Making the Best of a Challenging Situation

Corresponding Author

The prevalence of left main (LM) chronic total occlusion (CTO) among patients undergoing cardiac catheterization is ∼0.04% to 0.06%.¹ Among stable ischemic heart disease patients with obstructive LM disease, revascularization with coronary artery bypass grafting (CABG) offers survival benefit over medical therapy; and CABG is preferred over percutaneous coronary intervention (PCI) in LM disease with a high SYNTAX score.^2,3 Thus, in the vast majority of LM CTO, CABG remains the preferred mode of revascularization. For patients who are not surgical candidates, had prior CABG, or refuse surgery, LM CTO PCI may be considered after careful discussion of risks and benefits. The success rate of LM CTO PCI, constituting 0.45% of 4,436 CTO PCIs from the PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) registry, was 85% with the most successful crossing strategy being anterior wire escalation (50%) followed by retrograde (30%) and antegrade dissection/re-entry (10%).⁴ Although the success rate of LM CTO PCI in this registry is similar to that of overall CTO PCI, it must be emphasized that this data was collected from high-volume CTO centers with dedicated and experienced CTO operators and should not be extrapolated to all operators and centers.

In this issue of JACC: Case Reports, Chandra et al⁵ report the case of a 57-year-old diabetic man with Canadian Cardiovascular Society class III angina despite maximal medical therapy with normal left ventricular ejection fraction who was found to have LM CTO. After diagnostic angiography, the patient was transferred to the intensive care unit and the cardiothoracic surgery department was consulted regarding CABG. It is stated that the patient refused CABG due to timing issues, and a decision was made to proceed with LM CTO PCI. The LM CTO was crossed antegrade with a Gaia II coronary guidewire into the left anterior descending artery (LAD) and this segment was ballooned, but equipment (and wire position) was lost. Repeat attempts to re-cross failed, and the patient developed chest pain and became unstable. The operators contemplated between urgent CABG, reattempting further wiring of the LAD (including retrograde options), or attempting LM – left circumflex (LCx) CTO PCI. Ultimately, LM – LCx revascularization was successful with placement of a drug-eluting stent jailing the LAD. The patient was discharged home and brought back 8 weeks later for CTO PCI of the LAD. The lesion was crossed antegrade and ultimately rotational atherectomy of the calcified LAD lesion was performed, with a stent placed in the LM to LAD followed by kissing balloon inflations and LM dilation with a larger balloon. The patient tolerated the procedure well and was discharged home. A follow-up left heart catheterization (LHC) at 6 months showed patent LAD and LCx stents, and optical coherence tomography was performed at that time demonstrating apposed stents; however, measurements were not provided.

Chandra et al⁵ must be congratulated for successful PCI of a challenging LM CTO. Several points about this case are worth a discussion (Figure 1). This patient had clear indications for LM revascularization, both with respect to symptoms as well as prognosis.³ For stable patients, it is essential to take the patient off the table after diagnostic angiography to have a heart team discussion with shared decision-making regarding management options. The 2021 American College of Cardiology/American Heart Association revascularization guidelines recommend a heart team approach in making revascularization decisions for patients with complex coronary artery disease.³ This practice is more than theoretical, and its implementation has been described previously.^6,7 In this particular case, LM CTO in a diabetic individual is among the most complex anatomies we confront and, as such, CABG would strongly be preferred. In some cases, especially if CABG is declined due to “delay,” all efforts should be made to ensure that what the team suggests as the best treatment option can be offered to the patient. CTO PCI has a lower success rate and higher complication rates as compared with non-CTO PCI.⁸ However, specific CTO-based expertise and greater CTO volumes can increase the chances of CTO PCI success.⁹ Operators performing these procedures must be adept at various techniques of CTO PCI as well as the management of complications. The step-wise approach from Chandra et al⁵ in treating the LM CTO is notable. As such, we are sure that Chandra et al⁵ deliberated about stent implantation from the LM into the LCx across the ostium of the LAD (jailing the LAD) at the conclusion of the first procedure. Nonetheless, they were successful in recanalizing the LAD on the subsequent procedure and even performing rotablation through the side struts of the LM-LCx stent, a maneuver that requires additional care and expertise.

Figure 1.

LM CTO Prevalence and Revascularization

CABG = coronary artery bypass graft; CTO = chronic total occlusion; LM = left main; PCI = percutaneous coronary intervention; SYNTAX = Synergy between percutaneous coronary intervention with Taxus and coronary artery bypass surgery.

However, we would be remiss if we did not mention the critical role of intravascular imaging for cases such as this. The use of intracoronary imaging has been shown to improve outcomes in complex PCI including CTO, complex lesions, and LM disease.10, 11, 12 Especially in a diabetic patient with a LM CTO, all efforts must be made to optimize stent expansion to improve long-term outcomes.¹³ There should be concerns with the reported sizes of the stents within this report; typically, LM dimensions require at a minimum a 4.0-mm balloon for proximal optimization, and 3.5-mm or greater diameter stents in each of the respective branches. Although Chandra et al⁵ did not use intracoronary imaging during the LM CTO PCI, they report a 6-month follow-up left heart catheterization with OCT imaging; it is unclear whether minimal stent area was measured.

In conclusion, it is to be reiterated that LM CTO is rare, and LM CTO PCI is a complex procedure that must be performed by experienced operators in well-equipped catheterization labs to achieve technical success with good outcomes. In the end, “it is complex only until solved” and long-term outcomes for this patient remain to be seen.

Funding Support and Author Disclosures

Dr Velagapudi has received Speakers Bureau/speaking fees from Abiomed, Medtronic, Opsens, and Shockwave Medical; has been on advisory boards with Abiomed and Sanofi; and has received travel expenses/meals from Abbott Vascular, Boston Scientific, Chiesi, Medtronic, Phillips, and Zoll. Dr Kirtane has received institutional funding to Columbia University and/or Cardiovascular Research Foundation from Medtronic, Boston Scientific, Abbott Vascular, Amgen, CSI, Philips, ReCor Medical, Neurotronic, Biotronik, Chiesi, Bolt Medical, Magenta Medical, Canon, SoniVie, Shockwave Medical, and Merck; in addition to research grants, he has also received institutional funding includes fees paid to Columbia University and/or Cardiovascular Research Foundation for consulting and/or speaking engagements in which Dr. Kirtane controlled the content; has received consulting fees from IMDS; and has received travel expenses/meals from Medtronic, Boston Scientific, Abbott Vascular, CSI, Siemens, Philips, ReCor Medical, Chiesi, OpSens, Zoll, and Regeneron.