Assessment and Prediction of Cardiovascular Contributions to Severe Maternal Morbidity

Results of cardiovascular testing among pregnant and postpartum persons undergoing standardized cardiovascular risk assessment

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of maternal mortality in the United States, accounting for one in three pregnancy-related deaths. A standardized CVD Risk Assessment can guide clinicians in identifying patients at risk for CVD.

OBJECTIVE

The objective of this study was to evaluate whether a standardized CVD risk assessment yields more abnormal findings on follow-up CVD testing among pregnant and postpartum patients compared to assessments based on clinician judgment alone.

STUDY DESIGN

A retrospective chart review was performed across three geographically and ethnically diverse hospital networks that had implemented the CVD Risk Assessment algorithm. The analysis included a total of 31,232 pregnant and postpartum patients who had presented for obstetric care visit from September 2020 to August 2024. We calculated the proportion of patients with abnormal composite brain natriuretic peptide (BNP), electrocardiogram (EKG), and/or echocardiogram test results by risk assessment group, and a two Proportion Z-Test was conducted to compare proportions. We then calculated the odds of having abnormal tests for each risk assessment group.

RESULTS

Standardized CVD risk assessment yielded more abnormal composite test results than clinician judgment alone (6.9% vs. 4.2%; p<.0001). There was a greater proportion of abnormal test results among the risk-positive than the risk-negative group (23.4% vs. 6.6%; P<.0001). Patients assessed for CVD had 1.69 times the odds of having an abnormal test than those tested based on clinician judgment alone (P<.0001). Risk-positive patients had 4.31 times the odds of having an abnormal test than risk-negative patients (P<.0001).

CONCLUSION

Implementing a standardized CVD Risk Assessment algorithm may enhance the detection of cardiovascular disease in pregnant and postpartum patients with previously unknown CVD or at risk of developing CVD, providing a valuable tool that complements clinician judgment for improved perinatal outcomes.

Delivery-Related Maternal Morbidity and Mortality Among Patients With Cardiac Disease

OBJECTIVE

To assess the risk of severe maternal morbidity (SMM) and mortality among pregnant patients with cardiovascular disease (CVD).

METHODS

This was a retrospective cohort study of U.S. delivery hospitalizations from 2010 to 2020 using weighted population estimates from the National Inpatient Sample database. The primary objective was to evaluate the risk of SMM and maternal mortality among patients with CVD at delivery hospitalization. International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification codes were used to identify delivery hospitalizations, CVD, and SMM events. Multivariable logistic regression analyses were performed to compare SMM and mortality risk among patients with CVD and those without CVD. Given the substantial racial and ethnic disparities in SMM, mortality, and CVD burden, secondary objectives included evaluating SMM and mortality across racial and ethnic groups and assessing the population attributable fraction within each group. Lastly, subgroup analyses of SMM by underlying CVD diagnoses (eg, congenital heart disease, chronic heart failure) were performed. Variables used in the regression models included socioeconomic and demographic maternal characteristics, maternal comorbidities, and pregnancy-specific complications.

RESULTS

Among 38,374,326 individuals with delivery hospitalizations, 203,448 (0.5%) had CVD. Patients with CVD had an increased risk of SMM (11.6 vs 0.7%, adjusted odds ratio [aOR] 12.5, 95% CI, 12.0-13.1) and maternal death (538 vs 5 per 100,000 delivery hospitalizations, aOR 44.1, 95% CI, 35.4-55.0) compared with those without CVD. Patients with chronic heart failure had the highest SMM risk (aOR 354.4, 95% CI, 301.0-417.3) among CVD categories. Black patients with CVD had a higher risk of SMM (aOR 15.9, 95% CI, 14.7-17.1) than those without CVD with an adjusted population attributable fraction of 10.5% (95% CI, 10.0-11.0%).

CONCLUSION

CVD in pregnancy is associated with increased risk of SMM and mortality, with the highest risk of SMM among patients with chronic heart failure. Although CVD affects less than 1% of the pregnant population, it contributes to nearly 1 in 10 SMM events in the United States.

Hypertensive Disorders and Cardiovascular Severe Maternal Morbidity in the US, 2015-2019

Importance

The incidence of severe maternal morbidity (SMM)-and particularly cardiovascular SMM (cvSMM), the first cause of pregnancy-related mortality-has been rising in North America. Although hypertensive disorders of pregnancy (HDP) are common, their association with cvSMM specifically remains unclear.

Objective

To assess the association between individual subtypes of HDP and cvSMM, in addition to overall SMM, in a large, nationally representative sample.

Design, Setting, and Participants

A population-based cohort study using the United States National Inpatient Sample was conducted. Individuals with obstetric deliveries between 2015 and 2019 were included. Data analysis was performed from October 2023 to February 2024.

Exposure

HDP subtypes included gestational hypertension, chronic hypertension, preeclampsia without severe features, severe preeclampsia, and HELLP (hemolysis, elevated liver enzymes, and low platelet) syndrome.

Main Outcomes and Measures

The primary outcome was a composite of cvSMM (including conditions such as pulmonary edema, stroke, and acute myocardial infarction) and the secondary outcome was a composite of overall SMM (including cvSMM and other conditions such as respiratory failure, severe postpartum hemorrhage, and sepsis). Adjusted risk ratios (aRRs) for the association between HDP subtypes and the outcomes were estimated using modified Poisson regression models adjusted for demographic and clinical characteristics.

Results

Among 15 714 940 obstetric deliveries, 2 045 089 (13.02%) had HDP, 23 445 (0.15%) were affected by cvSMM, and 282 160 (1.80%) were affected by SMM. The mean (SD) age of the cohort was of 29 (6) years. The incidence of cvSMM was higher in participants with HDP than those without HDP (0.48% [9770 of 2 045 089] vs 0.10% [13 680 of 13 669 851]; P < .001). Participants with HELLP syndrome had the highest risk for cvSMM (aRR, 17.55 [95% CI, 14.67-21.01]), followed by severe preeclampsia (aRR, 9.11 [95% CI, 8.26-10.04]), and chronic hypertension (aRR, 3.57 [95% CI, 3.15-4.05]). Although HDP subtypes were also associated with overall SMM, the association with HELLP syndrome (aRR, 9.94 [95% CI, 9.44-10.45]), severe preeclampsia (aRR, 3.66 [95% CI, 3.55-3.78]), and chronic hypertension (aRR, 1.96 [95% CI, 1.88-2.03]) was attenuated compared with cvSMM.

Conclusions and Relevance

In this cohort study, a graded relationship by severity characterized the association between HDP and cvSMM. Although all HDP subtypes were associated with an increased risk of overall SMM, the risk was more pronounced for cvSMM.

Racial/ethnic differences in pre-pregnancy conditions and adverse maternal outcomes in the nuMoM2b cohort: A population-based cohort study

OBJECTIVES

To determine how pre-existing conditions contribute to racial disparities in adverse maternal outcomes and incorporate these conditions into models to improve risk prediction for racial minority subgroups.

STUDY DESIGN

We used data from the "Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b)" observational cohort study. We defined multimorbidity as the co-occurrence of two or more pre-pregnancy conditions. The primary outcomes of interest were severe preeclampsia, postpartum readmission, and blood transfusion during pregnancy or up to 14 days postpartum. We used weighted Poisson regression with robust variance to estimate adjusted risk ratios and 95% confidence intervals, and we used mediation analysis to evaluate the contribution of the combined effects of pre-pregnancy conditions to racial/ethnic disparities. We also evaluated the predictive performance of our regression models by racial subgroup using the area under the receiver operating characteristic curve (AUC) metric.

RESULTS

In the nuMoM2b cohort (n = 8729), accounting for pre-existing conditions attenuated the association between non-Hispanic Black race/ethnicity and risk of severe preeclampsia. Cardiovascular and kidney conditions were associated with risk for severe preeclampsia among all women (aRR, 1.77; CI, 1.61-1.96, and aRR, 1.27; CI, 1.03-1.56 respectively). The mediation analysis results were not statistically significant; however, cardiovascular conditions explained 36.6% of the association between non-Hispanic Black race/ethnicity and severe preeclampsia (p = 0.07). The addition of pre-pregnancy conditions increased model performance for the prediction of severe preeclampsia.

CONCLUSIONS

Pre-existing conditions may explain some of the association between non-Hispanic Black race/ethnicity and severe preeclampsia. Specific pre-pregnancy conditions were associated with adverse maternal outcomes and the incorporation of comorbidities improved the performance of most risk prediction models.

Cardio-obstetrics de novo: a state-level, evidence-based approach for addressing maternal mortality and severe maternal morbidity in Georgia

Georgia has a higher rate of severe maternal morbidity and mortality when compared with the rest of the United States. Evidence gained from the Georgia Maternal Mortality Review Committee identified areas of focus for high-yield clinical initiatives for improvement in maternal health outcomes. Cardiovascular disease, including cardiomyopathy, coronary conditions, and preeclampsia with or without eclampsia, is the most common cause of pregnancy-related death in non-Hispanic Black women in Georgia. The development of a cardio-obstetrics program is an initiative to advance health equity by decreasing cardiovascular morbidity and mortality. This report describes the following: (1) state-level advocacy for improving maternal health outcomes with funding gained through the legislative process and partnership with a governmental agency; (2) cardio-obstetrics program development based on evidence gained from the maternal mortality review process; and (3) implementation of a cardio-obstetrics service, beginning with a focused approach for capacity building and understanding barriers to care.

Maternal Cardiovascular Health Post-Dobbs

Maternal Cardiovascular Health Post-DobbsPregnancy is associated with increasing morbidity and mortality in the United States. In the post-Dobbs era, many pregnant patients at highest risk no longer have access to abortion, which has been a crucial component of standard medical care.

Risk Factors for Severe Maternal Morbidity Among Women Enrolled in Mississippi Medicaid

Importance

Mississippi has one of the highest rates of severe maternal morbidity (SMM) in the US, and SMMs have been reported to be more frequent among Medicaid-insured women. A substantial proportion of pregnant women in Mississippi are covered by Medicaid; hence, there is a need to identify potential risk factors for SMM in this population.

Objective

To examine the associations of health care access and clinical and sociodemographic characteristics with SMM events among Mississippi Medicaid-enrolled women who had a live birth.

Design, Setting, and Participants

A nested case-control study was conducted using 2018 to 2021 Mississippi Medicaid administrative claims database. The study included Medicaid beneficiaries aged 12 to 55 years who had a live birth and were continuously enrolled throughout their pregnancy period and 12 months after delivery. Individuals in the case group had SMM events and were matched to controls on their delivery date using incidence density sampling. Data analysis was performed from June to September 2022.

Exposure

Risk factors examined in the study included sociodemographic factors (age and race), health care access (distance from delivery center, social vulnerability index, and level of maternity care), and clinical factors (maternal comorbidity index, first-trimester pregnancy-related visits, and postpartum care).

Main Outcomes and Measures

The main outcome of the study was an SMM event. Adjusted odds ratio (aORs) and 95% CIs were calculated using conditional logistic regression.

Results

Among 13 485 Mississippi Medicaid-enrolled women (mean [SD] age, 25.0 [5.6] years; 8601 [63.8%] Black; 4419 [32.8%] White; 465 [3.4%] other race [American Indian, Asian, Hispanic, multiracial, and unknown]) who had a live birth, 410 (3.0%) were in the case group (mean [SD] age, 26.8 [6.4] years; 289 [70.5%] Black; 112 [27.3%] White; 9 [2.2%] other race) and 820 were in the matched control group (mean [SD] age, 24.9 [5.7] years; 518 [63.2%] Black; 282 [34.4%] White; 20 [2.4%] other race). Black individuals (aOR, 1.44; 95% CI, 1.08-1.93) and those with higher maternal comorbidity index (aOR, 1.27; 95% CI, 1.16-1.40) had higher odds of experiencing SMM compared with White individuals and those with lower maternal comorbidity index, respectively. Likewise, an increase of 100 miles (160 km) in distance between beneficiaries' residence to the delivery center was associated with higher odds of experiencing SMM (aOR, 1.14; 95% CI, 1.07-1.20).

Conclusions and Relevance

The study findings hold substantial implications for identifying high-risk individuals within Medicaid programs and call for the development of targeted multicomponent, multilevel interventions for improving maternal health outcomes in this highly vulnerable population.