What is the management of ST-Elevation Myocardial Infarction (STEMI) in pregnancy?

Management of ST-Elevation Myocardial Infarction (STEMI) in Pregnancy

Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for pregnant women with STEMI as it allows diagnosis of potential coronary artery dissection while minimizing fetal radiation exposure compared to thrombolysis. 1

Diagnosis and Initial Assessment

• STEMI is defined as ST-segment elevation >0.1 mV in at least two contiguous precordial or adjacent limb leads, a new left bundle branch block, or a true posterior MI 1
• In pregnant patients, symptoms may be atypical and can be confused with normal pregnancy discomforts, leading to potential delays in diagnosis 2, 3
• Obtain a 12-lead ECG promptly when STEMI is suspected, as minimizing time to reperfusion is critical 1
• Initial assessment should include evaluation of both maternal and fetal status, with consideration of gestational age 2

Reperfusion Strategy

Primary PCI

• Primary PCI is strongly preferred over fibrinolysis in pregnant STEMI patients 1
• Benefits of PCI in pregnancy include:
  • Ability to diagnose coronary artery dissection, which is more common in pregnancy 1
  • Reduced risk of maternal bleeding complications compared to thrombolysis 1
  • More effective restoration of coronary flow 1

Timing Considerations

• The goal for PCI is balloon inflation within 90 minutes of first medical contact 1
• If PCI cannot be performed within 120 minutes, fibrinolytic therapy should be considered, but only if there are no contraindications and PCI is not available 1, 4

Fibrinolysis

• Fibrinolytic therapy should be reserved for life-threatening STEMI when there is no access to PCI 1
• Risks include subplacental bleeding as recombinant tissue plasminogen activator does not cross the placenta 1
• Absolute contraindications include prior intracranial hemorrhage, known structural cerebral vascular lesion, active bleeding, and several others that must be carefully assessed 1

Stent Selection

• Bare metal stents are preferred over drug-eluting stents in pregnant women 1
• The safety of drug-eluting stents in pregnancy is unknown, and they require prolonged dual antiplatelet therapy 1

Pharmacological Management

Antiplatelet Therapy

• Low-dose aspirin is considered relatively safe in pregnancy 1
• Clopidogrel should only be used when strictly needed (e.g., after stenting) and for the shortest duration possible 1
• Duration of clopidogrel therapy varies based on stent type: 14 days for no stent, at least one month for bare-metal stent 1

Anticoagulation

• For patients undergoing PCI, anticoagulation should be administered according to standard protocols with careful monitoring 1
• If fibrinolysis is performed, anticoagulation should be continued for a minimum of 48 hours 1

Other Medications

• Beta-blockers are considered relatively safe in pregnancy 1
• ACE inhibitors, angiotensin receptor blockers (ARBs), and renin inhibitors are contraindicated during pregnancy 1
• NSAIDs (except for aspirin) should be discontinued due to increased risks of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 1

Special Considerations in Pregnancy

• Radiation exposure should be minimized during cardiac catheterization, with appropriate abdominal shielding 2
• The risk of potential damage to the fetus should be kept in mind, especially in the first trimester 1
• In cases of recurrent coronary dissections, pre-term delivery can be considered according to fetal viability 1
• A multidisciplinary team approach involving cardiology, maternal-fetal medicine, and anesthesiology is essential 2

Post-STEMI Management

• Close monitoring for both maternal and fetal complications is essential 3
• For non-ST elevation ACS with intermediate or high-risk criteria, an invasive approach to assess coronary anatomy is indicated 1
• For stable conditions with exertional symptoms, watchful waiting and medical therapy is the treatment of choice 1
• If clinical status deteriorates, an invasive strategy is indicated 1

Pitfalls and Caveats

• Delayed diagnosis is common in pregnant women due to atypical presentations and reluctance to perform diagnostic tests 2, 3
• The mortality rate for pregnancy-related MI is significantly higher than in non-pregnant women, reported between 5-37% 3
• Coronary artery dissection is more common in pregnant women than atherosclerotic disease, which affects management decisions 1
• Emergency coronary artery bypass surgery during pregnancy carries a potentially high mortality rate and should only be considered when other options have failed 1