What are the absolute and relative contraindications to thrombolytic therapy in acute myocardial infarction, and what alternative management should be used if thrombolysis is contraindicated?

Thrombolysis Contraindications in Myocardial Infarction

When thrombolysis is contraindicated in STEMI, immediate transfer for primary PCI is the recommended alternative, as it is the only effective reperfusion strategy that can salvage myocardium and reduce mortality in these patients. 1

Absolute Contraindications to Thrombolysis

Neurological Contraindications

• Prior intracranial hemorrhage at any time permanently excludes fibrinolysis 2
• Ischemic stroke within the preceding 3 months is an absolute contraindication 1, 2
• Known structural cerebral vascular lesions (arteriovenous malformation, aneurysm) forbid thrombolytic use 2
• Malignant intracranial neoplasm (primary or metastatic) precludes fibrinolysis 2
• Intracranial or intraspinal surgery within the past 2 months excludes thrombolysis 2
• Significant closed-head or facial trauma within 3 months is an absolute contraindication 2

Bleeding-Related Contraindications

• Active internal bleeding (excluding menstrual bleeding) absolutely contraindicates thrombolysis 1, 2
• Known bleeding diathesis including thrombocytopenia or coagulopathy precludes fibrinolytic therapy 1, 2
• GI bleeding within the last month is an absolute contraindication 1

Cardiovascular Contraindications

• Suspected aortic dissection is an absolute exclusion for thrombolytic therapy 1, 2
• Severe uncontrolled hypertension (SBP >180 mmHg or DBP >110 mmHg) unresponsive to emergency therapy contraindicates thrombolysis 2

Agent-Specific Contraindications

• Prior streptokinase administration within the previous 6 months is an absolute contraindication to repeat streptokinase due to antibody formation and risk of severe allergic reaction 2

Relative Contraindications

These require careful risk-benefit assessment but do not automatically preclude thrombolysis, especially in large infarcts or hemodynamic instability:

• Chronic severe poorly controlled hypertension 2
• Prior ischemic stroke occurring >3 months ago 2
• Dementia or other intracranial pathology not meeting absolute criteria 2
• Prolonged traumatic CPR (>10 minutes) 2
• Major non-cardiac surgery within the past 3 weeks 1, 2
• Recent internal bleeding within 2-4 weeks 2
• Non-compressible vascular puncture sites 2
• Pregnancy 2
• Active peptic ulcer disease 2
• Current oral anticoagulant therapy 2

Alternative Management When Thrombolysis is Contraindicated

Primary PCI as First-Line Alternative

Patients with absolute contraindications to thrombolysis should be immediately transferred for coronary angiography and primary PCI, as this is their only chance for quickly opening the coronary artery. 1

• Transfer directly to the catheterization laboratory, bypassing the emergency department, even if this requires inter-hospital transfer 1, 3
• Primary PCI has been shown to be safely feasible in the vast majority of patients with contraindications to thrombolysis 1
• Use radial access as the standard approach and implant drug-eluting stents routinely 3
• Administer aspirin plus prasugrel or ticagrelor (not clopidogrel) before PCI 1, 3
• Use unfractionated heparin as first-line anticoagulant 1, 3

Timing Considerations for Transfer

The decision to transfer depends on achievable door-to-balloon time:

• If primary PCI can be performed within 120 minutes of first medical contact, transfer is strongly recommended over thrombolysis even in patients without contraindications 1, 3
• The mortality benefit of primary PCI over thrombolysis is offset if door-to-balloon time exceeds 60 minutes, particularly in low- and intermediate-risk patients 4
• High-risk patients derive the greatest benefit from primary PCI regardless of transfer time, with mortality of 23.7% for PCI vs 30.6% for thrombolysis 4

Surgical Embolectomy

Surgical pulmonary embolectomy is recommended in patients with high-risk PE when thrombolysis is absolutely contraindicated or has failed. 1

• This recommendation applies primarily to massive pulmonary embolism rather than myocardial infarction 1
• Catheter embolectomy or fragmentation may be considered when surgery is not immediately available 1

Critical Clinical Pitfalls to Avoid

Age is NOT a Contraindication

Advanced age (>75 years) is not a contraindication to thrombolysis—elderly patients derive the greatest absolute mortality benefit, and only approximately 9% have true absolute contraindications. 2

Cardiogenic Shock is NOT a Contraindication

Cardiogenic shock does not preclude fibrinolysis when immediate PCI is unavailable; thrombolytic therapy should be used in patients with high-risk presentation and persistent arterial hypotension if PCI cannot be performed. 1, 2

Relative Contraindications Should Not Automatically Exclude Treatment

In patients with large infarcts, hemodynamic instability, or when PCI is unavailable, the mortality benefit of thrombolysis usually outweighs bleeding risk even in the presence of relative contraindications. 2

Late Presentation (>12 Hours) is NOT Absolute

Symptom onset >12 hours is not an absolute contraindication if ongoing ischemia, large myocardium at risk, or hemodynamic instability persists and PCI is unavailable. 2

Recent Surgery Distinction

Intracranial/intraspinal surgery within 2 months is an absolute contraindication, whereas non-cranial surgery within 3 weeks is only a relative contraindication. 2

Clinical Decision Algorithm

1. Confirm STEMI diagnosis with ≥2 contiguous leads showing ST-segment elevation or new left bundle-branch block, and symptom onset ≤12 hours 1, 2

2. Screen for absolute contraindications listed above—presence of any eliminates fibrinolysis as an option 2

3. Assess PCI availability: If primary PCI can be performed within 120 minutes of first medical contact, transfer for PCI is preferred 1, 3

4. If PCI unavailable and no absolute contraindications exist, initiate fibrin-specific thrombolytic (tenecteplase, alteplase, or reteplase) within 10 minutes, preferably pre-hospital 1, 3

5. For relative contraindications, weigh bleeding risk against ischemic benefit considering infarct size, hemodynamic status, and symptom duration 2

6. Administer adjunctive therapy: aspirin, clopidogrel (with fibrinolysis only), and enoxaparin or unfractionated heparin 1, 3

7. All patients receiving thrombolysis require transfer to PCI-capable center for angiography between 2-24 hours after successful fibrinolysis, or immediately if fibrinolysis fails 1