(549) Physiologic Treatment of Mild Chronic Hypertension and Pregnancy Outcomes

Thursday, January 30, 2025

4:00 PM – 6:00 PM

Submitting Author and Presenting Author(s)

Mariam Ayyash, MD, MSCR

Maternal-Fetal Medicine Fellow
Columbia University Irving Medical Center
New York, New York, United States

Coauthor(s)

Ayodeji Sanusi, MD, MPH (he/him/his)

Assistant Professor, Maternal Fetal Medicine
Center for Women’s Reproductive Health, University of Alabama at Birmingham
Birmingham, Alabama, United States

Objective: Among patients with hypertension (HTN) in pregnancy, emerging research suggests that improved blood pressure (BP) control can be achieved if the antihypertensive drug used accounts for the underlying maternal hemodynamic physiology. We evaluated whether physiologic treatment of mild chronic HTN is associated with a reduction in adverse pregnancy outcomes.

Study Design: We conducted a secondary analysis of CHAP, an open-label, multicenter, randomized trial of antihypertensive treatment (vs. none) for pregnant patients with mild chronic HTN. Patients with BPs≥160/105 were excluded from CHAP trial. Eligible participants for this analysis had either hyperdynamic– a pulse pressure (PP)≥65, or vasoconstrictive– diastolic BP≥100 physiology. Three groups were compared based on treatment of BP at randomization: 1) Physiologic- hyperdynamic receiving Labetalol or vasoconstrictive receiving Nifedipine; 2) Non-physiologic- hyperdynamic receiving Nifedipine or vasoconstrictive receiving Labetalol, and 3) control- not on medications. The primary outcome was a composite of superimposed preeclampsia with severe features, preterm birth before 35 weeks’ gestation, placental abruption, or fetal or neonatal death. Adjusted odds ratios (aORs) and 95% CIs were estimated with logistic regression.

Results: Of 2408 in CHAP, 542 (23.3%) participants met physiologic classification criteria and were analyzed: 136 (25.1%) had physiologic treatment, 125 (23.0%) had non-physiologic treatment, with 281 (51.8%) untreated controls. The primary outcome did not differ among those who received physiologic treatment (44.9%), non-physiologic (45.6%), or control (48.4%) with aOR (CIs) for physiologic vs control 0.85 (0.56-1.30), non-physiologic vs control 0.90 (0.59-1.39), and physiologic vs non-physiologic 0.95 (0.58-1.56).

Conclusion: Physiologic treatment of mild chronic HTN was not associated with a significant reduction in primary composite adverse outcome. Most patients did not meet criteria for physiologic classification. Further research using different thresholds to account for dynamic physiology over a greater BP range is needed.