Tight vs liberal control of mild postpartum hypertension: a randomized controlled trial

Antihypertensive therapy and unplanned maternal postpartum health care utilization in patients with mild chronic hypertension

OBJECTIVE

To test whether treatment of mild chronic hypertension (CHTN) in pregnancy is associated with lower rates of unplanned maternal healthcare utilization postpartum.

METHODS

This was a secondary analysis of the CHTN and pregnancy (CHAP) study, a prospective, open-label, pragmatic, multicenter, randomized treatment trial of pregnant people with mild chronic hypertension. All patients with a postpartum follow-up assessment were included. The primary outcome was unplanned healthcare utilization, defined as unplanned postpartum clinic visits, Emergency Department or triage visits, or unplanned hospital admissions within six weeks postpartum. Differences in outcomes were compared between study groups (Active Group: blood pressure goal of<140/90 mm Hg, and Control Group: blood pressure goal of <160/105 mm Hg) and factors associated with outcomes were examined using logistic regression.

RESULTS

A total of 2,293 patients were included with 1,157 (50.5%) in the active group and 1,136 (49.5%) in the control group. Rates of unplanned maternal postpartum health care utilization did not differ between treatment and control groups, (20.2% vs 23.3%, p=0.07, aOR 0.84, 95% CI 0.69-1.03. However, Emergency Department or triage/maternity evaluation unit visits were significantly lower in the Active group (10.2% vs 13.2%, p=0.03, aOR 0.76, 95% 0.58-0.99). Higher BMI at enrollment and cesarean delivery were associated with higher odds of unplanned postpartum healthcare utilization.

CONCLUSION

While treatment of mild CHTN during pregnancy and postpartum was not significantly associated with overall unplanned healthcare resource utilization, it was associated with lower rates of postpartum Emergency Department and triage visits.

Postpartum Management of Hypertensive Disorders of Pregnancy in Six Large U.S. Hospital Systems: Descriptive Review and Identification of Clinical and Research Gaps

Hypertensive disorders of pregnancy (HDPs) are a key contributor to maternal morbidity and mortality. Several gaps in knowledge remain regarding best practices in the postpartum management of HDPs. In this review, we describe postpartum HDPs management among six large academic U.S. hospital systems: Medical College of Wisconsin, University of Pittsburgh, University of Wisconsin-Madison, Northwestern University, University of Minnesota, and Boston Medical Center. We identified that all six health systems discharge patients with HDPs diagnosed with a blood pressure (BP) cuff and use the same two antihypertensive medications, nifedipine and labetalol, as first- and second-line treatment of HDPs. Northwestern University routinely adds oral furosemide for 5 days for patients with BP that exceeds 150/100 mm Hg. Most hospital systems administer magnesium sulfate routinely when readmission for HDPs occurs. In contrast, there was variation in BP threshold for antihypertensive treatment initiation, use of remote BP monitoring program, use of a transition clinic, delivery or lack of education on long-term cardiovascular disease risk, and BP management through the first 6 weeks postpartum and beyond. Based on the clinical review, we identified clinical gaps and formulated considerations for research priorities in the field of postpartum HDPs management. KEY POINTS: · Several gaps in knowledge remain regarding best practices in postpartum management of HDPs.. · There is a variation in the BP threshold for antihypertensive treatment initiation.. · Data are lacking on the reduction in severe maternal morbidity (SMM) and racial disparities in SMM with remote monitoring..

Postpartum blood pressure control and the rate of readmission

BACKGROUND

Postpartum hypertension is a major contributor to the rising maternal mortality rates in the United States, with nearly half of maternal deaths occurring after delivery. Previous studies have found evidence that the maximum blood pressure reading during labor and delivery admission can predict readmission; however, the optimal blood pressure to reduce the need for readmissions and additional medical treatment in the postpartum period is not known.

OBJECTIVE

This study aimed to investigate the relationship between postpartum blood pressure control at discharge and readmission within the first 6 weeks after delivery.

STUDY DESIGN

Data were obtained from Cosmos, an electronic health record-based, Health Insurance Portability and Accountability Act-defined limited dataset that includes more than 1.4 million birth encounters. All birthing parents with blood pressure data after delivery were included. Demographic information, medications, and readmissions were queried from the dataset. Patients were grouped into categories based on blood pressure readings in the 24 hours before discharge (≥160/110, ≥150/100, ≥140/90, ≥130/80, ≥120/80, and <120/80 mm Hg). The readmission rates across these groups were compared. Planned subanalyses included stratification by the use of antihypertensive medications and a sensitivity analysis using the highest blood pressure during admission. Covariates included maternal age, preexisting diabetes mellitus or lupus erythematosus, and body mass index.

RESULTS

The analysis included 1,265,766 total birth encounters, 391,781 (30.9%) in the referent group (120/80 mm Hg), 392,592 (31.0%) in the group with <120/80 mm Hg, 249,414 (19.7%) in the group with ≥130/80 mm Hg, 16,125 (1.3%) in the group with ≥140/90 mm Hg, 50,659 (4.0%) in the group with ≥150/100 mm Hg, and 20,196 (1.6%) in the group with ≥160/110 mm Hg. In the first 6 weeks after delivery, readmission rates increased with higher blood pressure readings. More than 5% of postpartum patients with the highest blood pressure readings (≥160/110 mm Hg) were readmitted. These patients were almost 3 times more likely to be readmitted than patients whose highest blood pressure reading fell into the referent group (120/80 mm Hg) (odds ratio [OR], 2.90; 95% confidence interval, 2.69-3.12). Patients with blood pressures of >150/100 mm Hg (odds ratio, 2.72; 95% confidence interval, 2.58-2.87), >140/90 mm Hg (odds ratio, 2.03; 95% confidence interval, 1.95-2.11), and >130/80 mm Hg (odds ratio, 1.43; 95% confidence interval, 1.37-1.49) all had higher odds of readmission, whereas patients with a blood pressure of <120/80 mm Hg had a lower odds of readmission (odds ratio, 0.78; 95% confidence interval, 0.75-0.81). Patients who had higher blood pressures during admission but had improved control in the 24 hours before discharge had lower rates of readmission than those whose blood pressures remained elevated. In all blood pressure categories, patients who received an antihypertensive prescription had higher rates of readmission.

CONCLUSION

In this large, national dataset, blood pressure control at discharge and readmission in the postpartum period were significantly correlated. Our data should inform postpartum hypertension treatment goals and the role of remote monitoring programs in improving maternal safety.

Factors associated with early readmission for postpartum hypertension

BACKGROUND

Hypertensive disorders of pregnancy are increasing in prevalence and a leading cause of early postpartum readmissions. Stricter blood pressure target goals for treatment of hypertension during pregnancy have recently been proposed, however, the treatment goals for management of postpartum hypertension are less well established.

OBJECTIVE

We sought to evaluate the clinical factors associated with early postpartum readmissions for hypertensive disease and to evaluate blood pressure thresholds associated with these readmissions.

STUDY DESIGN

We conducted a retrospective cohort study of women delivering at a tertiary care center between January 2018 and May 2022 who experienced a hospital readmission for postpartum hypertension or new onset postpartum preeclampsia. Charts were reviewed for clinical and sociodemographic data. Patients with early readmission (<72 hours after discharge) were compared with patients readmitted after 3 days of initial discharge. Data were analyzed using chi-square, Student t test, Mann-Whitney U test, and logistic regression where appropriate. The P value <.05 was considered significant.

RESULTS

During the study period, 23,372 deliveries occurred. Postpartum readmission due to worsening of a known diagnosis of hypertension or new onset postpartum preeclampsia occurred in 1.1% and 0.49% respectively. Patients with early readmission were more likely to have hypertensive disorders of pregnancy as the indication for delivery. Among patients readmitted, 93% had 2 or more systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, and 73% had blood pressure of either systolic between 130 and 139 mmHg or diastolic between 80 and 89 mmHg within 24 hours before initial discharge. Only 27 patients met criteria (blood pressure ≥160/110 mmHg on >1 vitals check during their hospitalization) to be started on antihypertensives before initial delivery discharge; of those 25 (93%) were discharged with a new prescription for an antihypertensive. After controlling for confounding variables, predischarge blood pressure between 130-140 mmHg/80-90 mmHg (adjusted odds ratio, 2.4 [1.5-4.0]) was associated with an increased likelihood of early readmission.

CONCLUSION

Patients with delivery for hypertensive disorders of pregnancy and predischarge blood pressure ≥140/90 mmHg were less likely to have an early readmission within 3 days of initial discharge, however, patients with predischarge blood pressure 130-139 mmHg/80-89 mmHg were more likely to have an early readmission for hypertensive disorders of pregnancy and postpartum preeclampsia. Further research is indicated to evaluate interventions to prevent postpartum readmission in patients at high risk for persistent hypertension or new onset postpartum preeclampsia.

Cardiovascular Disease Risk Factor Interventions in Women With Prior Gestational Hypertensive Disorders or Diabetes in North America: A Rapid Review

Women with previous hypertensive disorders of pregnancy (HDP) or gestational diabetes mellitus (GDM) have a 2- to 3-fold increased risk of cardiovascular disease (CVD). The goal of this rapid review was to summarize evidence of the effectiveness of CVD risk factor interventions for postpartum women with a history of HDP or GDM. A comprehensive search strategy was used to search articles published in 5 databases-Ovid MEDLINE, PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, and Embase). Observational and intervention studies that identified CVD prevention, screening, and/or risk factor management interventions among postpartum women with prior HDP or GDM in Canada and the US were included. The quality of observational and interventional studies, and their risk of bias, were assessed using appropriate critical appraisal checklists. Eight studies, including 4 observational cohorts, 3 randomized controlled trials, and 1 quasi-experimental study, merited inclusion for analysis. A total of 2449 participants were involved in the included studies. The most effective CVD risk factor intervention was comprised of postpartum transition and follow-up, CVD risk factor education, and advice on lifestyle changes. Most of the observational studies led to improvements in CVD risk factors, including improvements in CVD lifetime risk scores. However, none of the RCTs led to improvements in cardiometabolic risk factors. Few studies have investigated CVD risk factor interventions in the postpartum in women with previous HDP or GDM in North America. Further studies of higher quality are needed.

Pre-eclampsia and Cardiovascular Disease: From Pregnancy to Postpartum

Hypertensive disorders of pregnancy (HDP) complicate approximately 10% of pregnancies. In addition to multiorgan manifestations related to endothelial dysfunction, HDP confers an increased risk of cardiovascular disease during delivery hospitalisation, such as heart failure, pulmonary oedema, acute MI and cerebrovascular events. However, the cardiovascular legacy of HDP extends beyond birth since these women are significantly more likely to develop cardiovascular risk factors in the immediate postnatal period and major cardiovascular disease in the long term. The main mediator of cardiovascular disease in women with a history of HDP is chronic hypertension, followed by obesity, hypercholesterolaemia and diabetes. Therefore, optimising blood pressure levels from the immediate postpartum period until the first months postnatally could have beneficial effects on the development of hypertension and improve long-term cardiovascular health. Peripartum screening based on maternal demographic, and clinical and echocardiographic data could help clinicians identify women with HDP at highest risk of developing postpartum hypertension who would benefit from targeted primary cardiovascular prevention.

Assessing maternal cardiac function by obstetricians: technique and reference ranges

BACKGROUND

A strong body of evidence has now coalesced indicating that some obstetrical syndromes may result from maladaptive responses of the maternal cardiovascular system. Longitudinal studies have shown that these changes are complex and present before the clinical recognition of preeclampsia and fetal growth restriction, suggesting that hemodynamic maladaptation may play an etiologic role in obstetrical complications. Chronic hypertension is one of the most frequent complications of pregnancy, and recent evidence suggests that control of mild hypertension in early pregnancy improves outcome. The management of chronic hypertension can be improved by understanding specific cardiovascular hemodynamic abnormalities such as increased cardiac output or increased systemic vascular resistance, which can respond to either beta or calcium channel blockers, depending on the hemodynamic findings. Evaluation of maternal cardiac function has not been previously available to obstetrical healthcare providers using diagnostic ultrasound equipment used for fetal evaluation.

OBJECTIVE

Obstetrical ultrasound machines may be configured for various probes (endovaginal, abdominal, 3D/4D, and cardiac). This study used a cardiac probe placed in the suprasternal notch to image and measure the descending aorta diameter and the velocity time integral using pulsed and continuous wave Doppler ultrasound in normal pregnant women between 11 and 39 weeks of gestation. These measurements were followed by computation of maternal left ventricular preload, afterload, contractility, and blood flow.

STUDY DESIGN

This was a prospective cross-sectional study. A total of 400 pregnant women were recruited between 11 and 39 weeks of gestation. Imaging of the maternal aortic arch was performed by placing a cardiac probe in the suprasternal notch to identify the aortic arch using 2D and color Doppler ultrasound. The end-systolic diameter of the aorta was measured at the junction of the left subclavian artery with the descending aorta, which was followed by insonation of the descending aorta to obtain the Doppler waveform. Following insonation of the descending aorta, measurements of the aortic diameter, velocity time integral, ejection time, mean pressure gradient, heart rate, maternal weight and height, and systolic and diastolic blood pressures were entered into an Excel spreadsheet to compute the following: (1) preload measurements of stroke volume, stroke volume index, and stroke work index; (2) afterload measurements of systemic vascular resistance and the potential-to-kinetic energy ratio; (3) contractility measurements of inotropy and the Smith-Madigan inotropy index; and (4) blood flow measurements of cardiac output and the cardiac output index. Fractional polynomial regression analysis was performed for each of the above measurements using gestational age as the independent variable.

RESULTS

The diastolic and mean arterial blood pressure decreased from 11 to 18 weeks of gestation and then increased until term. The afterload measurements demonstrated similar characteristics, as all values decreased from 11 weeks until the mid and late second trimester, after which all values increased until term. Changes in contractility demonstrated an increase from 11 weeks to 25 to 28 weeks, followed by a decline until term. Changes in blood flow demonstrated an increase from 11 to 27 weeks and then declined until term. The continuous wave Doppler values were greater than the pulsed Doppler values except for the contractility measurements. Examples of abnormal cardiac measurements were identified in pregnant patients with hypertension and fetal growth restriction. An Excel calculator was created to provide quick computation of z-score measurements and their corresponding centiles described in this study.

CONCLUSION

The technique for evaluation of maternal cardiac function described in this study would allow screening of maternal left ventricular preload, afterload, contractility, and blood flow in the obstetrical clinical milieu once a cardiac probe is acquired for obstetrical ultrasound machines used for fetal evaluation. The above measurements would allow the clinician to select appropriate hypertensive medication on the basis of the results of the evaluation of the maternal left ventricle.