Acute coronary syndrome: STEMI, NSTEMI and the first-hour decisions

Telling the syndromes apart

The first hour

1. 01

   ECG within 10 minutes

   Repeat it if the first is non-diagnostic and symptoms continue. Consider posterior and right-sided leads when inferior or posterior infarction is suspected.

2. 02

   Aspirin

   A loading dose of chewed aspirin (162 to 325 mg) unless there is a true allergy or active serious bleeding.

3. 03

   Decide reperfusion for STEMI

   Primary PCI is preferred when it can be done with a first-medical-contact-to-device time of 120 minutes or less, and a door-to-device target of 90 minutes or less. If not available in time, give fibrinolysis within 30 minutes of arrival unless contraindicated, then transfer.

4. 04

   Antithrombotic therapy

   Add a P2Y12 inhibitor and an anticoagulant such as heparin per protocol and the local reperfusion strategy.

5. 05

   Treat pain and ischemia carefully

   Sublingual nitroglycerin for ongoing ischemic pain, after checking blood pressure and excluding right ventricular infarction and recent PDE-5 inhibitor use. Add a beta blocker when there is no heart failure, low output or other contraindication. Start a high-intensity statin.

More points that are commonly tested

• ·Cocaine-associated chest pain: benzodiazepines and nitrates first; avoid beta blockers early.
• ·Morphine is no longer routine because of possible harm and delayed antiplatelet absorption; use cautiously when pain persists.
• ·Oxygen is given only if SpO2 is below 90%, not routinely.
• ·Complications to anticipate: arrhythmia, heart failure, mechanical complications, and pericarditis.
• ·Discharge needs dual antiplatelet therapy, a high-intensity statin, a beta blocker where appropriate, an ACE inhibitor or ARB for reduced ejection fraction, and cardiac rehabilitation.