.9 ± 7.8 vs 50.6 ± 8.0, p=0.03) (Figure). Mean PP was positively associated with the composite outcome, severe preeclampsia and indicated preterm birth (PTB)< 35 weeks while active treatment was protective in the adjusted model (Table). Conversely, PP was negatively associated with SGA< 5th percentile but not SGA< 10th; active treatment was associated with neither. Mean PP was lower in pregnant participants with mild CHTN who were randomized to active treatment. Higher mean PP was associated with the CHAP primary composite outcome, severe preeclampsia and indicated PTB< 35 weeks, but negatively associated with SGA < 5th. Given potential variation in the relationship between treatment of CHTN in pregnancy and SGA, the role of PP as a mediator should be investigated in future studies to reduce adverse HTN-related outcomes without increasing SGA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)