Ischaemic Heart Disease (IHD), also known as coronary heart disease (CHD) or coronary artery disease, is characterised by inadequate blood and oxygen supply to the myocardium.
IHD is the leading cause of death globally.
Deaths from IHD peaked in the mid-1960s, and while they have decreased since, they remain a significant health concern.
Pathophysiology
Atherosclerosis: The most common cause of IHD, where cholesterol deposits within the artery wall cause endothelial dysfunction and plaque formation.
Begins as a fatty streak and can progress to an unstable atherosclerotic plaque, disrupting blood flow and leading to ischaemia.
Plaque Activation: Atherosclerosis alone doesn’t account for all IHD cases; inflammation, thrombosis, and coronary microvascular dysfunction (CMD) are also important factors.
Coronary Microvascular Dysfunction (CMD):
CMD affects the coronary microcirculation and accounts for about 60% of coronary resistance, contributing significantly to IHD.
It can result from ischaemia-reperfusion injury, distal embolisation, and individual susceptibility, impacting both acute coronary syndrome (ACS) development and prognosis.
Clinical Presentation
IHD can present as stable ischaemic heart disease (SIHD) or acute coronary syndrome (ACS).
Key Symptoms include:
Chest Pain (Angina): Often triggered by exertion, radiating to the jaw, neck, or left arm.
Dyspnoea: Shortness of breath, worsened by activity.
Other symptoms: Syncope, palpitations, tachypnea, oedema, orthopnea, and reduced exercise capacity.
Classification:
SIHD: Predictable chest pain relieved by rest or nitroglycerin.
ACS: Includes unstable angina, NSTEMI, and STEMI; caused by the rupture of an atherosclerotic plaque, leading to thrombus formation and restricted blood flow.
Diagnosis: Involves a combination of history, physical examination, and laboratory tests, including:
Cardiac enzymes (CK and troponin) for ischaemic events.
Electrocardiogram (ECG) to identify ischaemic patterns.
Management and Treatment
Lifestyle Modifications:
Smoking cessation, weight loss, exercise, and dietary changes (e.g., Oslo Diet).
Pharmacological Therapy:
Antiplatelet agents (e.g., aspirin, ticagrelor, clopidogrel) to prevent thrombus formation.
Statins to lower cholesterol.
Beta-blockers to reduce heart rate and myocardial oxygen demand.
ACE inhibitors to improve cardiac function.
Nitrates (e.g., nitroglycerin) to improve blood flow.
Ranolazine to improve ischaemic threshold and reduce angina.
Revascularisation Procedures:
Percutaneous Coronary Intervention (PCI) with stent placement.
Coronary Artery Bypass Graft (CABG) surgery to bypass blocked arteries.
Complications
Arrhythmias, ACS, congestive heart failure (CHF), mitral regurgitation, ventricular free wall rupture, pericarditis, aneurysm formation, and mural thrombi are possible complications of IHD.
Deterrence and Patient Education
Modifiable Risk Factor Management:
Control diabetes, hypertension, lipid levels, weight, and smoking cessation.
Public Health Initiatives: Increasing awareness through education programs and media campaigns is key for primary prevention.
Roth, G. A., Mensah, G. A., Johnson, C. O., & Addo, J. (2020). Global burden of cardiovascular diseases and risk factors. Journal of the American College of Cardiology, 76(25), 2982-3021. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC7663258/
Lüscher, T. F., & Corti, R. (2013). Pathogenesis and mechanisms of ischemic heart disease. In Endotext. MDText.com, Inc. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK209964/
