Heart attacks during pregnancy are uncommon, but the prevalence of heart disease in pregnant mothers has increased over the past decade as more women delay pregnancy until they are older. These women, who are generally less physically active than their younger peers, tend to have higher cholesterol levels and are at greater risk of heart disease and diabetes.
While research has shown that the heart typically functions better during pregnancy due to a rise in cardiac pumping capacity to meet increased demands, a new UCLA study in rats and mice demonstrates that heart attacks occurring in the last trimester or late months of pregnancy result in worse heart function and more damaged heart tissue than heart attacks among non-pregnant females.
"This very early study may help us identify and better understand the mechanisms involved in the higher risks of heart disease during pregnancy and may provide new opportunities to better treat pregnant women with cardiovascular complications and risk factors," said senior study author Mansoureh Eghbali, an assistant professor of anesthesiology at the David Geffen School of Medicine at UCLA.
For the study, researchers assessed heart differences after heart attacks among late-stage pregnant female rats and non-pregnant animals. They found that the pregnant animals’ hearts demonstrated poor functional recovery, with only 10 percent restoration of heart function, compared with 80 percent restoration among the non-pregnant group. The pregnant animals also had a four-fold increase in damaged heart tissue over the non-pregnant group.
"We observed worse heart function and a greater area of damage in hearts from the late-pregnancy group, compared to the non-pregnant group," said first author Jingyuan Li, a postdoctoral fellow in the department of anesthesiology at the Geffen School of Medicine.
"These findings show that the heart in late pregnancy may be particularly vulnerable to the type of injury caused by a heart attack," Eghbali said.