Commentary to "CTO PCI: Complexity Begets Complexity": If At First You Don’t Succeed… A Tour-de-Force in Complex CTO Intervention

“Success is (the ability to move) from failure to failure, with no loss of enthusiasm.”     

                — Winston Churchill

In this issue, Najar et al have reported a truly heroic effort of grit, skill, and determination in tackling a complex chronic total occlusion (CTO) percutaneous coronary intervention (PCI) of the right coronary artery.¹ Although there are potential issues in the case related to more detailed reporting of symptom relief, the overall intervention is impressive, given the challenges. 

In our evolving world of limited resources but increasing complexity, the author/operators in this case are to be congratulated on their persistence and skill in snatching victory from the jaws of defeat, repeatedly, over the course of the case. The final outcome is a result that all complex CTO operators and interventional cardiologists, in general, should be seeking for their patients; an excellent angiographic and clinical result, without significant complications. 

It is also becoming increasingly evident that we need to teach more of our fellows and partners complex skills in CTO PCI. Alternatively, both invasive and non-invasive cardiologists need to recognize the importance of hybrid CTO techniques to achieve complete revascularization, and to refer patients to well-trained, dedicated CTO operators. The days of single-vessel injection, rather than dual injection, and anterograde wire escalation as the only approach for CTOs should become of historical interest. The hybrid algorithm approach has significantly improved success rates in CTO PCI.^2-5

As the operators here have demonstrated, CTO intervention is not always easy, and often requires a dozen or more changes in plans and equipment. In this particular case, I count at least 32 steps in dealing with issues, changing the game plan, and ultimately achieving a successful result. Being a complex, hybrid algorithm CTO operator is not for everyone, and is not “easy.”

The “easy” path is what we see every day. The cardiology community still has some misguided concepts that include the following: 1) With medical treatment, CTO of a major epicardial vessel is a very low risk situation^3-6; 2) There is no evidence of clinical benefit, even in carefully selected, ischemic and symptomatic patients;^3-6 3) Medical therapy is appropriate and sufficient in ischemic/symptomatic CTO patients; and 4) When revascularization is needed, coronary artery bypass graft surgery (CABG) is preferred and superior.

Despite a lack of randomized, clinical data demonstrating a mortality benefit for CTO intervention versus medical therapy, each of the “concepts” above should be challenged. 

First, ischemia from a CTO, even with collaterals, and the failure to achieve complete revascularization is not benign.^3-7 The failure to successfully open a CTO is definitely associated with worsened clinical outcome, including persistence of symptoms on (expensive) triple-drug medical therapy, and with credible evidence of increased mortality.^3-7 Critics will point to a recent, randomized study, which failed to demonstrate a mortality benefit.⁸ This is an important study, but may not provide the definitive answer to the mortality issue. The full discussion of this is beyond the scope of this editorial.

Although somewhat anecdotal, the improvement in symptoms and quality of life in appropriately selected, successfully treated CTO patients is as dramatic as one may see with any surgical intervention. Case selection is critical. Since mortality benefit of CTO intervention remains uncertain, only patients with relatively high predicted anatomical success rates, with documented ischemia, and with lifestyle-limiting symptoms on anti-anginal medications should be considered as appropriate candidates. In this case, the patient was very symptomatic (Canadian Class 3) despite triple-drug therapy that included ranolazine.

Bypass surgery is a reasonable choice in patients with multivessel disease that includes a CTO. However, it is important to note that prospective studies suggest that nearly one-third of patients treated with CABG do not get a graft to the CTO vessel, presumably because the surgeons often think that the target is not adequate. In addition, recent studies suggest that the patency of saphenous vein grafts, and even the left internal mammary artery (LIMA) graft, are not as good as many think, with up to 40-50% of SVGs occluded at one year after CABG.⁹ 

CTO operators know that coronary angiography is often misleading and a distal vessel that looks “small” and “not bypassable,” is often large when opened with CTO techniques after stenting, and with a touch of intracoronary nitroglycerin. With best techniques, in best hands, CTO success rates are now in the 80-90% range, which may be a more reliable means to revascularize a CTO than referring the patient for CABG.^3-7 Assuming the remaining disease burden is easily managed using conventional PCI techniques, PCI with CTO intervention should be considered as a viable, if not preferred approach, compared to CABG. If the CTO cannot be successfully treated, CABG is an excellent option.

Finally, the current case report demonstrates a few other interventions that are important for interventional cardiologists, including the multi-step approach to profound radial artery spasm, and the use of the DyeVert system (Osprey Medical) to substantially reduce contrast use and the risk of contrast-induced nephropathy (CIN) in complex cases.  This attention to contrast use allowed the case to be done without any evidence of CIN.

In summary, we can all learn a lot from the case study reported. Although some may be critical of the operators for excessive contrast and radiation dose, it is likely that the patient did significantly benefit from this intervention. Hopefully the adoption of CTO intervention will increase, and carefully performed and randomized studies will ultimately demonstrate the value of CTO revascularization versus medical therapy in appropriately and carefully selected patients.

References

1. Najat H, Tajti P, Xenogiannis L, Brilakis E. CTO complexity begets complexity. Cath Lab Digest. 2018 May; 26(5):1, 18-22.
2. Brilakis ES, Grantham JA, Rinfret S, et al. A percutaneous treatment algorithm for crossing coronary chronic total occlusions. JACC Cardiovasc Interv. 2012; 5(4): 367-379.
3. Fefer P, Knudtson ML, Cheema AN, et al. Current perspectives on coronary chronic total occlusion — the Canadian multicenter CTO registry. J Am Coll Cardiol. 2012; 59: 991-997.
4. Joyal D, Afilalo J, Rinfret S. Effectiveness of recanalization of chronic total occlusions: a systematic review and meta-analysis. Am Heart J. 2010 Jul; 160(1): 179-187.
5. Olivari Z, Rubartelli P, Piscione F, et al. Immediate results and one-year clinical outcome after percutaneous coronary interventions in chronic total occlusion. J Am Coll Cardiol. 2003; 41: 1672-1678.
6. Jang JW, Yang JH, Choi SH, et al. Long-term survival benefit of revascularization compared with medical therapy in patients with coronary chronic total occlusion and well-developed collateral circulation. JACC Cardiovasc Interv. 2015; 8: 271-279.
7. Christopoulos G, Karmpaliotis D, Alaswad K, et al. Application and outcomes of a hybrid approach to chronic total occlusion percutaneous coronary intervention in a contemporary multicenter US registry. Int J Cardiol. 2015; 198: 222-228.
8. Lee PH, Lee SW, Park HS, et al. Successful recanalization of native coronary chronic total occlusion is not associated with improved long-term survival. JACC Cardiovasc Interv. 2016; 9: 530-538.
9. Widimsky P, Straka Z, Stros P, et al. One-year coronary bypass graft patency: a randomized comparison between off-pump and on-pump surgery angiographic results of the PRAGUE-4 trial. Circulation. 2004; 110: 3418-3423.