Pregnant women are four times more likely to suffer a heart attack, according to a new study.
Though acute myocardial infarction (AMI) is rare in women of child-bearing age, but with more and more women delaying childbirth and advances in advances in reproductive medicine enabling older women to conceive, the incidence of AMI associated with pregnancy is likely to increase.
"It's extremely important that physicians who take care of women during pregnancy and after delivery be aware of the occasional occurrence of AMI in pregnancy and not overlook symptoms in these young patients," said Dr. Uri Elkayam, who is a professor of Medicine and Obstetrics and Gynecology at USC.
"Although many of the standard principles for diagnosing and treating AMI in non-pregnant patients also apply to pregnant women, two patients need to be treated-the mother and her baby-and the health status of both should play a major role in the selection of diagnostic and therapeutic strategies," he added.
Some of the standard diagnostic tests and medications used to manage AMI can be harmful to the baby, whether in the womb or through breastfeeding; therefore, their use should take into account potential risks and benefits.
The researchers analysed 103 women with pregnancy-related AMI and compared them to 125 cases diagnosed prior to that time. Patients' ages ranged from 19 to 44 years, and older maternal age was shown to be a risk factor.
"The good news is that we've seen a significant drop in maternal deaths related to AMI during and immediately following pregnancy in the last decade," said Dr. Elkayam.
"Our initial report indicated a mortality rate of 20 percent, and nearly 40 percent was reported by other studies. In contrast, the new data suggest that only 5 percent to 10 percent of expectant and new mothers who have a heart attack die as a result," he added.
The gives credit to increased awareness, more aggressive clinical approaches to treating AMI in general, including standardized hospital protocols for screening and diagnosis, as well as the application of these approaches to pregnant women.
"Interestingly, the mechanism of AMI is somewhat different when it occurs in association with pregnancy. One in four women had a weakening and separation of the walls of the coronary arteries (coronary dissection), which is a rare cause of heart attack in the general population," explains Dr. Elkayam.
"Another 13 percent had normal coronary arteries. These findings signify the need to establish the cause of AMI in pregnancy in order to decide on appropriate therapy."
Dr. Elkayam said that those who experienced AMI within 24 hours before or after delivery are twice as likely to die from heart attack as those who have a cardiac event before labour or postpartum (24 hours to three months after delivery).
He hopes that guidelines presented in the paper will further increase awareness about AMI in pregnancy.
The study is published in the July 15, 2008, issue of the Journal of the American College of Cardiology.