Written and peer-reviewed by physicians—but use at your own risk. Read our disclaimer.

banner image


Trusted medical answers—in seconds.

Get access to 1,000+ medical articles with instant search
and clinical tools.

Try free for 5 days

Coronary artery disease

Last updated: March 5, 2021

Summarytoggle arrow icon

Coronary artery disease (CAD) is an ischemic heart disease that is most commonly caused by atherosclerosis and the subsequent reduction of blood supply to the myocardium, resulting in a mismatch between myocardial oxygen supply and demand. Acute retrosternal chest pain (angina) is the cardinal symptom of CAD. Other symptoms include dyspnea, dizziness, anxiety, and nausea. Severe ischemia may lead to myocardial infarction (MI). CAD is diagnosed using cardiac stress testing and/or coronary catheterization. Management of CAD involves primary and secondary prevention of atherosclerosis (e.g., weight reduction), antianginal treatment (e.g., beta blockers) and, in severe cases, revascularization (e.g., percutaneous transluminal coronary angioplasty).

This article provides a basic overview of coronary artery disease and stable angina. “Atherosclerosis” and “Acute coronary syndrome” (including myocardial infarction) are discussed in separate articles.

  • CAD is the leading cause of death in the US and worldwide. [1]
  • The lifetime risk of coronary artery disease at age 50 is approx. 50% for men and 40% for women. [2]

Epidemiological data refers to the US, unless otherwise specified.

Plaque formation and coronary artery stenosis [3][4]

Myocardial oxygen supply-demand mismatch [5]

An increased heart rate reduces oxygen supply and increases oxygen demand.

Effect of vascular stenosis on resistance to blood flow [6]

  • The resistance to blood flow within the coronary arteries is calculated using the Poiseuille equation: R = 8Lη/(πr4), where R = resistance to flow, L = length of the vessel, η = viscosity of blood, and r = radius of the vessel.
  • Provided the length of the vessel and viscosity of blood remain constant, the degree of resistance can be calculated using the simplified formula: R 1/r4

Vascular stenosis increases vascular resistance significantly. For example, a 50% reduction in radius results in a 16-fold increase in resistance: R ≈ 1/(0.5 x r)4 = [1/(0.5 x r)]4 = (2/r)4 = 16/r4.

Myocardial ischemia [5]

Coronary steal syndrome

Coronary steal syndrome should not be confused with coronary-subclavian steal syndrome.

Chronic ischemic heart disease


Angina is the cardinal symptom of CAD. Patients with CAD usually become symptomatic when the degree of coronary stenosis reaches ≥ 70%.

  • Typically retrosternal chest pain or pressure
    • Pain may radiate to the left arm, neck, jaw, epigastric region, or back.
    • Pain is not affected by body position or respiration.
    • No chest wall tenderness
    • May gradually increase in intensity
    • May present as gastrointestinal discomfort
    • May be absent, especially in geriatric and diabetic patients. [7]
  • Dyspnea
  • Dizzinesss, palpitations
  • Restlessness, anxiety
  • Autonomic symptoms (e.g., diaphoresis, nausea, vomiting, syncope)

Stable angina

  • Symptoms are reproducible/predictable
  • Symptoms often subside within minutes with rest or after administration of nitroglycerin
  • Common triggers include mental/physical stress or exposure to cold

Vasospastic angina

Patient history and physical exam

  • History of recurrent angina episodes
  • Signs of atherosclerotic vascular disease (e.g., absent foot pulses, carotid bruit)

Pretest probability of CAD

  • Clinical assessment of symptomatic patients to predict the probability of CAD, used to:
    • Help determine the need for further diagnostic tests
    • Guide the selection of best initial diagnostic test

Factors used to estimate the probability of CAD [12]

  • The pretest probability takes into consideration:
    • Patient's age and sex
    • Type of chest pain
      • Typical angina meets all of the following criteria:
        • Retrosternal chest pain of typical quality and duration (e.g., transient retrosternal pain)
        • Provoked by exertion or emotional stress
        • Relieved by rest and/or nitroglycerin
      • Atypical angina: meets only 2 of the aforementioned criteria
      • Noncardiac chest pain: meets one or none of the aforementioned criteria
Probability of CAD [13] Clinical presentation Next diagnostic step

Low (< 10%)

  • No further diagnostic tests are recommended
Intermediate (10–90%)
High (> 90%)

Resting ECG

Cardiac stress test [14]

Provocation methods


Findings in stress-induced ischemia [17]

Patients with new-onset chest pain, ST-depression, hypotension, or arrhythmias should undergo cardiac catheterization.

Cardiac catheterization

Additional tests

See “Differential diagnosis of chest pain.”

The differential diagnoses listed here are not exhaustive.

Approach [20]

Antianginal treatment [20]

Effects of drugs on MVO2 parameters
Parameter Beta blocker Nitrates Combination therapy

Blood pressure

Heart rate

↑ (reflectory)

Unchanged or slightly ↓
Inotropy ↑ (reflectory) Unchanged
Ejection time Unchanged
End-diastolic volume Unchanged or ↑ Unchanged or slightly ↓
MVO2 ↓↓


Prevention of atherosclerosis

Special considerations in coronary artery disease [25][26]

  1. Kochanek KD, Murphy S, Xu J, Arias E. Mortality in the United States, 2016.. NCHS Data Brief. 2017 : p.1-8.
  2. Lloyd-Jones DM, Leip EP, Larson MG, et al. Prediction of Lifetime Risk for Cardiovascular Disease by Risk Factor Burden at 50 Years of Age. Circulation. 2006; 113 (6): p.791-798. doi: 10.1161/circulationaha.105.548206 . | Open in Read by QxMD
  3. Kolli KK, Arif I, Peelukhana SV, et al. Diagnostic performance of pressure drop coefficient in relation to fractional flow reserve and coronary flow reserve. J Invasive Cardiol. 2014; 26 (5): p.188-195.
  4. Pijls NHJ, Van Gelder B, Van der Voort P. Fractional Flow Reserve: A Useful Index to Evaluate the Influence of an Epicardial Coronary Stenosis on Myocardial Blood Flow. Circulation. 1995; 92 : p.3183-3193. doi: 10.1161/01.CIR.92.11.3183 . | Open in Read by QxMD
  5. Physiology, Myocardial Oxygen Demand.
  6. Determinants of Resistance to Flow (Poiseuille's Equation). http://www.cvphysiology.com/Hemodynamics/H003. Updated: August 12, 2017. Accessed: April 16, 2018.
  7. Zunaira Gul, Amgad N. Makaryus.. Silent Myocardial Ischemia. StatPearls. 2020 .
  8. E. A. Amsterdam, N. K. Wenger, R. G. Brindis, D. E. Casey Jr., T. G. Ganiats, D. R. Holmes Jr., A. S. Jaffe, H. Jneid, R. F. Kelly, M. C. Kontos, G. N. Levine, P. R. Liebson, D. Mukherjee, E. D. Peterson, M. S. Sabatine, R. W. Smalling, S. J. Zieman. 2014 AHA/ACC Guideline for the Management of Patients With Non–ST-Elevation Acute Coronary Syndromes. Journal of the American College of Cardiology. 2014 . doi: 10.1016/j.jacc.2014.09.017 . | Open in Read by QxMD
  9. Mary Rodriguez Ziccardi; Jason D. Hatcher.. Prinzmetal Angina. StatPearls. 2020 .
  10. Kathryn Buchanan Keller, Louis Lemberg. Prinzmetal's angina. American Journal of Critical Care. 2004 .
  11. Walling A, Waters DD, Miller DD, Roy D, Pelletier GB, Théroux P. Long-term prognosis of patients with variant angina.. Circulation. 1987 .
  12. Fihn SD, Gardin JM, Abrams J, et al. 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease. J Am Coll Cardiol. 2012; 60 (24): p.e44-e164. doi: 10.1016/j.jacc.2012.07.013 . | Open in Read by QxMD
  13. Exercise Stress Testing. https://www.aafp.org/afp/2017/0901/p293.html. Updated: September 1, 2017. Accessed: January 20, 2020.
  14. Marwick TH. Stress echocardiography. Heart. 2003; 89 (1): p.113-118.
  15. Gibbons RJ, Balady GJ, Bricker JT, Chaitman BR, Fletcher GF, Froelicher VF, Mark DB, McCallister BD, Mooss AN, O'Reilly MG, Winters WL Jr, Gibbons RJ, Antman EM, Alpert JS, Faxon DP, Fuster V, Gregoratos G, Hiratzka LF, Jacobs AK, Russell RO, Smith SC Jr. ACC/AHA 2002 guideline update for exercise testing: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines).. Circulation. 2002 .
  16. Fletcher GF, Ades PA, Kligfield P, Arena R, Balady GJ, Bittner VA, Coke LA, Fleg JL, Forman DE, Gerber TC, Gulati M, Madan K, Rhodes J, Thompson PD, Williams MA. Exercise standards for testing and training: a scientific statement from the American Heart Association.. Circulation. 2013 .
  17. Darrow MD. Ordering and Understanding the Exercise Stress Test. Am Fam Physician. 1999; 59 (2): p.401-410.
  18. MARK D. DARROW. Ordering and Understanding the Exercise Stress Test. American Family Physician. 1999 .
  19. Mansour Al Moudi and Zhong-Hua Sun. Diagnostic value of 18F-FDG PET in the assessment of myocardial viability in coronary artery disease: A comparative study with 99mTc SPECT and echocardiography. Journal of Geriatric Cardiology. 2014 .
  20. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC Guideline for the Management of Patients With Non–ST-Elevation Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014; 130 : p.e344-e426. doi: 10.1161/CIR.0000000000000134 . | Open in Read by QxMD
  21. Lee L, Horowitz J, Frenneaux M. Metabolic manipulation in ischaemic heart disease, a novel approach to treatment.. European Heart Journal. 2004 .
  22. Connie W. Tsao, MD, MPH, Asya Lyass, PhD, and Ramachandran S. Vasan, MD. Prognosis of Adults with Borderline Left Ventricular Ejection Fraction. JACC. Heart failure. 2016 .
  23. Stephan D Fihn, Julius M Gardin, Jonathan Abrams, Kathleen Berra, James C Blankenship, Apostolos P Dallas, Pamela S Douglas, etal.. 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: executive summary: a report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2012 . doi: 10.1161/CIR.0b013e318277d6a0 . | Open in Read by QxMD
  24. Clinical Outcomes of Patients With Stable Angina.
  25. Olafiranye O, Zizi F, Brimah P, et al. Management of Hypertension among Patients with Coronary Heart Disease. Int J Hypertens. 2011; 2011 . doi: 10.4061/2011/653903 . | Open in Read by QxMD
  26. Cardiovascular Disease Prevention. http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/heart-disease-risk-reduction/. Updated: September 1, 2012. Accessed: February 20, 2017.