Angina pectoris, unstable / non ST elevation myocardial infarction (NSTEMI)

I20.0/I21.0-4/I21.9/I22.0-1/I22.8-9/I24.8-9/I25.6/I25.8-9

DESCRIPTION

Unstable angina is a medical emergency and if untreated can progress to NSTEMI. Presents as chest pain or discomfort similar to stable angina but with the following additional characteristics:

  • angina at rest or minimal effort
  • angina occurring for the first time, particularly if it occurs at rest
  • prolonged angina > 10 minutes, not relieved by sublingual nitrates
  • the pattern of angina accelerates and gets worse

DIAGNOSIS

  • Made from good history.
  • ECG may show ST segment depression or transient ST segment elevation.
  • Normal ECG does not exclude the diagnosis.

LoEI [14]

MEDICINE TREATMENT

  • Oxygen 40% via facemask, if saturation < 94% or if in distress.
  • Aspirin, oral, 150 mg as a single dose (chewed or dissolved) as soon as possible.

LoEI [15]

ADD

  • Nitrates, short acting, e.g.:
    • Isosorbide dinitrate, sublingual, 5 mg immediately as a single dose.
      • May be repeated at 5-minute intervals for 3 or 4 doses

LoEIII [16]

ADD

  • Morphine 10 mg diluted with 10 mL of water for injection or sodium chloride 0.9%, slow IV (Doctor prescribed).
    • Start with 5 mg; thereafter slowly increase by 1 mg/minute up to 10mg.
    • Can be repeated after 4–6 hours if necessary, for pain relief.
    • Beware of hypotension.

Continuation of aftercare treatment initiated at higher level of care:

Continue therapy with appropriate lifestyle modification and adherence support.

  • Aspirin, oral, 150 mg daily (continued indefinitely in absence of contraindications).

LoEI [17]

When clinically stable without signs of heart failure, hypotension, bradydysrhythmias or asthma:

  • Cardio-selective beta -blocker, e.g.:(Doctor initiated):
  • Atenolol, oral, 50 mg daily.

AND

  • HMGCoA reductase inhibitors (statins), e.g.:
  • Simvastatin, oral, 40 mg at night

LoEI [18]

Patients on protease inhibitor:

  • Atorvastatin, oral, 10 mg at night.

LoEI [19]

Patients on amlodipine (and not on a protease inhibitor):

  • Simvastatin, oral, 10-20 mg at night.

LoEIII [20]

If patient complains of muscle pain:

Reduce dose to:

  • Simvastatin, oral, 20 mg at night.
  • If 20 mg not tolerated, reduce to 10 mg.

OR

  • Refer for further management.

LoEIII [21]

AND

If there is cardiac failure or LV dysfunction (Doctor initiated):

  • ACE-inhibitor, e.g.:
  • Enalapril, oral, target dose 10 mg 12 hourly (usually titrated from 2.5 mg 12 hourly).

LoEIII [22]

Angioedema is a potentially serious complication of ACE-inhibitor treatment and if it occurs it is a contraindication to continued therapy or to re-challenge.

REFERRAL

Urgent

All suspected or diagnosed cases.