Coronary arteries are specialized blood vessels that supply oxygen-rich blood to the heart muscle itself, enabling it to pump effectively.

Unlike other arteries, the coronary arteries face unique challenges due to their constant exposure to high-pressure blood flow and metabolic demands.

Their health is critical because any impairment directly compromises the heart's ability to function, often leading to heart disease.

Coronary Artery Disease (CAD): The Primary Culprit

The most common heart disease linked to arteries is Coronary Artery Disease (CAD), characterized by the accumulation of atherosclerotic plaques within the arterial walls. These plaques narrow the arteries, restricting blood flow and oxygen delivery to the myocardium.

This ischemia can manifest as angina, acute coronary syndromes (ACS), or myocardial infarction (heart attack). According to the 2025 ACC/AHA guidelines, ACS results from plaque rupture or erosion leading to partial or complete thrombosis in coronary arteries, causing myocardial ischemia of varying severity.

Micro-vascular Dysfunction: The Hidden Player

While much attention focuses on large epicardial coronary arteries, recent research highlights the critical role of coronary micro-vascular dysfunction in heart disease. Dr. C. Noel Bairey Merz, a leading cardiologist, emphasizes that micro-vascular resistance accounts for over 70% of coronary vascular resistance, far surpassing the epicardial arteries contribution.

Dysfunction in these tiny vessels impairs vasodilation and can cause vasoconstriction, leading to ischemia even when larger arteries appear normal on angiograms. This explains cases of angina with "open arteries," where micro-vascular spasm or endothelial dysfunction is the underlying cause.

The Complexity of Vascular Resistance and Endothelial Health

The coronary artery system is not merely a set of pipes but a dynamic network regulated by endothelial cells and the autonomic nervous system. Endothelial dysfunction disrupts the delicate balance between vasodilation and vasoconstriction, promoting plaque formation and thrombosis. This dysfunction is a predictor of adverse cardiovascular events and persistent angina, often resistant to conventional treatments.

Diagnostic Advances: Seeing Beyond the Lumen

Traditional angiograms reveal only the arterial lumen, missing early atherosclerotic changes in the vessel walls. Innovations like coronary CT angiography (CTA) and intravascular ultrasound (IVUS) now allow visualization of plaque burden and arterial wall health, improving early detection and risk stratification. These tools have revealed that a significant portion of patients with angina have sub-clinical atherosclerosis undetectable by older methods.

Therapeutic Implications: Targeting Both Macro and Micro-vascular Disease

Management of heart disease now requires a dual approach:

Macro-vascular interventions such as stenting and coronary artery bypass grafting (CABG) remain crucial for obstructive lesions that significantly impair blood flow. Micro-vascular dysfunction demands pharmacologic strategies targeting endothelial function and vascular tone, including nitrates, calcium channel blockers, and novel agents under investigation.

Lifestyle modification and aggressive control of risk factors such as hypertension, diabetes, and hyperlipidemia are foundational to preserving arterial health and preventing progression of disease.

Dr. Valentin Fuster, a world-renowned cardiologist, notes, "Understanding the interplay between large vessel atherosclerosis and micro-vascular dysfunction is the frontier of cardiovascular medicine. Advances in imaging and molecular biology will soon allow personalized therapies that address the root causes of arterial disease, not just its consequences."

The arteries, particularly coronary arteries, are central to the pathogenesis and progression of heart disease. Beyond the traditional focus on large vessel obstruction, micro-vascular dysfunction and endothelial health play pivotal roles in clinical outcomes. Modern diagnostics and evolving therapies are reshaping how clinicians approach arterial disease, aiming for precision medicine that improves survival and quality of life.