What are the key aspects of Acute Coronary Syndrome (ACS)?

From the Guidelines

Acute Coronary Syndrome (ACS) is a serious cardiac condition that requires immediate medical attention, with key symptoms including chest pain or pressure, shortness of breath, sweating, nausea, and lightheadedness, and initial treatment typically involving aspirin, nitroglycerin, and oxygen, as recommended by the 2021 ESC guidelines 1. The clinical presentation of ACS is broad, ranging from cardiac arrest to patients who are already pain-free at the time of presentation, with the leading symptom being acute chest discomfort described as pain, pressure, tightness, and burning, and chest pain-equivalent symptoms such as dyspnoea, epigastric pain, and pain in the left arm 1.

Key Aspects of ACS

• The condition is characterized by a sudden reduction or blockage of blood flow to the heart muscle, usually due to plaque rupture in coronary arteries forming blood clots 1.
• Risk factors for ACS include smoking, high blood pressure, high cholesterol, diabetes, family history, and age 1.
• Prevention involves lifestyle changes such as quitting smoking, regular exercise, healthy diet, and medication adherence 1.
• Hospital treatment involves medications like antiplatelet agents, anticoagulants, statins, beta-blockers, and ACE inhibitors, as well as procedures such as coronary angiography, angioplasty, or stent placement 1.

Diagnosis and Management

• The diagnosis of ACS is based on the electrocardiogram (ECG), with two groups of patients being differentiated: those with persistent ST-segment elevation and those without persistent ST-segment elevation (non-ST-elevation ACS) 1.
• The management of ACS involves immediate reperfusion by primary percutaneous coronary intervention (PCI) or fibrinolytic therapy for patients with ST-elevation, and coronary angiography and revascularization for patients with non-ST-elevation ACS 1.
• The clinical spectrum of non-ST-elevation ACS may range from patients free of symptoms at presentation to individuals with ongoing ischemia, electrical or hemodynamic instability, or cardiac arrest 1.

From the FDA Drug Label

The CURE study included 12,562 patients with ACS without ST-elevation (UA or NSTEMI) and presenting within 24 hours of onset of the most recent episode of chest pain or symptoms consistent with ischemia Patients were required to have either ECG changes compatible with new ischemia (without ST-elevation) or elevated cardiac enzymes or troponin I or T to at least twice the upper limit of normal.

The key aspects of Acute Coronary Syndrome (ACS) include:

• Presentation: Chest pain or symptoms consistent with ischemia within 24 hours
• Diagnosis: ECG changes compatible with new ischemia or elevated cardiac enzymes (troponin I or T) at least twice the upper limit of normal
• Types: Unstable angina (UA), non-ST-elevation myocardial infarction (NSTEMI), and ST-elevation myocardial infarction (STEMI)
• Management: Medical management and/or coronary revascularization, with antiplatelet therapy (e.g., clopidogrel and aspirin) as a key component 2 2 2

From the Research

Definition and Classification of Acute Coronary Syndrome (ACS)

• Acute coronary syndromes (ACS) are characterized by a sudden reduction in blood supply to the heart and include ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), and unstable angina 3.
• ACS without significant ST-segment elevation on electrocardiography, termed NSTE-ACS, account for approximately 70% of ACS, are caused by partial or intermittent occlusion of the artery and are associated with ST-segment depressions, T-wave inversions, or neither 3.

Presentation and Diagnostic Evaluation of ACS

• Chest discomfort at rest is the most common presenting symptom of ACS and affects approximately 79% of men and 74% of women presenting with ACS 3.
• Electrocardiography should be performed immediately (within 10 minutes of presentation) and can distinguish between STEMI and non-ST-segment elevation ACS (NSTE-ACS) 3, 4.
• Elevated troponin levels without ST-segment elevation on electrocardiography suggest non-ST-segment elevation ACS 5.

Management of ACS

• For patients presenting with possible ACS, rapid reperfusion with primary percutaneous coronary intervention (PCI) within 120 minutes reduces mortality from 9% to 7% 3.
• Dual antiplatelet therapy (DAPT), consisting of aspirin and a P2Y12 inhibitor, reduces cardiovascular event rates after ACS 6.
• Patients with ACS should receive coronary angiography with percutaneous or surgical revascularization, and other important management considerations include initiation of dual antiplatelet therapy and parenteral anticoagulation, statin therapy, beta-blocker therapy, and sodium-glucose cotransporter-2 inhibitor therapy 5.

Risk Factors and Prevention of ACS

• Common risk factors for ACS include being at least 65 years of age or a current smoker or having hypertension, diabetes mellitus, hyperlipidemia, a body mass index greater than 25 kg per m2, or a family history of premature coronary artery disease 5.
• Additional interventions shown to reduce mortality in patients who have had a recent myocardial infarction include smoking cessation, annual influenza vaccination, and cardiac rehabilitation 5.