Remote Monitoring May Curb Recurring BP Problems of Pregnancy

Remote monitoring and other innovative solutions are needed to get a handle on the more than 80% of patients who experience ongoing blood pressure control problems that can land them back in the hospital following a pregnancy that was complicated by hypertensive disorders, researchers say.

Up to 20% of pregnant individuals in the United States experience preeclampsia or gestational hypertension, but gaps in evidence and in guidelines mean that significant variation exists in how BP is managed in the postpartum period, according to the authors of the new study, led by Alisse Hauspurg, MD (University of Pittsburgh School of Medicine, PA).

Through 6 weeks postpartum, severe hypertension (≥ 160/110 mm Hg) occurred in 14% of patients. Compared with patients whose BP had normalized, those who developed severe hypertension had increased likelihood of visits to the emergency department and hospital readmission after a postpartum discharge, which the authors say reinforces the need for remote home monitoring.

To TCTMD, Hauspurg said quantifying the scope of the problem is a first step toward highlighting the need for increased clinical and research attention direct at this population.

“For a long time, we didn't really understand these patterns of blood pressure after delivery,” she said. “We know there are gaps in guidelines and in how people are managed in this period. I think there really needs to be a focus on . . .  large-scale randomized trials to look at what our goals should be and what are the best methods [in terms of] how we are titrating medications.”

As Hauspurg and colleagues note in their paper, published yesterday in JAMA Cardiology, the most recent American College of Obstetricians and Gynecologists (ACOG) guidelines “do not explicitly state postpartum BP thresholds for treatment.” In prior guidelines, initiation of antihypertensives was recommended for persistent BP (systolic ≥ 150 and/or diastolic ≥ 100 mm Hg).

In an accompanying editorial, Sadiya S. Khan, MD, MSc (Northwestern University Feinberg School of Medicine, Chicago, IL), notes that despite nearly 40% of patients meeting the ACOG definition of hypertension while in the hospital, and 68% meeting the American College of Cardiology/American Heart Association (ACC/AHA) definition (systolic ≥ 140 to 149 mm Hg and/or diastolic ≥ 90 to 99 mm Hg), only 23.5% were discharged on antihypertensive medications.

The discordance between the guidelines for optimal targets of BP control, Khan says, “may be a major contributor to the observed heterogeneity in antihypertensive management strategies, and, subsequently, greater risk of readmission due to uncontrolled or severe hypertension.”

Nurse-Led Remote Intervention and Communication

For the study, Hauspurg and colleagues enrolled 2,705 postpartum patients (mean age 29.8 years; 15% Black) and followed them for 6 weeks after hospital discharge.

Enrolled patients received an automatic upper-arm BP monitor and were given directions for use by a nurse educator prior to discharge. BP was measured on both the hospital and remote device to confirm accuracy of the measurements.

At the start of the nurse-led program, patients were contacted at home and the information they were told in the hospital about BP measurements was reiterated. Patients were prompted to check their BP at least daily for the first 2 weeks and three to five times per week through 6 weeks postpartum. These measurements were reported back to the nurse call center via text messaging and entered into the electronic medical record. If a medication change was indicated or patients were experiencing severe symptoms, the nursing staff communicated directly with an on-call maternal-fetal medicine physician.

Persistent hypertension was seen in 81.8% of patients over the study period, with initiation of new antihypertensive medication in 22.6%. The average time of initiation was 7 days postpartum. BP control (< 140/90 mm Hg) was achieved in 14.6% of those who started a medication after discharge.

Severe hypertension led to more emergency department visits (adjusted OR 1.85; 95% CI 1.17-2.92) and hospital readmissions (adjusted OR 6.75; 95% CI 3.43-13.29) than resolution of normal BP in the postpartum period.

Those who did not have resolution of hypertension after discharge were more likely than those who did to have a higher early-pregnancy body mass index, self-identify as Black, and have a Cesarean delivery. Development of severe hypertension occurred more often in those with public versus private insurance.

More Data and Strategies Needed

The authors also compared postpartum BP categories with outpatient home BP trajectories to inform optimal thresholds for inpatient antihypertensive medication initiation. This showed significant overlap between postdischarge BP trajectories in those with inpatient systolic BP ≥ 140 to 149 mm Hg and/or diastolic ≥ 90 to 99 mm Hg and those with systolic BP ≥ 150 mm Hg and/or diastolic BP ≥ 100 mm Hg. The authors say these findings “suggest that using lower thresholds for medication initiation during the inpatient delivery hospitalization may be reasonable given the expected exacerbation of hypertension after hospital discharge.”

To TCTMD, Hauspurg said the remote-monitoring program achieved a compliance rate of 90% in the 7-10 days postpartum, which is the most critical time for maternal risk in postpartum hypertensive disorders. While they did see some drop-off in reporting of BP after that time, she said further research might be important in understanding how to better engage busy postpartum women and identifying barriers to their participation.

There also is a need to better estimate risk for worsening hypertension after discharge, which could include things like biomarkers that add information to patient characteristics that correlate with risk.

According to Khan, longitudinal data on postpartum BP levels and trajectories in the first year after giving birth could help inform guideline recommendations for ambulatory BP monitoring after a hypertensive disorder of pregnancy.

Finally, Khan notes that “strategies that address upstream social determinants of health are urgently needed given the disproportionate burden of hypertensive disorders of pregnancy, readmission after [these disorders], and lifetime risk of cardiovascular disease among minoritized individuals.”