BACKGROUND: It is unknown whether tightly controlled blood pressure in the postpartum period will improve outcomes. OBJECTIVES: The purpose of this study was to assess the effect of a lower treatment threshold (≥130/80 mm Hg) for initiating and titrating antihypertensive medication on reducing emergency department visits in postpartum patients with hypertension. METHODS: A prospective cohort of postpartum patients was recruited in a multicenter study between March 2023 and March 2024 and treated to maintain blood pressure <
130/80 mm Hg using remote blood pressure monitoring. These patients were compared to a propensity score-matched retrospective cohort from February 2021 to February 2023 who were treated to maintain blood pressures <
150/100 mm Hg. Eligible patients were 18 or older with a diagnosis of hypertensive disorder. The primary outcome was an emergency department visit for hypertension. RESULTS: There were 392 patients enrolled in the interventional cohort and 1,204 patients identified in the retrospective cohort. After the propensity score match, 276 and 429 patients remained in the prospective and retrospective groups, respectively. Emergency department visits for hypertensive disorders occurred in 10 patients (3.6%) in the intervention and 36 patients (8.4%) in the retrospective cohort (risk difference -4.8
95% CI: -8.2 to -1.3
doubly robust OR: 0.32
95% CI: 0.10-1.01). At 6 weeks postpartum, compared to the retrospective group, the intervention group had systolic and diastolic blood pressure that was 4.4 mm Hg (95% CI: -6.8 to -2.0) and 3.1 mm Hg (95% CI: -4.9 to -1.2) lower, respectively. CONCLUSIONS: Tighter blood pressure control was associated with reduced postpartum emergency department visits for hypertensive disorders.