• Finnish Medical Society Duodecim. Acute coronary syndromes: unstable angina pectoris and non-ST segment elevation myocardial infarction (NSTEMI). In: EBM Guidelines. Evidence-Based Medicine [Internet]. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2007 Nov 28 [Various]. [6 references]

This is the current release of the guideline.

This guideline updates a previous version: Finnish Medical Society Duodecim. Unstable angina pectoris. In: EBM Guidelines. Evidence-Based Medicine [Internet]. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2006 Mar 15 [Various].

The levels of evidence [A-D] supporting the recommendations are defined at the end of the "Major Recommendations" field.

Objective

• To recognize ischaemic chest pain suggesting myocardial infarction or unstable angina and to accompany the patient to a cardiac monitoring unit for active drug treatment or rapid revascularization (Hoenig et al., 2006) [A].
• To assess the patient's risk factors for coronary heart disease, and to refer high risk patients readily to a hospital for coronary angiography. The only symptom of ischaemia may be a general deterioration in patient's physical condition, or dyspnoea, without chest pain.

Definition

• Symptom complexes caused by a sudden narrowing or obstruction of a coronary artery are called acute coronary syndromes (ACS). These include
  • Unstable angina pectoris (UAP)
  • Myocardial infarction without ST-elevation
  • Myocardial infarction with ST-elevation (See the Finnish Medical Society Duodecim guideline "Thrombolytic therapy and balloon angioplasty in acute ST elevation myocardial infarction [STEMI]")
• The most common cause of an acute coronary syndrome is a tear in an atheroma plaque and a thrombus that is formed on it.

Risk Groups and Clinical Signs

• The presence of biochemical markers (troponins) is the single most important predictor for future coronary events. An increase in the concentration of markers is observed only after 9 to 12 hours from the symptom onset.
  • Marker-positive patients are referred to angiography and revascularization.
  • Marker-negatives are referred to exercise tolerance test.
• Unstable angina pectoris (UAP) is a heterogeneous group of conditions between stable angina pectoris (AP) and acute myocardial infarction (AMI).
• New (sudden) AP in a high-risk patient is always a serious condition.
• An aggravation in stable AP to unstable AP always necessitates a reassessment of risk and often a change in the line of treatment.
• There may not always be pain; rather, the main symptom is a decrease in exercise tolerance (sudden decrease in physical fitness) or acute left ventricle failure due to aggravated ischaemia.
• In the electrocardiogram (ECG) an ST segment depression precedes the pain. Symptomless (silent) ischaemia in a patient at risk is a significant finding. Ischaemia may not always be visible in a resting ECG. An ECG registered while the patient has pain is invariably valuable.
• If unstable AP is associated with an increase in the markers of myocardial damage, this is currently classified as a MI (non-Q infarction, or non-ST-elevation MI [NSTEMI]). See picture 1 ("Diagnostic classification of acute coronary syndromes based on ECG findings and troponin concentrations") in the original guideline document.

Treatment

• Treatment is normally carried out in a cardiac monitoring unit.
• Pharmacological treatment should be started in the first point of care.
• The mildest form (i.e. recent angina in an elderly person) may also be treated in a primary health care setting with appropriate medication and assessment of risk factors. This calls for careful monitoring and good patient information and the angina to remain stable.
• Severe or exacerbating angina requires a consideration of balloon angioplasty.
• Effective pharmacological treatment is often sufficient for the treatment of coronary heart disease if the symptoms are only mild.

Anti-ischaemic and Antithrombotic Treatment

• All patients with suspected unstable angina (no changes in ECG or myocardial markers)
  • Aspirin 100 milligrams (mg) per day continuously, unless there are contraindications (Natarajan, 2002; "Collaborative overview," 1994) [A].
  • Clopidogrel together with aspirin: first a loading dose of 300 mg, then 75 mg per day (Keller, Squizzato, & Middledorp, 2007; Yusuf et al., 2001) [A].
  • Nitrate (Natarajan, 2000) [D] intravenously (See the Finnish Medical Society Duodecim guideline "Nitrate infusion in angina pectoris and myocardial infarction") or orally according to the situation.
  • Beta-blocker (Natarajan, 2002) [C] (metoprolol). Heart rate should be 50 to 60 beats per minute and systolic pressure below 150 mmHg.
  • Low-molecular-weight (LMW) heparin (Zed, Tisdale, & Borzak, 1999; Nicholson, Milne, & Stein, 2000) [A] (e.g., dalteparin 100 to 120 IU/kg x 2 daily) is given for one week ("Low-molecular-weight heparin during instability in coronary artery disease." 1996). (NB: the dose is lower for elderly patients and for patients with renal failure.) Aspirin is given simultaneously.
  • Pharmacotherapy and invasive treatment do not exclude one another.
  • Glycoprotein IIb/IIIa inhibitors for selected high risk patient groups in hospital care.
  • There is no benefit from fibrinolytic therapy.

Further Treatment

• High-risk patients
  • Unstable angina and ischaemia on ECG or elevated myocardial markers (Olatidoye et al., 1998) [A], acute left ventricle failure (lung oedema, mitral regurgitation, hypotension)
    • Immediate angiography and revascularization. While waiting for the procedure, effective antithrombotic medication is given using clopidogrel (an initial dose of 300 mg before transportation, thereafter 75 mg daily) and an intravenous (i.v.) glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitor (Natarajan, 2002) [B] in addition to aspirin and LMW heparin. (Fibrinolytic treatment has no effect on a vessel obstruction caused by aggregated platelets.)
• Patients without symptoms or signs of ischaemia on ECG
  • Symptom-limited exercise test performed within 2–4 days
  • If the patient has symptoms or signs of ischaemia during the exercise test or signs in ECG at a low pulse-pressure product, refer immediately to angiography.
  • If there are no symptoms or signs of ischaemia or no signs in ECG during the exercise test, or if they occur only with a high pulse-pressure product, begin conservative treatment and elimination of risk factors. Prophylaxis can be intensified by adding clopidogrel to aspirin.
• Thrombolytic therapy or immediate percutaneous coronary intervention (PCI): balloon angioplasty with stenting is indicated if an ST-elevation myocardial infarction (STEMI) develops. (See the Finnish Medical Society Duodecim guideline, "Coronary Heart Disease (CHD): Symptoms, Diagnosis and Treatment"). After the insertion of a stent, clopidogrel is used in combination with aspirin for 3–12 months.

Organizing Treatment

• UAP is a serious but often curable syndrome. A well-organized care pathway and efficient follow-up care ensures that the appropriate treatment can be given rapidly.

Related Resources

Refer to the original guideline document for related evidence, including Cochrane reviews and other evidence summaries.

Definitions:

Classification of the Quality of Evidence

GRADE (Grading of Recommendations Assessment, Development and Evaluation) Working Group 2007 (modified by the EBM Guidelines Editorial Team).

A diagnostic classification of acute coronary syndromes based on ECG findings and troponin concentrations is included in the original guideline document (Picture 1).

Concise summaries of scientific evidence attached to the individual guidelines are the unique feature of the Evidence-Based Medicine Guidelines. The evidence summaries allow the clinician to judge how well-founded the treatment recommendations are. The type of supporting evidence is identified and graded for select recommendations (see the "Major Recommendations" field).

• Finnish Medical Society Duodecim. Acute coronary syndromes: unstable angina pectoris and non-ST segment elevation myocardial infarction (NSTEMI). In: EBM Guidelines. Evidence-Based Medicine [Internet]. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2007 Nov 28 [Various]. [6 references]

Not applicable: The guideline was not adapted from another source.

2001 Apr 30 (revised 2007 Nov 28)

Finnish Medical Society Duodecim - Professional Association

Finnish Medical Society Duodecim

Editorial Team of EBM Guidelines

Primary Authors: Editors

Not stated

This is the current release of the guideline.

This guideline updates a previous version: Finnish Medical Society Duodecim. Unstable angina pectoris. In: EBM Guidelines. Evidence-Based Medicine [Internet]. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2006 Mar 15 [Various].

None available

None available

This summary was completed by ECRI on August 28, 2001. The information was verified by the guideline developer as of October 26, 2001. This summary was updated by ECRI on December 9, 2002, April 2, 2004, February 22, 2005, and May 25, 2006. This summary was updated by ECRI Institute on June 22, 2007 following the U.S. Food and Drug Administration (FDA) advisory on heparin sodium injection. This summary was updated by ECRI Institute on July 12, 2007 following the U.S. Food and Drug Administration (FDA) advisory on Troponin-1 Immunoassay. This summary was updated by ECRI Institute on March 14, 2008 following the updated FDA advisory on heparin sodium injection and again on December 23, 2008.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.