Back To Search Results

Chronic Coronary Occlusion

Editor: Moien AB Khan Updated: 7/17/2023 8:56:03 PM


Chronic coronary occlusion or chronic total occlusion (CTO) refers to complete luminal diameter stenosis with resultant thrombolysis in myocardial infarction (TIMI) grade flow 0 or 1.[1] In such, there is no anterograde flow due to collaterals.[2] The occlusion should be of at least three months' duration to be labeled as chronic.[3] The main vessels that are affected due to CTO are the right coronary artery (43% to 55%), the left anterior descending artery (approximately 24%), and the left circumflex artery (17%-20%).[4][5] Functional CTOs represent severe occlusion, but not a complete occlusion of the coronary arteries. Such functional CTOs have collateral circulations presenting as anterograde flow.[6] However, even such collateral flow is unable to sustain future ischemic events in functional CTOs, indicating a need for revascularization.[7]


Register For Free And Read The Full Article
Get the answers you need instantly with the StatPearls Clinical Decision Support tool. StatPearls spent the last decade developing the largest and most updated Point-of Care resource ever developed. Earn CME/CE by searching and reading articles.
  • Dropdown arrow Search engine and full access to all medical articles
  • Dropdown arrow 10 free questions in your specialty
  • Dropdown arrow Free CME/CE Activities
  • Dropdown arrow Free daily question in your email
  • Dropdown arrow Save favorite articles to your dashboard
  • Dropdown arrow Emails offering discounts

Learn more about a Subscription to StatPearls Point-of-Care


Chronic total occlusions arise from a coronary thrombus that later becomes organized and fibrotic.[8] 40% of patients with chronic coronary occlusion have had a history of myocardial infarction.[2] The risk factors of developing a chronic total occlusion are similar to those of coronary artery disease.


The prevalence of total coronary occlusion seems to range from 18% to 35% of patients with coronary artery stenosis.[2][4][9] Chronic coronary occlusion is more predominant in males (85% to 98%) and the older population (median age around 64). However, a significant association of age and sex with procedural success has been inconsistent.[4][5] Increasing age seems to be associated with a higher risk of chronic coronary occlusion of the right coronary and left anterior descending arteries but not of the circumflex artery.[10]


CTO is due to complete or near-complete occlusion of a coronary artery, which is characterized by atherosclerotic plaque burden. Though such patients have collaterals, the collaterals are insufficient to sustain myocardial perfusion. This insufficiency leads to angina and ischemic symptoms.[11] Acute total occlusion (ATO) can present as an ST-elevated myocardial infarction.[12] It is important to recognize the difference between CTO and ATO. Management strategies of ATO versus CTO are totally different.[11] Furthermore, patients with CTO can present with acute coronary syndrome.[13]


Autopsy findings indicate that the total occlusion of coronary arteries happens due to the thrombus. The thrombus later gets reorganized with collagen dense fibrous tissues at the proximal and the distal end. As the lesion ages, the plaque becomes calcified and loses its previous microchannels.[14] Furthermore, histological studies have identified that the proximal part of the plaque is firmer than their distal part.[15] These histological changes are important when considering revascularization either through an anterograde or a retrograde approach.[16]

History and Physical

In general, history findings depend on the stage of coronary artery occlusion. The symptoms are related to myocardial ischemia or myocardial contractibility.[17] Patients can present with chest pain, shortness of breath, or tiredness. Patients with subtotal occlusion complain of chest pain, shortness of breath aggravated by exertion, and easy fatiguability. The symptoms usually resolve at rest. However, patients with total occlusion of coronary arteries have symptoms at rest and are refractory to medical therapy. Clinicians should take a detailed history to rule in or rule out important risk factors, i.e., family history, smoking, obesity, high blood pressure, decreased physical activity, excessive alcohol, diabetes, and a sedentary lifestyle.

Physical examination includes a complete general physical examination to look for xanthomas and general assessment of blood circulation followed by a detailed cardiovascular examination.


Electrocardiogram (EKG) can show ischemic changes in patients with chronic coronary occlusion. However, these findings are non-specific for diagnosis.[18] A chronic coronary occlusion is most often discovered on coronary angiography due to anginal chest pain, possible revascularization due to angina refractory to medical therapy, or diagnostic testing suggestive of myocardial ischemia or after a positive stress test. In coronary angiography, a catheter is inserted into a blood vessel of the leg or wrist. The catheter is advanced towards the heart, and the dye is injected into the blood vessels of the heart, which allows the clinician to see the flow of blood through coronary arteries and identify chronic coronary occlusion. Furthermore, patients with chronic coronary occlusion tend to be older, have comorbidities, and greater impairment of left ventricular function.[19]

Treatment / Management

Treatment mainly depends on the extent and severity of the disease and includes lifestyle modifications, medical therapy, and procedures like percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG).

Subtotal coronary occlusion is usually managed medically along the line of stable angina. Beta-blockers are preferred for initial treatment for the prevention of anginal symptoms.[20][21] Calcium channel blockers and long-acting nitrates are alternatives if beta-blockers are contraindicated or cause side effects; they can also be added as combination therapy if monotherapy is not successful.[22] Short-acting nitrates are used for immediate angina relief. Therapies known to prevent disease progression and reduce the incidence of adverse cardiovascular should also be started. These include aspirin, lipid-lowering therapy, smoking cessation, control of blood pressure, weight loss, and optimal management of diabetes mellitus.[23][24] Regular exercise and stress reduction are also recommended. The optimal management of these patients also requires periodic evaluation (every 6 to 12 months) of the patient's clinical status, using the history, physical examination, EKG, and echocardiogram.(A1)

Total coronary occlusion or subtotal occlusion refractory to medical therapy is managed by either percutaneous coronary intervention or coronary artery bypass grafting.[25][26]The choice of procedure depends on the involvement of coronary arteries.

In single-vessel disease, PCI is preferred over CABG. PCI is a minimally invasive procedure that involves an incision in the groin or wrist area. A wire is passed through the main blood vessel to the blocked artery in the heart. An opening is created in the blocked region with the help of guidewire. After this, a catheter is passed over the wire, then a balloon is inflated at the site of blockage to displace the plaque, and a stent is placed to normalize the blood flow and keep the artery open. In multivessel disease, CABG is the preferred.[27](B3)

Differential Diagnosis

Many diseases presenting with chest pain and shortness of breath may resemble chronic coronary occlusion.

Most common of these are:

  • Atherosclerosis
  • Angina pectoris
  • Unstable angina
  • Coronary artery vasospasm
  • Myocardial infarction
  • Hypertensive heart disease
  • Isolated coronary artery anomalies


Prognosis mainly depends on the severity of the disease. Those with subtotal chronic coronary occlusion have a better prognosis than with total chronic coronary occlusion. Total coronary occlusion is associated with a worse overall prognosis, with higher rates of death and non-fatal adverse cardiovascular events in several populations.[2][19] 

Patients with un-revascularized CTOs have been found to have higher mortality and a higher risk of major adverse cardiovascular events, including death from myocardial infarction compared to patients with multivessel coronary artery disease who are completely revascularized.[28][29]


The complications of the disease itself include a higher risk of cardiovascular events such as arrhythmias, myocardial infarction, and death. Complications can also occur during PCI, which includes major adverse cardiovascular events, myocardial infarction, significant Ellis grade ≥3 perforation, bleeding requiring treatment, acute kidney injury, and death and graft rejection in CABG.[30][31]

Deterrence and Patient Education

Successful revascularization improves long term survival, reduced need for coronary artery bypass graft, and an improvement in left ventricular systolic function in patients with CTO.[32][33] Smoking, high blood pressure, and diabetes are strongly associated with CTO.[34] Educating patients and establishing a supportive relationship are the most important steps in treating patients with chronic coronary occlusion. The clinician should educate the patients regarding the disease process, its nature and act to establish therapeutic goals like accomplishing lifestyle modifications, medication compliance, and adherence and explaining the risks/benefits of procedures. Moreover, patient education brochures and other materials related to disease should also be offered.

Enhancing Healthcare Team Outcomes

Chronic coronary occlusion has a wide spectrum, ranging from subtotal to total coronary involvement. Management of CTO should involve an interprofessional team that includes interventional cardiology, cardiac surgery, radiology, primary care, nursing staff, and pharmacists. The diagnosis is made by clinical/laboratory findings and angiography. Treatment depends on the extent and severity of the disease, which includes lifestyle modifications, medical therapy, percutaneous intervention, and coronary artery bypass grafting.



Mannem S, Rattanawong P, Riangwiwat T, Vutthikraivit W, Putthapiban P, Sukhumthammarat W, Kanitsoraphan C, Chongsathidkiet P. Sex Difference and Outcome after Percutaneous Intervention in Patients with Chronic Total Occlusion: A Systematic Review and Meta-Analysis. Cardiovascular revascularization medicine : including molecular interventions. 2020 Jan:21(1):25-31. doi: 10.1016/j.carrev.2019.03.003. Epub 2019 Mar 21     [PubMed PMID: 30952609]

Level 1 (high-level) evidence


Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, Gannot S, Samuel M, Weisbrod M, Bierstone D, Sparkes JD, Wright GA, Strauss BH. Current perspectives on coronary chronic total occlusions: the Canadian Multicenter Chronic Total Occlusions Registry. Journal of the American College of Cardiology. 2012 Mar 13:59(11):991-7. doi: 10.1016/j.jacc.2011.12.007. Epub     [PubMed PMID: 22402070]

Level 3 (low-level) evidence


Stone GW, Kandzari DE, Mehran R, Colombo A, Schwartz RS, Bailey S, Moussa I, Teirstein PS, Dangas G, Baim DS, Selmon M, Strauss BH, Tamai H, Suzuki T, Mitsudo K, Katoh O, Cox DA, Hoye A, Mintz GS, Grube E, Cannon LA, Reifart NJ, Reisman M, Abizaid A, Moses JW, Leon MB, Serruys PW. Percutaneous recanalization of chronically occluded coronary arteries: a consensus document: part I. Circulation. 2005 Oct 11:112(15):2364-72     [PubMed PMID: 16216980]

Level 3 (low-level) evidence


Tsai TT, Stanislawski MA, Shunk KA, Armstrong EJ, Grunwald GK, Schob AH, Valle JA, Alfonso CE, Nallamothu BK, Ho PM, Rumsfeld JS, Brilakis ES. Contemporary Incidence, Management, and Long-Term Outcomes of Percutaneous Coronary Interventions for Chronic Coronary Artery Total Occlusions: Insights From the VA CART Program. JACC. Cardiovascular interventions. 2017 May 8:10(9):866-875. doi: 10.1016/j.jcin.2017.02.044. Epub     [PubMed PMID: 28473108]


Tajti P, Karmpaliotis D, Alaswad K, Jaffer FA, Yeh RW, Patel M, Mahmud E, Choi JW, Burke MN, Doing AH, Dattilo P, Toma C, Smith AJC, Uretsky B, Holper E, Wyman RM, Kandzari DE, Garcia S, Krestyaninov O, Khelimskii D, Koutouzis M, Tsiafoutis I, Moses JW, Lembo NJ, Parikh M, Kirtane AJ, Ali ZA, Doshi D, Rangan BV, Ungi I, Banerjee S, Brilakis ES. The Hybrid Approach to Chronic Total Occlusion Percutaneous Coronary Intervention: Update From the PROGRESS CTO Registry. JACC. Cardiovascular interventions. 2018 Jul 23:11(14):1325-1335. doi: 10.1016/j.jcin.2018.02.036. Epub 2018 Apr 26     [PubMed PMID: 29706508]


Ivanhoe RJ, Weintraub WS, Douglas JS Jr, Lembo NJ, Furman M, Gershony G, Cohen CL, King SB 3rd. Percutaneous transluminal coronary angioplasty of chronic total occlusions. Primary success, restenosis, and long-term clinical follow-up. Circulation. 1992 Jan:85(1):106-15     [PubMed PMID: 1728439]


Werner GS, Richartz BM, Gastmann O, Ferrari M, Figulla HR. Immediate changes of collateral function after successful recanalization of chronic total coronary occlusions. Circulation. 2000 Dec 12:102(24):2959-65     [PubMed PMID: 11113046]


Katsuragawa M, Fujiwara H, Miyamae M, Sasayama S. Histologic studies in percutaneous transluminal coronary angioplasty for chronic total occlusion: comparison of tapering and abrupt types of occlusion and short and long occluded segments. Journal of the American College of Cardiology. 1993 Mar 1:21(3):604-11     [PubMed PMID: 8436741]


Kahn JK. Angiographic suitability for catheter revascularization of total coronary occlusions in patients from a community hospital setting. American heart journal. 1993 Sep:126(3 Pt 1):561-4     [PubMed PMID: 8362709]


Cohen HA, Williams DO, Holmes DR Jr, Selzer F, Kip KE, Johnston JM, Holubkov R, Kelsey SF, Detre KM, NHLBI Dynamic Registry. Impact of age on procedural and 1-year outcome in percutaneous transluminal coronary angioplasty: a report from the NHLBI Dynamic Registry. American heart journal. 2003 Sep:146(3):513-9     [PubMed PMID: 12947372]


Shah PB. Management of coronary chronic total occlusion. Circulation. 2011 Apr 26:123(16):1780-4. doi: 10.1161/CIRCULATIONAHA.110.972802. Epub     [PubMed PMID: 21518991]

Level 3 (low-level) evidence


Davies MJ. The pathophysiology of acute coronary syndromes. Heart (British Cardiac Society). 2000 Mar:83(3):361-6     [PubMed PMID: 10677422]


Rubartelli P, Verna E, Niccoli L, Giachero C, Zimarino M, Bernardi G, Vassanelli C, Campolo L, Martuscelli E, Gruppo Italiano di Studio sullo Stent nelle Occlusioni Coronariche Investigators. Coronary stent implantation is superior to balloon angioplasty for chronic coronary occlusions: six-year clinical follow-up of the GISSOC trial. Journal of the American College of Cardiology. 2003 May 7:41(9):1488-92     [PubMed PMID: 12742287]

Level 1 (high-level) evidence


Irving J. CTO pathophysiology: how does this affect management? Current cardiology reviews. 2014 May:10(2):99-107     [PubMed PMID: 24694103]


Srivatsa SS, Edwards WD, Boos CM, Grill DE, Sangiorgi GM, Garratt KN, Schwartz RS, Holmes DR Jr. Histologic correlates of angiographic chronic total coronary artery occlusions: influence of occlusion duration on neovascular channel patterns and intimal plaque composition. Journal of the American College of Cardiology. 1997 Apr:29(5):955-63     [PubMed PMID: 9120181]

Level 2 (mid-level) evidence


Godino C, Carlino M, Al-Lamee R, Colombo A. Coronary chronic total occlusion. Minerva cardioangiologica. 2010 Feb:58(1):41-60     [PubMed PMID: 20145595]


Cheng AS, Selvanayagam JB, Jerosch-Herold M, van Gaal WJ, Karamitsos TD, Neubauer S, Banning AP. Percutaneous treatment of chronic total coronary occlusions improves regional hyperemic myocardial blood flow and contractility: insights from quantitative cardiovascular magnetic resonance imaging. JACC. Cardiovascular interventions. 2008 Feb:1(1):44-53. doi: 10.1016/j.jcin.2007.11.003. Epub     [PubMed PMID: 19393143]


Shinde RS, Hiremath MS, Makhale CN, Durairaj M. Images in cardiology. ECG showing features of total left main coronary artery occlusion. Heart (British Cardiac Society). 2006 May:92(5):670     [PubMed PMID: 16614279]

Level 3 (low-level) evidence


Jeroudi OM, Alomar ME, Michael TT, El Sabbagh A, Patel VG, Mogabgab O, Fuh E, Sherbet D, Lo N, Roesle M, Rangan BV, Abdullah SM, Hastings JL, Grodin J, Banerjee S, Brilakis ES. Prevalence and management of coronary chronic total occlusions in a tertiary Veterans Affairs hospital. Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions. 2014 Oct 1:84(4):637-43. doi: 10.1002/ccd.25264. Epub 2013 Nov 13     [PubMed PMID: 24142769]

Level 2 (mid-level) evidence


Fihn SD, Gardin JM, Abrams J, Berra K, Blankenship JC, Dallas AP, Douglas PS, Foody JM, Gerber TC, Hinderliter AL, King SB 3rd, Kligfield PD, Krumholz HM, Kwong RY, Lim MJ, Linderbaum JA, Mack MJ, Munger MA, Prager RL, Sabik JF, Shaw LJ, Sikkema JD, Smith CR Jr, Smith SC Jr, Spertus JA, Williams SV, Anderson JL, American College of Cardiology Foundation/American Heart Association Task Force. 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: 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 Dec 18:126(25):e354-471. doi: 10.1161/CIR.0b013e318277d6a0. Epub 2012 Nov 19     [PubMed PMID: 23166211]

Level 1 (high-level) evidence


Fihn SD, Gardin JM, Abrams J, Berra K, Blankenship JC, Dallas AP, Douglas PS, Foody JM, Gerber TC, Hinderliter AL, King SB 3rd, Kligfield PD, Krumholz HM, Kwong RY, Lim MJ, Linderbaum JA, Mack MJ, Munger MA, Prager RL, Sabik JF, Shaw LJ, Sikkema JD, Smith CR Jr, Smith SC Jr, Spertus JA, Williams SV, American College of Cardiology Foundation. 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 Dec 18:126(25):3097-137. doi: 10.1161/CIR.0b013e3182776f83. Epub 2012 Nov 19     [PubMed PMID: 23166210]

Level 1 (high-level) evidence


Emanuelsson H, Egstrup K, Nikus K, Ellström J, Glud T, Pater C, Scheibel M, Tisell A, Tötterman KJ, Forsby M. Antianginal efficacy of the combination of felodipine-metoprolol 10/100 mg compared with each drug alone in patients with stable effort-induced angina pectoris: a multicenter parallel group study. The TRAFFIC Study Group. American heart journal. 1999 May:137(5):854-62     [PubMed PMID: 10220634]

Level 2 (mid-level) evidence


Winniford MD, Jansen DE, Reynolds GA, Apprill P, Black WH, Hillis LD. Cigarette smoking-induced coronary vasoconstriction in atherosclerotic coronary artery disease and prevention by calcium antagonists and nitroglycerin. The American journal of cardiology. 1987 Feb 1:59(4):203-7     [PubMed PMID: 3101478]


Winniford MD, Wheelan KR, Kremers MS, Ugolini V, van den Berg E Jr, Niggemann EH, Jansen DE, Hillis LD. Smoking-induced coronary vasoconstriction in patients with atherosclerotic coronary artery disease: evidence for adrenergically mediated alterations in coronary artery tone. Circulation. 1986 Apr:73(4):662-7     [PubMed PMID: 3948369]


Azzalini L, Jolicoeur EM, Pighi M, Millán X, Picard F, Tadros VX, Fortier A, L'Allier PL, Ly HQ. Epidemiology, Management Strategies, and Outcomes of Patients With Chronic Total Coronary Occlusion. The American journal of cardiology. 2016 Oct 15:118(8):1128-1135. doi: 10.1016/j.amjcard.2016.07.023. Epub 2016 Jul 28     [PubMed PMID: 27561190]


Tomasello SD, Boukhris M, Giubilato S, Marzà F, Garbo R, Contegiacomo G, Marzocchi A, Niccoli G, Gagnor A, Varbella F, Desideri A, Rubartelli P, Cioppa A, Baralis G, Galassi AR. Management strategies in patients affected by chronic total occlusions: results from the Italian Registry of Chronic Total Occlusions. European heart journal. 2015 Dec 1:36(45):3189-98. doi: 10.1093/eurheartj/ehv450. Epub 2015 Sep 2     [PubMed PMID: 26333367]


Stone GW, Reifart NJ, Moussa I, Hoye A, Cox DA, Colombo A, Baim DS, Teirstein PS, Strauss BH, Selmon M, Mintz GS, Katoh O, Mitsudo K, Suzuki T, Tamai H, Grube E, Cannon LA, Kandzari DE, Reisman M, Schwartz RS, Bailey S, Dangas G, Mehran R, Abizaid A, Moses JW, Leon MB, Serruys PW. Percutaneous recanalization of chronically occluded coronary arteries: a consensus document: part II. Circulation. 2005 Oct 18:112(16):2530-7     [PubMed PMID: 16230504]

Level 3 (low-level) evidence


Hannan EL, Racz M, Holmes DR, King SB 3rd, Walford G, Ambrose JA, Sharma S, Katz S, Clark LT, Jones RH. Impact of completeness of percutaneous coronary intervention revascularization on long-term outcomes in the stent era. Circulation. 2006 May 23:113(20):2406-12     [PubMed PMID: 16702469]

Level 2 (mid-level) evidence


Hannan EL, Wu C, Walford G, Holmes DR, Jones RH, Sharma S, King SB 3rd. Incomplete revascularization in the era of drug-eluting stents: impact on adverse outcomes. JACC. Cardiovascular interventions. 2009 Jan:2(1):17-25. doi: 10.1016/j.jcin.2008.08.021. Epub     [PubMed PMID: 19463393]


Sapontis J, Salisbury AC, Yeh RW, Cohen DJ, Hirai T, Lombardi W, McCabe JM, Karmpaliotis D, Moses J, Nicholson WJ, Pershad A, Wyman RM, Spaedy A, Cook S, Doshi P, Federici R, Thompson CR, Marso SP, Nugent K, Gosch K, Spertus JA, Grantham JA. Early Procedural and Health Status Outcomes After Chronic Total Occlusion Angioplasty: A Report From the OPEN-CTO Registry (Outcomes, Patient Health Status, and Efficiency in Chronic Total Occlusion Hybrid Procedures). JACC. Cardiovascular interventions. 2017 Aug 14:10(15):1523-1534. doi: 10.1016/j.jcin.2017.05.065. Epub     [PubMed PMID: 28797429]


Hess CN,Lopes RD,Gibson CM,Hager R,Wojdyla DM,Englum BR,Mack MJ,Califf RM,Kouchoukos NT,Peterson ED,Alexander JH, Saphenous vein graft failure after coronary artery bypass surgery: insights from PREVENT IV. Circulation. 2014 Oct 21;     [PubMed PMID: 25261549]

Level 1 (high-level) evidence


Suero JA, Marso SP, Jones PG, Laster SB, Huber KC, Giorgi LV, Johnson WL, Rutherford BD. Procedural outcomes and long-term survival among patients undergoing percutaneous coronary intervention of a chronic total occlusion in native coronary arteries: a 20-year experience. Journal of the American College of Cardiology. 2001 Aug:38(2):409-14     [PubMed PMID: 11499731]

Level 2 (mid-level) evidence


Sirnes PA, Myreng Y, Mølstad P, Bonarjee V, Golf S. Improvement in left ventricular ejection fraction and wall motion after successful recanalization of chronic coronary occlusions. European heart journal. 1998 Feb:19(2):273-81     [PubMed PMID: 9519321]

Level 2 (mid-level) evidence


Deshmukh V, Phutane MV, Munde K, Bansal N. Clinical Profile of Patients With Chronically Occluded Coronary Arteries: A Single Center Study. Cardiology research. 2018 Oct:9(5):279-283. doi: 10.14740/cr743w. Epub 2018 Oct 7     [PubMed PMID: 30344825]