Acute coronary syndrome

Red Flags

ST elevation ≥1 mm in two contiguous leads or new LBBB with chest pain — immediate reperfusion^[1]
Cardiogenic shock complicating ACS — emergent revascularisation; consider mechanical support^[1]
Mechanical complications (acute MR, VSR, free-wall rupture) — emergent surgical consult^[1]
High-risk NSTE-ACS (GRACE >140, dynamic ECG, refractory ischaemia) — early invasive strategy within 24 h^[1]

Primary PCI (preferred for STEMI)^[1]
FMC-to-device ≤90 min direct, ≤120 min if transfer; cath-lab activation parallel to drug initiation
Early invasive strategy for NSTE-ACS^[1]
Coronary angiography within 24 h for high-risk NSTE-ACS (dynamic troponin, ST changes, GRACE >140, refractory ischaemia)

Drug	Class	Adult	Paediatric	Notes
Aspirin^[1]	Antiplatelet (loading)	162–325 mg chewed at first medical contact then 75–100 mg daily lifelong	—	All ACS unless contraindicated
Ticagrelor or prasugrel^[1]	P2Y12 inhibitor	Ticagrelor 180 mg load → 90 mg BD × 12 months; prasugrel 60 mg load → 10 mg daily	—	Preferred over clopidogrel in PCI-treated ACS without high bleeding risk
Atorvastatin 80 mg^[1]	High-intensity statin	80 mg PO once daily started during admission	—	LDL-C goal <55 mg/dL post-ACS
Metoprolol succinate^[1]	Beta-blocker	25–200 mg PO once daily	—	Within 24 h if no contraindication (shock, severe HF, heart block)
Ramipril or perindopril^[1]	ACE inhibitor	Ramipril 1.25–5 mg BD; perindopril 4–8 mg daily	—	Within 24 h, especially with anterior MI, LVEF <40%, HF, or diabetes
Unfractionated heparin or enoxaparin^[1]	Parenteral anticoagulant	UFH 60 U/kg IV bolus + 12 U/kg/h infusion (PCI-driven); enoxaparin 1 mg/kg SC BD	—	Reduce enoxaparin dose if eGFR 15–30; UFH preferred if eGFR <15

Aspirin^[1]

Antiplatelet (loading)

Adult: 162–325 mg chewed at first medical contact then 75–100 mg daily lifelong
Paediatric: —

All ACS unless contraindicated

Ticagrelor or prasugrel^[1]

P2Y12 inhibitor

Adult: Ticagrelor 180 mg load → 90 mg BD × 12 months; prasugrel 60 mg load → 10 mg daily
Paediatric: —

Preferred over clopidogrel in PCI-treated ACS without high bleeding risk

Atorvastatin 80 mg^[1]

High-intensity statin

LDL-C goal <55 mg/dL post-ACS

Metoprolol succinate^[1]

Beta-blocker

Within 24 h if no contraindication (shock, severe HF, heart block)

Ramipril or perindopril^[1]

ACE inhibitor

Within 24 h, especially with anterior MI, LVEF <40%, HF, or diabetes

Unfractionated heparin or enoxaparin^[1]

Parenteral anticoagulant

Adult: UFH 60 U/kg IV bolus + 12 U/kg/h infusion (PCI-driven); enoxaparin 1 mg/kg SC BD
Paediatric: —

Reduce enoxaparin dose if eGFR 15–30; UFH preferred if eGFR <15

Take dual antiplatelet therapy every day for 12 months without interruption — stopping early sharply raises stent-thrombosis risk^[1]
New chest pain after discharge — call emergency services immediately^[1]
Attend cardiac rehabilitation — supervised exercise reduces death and re-admission by 20–30%^[1]

Diagnostic STEMI ECGActivate cath lab; transfer to PCI-capable centre if not on-site (FMC-to-device ≤120 min)^[1]
Cardiogenic shock or mechanical complicationHeart team plus mechanical circulatory support consideration^[1]
High-risk NSTE-ACSCardiology for coronary angiography within 24 h^[1]
Post-ACS LVEF ≤35% at 40 days despite optimal therapyCardiology for primary prevention ICD evaluation^[1]

Diagnostic and reperfusion management of STEMI and NSTE-ACS, anchored on early revascularisation and dual antiplatelet therapy.

1.Cardiological Society of India ACS Management Guidelines; 2025 ACC/AHA ACS Guideline (current global standard) (2022)