What is Chronic Coronary Syndrome (CCS)?

What is Chronic Coronary Syndrome (CCS)?

CCS is the term that replaced "stable coronary artery disease" to reflect the dynamic, progressive nature of coronary disease as a continuum rather than a static condition. 1, 2

Core Definition

CCS encompasses coronary artery disease as a chronic, evolving process that can destabilize at any moment and requires ongoing management through lifestyle modification, pharmacological therapy, and potentially revascularization. 1, 2 The terminology shift from "stable CAD" recognizes that this condition is never truly stable—patients may transition unpredictably between different CCS presentations and acute coronary syndromes throughout their lifetime. 1

Five Clinical Presentations of CCS

The 2024 ESC Guidelines define CCS patients as those presenting with any of these scenarios: 1

1. Symptomatic patients with reproducible stress-induced angina or ischemia due to obstructive epicardial CAD 1

2. Patients with angina or ischemia from vasomotor abnormalities (epicardial vasospasm) or microvascular dysfunction without obstructive epicardial CAD (ANOCA/INOCA) 1

3. Non-acute patients post-ACS or post-revascularization 1

4. Non-acute patients with heart failure of ischemic or cardiometabolic origin 1

5. Asymptomatic individuals with detected epicardial CAD found incidentally on imaging or during cardiovascular risk screening 1

Expanded Pathophysiological Understanding

The CCS concept reflects a broadened understanding beyond simple fixed stenoses: 1

Macrovascular Mechanisms

• Fixed flow-limiting atherosclerotic stenoses in large/medium coronary arteries 1
• Diffuse atherosclerotic lesions without identifiable luminal narrowing that cause ischemia under stress 1
• Structural abnormalities (myocardial bridging, congenital arterial anomalies) 1
• Dynamic epicardial vasospasm causing transient ischemia 1

Microvascular Mechanisms

• Coronary microvascular dysfunction (CMD) is now recognized as prevalent across the entire CCS spectrum, even in patients without obstructive epicardial disease 1, 3
• Functional and structural microcirculatory abnormalities can cause angina and ischemia independently 1, 3
• Risk factors promoting epicardial atherosclerosis simultaneously cause endothelial dysfunction throughout the entire coronary tree, including resistance arterioles 1, 3

Systemic Contributors

• Anemia, tachycardia, blood pressure changes 1, 3
• Myocardial hypertrophy and fibrosis 1, 3

Critical concept: Different ischemic mechanisms frequently act concomitantly in the same patient. 1, 3

Clinical Implications of the CCS Framework

Symptom Characteristics

The 2024 ESC Guidelines emphasize that only 10-25% of CCS patients present with classic angina, while 57-78% have less characteristic symptoms and 10-15% present primarily with exertional dyspnea. 1 Anginal chest pain is equally prevalent in men and women, though with slightly different characteristics. 1

Diagnostic Approach

The CCS framework mandates a four-step algorithmic approach: 1

Step 1: Clinical evaluation to differentiate non-cardiac causes and rule out ACS (12-lead ECG, basic labs, selected chest X-ray/pulmonary function testing) 1

Step 2: Cardiac examination including echocardiography and estimation of clinical likelihood of obstructive CAD 1

Step 3: Diagnostic testing to establish CCS diagnosis and determine event risk 1

Step 4: Lifestyle/risk-factor modification, disease-modifying medications, antianginal therapy, and consideration of revascularization for refractory symptoms or high-risk CAD 1

Management Philosophy

CCS is managed as a chronic process amenable to stabilization or regression through: 2

• Lifestyle adjustments 2
• Pharmacological therapies targeting platelet aggregation, coagulation, dyslipidemia, and systemic inflammation 4
• Invasive interventions (PCI, CABG) when indicated 2, 4

Common Pitfall

A critical error is assuming normal epicardial coronary arteries on angiography exclude significant coronary disease—coronary microvascular disease can cause myocardial ischemia and adverse outcomes even with completely normal-appearing epicardial vessels. 5 The CCS framework specifically addresses this by including ANOCA/INOCA as distinct clinical presentations requiring evaluation for coronary vasospasm and microvascular dysfunction. 1