Maternal Mortality

Addressing CVD’s role in U.S. maternal mortality: Multispecialty collaboration is needed


Nearly 700 women died from pregnancy-related complications in the United States in 2018, and almost a third of those deaths were associated with cardiovascular disease, according to the latest data from the Centers for Disease Control and Prevention.

Renee Patrice Bullock-Palmer, MD, cardiologist and director of the Women's Heart Center at Deborah Heart and Lung Center in Browns Mills, N.J.

Dr. Renee Patrice Bullock-Palmer

Strikingly, studies suggest that up to half of cardiovascular disease–related maternal deaths are preventable, yet CVD remains the leading cause of maternal morbidity and mortality – and the incidence has been rising steadily for 2 decades.

The American College of Obstetricians and Gynecologists says that acquired heart disease is the likely culprit in the rise in incidence of maternal mortality as women enter pregnancy with an increasingly heavy burden of CVD risk factors, including older age, obesity, diabetes, and hypertension.

“They are entering pregnancy while already at risk, and that has led to an increase in morbidity and mortality during pregnancy,” Renee Patrice Bullock-Palmer, MD, a cardiologist and director of the Women’s Heart Center at Deborah Heart and Lung Center in Browns Mills, N.J., explained in an interview. “Unfortunately, among developed countries, the U.S. has the highest rates of maternal morbidity and mortality, and that’s shocking.”

It’s a problem that requires collaboration between obstetricians, cardiologists, and others involved in the care of pregnant women, she said.

The data and the depth of the crisis

The maternal mortality rate in 1987 – the year the CDC’s Pregnancy Mortality Surveillance System was implemented – was 7.2 per 100,000 live births. The rate in 2016 was more than double that at 16.9, and the rate in 2018, the most recent year for which data are available, was 17.4 – and significant racial and ethnic disparities in those rates have persisted over time.

In an August 2019 article published on the American Heart Association website, Dr. Bullock-Palmer addressed the cardiovascular state of health for pregnant women and the role of the cardiologists in their care, noting that there is a “role for increased collaboration between the cardiologist and the obstetrician with regards to a pregnancy heart team.”

“It is vital that mothers who are at increased risk for CVD or have established CVD be referred to a cardiologist for cardiovascular assessment and management,” she wrote, adding it is important to raise awareness among ob.gyns. and to improve cardiologists’ recognition of women at risk when they present for care for the first time.

These referrals should be made in the antepartum and early postpartum period, she said in an interview. More attention also must be paid to racial and ethnic disparities, and the role of cardiologists in addressing these disparities.

The CDC has emphasized racial and ethnic disparities in maternal mortality, noting in a 2019 Morbidity and Mortality Weekly report that, compared with white women, black and American Indian/Alaskan Native women aged over 30 years have a 300%-400% higher rate of pregnancy-related deaths (Morb Mortal Wkly Rep. 2019 Sep 6;68[35]:762-5).

With regard to disparities, Dr. Bullock-Palmer said the causes are multifold and may be related to a higher prevalence of CVD risk factors like obesity and hypertension in non-Hispanic black women.

“There may also be limited access to adequate postpartum care in this patient population,” she wrote, adding that some attention has been paid to addressing disparities, but that “there is a lot of work left to be done in resolving these inequities in maternal health care.”

Partnerships across specialties will help in addressing most of the factors associated with CVD and maternal death, she said.

The urgent need for these partnerships is underscored by the latest findings on CVD-related complications in pregnancy. A study published in March 2020 in the Journal of the American College of Cardiology, for example, looked specifically at the incidence of serious cardiac events (SCEs) in pregnant women with heart disease, and whether the events were preventable.

In a prospective cohort of 1,315 pregnancies among women with heart disease, Birgit Pfaller, MD, of the University of Toronto Pregnancy and Heart Disease Research Program, and colleagues found that SCEs occurred in 3.6% of cases (47 women) – most often during the antepartum period – that 49% were preventable, and that 74% were related to provider management factors.

The most common SCEs were cardiac death or arrest, heart failure, arrhythmias, and urgent intervention, and they were more likely to occur in women with acquired heart disease, severe aortic or mitral stenosis, mechanical valves, and systemic ventricular dysfunction. Adverse fetal and neonatal outcomes more than doubled in cases involving SCEs, compared with those without (62% vs. 29%), and adverse obstetric events occurred most often in women with severe preeclampsia.

“The majority of the preventable events occurred due to provider management factors, including: failure to identify the patient condition prior to pregnancy, failure to identify the patient as high risk, late recognition in cardiac deterioration, delay in treatment/intervention, inappropriate treatment, and lack of preconception counseling,” Melinda Davis, MD, of the University of Michigan, Ann Arbor, wrote in a summary and editorial published in the Journal of the American College of Cardiology.

Some preventable events were attributable to patient failure to seek care, noncompliance with care recommendations, and lack of access to care, Dr. Davis noted.

“These findings suggest that provider training, patient education, and health care advocacy are all important interventions to improve outcomes among pregnant women,” she wrote, adding that “the development of multidisciplinary cardio-obstetric clinics at tertiary care centers may also be helpful.”

Dr. Bullock-Palmer added the need for greater risk-prediction tools to the list, explaining that these are needed to assess CVD risk in the prenatal, antenatal, and postnatal period.

“The recently concluded Cardiac Disease in Pregnancy [CARPREG II] study indicated that there were 10 predictors that could be utilized to asses maternal CVD risk,” she noted.

The CARPREG II authors identified five general predictors (prior cardiac events or arrhythmias, poor functional class or cyanosis, high-risk valve disease/left ventricular outflow tract obstruction, systemic ventricular dysfunction, no prior cardiac interventions), four lesion-specific predictors (mechanical valves, high-risk aortopathies, pulmonary hypertension, coronary artery disease), and one delivery-of-care predictor (late pregnancy assessment), and incorporated them into a risk index.

“It is hopeful that these new initiatives will assist providers in improving their ability to appropriately risk stratify women,” Dr. Bullock-Palmer said.


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