Acute Coronary Syndrome

Time is muscle. Rapid triage, ECG interpretation, and risk stratification dictate the invasive strategy for NSTE-ACS, while STEMI requires immediate reperfusion.

Initial Assessment (The First 10 Minutes)

• Targeted History & Exam: Nature of pain, radiation, diaphoresis, prior CAD. Rule out dissection (unequal pulses) and tension pneumothorax.
• 12-Lead ECG: Look for ST-elevation (STEMI) or new LBBB. If absent, evaluate for ST-depression or T-wave inversion (NSTE-ACS).
• High-Sensitivity Troponin (hs-cTn): 0/1h or 0/2h algorithm to rapidly rule-in or rule-out myocardial injury.

STEMI Management (Complete Occlusion)

Goal: Immediate reperfusion.

• Primary PCI: Preferred if achievable within 120 minutes of first medical contact. Door-to-balloon target < 90 mins.
• Fibrinolysis: If PCI cannot be achieved within 120 minutes (and no contraindications). Administer within 10 mins of diagnosis.
• Adjunctive Meds: Aspirin 300mg, P2Y12 inhibitor (Ticagrelor or Prasugrel preferred), Anticoagulation (Heparin).

NSTE-ACS Management (Subtotal Occlusion)

NSTEMI (positive troponin) and Unstable Angina (negative troponin but convincing clinical picture). Management is guided by risk stratification.

Use the GRACE Score or TIMI Score to estimate mortality risk and guide timing of angiography.

Risk Level	Criteria	Invasive Strategy
Very High	Hemodynamic instability, refractory angina, arrhythmias, mechanical complications	Immediate (< 2 hours)
High	Dynamic ST/T changes, GRACE score > 140, rising troponin	Early (< 24 hours)
Low	No recurrent pain, negative troponin, no ECG changes, GRACE < 140	Non-invasive testing / Conservative