Table of contents

Non-ST-elevation myocardial infarction

What's new

Updated 2023 CCS/CAIC guidelines for antiplatelet therapy in non-ST-elevation myocardial infarction.


Key sources

The following summarized guidelines for the evaluation and management of non-ST-elevation myocardial infarction are prepared by our editorial team based on guidelines from the American Academy of Family Physicians (AAFP 2024), the Canadian Cardiovascular Society (CCS/CAIC 2024), the European Society of Cardiology (ESC 2023), the Society for Cardiovascular Angiography and Interventions (SCAI/AHA/ACC 2022), the U.S. Preventive Services Task Force (USPSTF...
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Screening and diagnosis

Diagnosis: as per ESC 2023 guidelines, Base the diagnosis and initial short-term risk stratification of ACS on a combination of clinical history, symptoms, vital signs, other physical findings, ECG, and high-sensitivity cardiac troponin.
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Classification and risk stratification

Prognostic assessment: as per AAFP 2024 guidelines, Refer patients presenting with acute chest pain and high suspicion of ACS to the emergency department and use predictive risk scores there to aid in the prognosis, diagnosis, and management.

Diagnostic investigations

History and physical examination: as per AAFP 2024 guidelines, Elicit medical history and perform a physical examination in patients presenting with acute chest pain and high suspicion of ACS.

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  • ECG

  • Echocardiogram

  • Cardiac troponin

  • Coronary CTA

  • Cardiac MRI

  • Lipid profile

Diagnostic procedures

Coronary angiography: as per ESC 2023 guidelines, Do not perform routine immediate angiography after resuscitated cardiac arrest in hemodynamically stable patients without persistent ST-segment elevation (or equivalents).
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Respiratory support

Supplemental oxygen
As per ESC 2023 guidelines:
Administer oxygen in patients with hypoxemia (SaO2 < 90%).
Do not administer oxygen routinely in patients without hypoxemia (SaO2 > 90%).

Medical management

Outpatient management: as per ACC/AHA 2014 guidelines, Consider prescribing daily aspirin, short-acting nitroglycerin, and other medication if appropriate (such as β-blockers) with instructions about activity level and clinician follow-up in low-risk patients referred for outpatient testing.

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  • Transfer

  • Shared-decision making

  • Fibrinolysis

  • Nitrates

  • Beta-blockers (IV)

  • Beta-blockers (PO)

  • Renin-angiotensin system inhibitors

  • CCBs

  • Low-dose colchicine

  • Antiplatelet therapy (aspirin)

  • Antiplatelet therapy (P2Y12 inhibitors)

  • Antiplatelet therapy (intravenous GP IIb/IIIa inhibitors)

  • Anticoagulant therapy

  • Triple antithrombotic therapy

  • Management of cardiogenic shock (revascularization)

  • Management of cardiogenic shock (intra-aortic balloon counterpulsation)

  • Management of cardiogenic shock (mechanical circulatory support)

  • Management of cardiac arrest

  • Management of AF (antithrombotic therapy)

  • Management of AF (rate control)

  • Management of AF (rhythm control)

  • Management of bradyarrhythmias

  • Management of ventricular arrhythmias (revascularization)

  • Management of ventricular arrhythmias (pharmacotherapy)

  • Management of ventricular arrhythmias (transvenous pacing)

  • Management of ventricular arrhythmias (ICD)

  • Management of ventricular arrhythmias (radiofrequency ablation)

  • Management of LV thrombus

  • Management of pain and anxiety

  • Management of dyslipidemia

Inpatient care

Setting of monitoring: as per ESC 2023 guidelines, Keep all patients with very high-risk NSTEMI with successful reperfusion therapy and an uncomplicated clinical course in the coronary care unit/intensive cardiac care unit for at least 24 hours whenever possible, and consider transferring them thereafter to a step-down monitored bed for an additional 24-48 hours.
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  • ECG monitoring

  • Serial troponin measurements

  • Serial imaging assessment

  • Evaluation before discharge

Nonpharmacologic interventions

Lifestyle modifications: as per ESC 2023 guidelines, Advise adopting a healthy lifestyle, including smoking cessation, healthy diet (Mediterranean style), alcohol restriction, regular aerobic physical activity and resistance exercise, and reduced sedentary time, in all patients with ACS.

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  • Smoking cessation

  • Psychological interventions

Therapeutic procedures

Indications for PCI: as per AAFP 2024 guidelines, Offer early invasive therapy in patients with NSTEMI and high risk (such as patients with HF) to reduce cardiovascular events and mortality.

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  • Technical considerations for PCI (arterial approach)

  • Technical considerations for PCI (strategy)

  • Technical considerations for PCI (choice of stent)

  • Technical considerations for PCI (intravascular imaging)

  • Technical considerations for PCI (hemodynamic support device)

  • Technical considerations for PCI (aspiration thrombectomy)

  • Technical considerations for PCI (multivessel disease)

  • Technical considerations for PCI (non-infarct artery revascularization)

  • Blood transfusion

Perioperative care

General principles
As per ACC/AHA/SCAI 2022 guidelines:
Establish multidisciplinary, evidence-based perioperative management programs to optimize analgesia, minimize opioid exposure, prevent complications and to reduce time to extubation, length of stay, and healthcare costs in patients undergoing CABG.
Ensure a comprehensive approach to reduce sternal wound infection in patients undergoing CABG.

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  • Perioperative beta-blockers

  • Perioperative amiodarone

  • Perioperative management of antithrombotics

  • Intraoperative insulin infusion

Surgical interventions

Indications for CABG: as per ACC/AHA/SCAI 2022 guidelines, Calculate the STS risk score to help stratify patient risk in candidates for CABG.
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  • Bypass conduits

  • Cardiopulmonary bypass

Specific circumstances

Elderly patients: as per ESC 2023 guidelines, Apply the same diagnostic and treatment strategies in older patients as in younger patients.
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  • Female patients

  • Pregnant patients

  • Patients with diabetes mellitus

  • Patients with CKD

  • Patients with cancer

  • Patients with AF

  • Patients with preexisting HF

  • Patients with previous CABG

  • Patients with postoperative myocardial infarction

  • Patients with spontaneous coronary artery dissection

  • Patients with stress cardiomyopathy

  • Patients with MINOCA

  • Patients with microvascular angina

  • Patients with vasospastic angina

  • Cocaine and methamphetamine users

Patient education

Patient-centered care: as per ESC 2023 guidelines, Provide patient-centered care by assessing and adhering to individual patient preferences, needs, and beliefs, ensuring that patient values are used to inform all clinical decisions.
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  • Counseling before discharge

Preventative measures

Low-dose aspirin
As per CAIC/CCS 2024 guidelines:
Do not initiate aspirin routinely for primary prevention of ASCVD in patients without ASCVD, regardless of sex, age, or diabetes status.
Consider initiating aspirin for primary prevention of ASCVD in certain patients deemed at high risk of ASCVD but with low bleeding risk in the context of a patient-centered and informed shared decision-making process.

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  • Statin therapy

  • Hormone therapy

  • Vitamin supplements

  • Routine immunizations

Follow-up and surveillance

Discharge from hospital: as per ACC/AHA 2014 guidelines, Use posthospital systems of care designed to prevent hospital readmissions to facilitate the transition to effective, coordinated outpatient care for all patients with NSTEMI.
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  • Cardiac rehabilitation

  • Follow-up imaging

Quality improvement

Healthcare system and hospital requirements, pre-hospital settings: as per ESC 2023 guidelines, Ensure that:
pre-hospital management of patients with a working diagnosis of STEMI is based on regional networks designed to deliver reperfusion therapy expeditiously and effectively, with efforts made to make primary PCI available to as many patients as possible
patients transferred for primary PCI bypassing the emergency department and coronary care unit/ICU and are transferred directly to the catheterization laboratory
emergency medical services transfer patients with suspected STEMI to a PCI-capable center bypassing non-PCI centers
strategies are in place to facilitate the transfer of all patients with suspected ACS after resuscitated cardiac arrest directly to a hospital offering 24/7 primary PCI via one specialized emergency medical service
ambulance teams are trained and equipped to identify ECG patterns suggestive of acute coronary occlusion and to administer initial therapy, including defibrillation and fibrinolysis when applicable
all emergency medical services participating in the care of patients with suspected STEMI record and audit delay times and work together to achieve and maintain quality targets.

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  • Healthcare system and hospital requirements (hospital settings)