PCI for Chronic Total Occlusion: Guidelines, Benefits, Myths

Educational Objectives

After completing the activity, the clinician will be better able to summarize the evidence base for using percutaneous coronary intervention (PCI) to treat a chronic total occlusion (CTO) of a coronary artery and discuss myths that affect the use of CTO PCI.

Summary

Interviewer: Roger Blumenthal, MD, FACC

After completing the activity, the clinician will be better able to summarize the evidence base for using percutaneous coronary intervention (PCI) for a coronary chronic total occlusion (CTO) and myths that impact the use of CTO PCI.

Take-home Messages:

• There is a paucity of data on how best to determine the need for revascularization in patients with a coronary artery chronic total occlusion (CTO).
• Percutaneous coronary intervention (PCI) for CTO has been evolving, with constant improvement of equipment and techniques. Consequently, CTO PCI is being performed with high success and acceptable complication rates in various experienced centers.
• There are a number of myths about CTOs that continue to hamper patient care and access to CTO PCI.

Up to 20% of all coronary angiography reveals chronic total occlusions. Yet the lack of robust type A evidence with hard clinical outcomes supporting benefits of CTO revascularization has hampered efforts to develop specific guideline recommendations. Current U.S. guidelines do not distinguish between CTO and non-CTO PCI, but recent European guidelines have done so.

In trying to assess the value of CTO revascularization, studies have shown significant improvement in frequency of angina and quality of life following CTO PCI compared with optimal medical therapy alone. However, rates of major adverse cardiac event (MACE) typically have been comparable between the 2 groups.

A systematic review of 25 observational studies showed that at median follow-up of 3 years, successful CTO PCI was associated with improved clinical outcomes — but this was compared to failed revascularization.¹ The improved outcomes included overall survival, angina burden, and the requirement for bypass surgery.

A more recent analysis by Jaffer and colleagues described the outcomes of 3,122 CTO PCI procedures performed in 3,055 patients at 20 dedicated centers in the United States, Europe, and Russia between 2012 and 2017.²

Acute technical and procedural success rates were high — 87% and 85%, respectively — and the rate of major in-hospital complications (3%) was acceptable. Achieving success rates this high was due, in large part, to facility with the 3-pronged percutaneous treatment algorithm for crossing coronary CTOs: antegrade wire escalation, antegrade dissection and re-entry, and retrograde techniques, utilized in 46%, 19%, and 24% of cases, respectively. Operators needed real-time flexibility given that the initially selected CTO crossing strategy was successful in only 55% of cases, and more than one crossing strategy was required in 40.9% of patients.

In an accompanying commentary, Gregg Stone, MD (Mount Sinai, New York, NY), wrote, “Acknowledging the present report as the magnum opus of CTO PCI technique, the focus now needs to shift to 1) appropriate patient selection and demonstration of clinical utility; and 2) ensuring that most patients with CTOs who can derive benefit are provided access to expert care.”³

Guidelines

Recent guidelines from the European Society of Cardiology note that the decision to attempt CTO PCI should be considered against the risk of greater contrast volume, longer fluoroscopy time, and higher MACE rates in comparison with patients not undergoing CTO PCI.⁴ Still, the guideline authors note that, broadly speaking, the treatment of CTOs may be considered analogous to the treatment of non-CTO lesions.

This differs from past iterations of the guidelines. The ESC guidelines acknowledge recent developments in catheter and wire technology, as well as increasing operator expertise with both antegrade and retrograde approaches, plus wire escalation and dissection/re-entry techniques, that all have translated into increasing success rates of CTO PCI with low rates of MACE.

Of course, as suggested by Dr. Stone, success rates are strongly dependent on operator skills, experience with specific procedural techniques, and the availability of dedicated equipment. He noted a need for more widespread training to increase the number of expert operators and expand their geographic reach, as well as continuing efforts to improve PCI equipment and techniques to enhance success rates (and simplicity) for nonexpert operators.

Myths About CTO

Finally, at ACC.19, Farouc Jaffer, MD, PhD (Massachusetts General Hospital, Boston), acknowledged a need to dump myths about CTO PCI that hamper patient care.

Myth #1: Great collaterals mean the patient is fine. That was proved demonstratively false in a study showing that the myocardium supplied by a CTO is a persistently ischemic zone. Sachdeva et al. evaluated the presence and severity of ischemia using fractional flow reserve of the myocardium supplied by a CTO and compared the results with a non-CTO control group.⁵ Even with regional left ventricular impairment and/or excellent collateral development, there was an ischemic zone that can be normalized by PCI, with outcomes comparable to those for non-CTO patients.

Myth #2: The CTO territory is dead. Dr. Jaffer argues that ischemia present in most CTO patients indicates viable myocardium.

Myth #3: My patient has dyspnea but not angina, so does not need revascularization. Qintar et al. have shown that dyspnea is a common symptom among patients (81%) undergoing CTO PCI and that it improved significantly in 70% of study participants with successful PCI.⁶

Dr. Jaffer went on to consider a few other problems. First, he said, CTOs are common and not routinely treated by PCI or coronary artery bypass surgery. Second, when revascularization of a CTO does occur, incomplete revascularization is common and is a dangerous marker (of increased MACE risk). Third, he cited increasing surgical turndown of these high-risk patients that favors undertreatment. Consequently, Dr. Jaffer noted, interventionalists are more likely to fix non-CTOs, even when the area of blockage is not ischemic.

In summary, Dr. Jaffer noted that CTO PCI alleviates ischemic symptoms resistant to medical therapy. It is indicated in the presence of significant ischemia or significant ventricular arrhythmia, and possibly when there is demonstrated viability in the setting of left ventricular dysfunction. Undertreatment of CTO is a far bigger issue than overtreatment. Having more centers with CTO PCI programs will enable the best care for patients with multivessel or symptom-limited coronary artery disease.

References:

1. Christakopoulos GE, Christopoulos G, Carlino M, et al. Meta-analysis of clinical outcomes of patients who underwent percutaneous coronary interventions for chronic total occlusions. Am J Cardiol 2015;115:1367-75.
2. Tajti P, Karmpaliotis D, Alaswad K, et al. The Hybrid Approach to Chronic Total Occlusion Percutaneous Coronary Intervention: Update from the PROGRESS CTO Registry. JACC Cardiovasc Interv 2018;11:1325-35. http://interventions.onlinejacc.org/content/11/14/1325
3. Stone GW. Percutaneous Coronary Intervention of Chronic Total Occlusions: Conquering the Final Frontier. JACC Cardiovasc Interv 2018;11:1336-9. http://interventions.onlinejacc.org/content/11/14/1336
4. Neumann FJ, Sousa-Uva M, Ahlsson A, et al. 2018 ESC/EACTS Guidelines on myocardial revascularization. Eur Heart J 2019;40:87-165.
5. Sachdeva R, Agrawal M, Flynn SE, Werner GS, Uretsky BF. The myocardium supplied by a chronic total occlusion is a persistently ischemic zone. Catheter Cardiovasc Interv 2014;83:9-16.
6. Qintar M, Grantham JA, Sapontis J, et al. Dyspnea Among Patients with Chronic Total Occlusions Undergoing Percutaneous Coronary Intervention: Prevalence and Predictors of Improvement. Circ Cardiovasc Qual Outcomes 2017 Dec;10(12). doi: 10.1161/CIRCOUTCOMES.117.003665.

Readings

Disclosures

Farouc A. Jaffer, MD, PhD, FACC, Boston, MA

Abbott (C), Acrostak Int (C); Boston Scientific Corporation (C); Koninklijke Philips N V (C); Canon USA (G); Siemens AG (G)

Interviewer: Roger Blumenthal, MD, FACC

This author has nothing to disclose.

Acknowledgements

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

AC511117

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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