Makindo Medical Notes

Related Subjects: |Atherosclerosis |Ischaemic heart disease |Assessing Chest Pain |ACS: general |ACS: STEMI |Cardiac Thrombolysis |Stroke Thrombolysis |Alteplase |Tenecteplase |Streptokinase |Reteplase |ACS: Right Ventricular STEMI

Thrombolysis has been a cornerstone of treatment for patients with ST-segment elevation myocardial infarctions (STEMI), improving outcomes and preserving left ventricular function. However, it has largely been replaced by Primary PCI in many settings. The door-to-needle time for thrombolysis should be <30 minutes.

Usual Criteria for Thrombolysis (seek advice if unsure)

• STEMI with symptom onset <12 hours prior (may consider up to 24 hours in some cases).
• STEMI with persistent symptoms.
• STEMI with ongoing ST elevation, rising troponin levels, or haemodynamic instability.
• Primary PCI is unavailable.
• ≥ 1 mm of ST elevation in at least 2 contiguous limb leads (I, II, III, AVF, AVL).
• ≥ 2 mm of ST elevation in at least 2 contiguous chest leads (V1-V6).
• New onset left bundle branch block (LBBB).

Absolute Contraindications

• Suspected or confirmed dissecting aortic aneurysm (consider CTA if unsure).
• Ischaemic stroke within the last 3 months (seek advice if acute stroke is suspected).
• Known intracranial neoplasm or arteriovenous malformation.
• Active, uncontrollable bleeding.
• Known bleeding diathesis.
• Recent gastrointestinal haemorrhage or active peptic ulcer disease.
• Uncontrolled hypertension (systolic BP > 180 mmHg or diastolic BP > 100 mmHg).
• Significant closed-head or facial trauma within the past 3 months.
• History of intracranial haemorrhage.
• Recent intracranial or intraspinal surgery.
• Recent trauma with high risk of haemorrhage.
• Cancer with a high risk of bleeding.

Relative Contraindications (seek senior advice)

• Severe chronic hypertension (BP > 180/110 mmHg) – consider IV labetalol.
• History of haemorrhagic stroke or intracerebral haemorrhage (ICH).
• Trauma within the past 2 weeks.
• Recent gastrointestinal bleeding or uncontrolled bleeding.
• Prolonged CPR (>10 minutes).
• Active peptic ulcer disease.
• Patients on warfarin – check INR.
• Recent use of direct oral anticoagulants (DOAC) or high-dose low molecular weight heparin (LMWH).
• Active menstruation or pregnancy.
• Cancer with or without metastases.
• Haemorrhagic or diabetic retinopathy.
• Presence of an abdominal or thoracic aortic aneurysm.
• Recent invasive or surgical procedure (within the past 3 weeks).

Side Effects

• Bleeding – the most common and serious complication.
• Anaphylaxis – rare, but can occur with agents like streptokinase.
• Angioedema – particularly in patients on ACE inhibitors.

Management of Life-Threatening Bleeding Due to Thrombolysis

• Administer IV fluids and packed red blood cells as necessary.
• Start with 10 units of cryoprecipitate and check fibrinogen levels.
• If fibrinogen is <1 g/L, administer an additional 10 units of cryoprecipitate.
• If bleeding persists despite a fibrinogen level >1 g/L, or if fibrinogen remains <1 g/L after 20 units of cryoprecipitate, administer 2 units of fresh frozen plasma (FFP).
• Consider administering platelets or antifibrinolytics (aminocaproic acid or tranexamic acid) if bleeding continues.

Management Options

• Tenecteplase
• Streptokinase
• Reteplase