Study Suggests Increased Risk of Coronary Artery Disease in Black Women With Complications During Pregnancy

Fahad Alkhalfan, M.D.
By Fahad Alkhalfan, M.D. on

A study led by Dr. Julian Wichmann published in JACC: Cardiovascular Imaging showed that black women with a history of pregnancy complications had a higher prevalence of coronary artery disease (CAD) on coronary computed tomographic angiography (CCTA). Additionally, having a history of gestational diabetes mellitus was independently associated with any and obstructive CAD and CCTA.

An association between pregnancy complications, especially preeclampsia and gestational diabetes, and an increased incidence of a cardiovascular event. However, little is known about the association of other pregnancy complications and CAD, especially in black women. Black women have a higher prevalence of CAD and poorer outcomes as compared to other races. In this study, the investigators aimed to evaluate the association of three known pregnancy complications (preeclampsia, gestational diabetes mellitus and preterm delivery) and the prevalence and severity of CAD in black women.

“The results of our study indicate that among 884 black women with similar baseline characteristics and traditional risk factors for atherosclerotic cardiovascular disease, a history of pregnancy complications is associated with a higher prevalence of CAD on CCTA imaging. Our results support the concept that women who experience pregnancy complications, particularly gestational diabetes mellitus, have a higher risk for CAD and should subsequently be monitored more closely for coronary risk factors than women without such pregnancy complications.” – Julian Wichmann, M.D.

This was a retrospective multicenter study of hospitals in the Medical University of South Carolina health network. All black women who had a CCTA between June 2005 and May 2014 and a previous pregnancy with or without a history of complications were included. Women who had multiple or repeated complications or a nonspontaneous preterm delivery were excluded from the analysis. Other risk factors, including smoking and obesity, were identified. In order to limit the influence of other baseline characteristics, propensity score analysis with matching in a 1:1 fashion was used to identify the controls. The CCTA reports were analyzed, as the images were not available for a majority of cases. Patients were considered to have “any CAD” if they had a greater than 20% luminal narrowing in the left main, left anterior descending, left circumflex or right coronary arteries. The lesions were considered to be obstructive if they had a luminal narrowing of 50% or greater.

A total of 439 black women who had a previous pregnancy complication and a CCTA were identified. Preterm delivery occurred in 154 women (35.1%), preeclampsia in 137 women (31.2%), and gestational diabetes in 148 women (33.7%). The matched control group consisted of 445 women. Women with gestational diabetes had a higher prevalence of type 2 diabetes in the future. Additionally, women with a history of preterm delivery had a lower prevalence of type 2 diabetes as compared to the control group. As compared to the control group, all three groups had higher rates of any CAD and obstructive CAD (Preterm delivery: 29.2% for any CAD and 9.1% for obstructive CAD; preeclampsia: 29.2% for any CAD for any CAD and 7.3% for obstructive CAD; and gestational diabetes mellitus: 47.3% for obstructive CAD and 15.5% for any CAD) compared with control women (23.8% for obstructive CAD and 5.4% for any CAD). However, this difference was only significant when comparing patients with gestational diabetes and the control group (GDM vs control: OR 2.87 for any CAD, p <0.001, and OR 3.22 for obstructive CAD, p <0.001). Finally, when patients with a history of pregnancy complications were combined, having any of the three conditions was associated with a higher risk of any CAD (OR 1.76, p <0.001) and obstructive CAD (OR 2.10, p = 0.004).

This study demonstrated that in black women with a history of pregnancy complications had a higher rate of CAD as compared to black women who previously had a normal pregnancy. The investigators describe the potential mechanism linking each of the three complications with CAD. The pathophysiological mechanism linking preterm delivery and CAD is not known but could potentially be as a result of excess endocrine stimulation.  As for preeclampsia, it is believed that it is a systemic disease that manifests during pregnancy, but that its effect continues to persist even after delivery. This could lead to impaired endothelial and angiogenetic function, thus contributing to CAD. Finally, the occurrence of gestational diabetes in pregnant women has been shown to be associated with an increased risk of type 2 diabetes. Therefore, these patients would be at an increased risk of CAD. While this study does demonstrate an increased risk of CAD in women with pregnancy complications, the study does have its limitations. Its retrospective nature and the fact that it excluded patients with multiple complications could limit its generalizability. Ultimately, the authors recommend that women who suffer from complications in pregnancy are at a higher risk of CAD and should be monitored more closely.

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