Pregnant Women With Heart Disease at Risk for Serious Cardiac Events

pregnant patient with nurse
pregnant patient with nurse
Pregnant women with heart disease were found to be at risk for serious cardiac events.

Pregnant women with heart disease were found to be at risk for serious cardiac events, according to study results published in the Journal of the American College of Cardiology.

Data for 1315 pregnancies were collected from the Canadian Cardiac Disease in Pregnancy study, in particular, data on serious or life-threatening cardiac and obstetric events that occurred during pregnancy and up to 6 months postpartum. Cases were reviewed by ≥2 cardiologists to determine whether the events were preventable.

Serious cardiac events occurred in 47 pregnancies (3.6%) and predominantly in the antepartum period (66%). The most frequent cardiac events were urgent cardiac intervention (n=9), heart failure (n=8), serious arrhythmias (n=5), and cardiac death (n=5). Cardiac death was secondary to cardiac arrest in 80% of cases. Four women survived cardiac arrest.

Of the serious cardiac events that occurred, 49% were considered preventable, including 2 maternal deaths. Urgent cardiac interventions and congestive heart failure accounted for 48% of the preventable cardiac events. Of preventable serious cardiac events, 74% were secondary to provider management factors. The most common factors were failure to identify the underlying cardiac condition prior to pregnancy, failure to identify a high-risk patient, delay in treatment, and delayed recognition of cardiac deterioration.

Live births occurred in 42 of the pregnancies with serious cardiac events. Adverse fetal and neonatal events occurred more frequently in pregnancies with serious vs nonserious/no cardiac events (62% vs 32% vs 29%, respectively; P <.001). The most common fetal events in pregnancies with serious cardiac events were preterm delivery (45%), small size for gestational age (21%), and respiratory distress syndrome (15%). Preventable antepartum events were more frequently associated with adverse fetal or neonatal events (68%).

Serious obstetric events occurred in 22 pregnancies (1.7%). The most common obstetric event was severe preeclampsia (n=18). Preterm delivery or small size for gestational age occurred in two-thirds of these pregnancies. There were no maternal obstetric deaths. Serious obstetric events occurred in 2 pregnancies with serious cardiac events (4.3%).

Study limitations include a possible overestimation of the incidence of serious cardiac complications.

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“Pregnant women with heart disease are at risk for serious and life-threatening cardiac and obstetric complications. Approximately one-half of these cardiac events are preventable,” the study authors concluded. “Strategies to prevent serious maternal cardiac complications in this high-risk cohort of women need to be developed.”


Pfaller B, Sathananthan G, Grewal J, et al. Preventing complications in pregnant women with cardiac disease. J Am Coll Cardiol. 2020;75(12):1443–1452. doi:10.1016/j.jacc.2020.01.039