Note from the Scottish Intercollegiate Guidelines Network (SIGN) and National Guideline Clearinghouse (NGC): In addition to these evidence-based recommendations, the guideline development group also identifies points of best clinical practice in the full-text guideline document.
The grades of recommendations (A–D) and levels of evidence (1++, 1+, 1-, 2++, 2+, 2-, 3, 4) are defined at the end of the "Major Recommendations" field.
Presentation, Assessment, and Diagnosis
Clinical Presentation and Immediate Assessment
D - Patients with suspected acute coronary syndrome (ACS) should be assessed immediately by an appropriate healthcare professional and a 12 lead electrocardiogram should be performed.
Biochemical Diagnosis in ACS
C - In patients with suspected acute coronary syndrome, serum troponin concentration should be measured on arrival at hospital to guide appropriate management and treatment.
B - To establish a diagnosis in patients with an acute coronary syndrome, a serum troponin concentration should be measured 12 hours from the onset of symptoms.
Initial Management
Service Delivery
C - Patients with an acute coronary syndrome should be managed within a specialist cardiology service.
Cardiac Monitoring
D - Patients with an acute coronary syndrome should have continuous cardiac rhythm monitoring.
Oxygen Therapy
D - Oxygen therapy should be administered to patients with hypoxia, pulmonary oedema or continuing myocardial ischaemia.
Antiplatelet Therapy
A - Patients with an acute coronary syndrome should be treated immediately with aspirin (300 mg).
A - In the presence of ischaemic electrocardiographic changes or elevation of cardiac markers, patients with an acute coronary syndrome should be treated immediately with both aspirin (300 mg) and clopidogrel (300 mg) therapy.
B - High-risk patients with non-ST elevation acute coronary syndrome should be treated with an intravenous glycoprotein IIb/IIIa receptor antagonist, particularly if they are undergoing percutaneous coronary intervention.
Anticoagulant Therapy
A - In the presence of ischaemic electrocardiographic changes or elevation of cardiac markers, patients with an acute coronary syndrome should be treated immediately with low molecular weight heparin or fondaparinux.
B - Patients with an ST elevation acute coronary syndrome who do not receive reperfusion therapy should be treated immediately with fondaparinux.
Beta Blockers
B - In the absence of bradycardia or hypotension, patients with an acute coronary syndrome in Killip class I should be considered for immediate intravenous and oral beta-blockade.
Glycaemic Control
B - Patients with clinical myocardial infarction and diabetes mellitus or marked hyperglycaemia (>11.0 mmol/l) should have immediate intensive blood glucose control. This should be continued for at least 24 hours.
Reperfusion Therapy for ST Elevation Acute Coronary Syndromes
Primary Percutaneous Coronary Intervention
A - Patients with an ST elevation acute coronary syndrome should be treated immediately with primary percutaneous coronary intervention.
A - Patients undergoing primary percutaneous coronary intervention should be treated with a glycoprotein IIb/IIIa receptor antagonist.
A - Intracoronary stent implantation should be used in patients undergoing primary percutaneous coronary intervention.
Thrombolytic Therapy
D - When primary percutaneous coronary intervention cannot be provided within 90 minutes of diagnosis, patients with an ST elevation acute coronary syndrome should receive immediate thrombolytic therapy.
C - Local protocols should be developed for the rapid treatment of patients presenting with ST elevation acute coronary syndromes. Consideration should be given to pre-hospital and admission thrombolysis, and to the emergency transfer of patients to interventional centres for primary percutaneous coronary intervention.
B - Thrombolysis should be conducted with a fibrin-specific agent.
'Rescue' Percutaneous Coronary Intervention
B - Patients presenting with ST elevation acute coronary syndrome within six hours of symptom onset, who fail to reperfuse following thrombolysis, should be considered for rescue percutaneous coronary intervention.
Risk Stratification and Non-Invasive Testing
Risk Stratification
C - Risk stratification using clinical scores should be conducted to identify those patients with an acute coronary syndrome who are most likely to benefit from early therapeutic intervention.
Assessment of Cardiac Function
C - In patients with an acute coronary syndrome, assessment of cardiac function should be conducted in order to identify those patients at high risk and to aid selection of appropriate therapeutic interventions.
Invasive Investigation and Revascularisation
Non-ST Elevation Acute Coronary Syndrome
B - Patients with non-ST elevation acute coronary syndromes at medium or high risk of early recurrent cardiovascular events should undergo early coronary angiography and revascularisation.
ST Elevation Acute Coronary Syndrome
C - Patients with ST elevation acute coronary syndromes treated with thrombolytic therapy should be considered for early coronary angiography and revascularisation.
Early Pharmacologic Intervention
Antiplatelet Therapy
A - Following an acute coronary syndrome all patients should be maintained on long term aspirin therapy.
B - In addition to long term aspirin, clopidogrel therapy should be continued for three months in patients with non-ST elevation acute coronary syndromes.
A - In addition to long term aspirin, clopidogrel therapy should be continued for up to four weeks in patients with ST elevation acute coronary syndromes.
Statin Therapy
B - Patients with an acute coronary syndrome should be commenced on long term statin therapy prior to hospital discharge.
Beta-Blocker and Antianginal Therapy
C - Patients with unstable angina or evidence of myocyte necrosis should be maintained on long term beta-blocker therapy.
A - Patients with clinical myocardial infarction should be maintained on long term beta-blocker therapy.
Angiotensin-Converting Enzyme (ACE) Inhibitors
B - Patients with unstable angina or myocyte necrosis should be commenced on long term angiotensin-converting enzyme inhibitor therapy.
A - Patients with clinical myocardial infarction should be commenced on long term angiotensin-converting enzyme inhibitor therapy within the first 36 hours.
Angiotensin Receptor Blockers
A - Patients with clinical myocardial infarction complicated by left ventricular dysfunction or heart failure should be commenced on long term angiotensin receptor blocker therapy if they are intolerant of angiotensin converting-enzyme inhibitor therapy.
Aldosterone Receptor Antagonists
B - Patients with clinical myocardial infarction complicated by left ventricular dysfunction (ejection fraction <0.40) in the presence of either clinical signs of heart failure or diabetes mellitus should be commenced on long term eplerenone therapy.
Treatment of Hypoxia and Cardiogenic Shock
Non-Invasive Ventilation
B - Patients with an acute coronary syndrome complicated by acute cardiogenic pulmonary oedema and hypoxia should be considered for non-invasive positive airway pressure ventilation.
Intravascular Volume Loading and Inotropic Therapy
D - In the absence of clinical evidence of volume overload, patients with an acute coronary syndrome complicated by hypotension and cardiogenic shock should be considered for intravascular volume loading.
D - In the presence of clinical evidence of volume overload, patients with an acute coronary syndrome complicated by hypotension and cardiogenic shock should be considered for inotropic therapy.
Intra-Aortic Balloon Counterpulsation
D - Patients with an acute coronary syndrome complicated by cardiogenic shock, myocardial rupture (ventricular septal defect and papillary muscle rupture) or refractory ischaemia should be considered for intra-aortic balloon counterpulsation especially when contemplating emergency coronary revascularisation or corrective surgery.
Coronary Revascularisation
C - Patients presenting with cardiogenic shock due to left ventricular failure within six hours of acute myocardial infarction should be considered for immediate coronary revascularisation.
Cardiac Surgery
D - Patients with mechanical complications of acute myocardial infarction (ventricular septal, free wall or papillary muscle rupture) should be considered for corrective surgery within 24 to 48 hours.
Patient Support and Information Needs
Early Psychosocial Interventions
B - Patients with acute coronary syndromes should be offered early psychosocial assessment and individualised psychosocial intervention with an emphasis on identifying and addressing health beliefs and cardiac misconceptions.
Information Needs of Patients
C - Provision of patient information should be determined by individual patient needs. Partner/family inclusion in receiving information should be considered and appropriate audiovisual materials employed.
D - Physicians should be involved in providing information to patients.
Definitions:
Grades of Recommendation
Note: The grade of recommendation relates to the strength of the evidence on which the recommendation is based. It does not reflect the clinical importance of the recommendation.
A: At least one meta-analysis, systematic review of randomized controlled trials (RCTs), or RCT rated as 1++ and directly applicable to the target population; or
A body of evidence consisting principally of studies rated as 1+, directly applicable to the target population, and demonstrating overall consistency of results
B: A body of evidence including studies rated as 2++, directly applicable to the target population, and demonstrating overall consistency of results; or
Extrapolated evidence from studies rated as 1++ or 1+
C: A body of evidence including studies rated as 2+, directly applicable to the target population and demonstrating overall consistency of results; or
Extrapolated evidence from studies rated as 2++
D: Evidence level 3 or 4; or
Extrapolated evidence from studies rated as 2+
Good Practice Points: Recommended best practice based on the clinical experience of the guideline development group
Levels of Evidence
1++: High quality meta-analyses, systematic reviews of randomised controlled trials (RCTs), or RCTs with a very low risk of bias
1+: Well-conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of bias
1-: Meta-analyses, systematic reviews of RCTs, or RCTs with a high risk of bias
2++: High quality systematic reviews of case control or cohort studies
High quality case control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal
2+: Well-conducted case control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal
2-: Case control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal
3: Non-analytic studies (e.g. case reports, case series)
4: Expert opinion
