Placental Abruption as a Risk Factor for Heart Failure

Abstract

Complications of pregnancy present an opportunity to identify women at high risk of cardiovascular disease (CVD). Placental abruption is a severe and understudied pregnancy complication, and its relationship with CVD is poorly understood. The California Healthcare Cost and Utilization Project database was used to identify women with hospitalized pregnancies in California between 2005 and 2009, with follow-up through 2011. Pregnancies, exposures, covariates, and outcomes were defined by International Classification of Diseases Ninth Revision codes. Cox proportional-hazards regression was used to examine the association between placental abruption and myocardial infarction (MI), stroke, and heart failure (HF). Multivariate models controlling for age, race, medical co-morbidities, pregnancy complications, psychiatric and substance use disorders, and socioeconomic factors were employed. Among over 1.5 million pregnancies, placental abruption occurred in 14,881 women (1%). Median follow-up time from delivery to event or censoring was 4.87 (interquartile range 3.54 to 5.96) years. In unadjusted models, placental abruption was associated with risk of HF, but not MI or stroke. In fully-adjusted models, placental abruption remained significantly associated with HF (Hazard ratio 1.44; 95% confidence interval 1.09 to 1.90). Among women with placental abruptions, hypertensive disorders of pregnancy and preterm birth respectively modified and mediated the association between placental abruption and HF. In conclusion, placental abruption is a risk factor for HF, particularly in women who also experience hypertensive disorders of pregnancy and preterm birth. Placental abruption is a specific adverse pregnancy outcome associated with risk of HF.