Preventing Complications in Pregnant Women With Cardiac Disease.

BACKGROUND: Pregnancy can lead to complications in women with heart disease, and these complications can be life threatening. Understanding serious complications and how they can be prevented is important.

OBJECTIVES: The primary objectives were to determine the incidence of serious cardiac events (SCEs) in pregnant women with heart disease, whether they were preventable, and their impact on fetal and neonatal outcomes. Serious obstetric events were also examined.

METHODS: A prospectively assembled cohort of 1,315 pregnancies in women with heart disease was studied. SCEs included cardiac death or arrest, ventricular arrhythmias, congestive heart failure or arrhythmias requiring admission to an intensive care unit, myocardial infarction, stroke, aortic dissection, valve thrombosis, endocarditis, and urgent cardiac intervention. The Harvard Medical Study criteria were used to adjudicate preventability.

RESULTS: Overall, 3.6% of pregnancies (47 of 1,315) were complicated by SCEs. The most frequent SCEs were cardiac death or arrest, heart failure, arrhythmias, and urgent interventions. Most SCEs (66%) occurred in the antepartum period. Almost one-half of SCEs (49%) were preventable; the majority of preventable SCEs (74%) were secondary to provider management factors. Adverse fetal and neonatal events were more common in pregnancies with SCEs compared with those without cardiac events (62% vs. 29%; p < 0.001). Serious obstetric events were less common (1.7%) and were primarily due to pre-eclampsia with severe features.

CONCLUSIONS: Pregnant women with heart disease are at risk for serious cardiac complications, and approximately one-half of all SCEs are preventable. Strategies to prevent serious cardiac complications in this high-risk cohort of women need to be developed.