ANAHEIM, CALIF. – Women who experience placental abruption are at significantly increased risk for multiple forms of cardiovascular disease beginning within the first few years after their pregnancy complication, according to a study of more than 1.6 million California women.
While gestational hypertension, preeclampsia, and fetal growth restriction have previously all been shown to be associated with increased risk of incident cardiovascular disease, this huge California study provides the first strong epidemiologic evidence that placental abruption is as well. Prior studies looking at the issue have been underpowered, Michael J. Healey, MD, said at the American Heart Association scientific sessions.
“Our hypothesis is that there might be some type of shared mechanism, probably involving microvascular dysfunction, that explains the relationships we see between these pregnancy complications and increased near-term risk of cardiovascular disease,” he explained in an interview.
Dr. Healy, a hospitalist attached to the heart failure service at the University of California, San Francisco, presented a retrospective study of a multiethnic cohort comprising 1,614,950 parous women aged 15-50 years who participated in the California Healthcare Cost and Utility Project during 2005-2009. Placental abruption occurred in 15,057 of them at a mean age of 29.2 years.
During a median 4.9 years of follow-up, women who experienced abruptio placenta were at 6% increased risk for heart failure, 11% greater risk for MI, 8% increased risk for hypertensive urgency, and 2% greater risk for myocardial infarction with no obstructive atherosclerosis (MINOCA) in an age- and race-adjusted analysis. All of these were statistically significant differences.
Of note, however, in a multivariate analysis fully adjusted for standard cardiovascular risk factors, as well as hypercoagulability, preterm birth, grand multiparity, and insurance status, placental abruption was independently associated with a 2.14-fold risk of MINOCA, but it was no longer linked to significantly increased risks of the other cardiovascular events.
The implication is that the increased risk of these other forms of cardiovascular disease is mediated through the women’s increased prevalence of the traditional cardiovascular risk factors, whereas a novel mechanism – most likely microvascular dysfunction – underlies the association between placental abruption and MINOCA, according to Dr. Healy.
He plans to extend this research by taking a look at the relationship between placental abruption and the various subtypes of MINOCA, including coronary dissection, vasospasm, thrombophilia disorders, and stress cardiomyopathy, in order to examine whether the increased risk posed by placental abruption is concentrated in certain forms of MINOCA. Data on MINOCA subtypes were recorded as part of the California project.
He reported having no financial conflicts of interest regarding his study.