Abstract Body (Do not enter title and authors here): Background: There is ongoing debate about hypertension (HTN) management during pregnancy with a range of recommended targets. Whether HTN is related to subclinical cardiac injury during pregnancy is unclear.
Objective: To determine the relationship between HTN with subclinical cardiac injury during and immediately after pregnancy, measured via high sensitivity cardiac troponin I (hs-cTnI).
Methods: In a prospective, 1:1 case-control design, we enrolled pregnant women with HTN and without HTN (control group) between 24-32 weeks gestation from 2019-22. HTN was defined by a clinician diagnosis or a baseline blood pressure (BP) ≥140/90 mm Hg. The no HTN group had SBP <120 mm Hg. Hs-cTnI was collected at baseline, the delivery admission, and postpartum day 1. We used mixed effects tobit models to compare the groups (HTN vs. no HTN) using log-transforming hs-cTnI, adjusted for age and body mass index.
Results: The mean age of the HTN group (N=38) was 33.6 (SD 5.4) vs. 30.3 (5.8) years for the no HTN group (N=38), with similar race/ethnicity. Mean (SD) baseline BP was 131.1 (14.7)/88.2 (13.5) for the HTN group and 110.1 (7.2)/70.9 (8.2) mm Hg for no HTN. At baseline, hs-cTnI was 1.3 (0.2) in the HTN group and 0.6 (0.1) ng/L in the control (Figure). Compared to baseline, hs-cTnI increased 73.1% (95% CI: 18.8-152.3%) and 109.6% (45.8-201.3%) for the HTN group, and 92.4% (11.7-231.5%) and 264.5% (122.1-498.4%) for no HTN at delivery and postpartum, respectively. Across pregnancy, the HTN group had a higher hs-cTnI of 1.05 (0.07-2.03) ng/L vs. no HTN.
Discussion: HTN was associated with subclinical cardiac injury during pregnancy, with increasing hs-cTnI seen through the early postpartum period in both groups. These findings support better BP control throughout pregnancy to decrease the risk of cardiac injury.