6th March 2024

Management

The management of acute coronary syndrome is divided into two subtypes: 

1. STEMI 
2. NSTEMI and unstable angina 

All patients with acute coronary syndrome should receive aspirin 300mg in the absence of contraindications. Routine administration of oxygen is no longer recommended, and oxygen should be administered if SpO2 < 94% in keeping with the British thoracic guidelines. Routine administration of IV morphine has been shown to have adverse effects and is recommended for patients with severe pain. If the patient has ongoing pain or hypertension, nitrates can be administered intravenously. 

STEMI

In patients with acute STEMI, NICE guidelines recommend the following: 

• If the patient presents within 12h of onset of symptoms, a coronary angiogram with follow-on primary percutaneous coronary intervention (PPCI) is the first management option if PPCI can be delivered within 120 mins where fibrinolysis could have been administered. 
• If PPCI is possible, then the patient should be loaded with prasugrel if they are not taking an oral anticoagulant or clopidogrel if they are. 
• When PPCI is possible, access through the radial artery is preferred and, in that case, NICE recommends the administration of unfractionated heparin with bailout glycoprotein IIb/IIIa inhibitor.  
• If radial access is not possible and femoral access is being used, then NICE recommends bivalirudin with bailout glycoprotein IIb/IIIa inhibitor. 
• If stenting is indicated, NICE recommends the use of a drug eluting stent.
• If the patient presents within 12 hours of onset of symptoms and PPCI is not possible, then fibrinolysis should be offered. The preferred agents are tenecteplase and alteplase and they should be given together with an antithrombin drug.  
• An ECG should be repeated 60-90 mins after administration of fibrinolysis. If this fails to show > 50% resolution of ST segment elevation, then PCI should be offered to the patient as rescue PCI is superior to repeat fibrinolysis.
• NICE also recommends considering coronary angiography during the same admission for patients who have successfully been treated with fibrinolysis. 

NSTEMI

In patients with acute NSTEMI or unstable angina, NICE guidelines recommend the following: 

• Patients presenting with NSTEMI should be offered fondaparinux in the absence of contraindications if there is no immediate PCI planned. 
• NICE recommends using a 6-month mortality risk using an established scoring system (e.g: GRACE score) to determine who should be offered coronary angiography with follow-on PCI.  As a rule of thumb, patients with a 6-month intermediate to high mortality risk should be offered coronary angiography with follow on PCI within 72h whereas patients with low mortality risk can be managed conservatively. 
• For those patients undergoing coronary angiography, NICE recommends giving unfractionated heparin and a second antiplatelet agent (if taking an oral anticoagulant, clopidogrel is the drug of choice; if not taking an anticoagulant, then prasugrel or ticagrelor is advised). 
• If the patient has a low risk of cardiovascular adverse events and is stable, NICE recommends conservative management with dual antiplatelet therapy (aspirin + ticagrelor (low bleeding risk) or aspirin + clopidogrel (high bleeding risk). 

Secondary prevention

The following classes of medication are used to reduce the risk of further cardiac events following an MI:   

• Dual antiplatelet therapy unless contraindicated 
• ACE inhibitor 
• Beta blocker 
• Statin