Peripartum myocardial ischemia: a review of Canadian deliveries from 1970 to 1998

Pregnancy-Associated Myocardial Infarction in Alberta: A Population-Based Study

Background

Cardiac disease is the leading cause of maternal mortality in developed countries, and myocardial infarction (MI) is an important cause of pregnancy-associated morbidity and mortality. These infrequent, but very serious, events are not optimally described in the medical literature.

Objectives

This study describes a 15-year consecutive, retrospective cohort of confirmed pregnancy-associated MIs (PAMIs) identified in Alberta, Canada (2003-2017).

Methods

Utilizing a provincial administrative database, a cohort of women with PAMI were identified using a validated algorithm. Additional cases were identified by reviewing provincial maternal mortality records. Medical record review was conducted on each case with further details obtained via linkage with a provincial coronary heart disease registry. Available angiographic images were also reviewed.

Results

Forty-three cases of PAMI were identified in Alberta between 2003 and 2017, providing a crude incidence of ∼5.64/100,000 births. Rates of PAMI increased over the study period. Of the identified MIs, 16.3% occurred antepartum (mean gestational age of 18 weeks), while 30.2% were peripartum and 53.4% occurred within 6 months postpartum (at a mean of 7.8 weeks after delivery). The most common mechanism of PAMI was spontaneous coronary artery dissection (44.2%) and this mechanism predominated postpartum. Coronary artery disease was a frequent antepartum cause of MI, whereas demand ischemia was the leading cause of peripartum MI. Maternal mortality was approximately 9%.

Conclusions

PAMI is an increasing cause of maternal morbidity and mortality in Alberta. Clinicians should have a high index of suspicion for PAMI and ensure optimal management of this dangerous complication of pregnancy.

Incidence of myocardial infarction in pregnancy: a systematic review and meta-analysis of population-based studies

Aims

Cardiac disease is one of the leading causes of indirect maternal death, and myocardial infarction (MI) is one of its most common aetiologies. The objectives of this systematic review and meta-analysis were to characterize the incidence of pregnancy-associated MI (PAMI), as well as the maternal mortality and the case-fatality rates due to PAMI.

Methods and results

Articles were obtained by searching electronic databases, bibliographies and conference proceedings with no language or date restrictions. Two reviewers independently selected population-based cohort and case-control studies reporting on incidence, mortality and case-fatality rates for pregnancy-associated MI. Meta-analysis was performed to estimate pooled maternal incidence, mortality and case-fatality rates. Meta-regression was performed to explore heterogeneity. Based on 17 included studies, the pooled incidence of PAMI and maternal mortality from PAMI were 3.34 (2.09–4.58) and 0.20 (0.10–0.29) per 100 000 pregnancies, respectively. The case-fatality rate was 5.03% (3.78–6.27%). Country/region (meta-regression P = 0.006) and years of study (meta-regression P = 0.04) were potential explanations for the observed heterogeneity in the pooled incidence estimates of maternal MI and its associated mortality, with more recent studies and those conducted in the USA revealing the highest rates.

Conclusion

This article provides a global estimate of the incidence, mortality rate, and case fatality rate of pregnancy-associated MI. We identified higher rates of PAMI in the USA (relative to Canada and European countries) and rising rates over time. Further research regarding this population is needed, especially given rising maternal age and the increasing prevalence of cardiovascular risk factors.

Pregnancy-associated myocardial infarction : case report and review of the literature

Acute myocardial infarction (AMI) is a rare, but possibly catastrophic event during pregnancy, delivery, or puerperium, leading to a high mortality rate. It has different pathogenic mechanisms, such as atherosclerosis, vasospasm, thrombosis, and coronary dissection. Although MI has been reported in pregnant women at all stages of pregnancy and postpartum, it occurs more commonly in the third trimester. Pregnancy-associated MI most commonly involves the anterior wall. Pregnancy itself is an independent risk factor for MI, conferring a fourfold higher risk than that of nonpregnant women matched for age. We report the case of a 27-year-old primigravida at 30 weeks' gestation presenting with anterior MI, secondary to severe stenosis of the left anterior descending coronary artery, treated with emergency percutaneous coronary intervention.

Acute coronary syndrome in pregnant women

The purpose of this article is to review the available information on the pathophysiology, diagnosis, treatment and prognosis of acute coronary syndromes (ST-elevation myocardial infarction [STEMI] and non-ST-elevation myocardial infarction [NSTEMI]) during all stages of pregnancy. We searched the English-language literature indexed in MEDLINE, Scopus and EBSCO host research databases from 1980 through to August 2010 using the indexing terms 'pregnancy', 'ante-,peri-, and postpartum', 'acute coronary syndrome', 'myocardial infarction', 'STEMI' and 'NSTEMI'. Symptomatic coronary artery disease is still infrequent in women of childbearing age, but the recent increase in its prevalence in pregnancy has been attributed to the modern trend of childbearing in older years because many young working women are postponing having children. Although rare, acute pregnancy-related MI is a devastating event that may claim the life of a mother and her fetus. The incidence of MI is estimated at 0.6-1 per 10,000 pregnancies. The case fatality rate has been reported to be 5-37%. Owing to the rarity of the event, information related to MI in pregnancy is derived from case reports and, therefore, is subject to considerable reporting bias. Treatment needs to be prompt and urgent because of the very high mortality rate. Current guidelines for the diagnosis and treatment of MI should be expanded to include pregnancy-related MI. Screening and management of cardiovascular risk factors should be achieved before pregnancy.

Coronary heart disease and pregnancy

The prevalence of coronary artery disease in female patients is increasing due to changing lifestyle patterns including cigarette smoking, diabetes and stress. Since women are delaying childbearing until older age, acute coronary syndrome will more frequently occur during pregnancy. Although rare, acute coronary syndrome during pregnancy often has devastating consequences. It is associated with increased maternal and neonatal mortality and morbidity compared with the nonpregnant situation. Furthermore, it constitutes an important problem for the patient and the treating physician, because the selection of diagnostic and therapeutic approaches is greatly influenced not only by maternal, but also by fetal safety.