272.1 🎓 醫孞生版

272.1.0.1 📌 䞀頁重點

272.1.0.1.1 Definitions
272.1.0.1.1.1 Ischemic Heart Disease (IHD)
  • Imbalance between myocardial O₂ supply ↔ demand
  • Usually due to atherosclerotic CAD
  • Spectrum:
    • Chronic coronary syndromes (CCS) — stable angina, vasospastic angina, microvascular angina, post-MI stable, ischemic cardiomyopathy
    • Acute coronary syndromes (ACS) — UA, NSTEMI, STEMI (see Ch272-273)
272.1.0.1.1.2 Stable Angina (Chronic CCS)
  • Reproducible chest discomfort with exertion/stress
  • Relieved by rest or nitroglycerin
  • No change in pattern over weeks
  • Reflects fixed coronary stenosis (typically ≥ 70%)
272.1.0.1.1.3 Epidemiology (Global / Taiwan)
  • IHD = #1 cause of death worldwide (~ 9 million deaths/year)
  • Taiwan 2024 statistics: heart disease #2 cause of death after malignancy
  • Rising in younger populations (DM, obesity, sedentary)
272.1.0.1.2 Pathophysiology
272.1.0.1.2.1 Atherosclerosis
  • Endothelial dysfunction → LDL infiltration → oxidized LDL → macrophage foam cells → fatty streak → fibrous plaque → unstable plaque
  • Plaque rupture → thrombosis → ACS
  • Stable plaque → progressive narrowing → angina with exertion
272.1.0.1.2.2 Risk Factors
  • Non-modifiable: age (♂ > 45, ♀ > 55), family history (1° relative < 55♂, < 65♀), male sex
  • Modifiable:
    • Dyslipidemia (↑ LDL, ↓ HDL, ↑ TG, ↑ Lp(a))
    • Hypertension
    • Diabetes mellitus
    • Smoking
    • Obesity / metabolic syndrome
    • Physical inactivity
    • Chronic kidney disease
    • Inflammation (CRP)
272.1.0.1.2.3 Supply-Demand Mismatch
  • ↓ Supply: coronary stenosis, vasospasm, anemia, hypoxia, ↓ diastolic perfusion time
  • ↑ Demand: tachycardia, ↑ BP (afterload), ↑ wall stress (LVH), ↑ contractility
272.1.0.1.3 Clinical Presentation
272.1.0.1.3.1 Typical Angina (3/3 features)
  1. Substernal chest discomfort with characteristic quality + duration
  2. Provoked by exertion or stress
  3. Relieved by rest or nitroglycerin within minutes
  • Atypical angina = 2/3
  • Non-anginal chest pain = 0-1/3
272.1.0.1.3.2 Quality
  • Heaviness, pressure, squeezing, tightness, burning
  • “Like a band around my chest”
  • “Like an elephant sitting on my chest”
  • NOT sharp, stabbing, pleuritic, or reproducible by palpation
272.1.0.1.3.3 Location
  • Substernal (most common)
  • Radiation to arms (L > R), jaw, neck, back, epigastrium
  • Levine’s sign (clenched fist over sternum)
272.1.0.1.3.4 Duration
  • 2-10 minutes (angina)
  • Persistent > 20 min suggests MI
  • < 30 sec or > 30 min less likely angina
272.1.0.1.3.5 Provocation
  • Exertion (walking, climbing stairs)
  • Emotional stress
  • Cold weather
  • Heavy meals
  • Sexual activity
272.1.0.1.4 Classification of Severity
272.1.0.1.4.1 Canadian Cardiovascular Society (CCS)
  • Class I: Angina only with strenuous activity
  • Class II: Slight limitation (walking > 2 blocks)
  • Class III: Marked limitation (1-2 blocks)
  • Class IV: At rest or minimal activity
272.1.0.1.5 Diagnosis
272.1.0.1.5.1 History + Physical
  • Risk factors
  • Symptoms (typical vs atypical)
  • Examination usually normal between episodes
272.1.0.1.5.2 Pretest Probability (2024 ESC Updated)
  • Age + sex + symptoms (typical / atypical / non-anginal)
  • Diamond-Forrester original; updated 2019 ESC + 2024 PREDICT/Local data
  • Low (< 5%): no testing
  • Intermediate (5-50%): functional or anatomic testing
  • High (> 50%): consider direct cath
272.1.0.1.5.3 Initial Investigations
  • ECG: usually normal at rest; look for old MI (Q waves), LVH, LBBB
  • Labs: lipid panel, HbA1c, eGFR, CBC, TSH
  • Echocardiogram: assess LV function, regional wall motion, valvular disease
272.1.0.1.5.4 Stress Testing — Functional
  • Exercise treadmill (ETT) — gold standard if can exercise + normal resting ECG
    • Bruce protocol
    • Diagnostic: ≥ 1 mm horizontal/downsloping ST depression
    • Stop for chest pain, ST depression, BP drop, arrhythmia
  • Pharmacologic stress — can’t exercise or has LBBB:
    • Dobutamine + echo (↑ HR + contractility)
    • Vasodilator (adenosine, regadenoson, dipyridamole) + nuclear / CMR
  • Stress imaging (echo, nuclear SPECT, CMR, PET):
    • More sensitive + specific than ETT
    • Useful for women, abnormal baseline ECG, prior PCI/CABG
272.1.0.1.5.5 Anatomic — CT Coronary Angiography (CCTA)
  • 2019 ESC + 2024 NICE Class I for stable chest pain workup
  • High NPV (rules out CAD)
  • SCOT-HEART trial 2018 — CCTA reduced 5-year MI vs functional only
  • ISCHEMIA trial 2020 — CCTA can exclude LM disease before randomization
  • Coronary calcium scoring (CACS) — risk stratification
272.1.0.1.5.6 Invasive Coronary Angiography
  • Gold standard for anatomy
  • Indications:
    • High-risk stress test
    • Refractory symptoms despite OMT
    • LV dysfunction
    • Concerning CCTA findings
  • FFR / iFR for hemodynamic significance (FFR ≀ 0.80 = significant)
272.1.0.1.6 Treatment of Stable Angina
272.1.0.1.6.1 Lifestyle (foundation)
  • Smoking cessation
  • Mediterranean diet
  • Exercise (150 min/week moderate)
  • Weight loss (BMI < 25)
  • Stress management
272.1.0.1.6.2 Anti-Anginal Medications

Tier 1 (first-line, all patients): - Beta-blockers (metoprolol, bisoprolol, carvedilol, atenolol) - ↓ HR, ↓ contractility, ↓ O₂ demand - Especially helpful post-MI or with HF - Target resting HR 55-60 bpm - Sublingual NTG PRN for acute relief

Tier 2 (add if symptomatic): - Calcium channel blockers: - Dihydropyridines (amlodipine, felodipine) — vasodilation - Non-DHP (verapamil, diltiazem) — ↓ HR + contractility - Useful for vasospastic angina - Long-acting nitrates (isosorbide mononitrate / dinitrate) - 12-hour nitrate-free interval to avoid tolerance

Tier 3 (refractory): - Ranolazine (late sodium current inhibitor) — no HR/BP effect - Ivabradine (If channel inhibitor in SA node) — ↓ HR only, for sinus rhythm - Nicorandil (K-ATP opener) — Europe/Asia, not US - Trimetazidine (metabolic agent)

272.1.0.1.6.3 Secondary Prevention (“ABCDE”)
  • A: Antiplatelet (ASA 81-100 mg daily) + ACEi/ARB
  • B: Beta-blocker, BP control (< 130/80)
  • C: Cholesterol (high-intensity statin, LDL goal < 55 mg/dL post-event; < 70 high-risk)
  • D: Diet, Diabetes control (HbA1c < 7%)
  • E: Exercise + Education
272.1.0.1.6.4 Statin Therapy (2024 ESC/AHA)
  • Atorvastatin 40-80 mg or rosuvastatin 20-40 mg (high-intensity)
  • LDL target:
    • Very high risk: < 55 mg/dL + ≥ 50% reduction
    • High risk: < 70 mg/dL
  • Add ezetimibe if not at goal
  • Add PCSK9 inhibitor (alirocumab, evolocumab) for very high risk not at goal
  • Inclisiran (siRNA, q6mo) — alternative
  • Bempedoic acid — for statin-intolerant
272.1.0.1.6.5 Antiplatelet Therapy
  • ASA 81-100 mg lifelong for CCS
  • Clopidogrel 75 mg alternative if ASA intolerant
  • Post-PCI: DAPT (ASA + P2Y12) for 6-12 months (see Ch272-273)
  • Rivaroxaban 2.5 mg BID + ASA (COMPASS trial) — for high-risk vascular disease
272.1.0.1.6.6 Other Adjuncts
  • ACEi/ARB: for DM, CKD, LV dysfunction, or HTN
  • SGLT2 inhibitor: for DM + ASCVD (EMPA-REG, DECLARE)
  • GLP-1 RA: for DM + ASCVD (LEADER, SUSTAIN-6)
  • Influenza + pneumococcal + COVID-19 vaccinations
272.1.0.1.7 Revascularization Decision
272.1.0.1.7.1 When to revascularize (PCI or CABG)?
  • Symptomatic refractory to OMT
  • High-risk anatomy:
    • Left main > 50%
    • Proximal LAD
    • 3-vessel disease + LV dysfunction
    • Large area of ischemia on stress test (> 10% LV)
  • CABG preferred over PCI:
    • LM + complex disease
    • 3-vessel + DM (FREEDOM trial)
    • Low EF
    • High SYNTAX score
272.1.0.1.7.2 Key Trials (Stable IHD)
  • COURAGE 2007 — PCI vs OMT, no mortality benefit
  • BARI 2D 2009 — DM, no mortality benefit
  • ORBITA 2017 — PCI vs sham PCI, no symptom benefit (controversial)
  • ISCHEMIA 2020 — invasive vs conservative, no mortality benefit, modest symptom benefit
  • ORBITA-2 2023 — PCI vs sham showed symptom benefit (improving methodology)
272.1.0.1.7.3 Take-home
  • PCI for symptom relief, not mortality (in stable CCS)
  • CABG for prognosis in select high-risk anatomy
  • OMT is mandatory in all patients
272.1.0.1.8 Vasospastic Angina (Prinzmetal/Variant)
  • Coronary artery spasm → transient ST elevation
  • Often at rest, early morning, cyclic
  • Risk: smoking, cocaine, magnesium deficiency
  • Diagnosis: ergonovine / acetylcholine provocation
  • Treatment:
    • Calcium channel blockers (mainstay)
    • Long-acting nitrates
    • Avoid beta-blockers (unopposed alpha → worsen spasm)
    • Stop smoking, cocaine
272.1.0.1.9 Microvascular Angina (Cardiac Syndrome X)
  • Angina + ischemic stress test BUT normal epicardial coronaries
  • Women > men
  • Endothelial / microvascular dysfunction
  • CMR with stress perfusion or invasive CFR helpful
  • Treatment: standard anti-anginal + statin + ACE inhibitor

272.1.0.2 🩺 床邊速查

  • Typical angina: substernal, exertional, relieved by rest/NTG (3/3)
  • CCS classes: I–IV (CCS class III = walking 1-2 blocks)
  • ISCHEMIA take-home: stable CCS → OMT first, no mortality benefit for routine invasive
  • LDL goal post-ACS: < 55 mg/dL with ≥ 50% reduction
  • Vasospastic angina: CCB + nitrate; AVOID beta-blocker
  • ACSDE secondary prevention: ASA, β-blocker, Cholesterol (statin), Diet/DM, Exercise