Management of myocardial infarction in pregnant women: A narrative review of recommendations

Introduction

The incidence of pregnancy-associated myocardial infarction (PAMI) is low, ranging from 1.7 to 6.2 cases per 100,000 pregnancies [1-3]. Nevertheless, myocardial infarction accounts for approximately 20% of maternal deaths. Based on data from the National Inpatient Sample (2003-2015), only 913 episodes of PAMI were recorded among 11,297,849 hospitalizations (0.008%) [4]. Of these, 111 (12.2%) occurred during labor, 338 (37.0%) during pregnancy, and 464 (50.8%) in the early postpartum period.
This review aimed to analyze existing studies and synthesize current knowledge regarding the management of PAMI. Specifically, this narrative review addressed the question: How should clinicians balance the risks and benefits of diagnostic and therapeutic interventions in pregnant patients with acute myocardial infarction in the absence of dedicated guidelines?

Material and methods

This review article was based on an analysis of seventeen scientific papers published between 2005 and 2025, all publicly available through PubMed (www.pubmed.ncbi.nlm.nih.gov). The authors focused on studies concerning acute coronary syndromes associated with pregnancy, their treatment, and the impact of pharmacotherapy and ionizing radiation on the fetus. Literature search was conducted between April and May 2025 using the following key words: “PAMI”, “myocardial infarction in pregnancy”, “spontaneous coronary artery dissection”, “acute coronary syndrome and pregnancy”, and “dual antiplatelet therapy during pregnancy”.
Inclusion criteria comprised English-written peer-reviewed articles, reporting on the diagnosis, treatment, and outcomes of PAMI, including case reports, cohort studies, systematic reviews, and clinical guidelines. Exclusion criteria were non-English publications, studies unrelated to acute coronary syndromes in pregnancy, and animal model research.
The initial search yielded 74 articles. After screening for titles, abstracts, and full texts, 17 studies were selected based on relevance to the topic. A basic quality assessment of the included studies was performed by evaluating clarity of clinical data, applicability to pregnancy-related cardiac care, and study design. For clarity and better illustration, a summary table of the reviewed publications is included in the article, presenting the study type, country of origin, and key characteristics of the included works (Table 1).

Pathophysiology

The etiology of PAMI differs from that in the general population. Spontaneous coronary artery dissection (SCAD) (27-43%) and atherosclerosis (27-40%) are the most common causes, followed by thrombosis without an atherosclerotic basis (8-17%) and coronary artery spasm (2%). Pregnancy increases the risk of myocardial infarction three- to four-fold compared with non-pregnant women of reproductive age [5]. This is attributed to the physiological, metabolic, and hormonal changes in pregnancy, including increased blood volume and coagulation, elevated cardiac output and blood pressure as well as heightened myocardial oxygen demand.
Placental hormones stimulate erythropoiesis, but the increase in red blood cell mass is lower than the rise in plasma volume, resulting in physiological anemia due to hemodilution. An elevated prothrombotic factors, combined with venous compression and decreased physical activity, further increase the risk of PAMI [6]. Additionally, hormones, such as human placental lactogen, cortisol, prolactin, growth hormone, and progesterone, increase insulin resistance and glucose levels, potentially leading to gestational diabetes, a key risk factor for acute coronary syndromes.
Plasma triglyceride levels triple during pregnancy, peaking in the third trimester. Also, both high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels rise. Insulin resistance and lipid metabolism disturbances can contribute to coronary artery disease (CAD), predisposing pregnant women to additional risk factors for myocardial infarction [7].
A trend towards increased diagnosis of myocardial infarction during pregnancy may be attributed to increasing maternal age. Women aged over 35 years are more likely to have risk factors, including obesity, smoking, dyslipidemia, hypertension, and diabetes. Long-term registry analyses also indicate that complications, such as pre-eclampsia and eclampsia, elevate the risk of myocardial infarction both during and after pregnancy [8].

Diagnosis and treatment

PAMI as a rare condition presents a significant diagnostic and therapeutic challenge. The lack of reported cases supports the absence of specific guidelines on the management and medication safety. Pregnant individuals are generally excluded from clinical trials. Whereas in non-pregnant patients, revascularization within 120 minutes of diagnosis is advised for ST elevation myocardial infarction (STEMI). Indications for urgent coronary angiography with potential revascularization include hemodynamic instability, refractory chest pain, acute heart failure likely secondary to ischemia, life-threatening arrhythmia, or cardiac arrest.
The European Society of Cardiology (ESC) recommends conservative treatment for stable, low-risk non-ST elevation myocardial infarction (NSTEMI) in pregnant patients. Risk stratification tools, such as the GRACE score, can assist in decision management. In cases of SCAD, which often present as STEMI, conservative treatment is preferred due to the risk of dissection propagation during catheterization and high-pressure contrast administration [9].
Patients with cardiogenic shock should receive mechanical circulatory support, including intra-aortic balloon pumps, percutaneous ventricular assist devices, or extra corporeal membrane oxygenation (ECMO). Concerns exist regarding ionizing radiation during coronary angiography; fetal vulnerability is highest during the first trimester, but decreases in later pregnancy [10]. Studies show that radiation exposure to the fetus during coronary angiography (approximately 20 mGy) is well below the 100 mGy threshold considered harmful [11].

Pharmacological treatment

Antiplatelet therapy is essential in managing PAMI. Dual antiplatelet therapy (DAPT) is required when stents are implanted, while aspirin monotherapy is often sufficient in SCAD-related PAMI. A loading dose of aspirin is considered safe up to 32 weeks of gestation, with maintenance doses deemed safe throughout pregnancy. The loading dose blocks COX-1 activity in over 95% of platelets, which is crucial for inhibiting platelet aggregation in occluded vessels. Nonetheless, this approach should balance the risks and benefits [12]. Doses above 180 mg are discouraged due to risks, such as bleeding, premature ductus arteriosus closure, and intra-uterine growth restriction.
Clopidogrel is the preferred agent when DAPT is necessary. It should be discontinued 5-7 days before epidural anesthesia for caesarean section. The American Society of Regional Anesthesia and Pain Medicine advises cessation periods of 5-7 days for clopidogrel and ticagrelor, 7-10 days for prasugrel, and 10 days for ticlopidine. In one study, clopidogrel was discontinued a week before delivery in 13 cases, 10 of whom were on DAPT, and no delivery complications occurred. Moreover, clopidogrel was continued through delivery in 16 patients, with two cases of post-caesarean bleeding requiring transfusion [13].
Cardioselective b-blockers are generally safe, but non-selective agents may induce uterine contractions and preterm labor. Atenolol is contraindicated due to its association with neonatal apnea, bradycardia, and hypoglycemia. Nitrates are not contraindicated but should be used cautiously to avoid maternal hypotension and placental hypoperfusion. Statins and renin-angiotensin system inhibitors (ACE inhibitors and ARBs) are contraindicated due to the risks of fetal renal impairment, skeletal anomalies, and pulmonary hypoplasia [14].
For anticoagulation, unfractionated heparin (UFH) is preferred due to its short half-life, ease of monitoring, and reversibility with protamine sulphate. ESC guidelines recommend stopping UFH 4-6 hours before delivery and resuming it 6-12 hours post-partum, assuming no hemorrhagic complications [15].

Childbirth and further pregnancy planning

In PAMI cases, postponing delivery by at least two weeks is advisable, if maternal and fetal conditions allow. Ideally, delivery should occur no earlier than 39 weeks to optimize neonatal outcomes [16]. Vaginal delivery is preferred, as it avoids the need for DAPT suspension or epidural anesthesia.
According to ESC guidelines, pregnancy is not contraindicated in women with stable CAD, provided there is no residual ischemia or left ventricular dysfunction. Pregnancy should be postponed for approximately 12 months post-PAMI. Furthermore, all women with confirmed or suspected CAD or aortic disease should undergo risk assessment using the modified WHO (mWHO) classification. This tool stratifies maternal cardiovascular risk into four classes, and provides recommendations for monitoring, frequency of visits, and delivery planning.
Post-PAMI patients require close monitoring, as the risk of recurrence remains high for up to six months postpartum. The highest recurrence rate (20%) was observed in women with prior SCAD [17].

Conclusions

Although myocardial infarction during pregnancy remains rare, its incidence is increasing. Despite this fact, no dedicated guidelines for PAMI management currently exist. PAMI presents a complex clinical scenario, necessitating multidisciplinary cooperation among cardiologists, obstetricians, anesthetists, and cardiac surgeons. Optimal management involves careful risk-benefit analysis. All women planning pregnancy should undergo cardiovascular risk stratification, including detailed history, laboratory assessment, and evaluation of prior pregnancy complications or known risk factors, to enhance the efficacy of both primary and secondary prevention.

Disclosures

This review received no external funding.
Approval of the Bioethics Committee was not required.
The authors declare no conflict of interest.

References