Are heart attacks linked to pregnancy on the rise in US? Study says it is and most often in women 30 and older
Heart attacks related to pregnancy, especially in the period after childbirth, are on the rise in women who are 30 years or older, according to researchers. While still considered uncommon, their analysis of close to 11.3 million records for pregnancy, labor, and postpartum (after childbirth) cases reveals that nearly three-fourths of the 913 women who had heart attacks from 2003 to 2015 were 30 years or older. This warrants a further understanding of the cause and risk, suggest the authors.
Of the women who had heart attacks in the study, 37% experienced it during pregnancy, 12% during labor and delivery, and 51% during postpartum. According to the investigators, the increase in heart attack has occurred with increases in maternal age, as well as a rise in obesity. It may also be related to increases before pregnancy in other traditional heart disease risk factors such as diabetes, high cholesterol, high blood pressure, and smoking, they add.
“Pregnancy-associated myocardial infarction (the medical term for a heart attack) is becoming more common in the US and internationally, although the incidence may be highest in the US. Increases in acute myocardial infarction (AMI) incidence have occurred in lockstep with increases in maternal age, as well as a global rise in obesity and metabolic syndrome,” write authors in the study published in the Journal of the American Heart Association.
What did the researchers find?
Pregnancy increases the risk of heart attack, say experts, and the purpose of the current analysis was to examine timing and risk factors for AMI in pregnancy and poor outcome. A national inpatient sample (2003-2015) was screened in pregnancy, labor and delivery, and postpartum. There were 11,297,849 records extracted with 913 instances of a heart attack. The investigators found that 111 (12.2%) women experienced acute myocardial infarction during labor and delivery, 338 (37%) during pregnancy, and most (464 or 50.8%) during the postpartum period. “The prevalence of AMI in pregnancy has increased. Most major adverse cardiovascular and cerebrovascular events occurred in the postpartum period (63.5%). Inpatient mortality was 4.5%,” the findings state.
According to senior author Dr Kathleen Stergiopoulos, director of ambulatory echocardiography at St Francis Hospital, The Heart Center in Roslyn, New York, pregnancy is a cardiovascular stress test. In a normal pregnancy, blood pressure decreases most commonly in the first and second trimester and then increases to pre-pregnancy levels by the third trimester, she explains.
“People often forget about the postpartum period but that is a period of high risk because of changes in the maternal cardiovascular system. Most patients have left the hospital by the time symptoms begin. With a new baby at home, the last place mothers want to be is back in the hospital. Could I be having a heart attack or could I be having a stroke is almost not on a woman’s radar, but it's especially not on a young woman’s radar,” says Stergiopoulos.
Among the women who experienced a heart attack, 661 (72.4%) were 30 years and older, and this increased with age. Most women were White (38.4%), followed by those of the Black race (23.4%) as secondarily most frequent. “Although the most frequently affected race in our study was White women, the proportion of Black women with AMI was nearly 2‐fold higher than those without AMI,” write authors. A large proportion of records (44.9%) were described as insured by public insurance, that is, Medicaid or Medicare
Be aware of the risk factor, say experts
Stergiopouloss cautions it is essential to be aware of the heart attack risk factors during pregnancy, which includes known coronary artery disease, gestational high blood pressure disorders, high cholesterol, blood clotting conditions, substance abuse history, smoking history, and obesity. Stergiopoulos recommends women with cardiovascular disease, or at high risk of developing it during pregnancy, work with a group of specialists ideally before pregnancy, during, and after delivery.
The researchers emphasize that risk factor modification as well as increased implementation in public health resources for pregnant patients may facilitate steps towards decreasing the rates of a heart attack in this population. “AMI is associated with modifiable, nonmodifiable, and obstetric risk factors. These risk factors can lead to devastating adverse outcomes and highlight the need for risk factor modification and public health resource initiatives toward the goal of decreasing AMI in the pregnant population,” they explain.
A scientific statement published in May by the American Heart Association (AHA) had also suggested that pregnant women with heart disease be cared for by specialized cardio-obstetric teams.
“Pregnancy can place a lot of stress on the body, especially your heart. If you have an underlying cardiac history, you really need to have a cardio-obstetrics team – a cardiologist, an obstetrician, an anesthesiologist, the right team of players to help carry you through to the end,” recommends Dr Laxmi Mehta, a non-invasive cardiologist at The Ohio State University in Columbus, who was not involved in the study.
Mehta, who led the writing of the AHA scientific statement, adds, “As we get older when we’re thinking of pregnancy, we really do need those close discussions with your gynecologist about what the risks are.”
Meanwhile, Stergiopoulos suggests that future research should specifically examine socioeconomic status and race as other potential risk factors for heart disease during pregnancy. “Public insurance – Medicaid insurance – came up as a predictor of (heart attacks). So, there’s likely a socioeconomic factor, but it was not fully explored. There was also an indication that the Black race was a factor, another area that requires further exploration,” she explains.