II. Indications (Inclusion Criteria - all must be present)
- Chest Pain >15 minutes and less than 12 hours
- EKG demonstrates STEMI or new LBBB
III. Contraindications: Absolute (Exclusion Criteria - all must be absent)
- History of prior Intracranial Hemorrhage
- Structural CNS Disease
- Intracranial neoplasm
- AV Malformation
- Cerebral Aneurysm
- Ischemic Cerebrovascular Accident in last 3 months (but may be indicated if CVA in last 4.5 hours)
- Suspected Aortic Dissection (e.g. Systolic Blood Pressure difference between arms >15 mmHg)
- Significant Closed Head Injury or facial Trauma in last 3 months
- Intracranial or intraspinal surgery in last 2 months
- Active bleeding or Bleeding Diathesis (except Menstrual Bleeding)
- Severe, Uncontrolled Hypertension, refractory to emergency management
IV. Contraindications: Relative based on bleeding risk
- Chronic, severe and poorly controlled Hypertension
- Signficant Hypertension on presentation (SBP >180 mmHg or DBP >110 mmHg)
- Major Trauma or surgery (includes Retinal laser surgery) in the last 3 weeks
- Internal bleeding (e.g. GI or GU Bleeding) in the last 2-4 weeks
- Bleeding or clotting disorder or on blood thinners (e.g. Warfarin and especially with higher INR)
- Traumatic or prolonged Cardiopulmonary Resuscitation (CPR) for >10 minutes
- Non-compressible vascular puncture
- Pregnant female
- Active Peptic Ulcer
- Dementia
- Serious underlying systemic disease
- Advanced or terminal cancer
- Severe liver disease
- Severe Kidney disease
V. Contraindications: Relative based on better benefit with PCI (Angioplasty)
- Pulmonary Edema
- Systolic Blood Pressure <100 mmHg and Heart Rate >100 bpm
- Associated shock-related findings (e.g. Cool and clammy skin)
- Cardiopulmonary Resuscitation was needed
VI. Preparations: Thrombolytics
-
Tenecteplase (TNK-tPA)
- Single weight-based dose, with high fibrin Specificity and 85% patency rate at 90 minutes
- Reteplase (rPA)
- Two 10 unit doses at 30 minute intervals with moderate fibrin Specificity, and 84% patency rate at 90 min
-
Alteplase (tPA) - typical standard agent used in U.S. as of 2017
- Bolus and infusion over 90 minutes with moderate fibrin Specificity, and 73 to 84% patency rate at 90 min
-
Streptokinase
- Older agent, replaced by Fibrin specific agents
- Highly Antigenic and Streptokinase cannot be repeated within 6 months of prior dose
- Not available in U.S., but still used in some parts of world, with patency rates 60 to 68% at 90 min
VII. Protocol
VIII. Dosing: Acute Myocardial Infarction, Alteplase (tPA) dosing
- Weight 67 kg or less
- Bolus: 15 mg IV
- Next: 0.75 mg/kg (max 50 mg) IV over 30 minutes
- Next: 0.5 mg/kg (max 35 mg) IV over 60 minutes
- Weight more than 67 kg
- Bolus: 15 mg IV
- Next: 50 mg IV over 30 minutes
- Next: 35 mg IV over 60 minutes
IX. Precautions: Early Thrombolysis saves lives
- Goal: Thrombolytics in Acute MI within 30 min
- Mortality related to delay in Thrombolytic use
- Meta-analysis: 50,246 patients in 22 trials 1983-1993
- Thrombolytic delayed 0-1 hours: 65/1000 lives saved
- Thrombolytic delayed 1-2 hours: 37/1000 lives saved
- Thrombolytic delayed 2-3 hours: 26/1000 lives saved
- Thrombolytic delayed 3-6 hours: 29/1000 lives saved
- Reference
- Meta-analysis: 50,246 patients in 22 trials 1983-1993