Coronary Artery Disease — Causes, Symptoms, Stents, CABG & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Coronary artery disease (CAD), also called ischaemic heart disease (IHD), is caused by atherosclerosis — the build-up of cholesterol-rich plaques (atheromas) within the walls of the coronary arteries supplying blood to the heart muscle. This narrowing reduces blood flow and oxygen supply to the myocardium. Stable atherosclerotic plaques cause stable angina (predictable chest pain on exertion). Plaque rupture triggers platelet aggregation and thrombus formation — causing acute coronary syndrome (ACS): unstable angina, NSTEMI (non-ST elevation myocardial infarction), or STEMI (ST-elevation myocardial infarction — 'heart attack'). CAD is the single largest cause of death globally, accounting for 8.9 million deaths annually. Atherosclerosis is a systemic disease affecting multiple vascular beds simultaneously — individuals with established coronary artery disease have significantly elevated risk of cerebrovascular disease (stroke) and peripheral arterial disease, justifying a comprehensive, multi-territory cardiovascular risk management approach rather than focusing exclusively on the coronary circulation.

Atherosclerosis begins in childhood with fatty streaks and progresses over decades. Risk factors — non-modifiable: age (men over 45, women over 55), male sex, family history of premature CAD (first-degree relative with MI before age 55 in men or 65 in women), South Asian ethnicity (2x higher risk). Modifiable risk factors: dyslipidaemia (elevated LDL cholesterol — the most important modifiable risk factor), hypertension (systolic BP above 140 mmHg), diabetes mellitus and insulin resistance, cigarette smoking (2-4x increased CAD risk, dose-dependent), obesity (BMI over 30), physical inactivity, unhealthy diet (high saturated fat, low fruit and vegetable intake), excess alcohol, chronic kidney disease, obstructive sleep apnoea, and chronic psychological stress.

Stable angina: central crushing pressure or tightness in the chest on exertion (walking uphill, cold weather, emotional stress) — relieved by rest or GTN (glyceryl trinitrate) spray within 5 minutes; may radiate to the left arm, jaw, neck, or back; reproducible and predictable. Unstable angina: chest pain at rest or minimal exertion; new-onset severe angina; rapidly worsening (crescendo) angina — requires emergency evaluation. STEMI/NSTEMI (heart attack): severe central chest pain at rest lasting over 20 minutes, unrelieved by GTN, with diaphoresis (sweating), nausea, dyspnoea, and pallor. 20-30% of MIs present atypically — especially in women, diabetics, and elderly — with jaw pain, epigastric discomfort, breathlessness, syncope, or fatigue without chest pain. Call emergency services immediately for any suspected heart attack.

12-lead ECG: ST elevation in STEMI; ST depression or T-wave changes in NSTEMI; Q waves indicate prior infarction. High-sensitivity troponin I or T (hs-cTnI/hs-cTnT): measured at 0 and 1-3 hours — elevated in NSTEMI and STEMI; the most sensitive and specific biomarker for myocardial injury. Echocardiogram (TTE): assesses left ventricular ejection fraction, regional wall motion abnormalities (indicating ischaemia or infarction), valvular disease. Stress testing (exercise ECG, stress echo, nuclear perfusion scanning, cardiac MRI stress perfusion): diagnoses stable angina; assesses ischaemia burden. CT coronary angiography (CTCA): non-invasive anatomical coronary assessment — high negative predictive value for excluding significant CAD. Invasive coronary angiography (cardiac catheterisation): gold standard for delineating coronary anatomy; guides decision for PCI or CABG.

Emergency STEMI: primary PCI (percutaneous coronary intervention — balloon angioplasty and drug-eluting stent) within 90-120 minutes of first medical contact is the gold standard; thrombolysis if PCI unavailable within 120 minutes. NSTEMI/unstable angina: risk-stratify using GRACE score; early invasive strategy (coronary angiography within 24-72 hours for high-risk). Medical therapy (all CAD): dual antiplatelet therapy — aspirin 75 mg lifelong plus clopidogrel/ticagrelor/prasugrel for 12 months after ACS or PCI; high-intensity statin (atorvastatin 40-80 mg — target LDL below 1.4 mmol/L); beta-blocker (reduces heart rate and myocardial oxygen demand); ACE inhibitor or ARB (cardioprotective with LV impairment or diabetes); GTN spray PRN for angina. Stable angina: symptom-driven revascularisation (PCI or CABG) vs medical therapy — ISCHEMIA trial showed medical therapy alone is valid for stable CAD without severe ischaemia. Multivessel/left main disease or diabetes: CABG provides better long-term outcomes than PCI (SYNTAX trial). Cardiac rehabilitation: 8-12 week supervised exercise programme — reduces cardiovascular mortality by 25%.

Untreated or undertreated CAD progresses to recurrent MI, left ventricular impairment, heart failure, dangerous ventricular arrhythmias (ventricular tachycardia, ventricular fibrillation causing sudden cardiac death), and death. After a first MI, 20% of patients will have a second MI within 5 years without optimal secondary prevention. Heart failure from extensive infarction causes progressive dyspnoea and reduced exercise tolerance. Cardiogenic shock (failure of the heart to maintain adequate circulation) after large MI carries 30-40% in-hospital mortality. Mechanical complications of MI: papillary muscle rupture (acute mitral regurgitation), ventricular septal defect, LV free wall rupture — rare but immediately life-threatening. Complete revascularisation and optimal medical therapy significantly reduce long-term mortality and hospitalisation.

Primary prevention: assess cardiovascular risk using validated calculators (QRISK3 in UK, PCE in USA) every 5 years from age 40. Treat modifiable risk factors: target BP below 130/80 mmHg; target LDL below 3.0 mmol/L (statin for 10-year CV risk above 10%); optimise diabetes management with SGLT2 inhibitors that have proven CV benefit; smoking cessation (single most effective intervention); weight reduction; Mediterranean diet (olive oil, fish, nuts, legumes, fruit, vegetables); physical activity (150-300 min/week of moderate intensity). Secondary prevention (established CAD): lifelong aspirin, high-intensity statin (atorvastatin 40-80 mg), BP optimisation, diabetes control, annual influenza vaccination, cardiac rehabilitation, and psychosocial support including depression screening and treatment.

Call 999 immediately for: central chest pain or pressure described as crushing, squeezing, tightening, or a heavy weight on the chest — particularly lasting more than 15 minutes; chest pain radiating to the jaw, left arm, or neck; chest pain accompanied by sweating, nausea, breathlessness, or lightheadedness; sudden severe breathlessness at rest; or sudden cardiac arrest (collapse, not breathing). Chew aspirin 300 mg immediately while waiting for ambulance (if not allergic). These symptoms may indicate a heart attack (acute myocardial infarction) — a medical emergency where 'time is muscle' and every minute of delay causes irreversible heart damage. See a GP urgently for: new exertional chest tightness or breathlessness that reliably comes on with activity and improves with rest (stable angina); worsening frequency or severity of previously diagnosed angina (unstable angina — requires same-day assessment); or multiple cardiovascular risk factors (diabetes, hypertension, high cholesterol, smoking, family history) without recent cardiovascular assessment.