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World J Cardiol. Jul 26, 2014; 6(7): 621-629
Published online Jul 26, 2014. doi: 10.4330/wjc.v6.i7.621
Chronic total occlusion: To treat or not to treat
Alfredo Bardají, Judit Rodriguez-López, Mauricio Torres-Sánchez
Alfredo Bardají, Judit Rodriguez-López, Mauricio Torres-Sánchez, Servicio de Cardiología, Hospital Universitario de Tarragona Joan XXIII, Universitat Rovira Virgili, 3007 Tarragona, España
Author contributions: Bardají A, Rodriguez-López J and Torres-Sánchez M performed research; Bardají A wrote the paper.
Correspondence to: Alfredo Bardají, MD, PhD, FESC, Servicio de Cardiología, Hospital Universitario de Tarragona Joan XXIII, Universitat Rovira Virgili, Calle Dr Mallafré Guasch 4, 43007 Tarragona, España.
Telephone: +34-97-7295834 Fax: +34-97-7295859
Received: December 23, 2013
Revised: January 20, 2014
Accepted: May 16, 2014
Published online: July 26, 2014


Over the last two decades, there has been increasing interest in new techniques for the percutaneous treatment of coronary chronic total occlusions (CTO), which have a success rate that is much higher than that of a few years ago. The rise in percutaneous treatment for these lesions is due to its ability to improve the symptoms and prognosis of patients in the chronic and stable phase of coronary disease. Current data suggest that successful percutaneous coronary intervention for CTO is associated with improvement in patient symptoms, quality of life, left ventricular function, and survival, compared with those with unsuccessful CTO PCI. However, all the scientific evidence supporting this treatment comes from observational studies, and no randomized study comparing percutaneous treatment with medical treatment has yet been published. A major limitation of these studies is their observational design, with limited information with regard to potential baseline differences between the successful vs unsuccessful cohorts. Pending randomized studies, patients should be selected very carefully, especially if they are asymptomatic or very few symptoms, and the benefits obtained in terms of complications during the procedure, the quality of life obtained and further ischemic events avoided should be evaluated systematically. In this review, we will consider the available information supporting percutaneous treatment for chronic occlusions, as well as the areas of uncertainty where more research projects are required.

Key Words: Chronic total occlusion, Percutaneous coronary intervention

Core tip: This is a critical review about the available information supporting percutaneous treatment for chronic occlusions, as well as the areas of uncertainty where more research projects are required.

Citation: Bardají A, Rodriguez-López J, Torres-Sánchez M. Chronic total occlusion: To treat or not to treat. World J Cardiol 2014; 6(7): 621-629

Chronic total occlusions (CTO) are considered to be 100% coronary lesions, of more than 3 mo evolution[1]. They are therefore always found in stable chronic patients, with varying levels of symptoms. After the culprit artery has been treated, patients with acute coronary syndrome may occasionally also have a chronic occlusion in another artery that was not responsible for the acute event, and is therefore considered a CTO.


The prevalence of CTO in patients undergoing coronary angiography varies, ranging between 18% and 52% depending on the clinical profile of the patient being examined[2-7] (Table 1). Although revascularization surgery is the most frequent treatment, clinicians and invasive cardiologists often consider the need and feasibility of percutaneous treatment for these lesions, based on symptoms and prognostic factors. However, as it is a common problem in all Cath Labs, the extensive variability between different centres is striking. For example, in North American centres[4], with an incidence rate of CTO of between 29% and 33% in all the catheterizations performed, only between 6% and 9% of patients were treated percutaneously. However, in Japanese centres, with an incidence of 19% of CTO in all the catheterizations performed, 61.2% of all cases were treated percutaneously[5]. There are also significant differences in the treatment of CTO within the same geographical area or healthcare system. For example, in the Canadian CTO registry[6], some hospitals percutaneously treat 16% of their patients, while others only do so for 1%. These differences are very striking, and can only be justified by some generally ill-defined indications, as well as the technical difficulty that means that not all invasive cardiologists can or should deal with complex lesions of this type. However, there is another factor that also needs to be mentioned. Patients with CTO probably have a clinical profile that is different to that of patients with chronic coronary ischemic disease in general. There not only are differences in terms of greater severity of coronary disease, but also in terms of increased non-coronary comorbidity, such as a higher rates of prevalence of diabetes, peripheral arterial disease, heart failure and a history of strokes[8]. The indications for percutaneous treatment of CTO are not well defined in the European guidelines for revascularization[9], or in the guidelines for patients with stable chronic coronary disease[1] (Table 2). The American guidelines on revascularization[10,11] and chronic stable ischemic heart disease[12] are also unclear as regards the indications for treatment of CTO. Only the American guidelines for the appropriate use of percutaneous coronary treatment[13] contain a clear position on treatment that is appropriate, uncertain or not indicated in CTO lesions (Table 3).

Table 1 Chronic total occlusion prevalence, location and treatment applied in different studies n (%).
Ref.Type of studyPopulationCTO prevalenceCTO location
Medical treatmentPCICABG
Kahn et al[2], 1993Retrospective333 Coronary disease (stenoses ≥ 50%)101 (35)58%18%24%---
Christofferson et al[3], 2005Retrospective6581 Underwent coronarography because of suspected CD1612 (25)49.4%22%28.60%49%11%40%
3087 Coronary disease (stenoses ≥ 70%)1612 (52)
Srinivas et al[4], 2002Retrospective1761 Multivessel disease545 (31)----14.50%-
Yamamoto et al[5], 2013Prospective15263 First revascularization procedure2491 (19)44.9%41.10%28.50%-61.18%-
Fefer et al[6], 2012Prospective14439 Underwent coronariography because of suspected CD2630 (18.2)46.9%19.86%15.43%64%10%26%
Jeroudi et al[7], 2013Prospective1015 Coronary disease (stenoses ≥ 50%)319 (31.34)---19% (61)50% (161)30% (97)
Table 2 Specific recommendations on the treatment of chronic total occlusion in the American and European Practice Guidelines.
SocietyGuidelineSpecific recommendation on the treatment of CTO
EUROPEAN2010 Guidelines of myocardial revascularization[9]“Revascularization of CTO may be considered in the presence of angina or ischemia related to the corresponding territory”
2013 ESC guidelines on the management of stable coronary artery disease[1]“Revascularization needs to be discussed in patients with symptoms of occlusion or large ischemic areas”
AMERICAN2011 ACCF/AHA Guideline for Coronary Artery Bypass Graft Surgery[10]Not mentioned
2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention[11]Recommendation IIa. Evidence level B. PCI of a CTO in patients with appropriate clinical indications and suitable anatomy is reasonable when performed by operators with appropriate expertise “The decision to try PCI for a CTO (vs continued medical therapy or surgical revascularization) requires an individualized risk-benefit analysis encompassing clinical, angiographic, and technical considerations”
2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease[12]Not mentioned
Table 3 Specific recommendations on the treatment of chronic total occlusion in the 2012 ACCF/SCAI/STS/AATS/ASNC/HFSA/SCCT Appropriate Use Criteria for Coronary Revascularization Focused Update[14].
Risk in the ischemia testHighUncertainAppropriateAppropriateAppropriateAppropriateMaxTreatment level

There should be no doubt that a treatment of a CTO affecting an ischemic myocardial area that causes symptoms such as angina should improve patients’ symptoms, by providing a greater perfusion flow than that provided by collateral circulation, as a consequence of opening the occluded artery[14]. However, this has been poorly studied and quantified in the medical literature. Very few studies have specifically evaluated the changes in the ischemic threshold and quality of life scales of symptomatic and asymptomatic patients with percutaneously treated CTO. In the FACTOR Trial (FlowCardia Approach to CTO Recanalization), 125 patients completed the Seattle Angina Questionnaire at baseline and one month after percutaneous coronary intervention[15]. Successful treatment was associated in overall terms with an improvement in the frequency of angina, physical capacity and quality of life. However, this improvement was only observed in previously symptomatic patients but not in asymptomatic patients. In fact, this symptomatic improvement is similar to that obtained with percutaneous coronary intervention in the treatment of lesions without chronic total occlusion[16].


Often no distinction is made between patients with angina and patients with myocardial ischemia when percutaneous treatment of CTO is indicated[17]. However, these two concepts are different in our opinion, and should be clarified. In patients with angina (and therefore with ischemia), the benefit of CTO treatment is for the symptoms and possibly the prognosis. However, as mentioned above, in patients with ischemia but without angina, the benefit is not symptomatic and can only be evaluated in prognostic terms. It is therefore important to determine whether patients with myocardial ischemia but who are asymptomatic benefit from percutaneous treatment of a CTO. The rationale for this approach is based on relatively early studies in which the improvement of ischemia provided by the revascularization obtained by an angioplasty, in both symptomatic patients[18] and asymptomatic patients[19], was associated with an improved prognosis. In the SWISSI II Trial[19] in the late 1990s, on asymptomatic patients after myocardial infarction, with coronary disease in 1 or 2 vessels and inducible myocardial ischemia in an imaging stress test, coronary angioplasty significantly reduced coronary events during a long-term follow-up period. However, in this study, both the medical treatment, which was very limited, and the percutaneous treatment (the use of bare metal stents) were obviously different to those currently in use. More recent studies of symptomatic patients with chronic coronary disease, frequently presenting a positive test for ischemia, have failed to show that percutaneous revascularization improves prognosis[20], even in diabetic patients[21]. In the COURAGE trial, the small benefit in terms of improved quality of life in percutaneously treated patients compared to those receiving medical therapy without revascularization disappeared after 36 mo follow-up[22]. The data from the COURAGE trial substudy, with quantification of ischemia by a stress test with nuclear imaging, show that in patients with stable chronic ischemic heart disease, angioplasty provides a greater improvement in the ischemic area than medical treatment[23]. However, this improvement in the ischemic area had no effect on the medium-term prognosis[24]. A recent meta-analysis including all the randomized studies in patients with stable chronic ischaemic cardiopathy and proven myocardial ischemia concluded that percutaneous treatment does not affect rates of mortality, myocardial infarction, unplanned revascularization or angina compared to medical treatment alone[25]. At present, the hypothesis that moderate to severe myocardial ischemia should be revascularized in order to improve the prognosis must therefore be reviewed[26]. In the context of patients with chronic coronary artery disease, the ISCHEMIA clinical trial will attempt to demonstrate whether the strategy of cardiac catheterization for revascularization is better than strategy of medical treatment in patients with moderate to severe ischemia detected in a stress test with imaging[27]. In this trial, there will presumably be few patients with CTO, meaning that it is possible that its findings cannot be fully extrapolated to this specific population. As regards patients specifically with CTO, there are two ongoing clinical trials that are randomizing patients with angina or ischemia in an imaging test for medical treatment or angioplasty. The EURO-CTO clinical trial, being run at a European level, has the primary objective of evaluating quality of life at 12 mo, as well as assessing major coronary events after 3 years[28]. The DECISION-CTO clinical trial, conducted in Asian countries, has a composite primary endpoint (cardiac death, myocardial infarction, stroke or further revascularization) evaluated after 3 years[29].


Chronic hypoperfusion due to the presence of a CTO on a viable myocardium can cause ventricular dysfunction, and may lead to symptoms such as exercise intolerance and heart failure resulting from this dysfunction. It therefore seems logical that the opening of an occluded artery which irrigates a viable but dysfunctional myocardium could reverse this dysfunction and improve these patients’ symptoms and prognosis. There are few studies, all of which are observational, that have specifically addressed this issue (Table 4). Most available data suggest a very modest improvement in ventricular function as a result of opening an occluded artery. For example, Sirnes assessed the changes in ventricular function by ventriculography and was only able to demonstrate a 2% increase in ejection fraction, although the regional radial shortening increased by 16% in the revascularized areas[30]. This slight improvement in regional ventricular function does not appear to depend on the presence of pre-existing collaterals, but probably on preserved microvascular integrity[31]. The use of more accurate methods for quantifying ventricular function, such as cardiac magnetic resonance imaging, also confirms that the improvement in ventricular function as a result of opening an occluded artery is very modest[32]. The improvement in the prognosis of patients with ventricular dysfunction due to revascularization is currently a topic of heated debate, following the results of randomized STICH study[33]. In this clinical trial, patients with multivessel disease and ventricular dysfunction did not improve their prognosis as a result of revascularization surgery, in comparison with the medically treated group. Surprisingly, even the specifically studied patients with myocardial viability did not benefit from revascularization[34]. The STICH study did not include patients with CTO, but the concept and the comments are relevant, because the percutaneous treatment of CTO is often justified simply on the basis of viability.

Table 4 Findings on left ventricular ejection fraction and regional wall motion variations after percutaneous coronary intervention treatment of chronic total occlusion.
Type of studyPopulationLVEF estimationFollow upResults
LVEFRegional wall motionSymptomsCollateral functionVentricular remodeling
1994-1995 Sirnes et al[30]Prospective95 CTOs treated with PCIVentriculographyAngiography 6 moLVEF increase (from 0.62 ± 0.13 to 0.67 ± 0.12) P < 0.001Increase in regional radial shortening (from 0.279 ± 0.106 to 0.319 ± 0.107) P < 0.001Improvement in angina classNot mentionedNot mentioned
1999-2003 Werner et al[31]Prospective126 CTOs treated with PCIVentriculographyAngiographyLVEF increase (from 0.60 ± 0.19 to 0.67 ± 0.16) P < 0.001Increase in wall motion severity index (from -1.92 ± 1.32 to -1.30 ± 1.28) P < 0.001Not mentionedNo changes in collateral functionNot mentioned
2008 Kirschbaum et al[32]Prospective21 CTOs treated with PCINMRNMR 5 mo and 3 yrLVEF increase (from 60% ± 9% to 63% ± 11%) P = 0.11Increase in segmental wall thickening. From 19% ± 21% to 31% ± 30% at 5 mo (P < 0.001) and 47% ± 46% at 3 yr (P = 0.04)Not mentionedNot mentionedLess ventricular remodeling in NMR at 3 yr

Meanwhile, the treatment of a CTO as a cause of deterioration in the ejection fraction due to complications during the procedure should not be ruled out. In recent years, major breakthroughs have been described in the material used for the percutaneous treatment of CTO, which has led to a significant reduction in complications[35]. However, the statement that today’s complication rates are similar to those occurring in the treatment of less complex lesions could not be further from the truth. The Multinational CTO Registry mentions a rate of residual coronary dissection and perforation of 4.3% and 1.7% in successfully patients treated. However, among patients treated without success, these rates are 9.4% and 7.4%, respectively[35]. In the series from a large Japanese centre, the overall rate of perforation in all percutaneous coronary intervention procedures is 1.2%, but 44% of these occur in patients with CTO[36]. In another large Japanese centre, the rates of coronary dissection, perforation, distal embolization are 14.7%, 8.2% and 3.7% respectively, when a antegrade approach is used, and 10.1%, 13% and 1.4% respectively, when the procedure is performed via the retrograde route[37]. Some authors have postulated that this high rate of complications in unsuccessfully treated patients partially explains their worse prognosis compared with those who are successfully treated[38,39] .


Some registries have reported that patients with complete revascularization have a better prognosis than those with incomplete revascularization, including the presence of an untreated CTO[40]. On this basis, the main argument which normally supports the treatment of CTO is that successfully treated patients have a better prognosis than those treated without success. This is apparent in the Joyal meta-analysis, in which successful treatment was associated with a significant improvement in mortality compared to unsuccessfully treated patients[41]. This meta-analysis, conducted on studies with mainly retrospective data, seems to suggest that the baseline characteristics of successfully treated patients are similar to those treated without success, and that the unsuccessfully treated patients act as a medically treated control group. However, the studies performed with retrospective data[42-54] often lack information on some of the baseline characteristics of patients which have a clear effect on prognosis (Table 5). When studies with prospectively collected data are analyzed, it becomes apparent that the baseline characteristics of patients treated without success are clearly different from those who are successfully treated. For example, the Canadian prospective registry contains many variables of poor prognosis among the unsuccessfully treated patients, such as having a longer history of prior infarction, prior multivessel disease, a longer CTO, higher rate of residual dissection and perforation during the procedure, which undoubtedly influences the these patients’ poor prognosis[36]. Furthermore, when the collection of variables is prospective and they are included in the predictive statistical model[55], the benefit of successful treatment of CTO is cancelled out as these patients have baseline characteristics with a better prognosis than those treated without success. This hypothesis is corroborated by the recent publication of the long-term results of patients in the CREDO-Kyoto Registry[5]. In this large series, the clinical evolution of 1192 successfully treated patients was compared with 332 unsuccessfully treated patients. Hospital mortality tended to be lower among the successfully treated patients than among those who were unsuccessfully treated (1.4% vs 3%, P = 0.053). During a three-year follow-up period, all-cause mortality did not differ between the two groups (9% vs 13.1%, P = 0.18), while the incidence of cardiac-related death was significantly lower in the successfully treated group (4.5% vs 8.4%, P = 0.03). However, after adjustment for confounding variables, successful treatment was not associated with either reduced total mortality (hazard ratio 0.93, 95%CI: 0.64 to 1.37, P = 0.69) or cardiac mortality (HR = 0.71, 95%CI: 0.44-1.16, P = 0.16). The only benefit associated with success in the treatment of CTO was a lower rate of surgical revascularization.

Table 5 Baseline characteristics of clinical and angiographic variables in studies included on Joyal meta-analisis[42].
Ref.Age (yr)
Male sex (%)
Multivessel disease(%)
Diabetes (%)
LVEF (%)
NYHA class 3-4 (%)
Renal dysfunction(%)
Occlusion length (mm)
Calcified vessel (%)
Ischemic burden
Finci et al[42], 199055 ± 1155 ± 1293882423n/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/d
Warren et al[43], 1990545553474852n/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/d
Ivanhoe et al[44], 199255 ± 1056 ± 1181823054 (0.0001)101555 ± 1056 ± 1133n/dn/dn/dn/dn/dn/dn/dn/d
Angioï[45], 200055 ± 1056 ± 1152883745101159 ± 1459 ± 14n/dn/dn/dn/dn/dn/dn/dn/dn/dn/d
Noguchi et al[46], 200061 ± 961 ± 1178804767 (0.01)263256 ± 1254 ± 9n/dn/dn/dn/d11.3 ± 8.314.1 ± 8.1 (< 0.05)3756 (< 0.01)n/dn/d
Suero et al[47], 200160 ± 1161 ± 1278807382 (0.001)212051 ± 1452 ± 14n/dn/d8.27.1n/dn/dn/dn/dn/dn/d
Olivari et al[48], 200358 ± 1059 ± 1186854560 (0.014)172056 ± 1056 ± 1097n/dn/dn/dn/dn/dn/dn/dn/d
Hoye et al[49], 200560 ± 1161 ± 1074725467(0.03)129.1n/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/d
Drozd et al[50], 200657 ± 1058 ± 10818046531111n/dn/d14.418 (NYHA ≥ 2)n/dn/dn/dn/dn/dn/dn/dn/d
Aziz et al[51], 2007595976815040 (0.006)149535312.
Prasad et al[52], 200763 ± 1164 ± 1176757074n/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/dn/d
Valenti et al[53], 200867 ± 1170 ± 1181838587242142 ± 1341 ± 14n/dn/dn/dn/d25 (15-52.5)28 (21-47.5)n/dn/dn/dn/d
de Labriolle et al[54], 200861 ± 1264 ± 1072874566 (0.002)1940.5 (0.005)50 ± 1248 ± 15n/dn/d9.16.3n/dn/dn/dn/dn/dn/d

One group of patients deserves special consideration. These are patients with acute coronary syndrome in which the culprit artery is treated initially, but who have another chronically occluded artery which is considered for recanalization in a second procedure. This argument is based on the fact that these patients have a worse prognosis than patients with acute coronary syndrome with no CTO[56]. The EXPLORE clinical trial, which randomizes patients with CTO with no culprit artery after an acute coronary artery syndrome on revascularization treatment within 7 d of the ischemic event vs medical treatment[57] attempts to clarify this important issue, which is currently performed frequently without any scientific evidence.


Treatment of CTO has emerged in recent years as a result of a revolution in medical equipment that enables these patients to be managed with success rates well above those of a few years ago. However, there is an urgent need for randomized studies to support this therapy as it is not risk-free, and is very expensive. Pending randomized studies, patients should be selected very carefully, especially if they are asymptomatic or very few symptoms, and the benefits obtained in terms of complications during the procedure, the quality of life obtained and further ischemic events avoided should be evaluated systematically.


P- Reviewer: Avanzas P, Kettering K S- Editor: Wen LL L- Editor: A E- Editor: Wu HL

1.  Montalescot G, Sechtem U, Achenbach S, Andreotti F, Arden C, Budaj A, Bugiardini R, Crea F, Cuisset T, Di Mario C. 2013 ESC guidelines on the management of stable coronary artery disease: the Task Force on the management of stable coronary artery disease of the European Society of Cardiology. Eur Heart J. 2013;34:2949-3003.  [PubMed]  [DOI]
2.  Kahn JK. Angiographic suitability for catheter revascularization of total coronary occlusions in patients from a community hospital setting. Am Heart J. 1993;126:561-564.  [PubMed]  [DOI]
3.  Christofferson RD, Lehmann KG, Martin GV, Every N, Caldwell JH, Kapadia SR. Effect of chronic total coronary occlusion on treatment strategy. Am J Cardiol. 2005;95:1088-1091.  [PubMed]  [DOI]
4.  Srinivas VS, Brooks MM, Detre KM, King SB, Jacobs AK, Johnston J, Williams DO. Contemporary percutaneous coronary intervention versus balloon angioplasty for multivessel coronary artery disease: a comparison of the National Heart, Lung and Blood Institute Dynamic Registry and the Bypass Angioplasty Revascularization Investigation (BARI) study. Circulation. 2002;106:1627-1633.  [PubMed]  [DOI]
5.  Yamamoto E, Natsuaki M, Morimoto T, Furukawa Y, Nakagawa Y, Ono K, Mitsudo K, Nobuyoshi M, Doi O, Tamura T. Long-term outcomes after percutaneous coronary intervention for chronic total occlusion (from the CREDO-Kyoto registry cohort-2). Am J Cardiol. 2013;112:767-774.  [PubMed]  [DOI]
6.  Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, Gannot S, Samuel M, Weisbrod M, Bierstone D. Current perspectives on coronary chronic total occlusions: the Canadian Multicenter Chronic Total Occlusions Registry. J Am Coll Cardiol. 2012;59:991-997.  [PubMed]  [DOI]
7.  Jeroudi OM, Alomar ME, Michael TT, Sabbagh AE, Patel VG, Mogabgab O, Fuh E, Sherbet D, Lo N, Roesle M. Prevalence and management of coronary chronic total occlusions in a tertiary veterans affairs hospital. Catheter Cardiovasc Interv. 2013;Oct 19; Epub ahead of print.  [PubMed]  [DOI]
8.  Jeroudi OM, Alomar ME, Michael TT, Sabbagh AE, Patel VG, Mogabgab O, Fuh E, Sherbet D, Lo N, Roesle M, Rangan BV, Abdullah S, Hastings JL, Grodin J, Banerjee S, Brilakis ES, UT Southwestern Medical Ctr and VA North Texas Health Care System, Dallas, TX. Clinical Profile of Patients With Coronary Chronic Total Occlusions at a Tertiary Veterans Affairs Medical Center Session Clinical and Hospital-Based Observational Studies (Abstract). Poster Session AHA. 2013;9678.  [PubMed]  [DOI]
9.  Wijns W, Kolh P, Danchin N, Di Mario C, Falk V, Folliguet T, Garg S, Huber K, James S, Knuuti J. Guidelines on myocardial revascularization. Eur Heart J. 2010;31:2501-2555.  [PubMed]  [DOI]
10.  Hillis LD, Smith PK, Anderson JL, Bittl JA, Bridges CR, Byrne JG, Cigarroa JE, DiSesa VJ, Hiratzka LF, Hutter AM. 2011 ACCF/AHA guideline for coronary artery bypass graft surgery: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Thorac Cardiovasc Surg. 2012;143:4-34.  [PubMed]  [DOI]
11.  Levine GN, Bates ER, Blankenship JC, Bailey SR, Bittl JA, Cercek B, Chambers CE, Ellis SG, Guyton RA, Hollenberg SM. 2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions. Circulation. 2011;124:2574-2609.  [PubMed]  [DOI]
12.  Fihn SD, Gardin JM, Abrams J, Berra K, Blankenship JC, Dallas AP, Douglas PS, Foody JM, Gerber TC, Hinderliter AL. 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;126:e354-e471.  [PubMed]  [DOI]
13.  Patel MR, Dehmer GJ, Hirshfeld JW, Smith PK, Spertus JA. ACCF/SCAI/STS/AATS/AHA/ASNC/HFSA/SCCT 2012 Appropriate use criteria for coronary revascularization focused update: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, American Society of Nuclear Cardiology, and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol. 2012;59:857-881.  [PubMed]  [DOI]
14.  Jaguszewski M, Targonski R, Fijalkowski M, Masiewicz E, Dubaniewicz W, Templin C, Koprowski A, Ciecwierz D, Nallamothu BK, Rynkiewicz A. Recanalization of isolated chronic total occlusions in patients with stable angina. Int J Cardiol. 2013;167:1542-1546.  [PubMed]  [DOI]
15.  Grantham JA, Jones PG, Cannon L, Spertus JA. Quantifying the early health status benefits of successful chronic total occlusion recanalization: Results from the FlowCardia’s Approach to Chronic Total Occlusion Recanalization (FACTOR) Trial. Circ Cardiovasc Qual Outcomes. 2010;3:284-290.  [PubMed]  [DOI]
16.  Safley DM, Grantham JA, Hatch J, Jones PG, Spertus JA. Quality of life benefits of percutaneous coronary intervention for chronic occlusions. Catheter Cardiovasc Interv. 2013;Nov 21; Epub ahead of print.  [PubMed]  [DOI]
17.  Sianos G, Werner GS, Galassi AR, Papafaklis MI, Escaned J, Hildick-Smith D, Christiansen EH, Gershlick A, Carlino M, Karlas A. Recanalisation of chronic total coronary occlusions: 2012 consensus document from the EuroCTO club. EuroIntervention. 2012;8:139-145.  [PubMed]  [DOI]
18.  Pfisterer M. Long-term outcome in elderly patients with chronic angina managed invasively versus by optimized medical therapy: four-year follow-up of the randomized Trial of Invasive versus Medical therapy in Elderly patients (TIME). Circulation. 2004;110:1213-1218.  [PubMed]  [DOI]
19.  Erne P, Schoenenberger AW, Burckhardt D, Zuber M, Kiowski W, Buser PT, Dubach P, Resink TJ, Pfisterer M. Effects of percutaneous coronary interventions in silent ischemia after myocardial infarction: the SWISSI II randomized controlled trial. JAMA. 2007;297:1985-1991.  [PubMed]  [DOI]
20.  Boden WE, O’Rourke RA, Teo KK, Hartigan PM, Maron DJ, Kostuk WJ, Knudtson M, Dada M, Casperson P, Harris CL. Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med. 2007;356:1503-1516.  [PubMed]  [DOI]
21.  Frye RL, August P, Brooks MM, Hardison RM, Kelsey SF, MacGregor JM, Orchard TJ, Chaitman BR, Genuth SM, Goldberg SH. A randomized trial of therapies for type 2 diabetes and coronary artery disease. BARI 2D Study Group. N Engl J Med. 2009;360:2503-2515.  [PubMed]  [DOI]
22.  Weintraub WS, Spertus JA, Kolm P, Maron DJ, Zhang Z, Jurkovitz C, Zhang W, Hartigan PM, Lewis C, Veledar E. Effect of PCI on quality of life in patients with stable coronary disease. N Engl J Med. 2008;359:677-687.  [PubMed]  [DOI]
23.  Shaw LJ, Berman DS, Maron DJ, Mancini GB, Hayes SW, Hartigan PM, Weintraub WS, O’Rourke RA, Dada M, Spertus JA. Optimal medical therapy with or without percutaneous coronary intervention to reduce ischemic burden: results from the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial nuclear substudy. Circulation. 2008;117:1283-1291.  [PubMed]  [DOI]
24.  Shaw LJ, Weintraub WS, Maron DJ, Hartigan PM, Hachamovitch R, Min JK, Dada M, Mancini GB, Hayes SW, O’Rourke RA. Baseline stress myocardial perfusion imaging results and outcomes in patients with stable ischemic heart disease randomized to optimal medical therapy with or without percutaneous coronary intervention. Am Heart J. 2012;164:243-250.  [PubMed]  [DOI]
25.  Stergiopoulos K, Boden WE, Hartigan P, Möbius-Winkler S, Hambrecht R, Hueb W, Hardison RM, Abbott JD, Brown DL. Percutaneous coronary intervention outcomes in patients with stable obstructive coronary artery disease and myocardial ischemia: a collaborative meta-analysis of contemporary randomized clinical trials. JAMA Intern Med. 2014;174:232-240.  [PubMed]  [DOI]
26.  Califf RM. The trouble with ischemia. Am Heart J. 2012;164:133-134.  [PubMed]  [DOI]
27.   Available from:  [PubMed]  [DOI]
28.   Available from:  [PubMed]  [DOI]
29.   Available from: CTO&rank=1.  [PubMed]  [DOI]
30.  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. Eur Heart J. 1998;19:273-281.  [PubMed]  [DOI]
31.  Werner GS, Surber R, Kuethe F, Emig U, Schwarz G, Bahrmann P, Figulla HR. Collaterals and the recovery of left ventricular function after recanalization of a chronic total coronary occlusion. Am Heart J. 2005;149:129-137.  [PubMed]  [DOI]
32.  Kirschbaum SW, Baks T, van den Ent M, Sianos G, Krestin GP, Serruys PW, de Feyter PJ, van Geuns RJ. Evaluation of left ventricular function three years after percutaneous recanalization of chronic total coronary occlusions. Am J Cardiol. 2008;101:179-185.  [PubMed]  [DOI]
33.  Velazquez EJ, Lee KL, Deja MA, Jain A, Sopko G, Marchenko A, Ali IS, Pohost G, Gradinac S, Abraham WT. Coronary-artery bypass surgery in patients with left ventricular dysfunction. N Engl J Med. 2011;364:1607-1616.  [PubMed]  [DOI]
34.  Bonow RO, Maurer G, Lee KL, Holly TA, Binkley PF, Desvigne-Nickens P, Drozdz J, Farsky PS, Feldman AM, Doenst T. Myocardial viability and survival in ischemic left ventricular dysfunction. N Engl J Med. 2011;364:1617-1625.  [PubMed]  [DOI]
35.  Mehran R, Claessen BE, Godino C, Dangas GD, Obunai K, Kanwal S, Carlino M, Henriques JP, Di Mario C, Kim YH. Long-term outcome of percutaneous coronary intervention for chronic total occlusions. JACC Cardiovasc Interv. 2011;4:952-961.  [PubMed]  [DOI]
36.  Fujimoto Y, Iwata Y, Yoshio . Coronary Perforation During Percutaneous Coronary Intervention in Current Era Session The Spectrum of PCI: From Acute Coronary Syndromes to Chronic Occlusions. Abstract Poster Session AHA. 2013;11429.  [PubMed]  [DOI]
37.  Kimura M, Toyohashi Heart Ctr, Toyohashi, Japan. Difference in the Frequency of Procedural Complications Related to Percutaneous Coronary Intervention of Chronic Total Occlusions Between via Retrograde Approach vs. via Antegrade Approach. - A Toyohashi Experience- Session The Full Spectrum of Interventional Cardiology Procedures. Abstract Poster Session AHA. 2013;15305.  [PubMed]  [DOI]
38.  Movahed MR. Very high perforation rate in patients undergoing unsuccessful percutaneous coronary interventions of chronic total occlusions could explain worse outcome in these patients and not chronically occluded artery. JACC Cardiovasc Interv. 2012;5:116; author reply 117-118.  [PubMed]  [DOI]
39.  Badr S, Dvir D, Waksman R. Chronic total occlusion recanalization: a call for a randomized trial. JACC Cardiovasc Interv. 2012;5:116-17; author reply 116-117;.  [PubMed]  [DOI]
40.  Hannan EL, Racz M, Holmes DR, King SB, 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;113:2406-2412.  [PubMed]  [DOI]
41.  Joyal D, Bertrand OF, Rinfret S, Shimony A, Eisenberg MJ. Meta-analysis of ten trials on the effectiveness of the radial versus the femoral approach in primary percutaneous coronary intervention. Am J Cardiol. 2012;109:813-818.  [PubMed]  [DOI]
42.  Finci L, Meier B, Favre J, Righetti A, Rutishauser W. Long-term results of successful and failed angioplasty for chronic total coronary arterial occlusion. Am J Cardiol. 1990;66:660-662.  [PubMed]  [DOI]
43.  Warren RJ, Black AJ, Valentine PA, Manolas EG, Hunt D. Coronary angioplasty for chronic total occlusion reduces the need for subsequent coronary bypass surgery. Am Heart J. 1990;120:270-274.  [PubMed]  [DOI]
44.  Ivanhoe RJ, Weintraub WS, Douglas JS, Lembo NJ, Furman M, Gershony G, Cohen CL, King SB. Percutaneous transluminal coronary angioplasty of chronic total occlusions. Primary success, restenosis, and long-term clinical follow-up. Circulation. 1992;85:106-115.  [PubMed]  [DOI]
45.  Angioï M, Danchin N, Juillière Y, Feldmann L, Berder V, Cuillière M, Buffet P, Anconina J, Cherrier F. Is percutaneous transluminal coronary angioplasty in chronic total coronary occlusion justified? Long term results in a series of 201 patients. Arch Mal Coeur Vaiss. 1995;88:1383-1389.  [PubMed]  [DOI]
46.  Noguchi T, Miyazaki MD S, Morii I, Daikoku S, Goto Y, Nonogi H. Percutaneous transluminal coronary angioplasty of chronic total occlusions. Determinants of primary success and long-term clinical outcome. Catheter Cardiovasc Interv. 2000;49:258-264.  [PubMed]  [DOI]
47.  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. J Am Coll Cardiol. 2001;38:409-414.  [PubMed]  [DOI]
48.  Olivari Z, Rubartelli P, Piscione F, Ettori F, Fontanelli A, Salemme L, Giachero C, Di Mario C, Gabrielli G, Spedicato L. Immediate results and one-year clinical outcome after percutaneous coronary interventions in chronic total occlusions: data from a multicenter, prospective, observational study (TOAST-GISE). J Am Coll Cardiol. 2003;41:1672-1678.  [PubMed]  [DOI]
49.  Hoye A, van Domburg RT, Sonnenschein K, Serruys PW. Percutaneous coronary intervention for chronic total occlusions: the Thoraxcenter experience 1992-2002. Eur Heart J. 2005;26:2630-2636.  [PubMed]  [DOI]
50.  Drozd J, Wójcik J, Opalińska E, Zapolski T, Widomska-Czekajska T. Percutaneous angioplasty of chronically occluded coronary arteries: long-term clinical follow-up. Kardiol Pol. 2006;64:667-73; discussion 674.  [PubMed]  [DOI]
51.  Aziz S, Stables RH, Grayson AD, Perry RA, Ramsdale DR. Percutaneous coronary intervention for chronic total occlusions: improved survival for patients with successful revascularization compared to a failed procedure. Catheter Cardiovasc Interv. 2007;70:15-20.  [PubMed]  [DOI]
52.  Prasad A, Rihal CS, Lennon RJ, Wiste HJ, Singh M, Holmes DR. Trends in outcomes after percutaneous coronary intervention for chronic total occlusions: a 25-year experience from the Mayo Clinic. J Am Coll Cardiol. 2007;49:1611-1618.  [PubMed]  [DOI]
53.  Valenti R, Migliorini A, Signorini U, Vergara R, Parodi G, Carrabba N, Cerisano G, Antoniucci D. Impact of complete revascularization with percutaneous coronary intervention on survival in patients with at least one chronic total occlusion. Eur Heart J. 2008;29:2336-2342.  [PubMed]  [DOI]
54.  de Labriolle A, Bonello L, Roy P, Lemesle G, Steinberg DH, Xue Z, Kaneshige K, Suddath WO, Satler LF, Kent KM. Comparison of safety, efficacy, and outcome of successful versus unsuccessful percutaneous coronary intervention in “true” chronic total occlusions. Am J Cardiol. 2008;102:1175-1181.  [PubMed]  [DOI]
55.  Lee SW, Lee JY, Park DW, Kim YH, Yun SC, Kim WJ, Suh J, Cho YH, Lee NH, Kang SJ. Long-term clinical outcomes of successful versus unsuccessful revascularization with drug-eluting stents for true chronic total occlusion. Catheter Cardiovasc Interv. 2011;78:346-353.  [PubMed]  [DOI]
56.  Claessen BE, Dangas GD, Weisz G, Witzenbichler B, Guagliumi G, Möckel M, Brener SJ, Xu K, Henriques JP, Mehran R. Prognostic impact of a chronic total occlusion in a non-infarct-related artery in patients with ST-segment elevation myocardial infarction: 3-year results from the HORIZONS-AMI trial. Eur Heart J. 2012;33:768-775.  [PubMed]  [DOI]
57.  van der Schaaf RJ, Claessen BE, Hoebers LP, Verouden NJ, Koolen JJ, Suttorp MJ, Barbato E, Bax M, Strauss BH, Olivecrona GK. Rationale and design of EXPLORE: a randomized, prospective, multicenter trial investigating the impact of recanalization of a chronic total occlusion on left ventricular function in patients after primary percutaneous coronary intervention for acute ST-elevation myocardial infarction. Trials. 2010;11:89.  [PubMed]  [DOI]