Pulmonary Hypertension and Pregnancy Outcomes: Insights From the National Inpatient Sample

BACKGROUND: Pregnant women with pulmonary hypertension (PH) are at risk for adverse cardiac outcomes, particularly at the time of labor and delivery. The purpose of this study is to define the impact of PH on pregnancy outcomes and the risk of major adverse cardiac events (MACE). METHODS AND RESULTS: The National Inpatient Sample was screened for hospital admissions of women delivering during the years 2003 to 2012. The primary outcome was MACE, a composite of death, cardiac arrest, cardiogenic shock, myocardial infarction, respiratory failure, arrhythmia, stroke, and embolic event. Data on 1519 patients with PH and 6 757 582 without heart disease or PH were available. There were 59.6% with isolated PH; 10.7% with PH and congenital heart disease; 18.1% with PH and valvular heart disease; 3% with PH and valvular heart disease and congenital heart disease; 6.6% PH and cardiomyopathy; and 1.9% with PH and cardiomyopathy and valvular heart disease. Compared with women without heart disease or PH, women with PH experienced significantly higher MACE (24.8 versus 0.4%, P<0.0001). Among the subsets of women with PH, the highest MACE was noted in women with the combination of PH and cardiomyopathy and valvular heart disease, and PH and cardiomyopathy, primarily because of heart failure and arrhythmia. Women with PH were significantly more likely to experience eclampsia syndromes, preterm delivery, and intrauterine fetal demise (P<0.0001 for all). PH subtype was significantly associated with MACE in multivariable analysis (P<0.001). CONCLUSIONS: In a contemporary data set of pregnant women in the United States, PH was associated with an increase in MACE during the hospitalization for delivery, with an exceptionally elevated risk among women with associated cardiomyopathy.