Surveillance of myocardial infarction in pregnancy
Cardiac disease is a leading cause of maternal deaths in the developed world, responsible for one fifth of all maternal deaths in the UK.Myocardial infarction (MI) in pregnancy is known to be associated with significant maternal and fetal mortality. The widely quoted incidence estimate of 1 in 10,000 births is based on a study conducted in 1970. However, with current trends in lifestyle factors associated with cardiovascular disease and increasing age at childbirth, the incidence of MI during pregnancy can be expected to have increased. This study, conducted using UKOSS, provided a national picture of the incidence of the disease, its epidemiology and management.
- Twenty-five cases of MI in pregnancy were reported, giving an estimated incidence of 0.7 per 100,000 maternities (95%CI 0.5-1.1), which may represent an underestimate of the true incidence.
- Many risk factors identified were both recognisable and modifiable: maternal age (aOR 1.3 for every one year increase, 95%CI 1.2-1.4, p<0.001), smoking (aOR 3.1 95%CI 1.3-7.5, p=0.014), hypertension (aOR 8.1 95%CI 1.5-42.3, p=0.018), twin pregnancy (aOR 11.3 95%CI 2.9-44.6, p=0.002) and pre-eclampsia (aOR 4.5 95%CI 1.2-17.2, p=0.038) were all independently associated with MI in pregnancy.
- Fifteen women (60%) underwent coronary angiography; nine (60%) had coronary atherosclerosis, three (21%) had coronary artery dissection, one (7%) had a coronary thrombus, and two (13%) had normal coronary arteries. No women died.
- Management of MI in pregnancy was highly variable, indicating a clear need for further information regarding the safety and outcomes of different interventions.
- The addition of pregnancy status as a compulsory field in cardiac audit databases would enable routine collection of this information