What is the role of thrombolysis in the management of acute coronary syndrome in pregnancy?

Thrombolysis in Acute Coronary Syndrome During Pregnancy

Thrombolysis should be reserved exclusively for life-threatening acute coronary syndrome when primary percutaneous coronary intervention (PCI) is not accessible, as coronary angiography with PCI is strongly preferred and significantly improves maternal survival. 1

Primary Management Strategy: PCI Over Thrombolysis

Primary PCI is the gold standard and should be performed immediately for ST-elevation myocardial infarction in pregnancy, with immediate referral to a skilled interventional center for diagnostic angiography. 1, 2 This approach offers critical advantages:

• Directly visualizes and diagnoses coronary artery dissection, which is the most common cause of pregnancy-associated acute coronary syndrome and occurs predominantly in the peripartum period. 2, 3, 4
• Significantly improves maternal survival compared to thrombolysis, with maternal mortality after ACS estimated at 5-10% and highest during the peripartum period. 1, 2
• Avoids the bleeding complications associated with thrombolytic therapy, particularly subplacental bleeding. 1

When Thrombolysis May Be Considered

Thrombolytic therapy should only be used when there is no access to PCI and the patient has life-threatening ACS. 1 The European Society of Cardiology guidelines are explicit that this is a last-resort option. 1

Critical Limitations of Thrombolysis in Pregnancy:

• Recombinant tissue plasminogen activator (rt-PA) does not cross the placenta but may induce serious bleeding complications, particularly subplacental bleeding. 1
• Cannot diagnose coronary artery dissection, which requires direct visualization and may worsen with thrombolysis. 1, 2
• Higher complication rates compared to PCI, though overall reported complication rates are relatively low given the severity of underlying conditions. 5
• Contraindicated in most cases due to high bleeding risk, especially near delivery or postpartum. 6

Practical Algorithm for Decision-Making

For ST-Elevation Myocardial Infarction:

1. Immediate transfer to interventional cardiology center for diagnostic angiography and primary PCI. 1, 2
2. If PCI unavailable and life-threatening presentation: Consider thrombolysis only after weighing maternal mortality risk against bleeding complications. 1
3. Never delay for delivery planning - proceed with definitive treatment first. 3

For Non-ST-Elevation ACS:

• Invasive strategy with angiography for intermediate or high-risk criteria (including NSTEMI). 1, 2
• Conservative management only for stable patients without risk criteria. 1

Critical Pitfalls to Avoid

Do not withhold coronary angiography due to fetal radiation concerns - maternal mortality risk far exceeds fetal radiation risk, especially outside the first trimester. 7 The diagnostic and therapeutic benefits of PCI dramatically outweigh theoretical radiation risks. 2, 7

Do not assume thrombolysis is safer than PCI in pregnancy - this is a dangerous misconception. The inability to diagnose coronary dissection (the most common cause of pregnancy-associated ACS) makes thrombolysis potentially harmful. 1, 2

Avoid ergometrine for postpartum bleeding management in any patient with coronary concerns, as it can cause coronary vasospasm and worsen ischemia. 1, 2

Stenting Considerations When PCI Is Performed

Use bare metal stents only - drug-eluting stents should be avoided due to unknown safety profile in pregnancy and the requirement for prolonged dual antiplatelet therapy. 1, 2, 7

Clopidogrel should be used only when strictly necessary (e.g., after stenting) and for the shortest duration possible due to limited safety data. 1, 2, 7