Angina pectoris, stable

I20.0-I20.9

DESCRIPTION

Characteristic chest pain due to myocardial ischaemia usually occurring on exercise and relieved by rest. Discomfort may occasionally be experienced in a site of referral (shoulder, jaw) but the characteristic provocation by exercise and relief by rest is a valuable clue.

GENERAL MEASURES

Lifestyle modification. See: Ischaemic heart disease and atherosclerosis, prevention.

MEDICINE TREATMENT

Long-term prophylaxis for thrombosis:

  • Aspirin, oral, 150 mg immediately as a single dose (chewed or dissolved).
    • Followed with 150 mg daily (continued indefinitely in absence of contraindications).

LoEI [29]

AND

Relief of angina:

  • Nitrates, short acting e.g.:
    • Isosorbide dinitrate, SL, 5 mg.
      • May be repeated if required at 5-minute intervals for 3 or 4 doses.
      • Instruct patients to keep the tablets in the airtight and lightproof container in which they are supplied.
      • Instruct patients that nitrates are not addictive.
      • Instruct patients to use prophylactically, before activities which may provoke angina.

AND

Step 1

  • Cardio-selective ß-blocker, e.g.:
    • Atenolol, oral, 50–100 mg daily.
      • Titrate to resting heart rate of approximately 60 bpm.

If ß-blocker cannot be tolerated or is contraindicated, use a long acting calcium channel blocker.

Step 2

ADD

  • Long-acting calcium channel blocker, e.g.:
    • Amlodipine, oral, 5mg daily.
      • Increase to 10 mg daily if required.

Step 3

ADD

  • Organic nitrates, e.g.:
    • Isosorbide mononitrate: 10–20 mg twice daily.

OR

  • Isosorbide dinitrate: 20–30 mg twice daily
    • Taken at 8:00 and 14:00 as this provides a nitrate-free period to prevent tolerance.
    • Modify for night shift workers.

LoEI [30]

ADD

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

LoEI [31]

Patients on protease inhibitor:

  • Atorvastatin, oral, 10 mg at night.

LoEI [32]

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

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

LoEI [33]

If patient complains of muscle pain:

Reduce dose:

  • HMGCoA reductase inhibitors (statins), e.g.:
    • Simvastatin, oral, 10 mg at night.

OR

  • Consult specialist for further management.

LoEI [34]

REFERRAL

  • When diagnosis is in doubt, despite exercise stress testing.
  • Failed medical therapy. A common reason for “failed” therapy is that the patient has an alternative diagnosis. Therefore, this conclusion should be reached after reasonable effort for non-invasive diagnosis including exercise stress test.