We have read with great interest the article entitled “Importance of IVUS in the treatment with retrograde approach of long in-stent chronic total occlusion of ostial right coronary artery: A case report” by Talanas and Garbo . The authors describe their efforts to treat in-stent chronic total occlusion (ISR-CTO) of an ostial right coronary artery (RCA) using various approaches (classical antegrade and retrograde techniques and knuckle-wire approach), many types of guiding catheters, and four bioresorbable polymer sirolimus-eluting stents. Their manuscript emphasized the key role of IVUS guidance in successfully reopening occluded stents. We congratulate the team for this hard work. In addition, we would like to discuss some further considerations.

The indications for percutaneous intervention in CTO (CTO-PCI) are not well defined in the European or American guidelines for revascularization , or in the guidelines for the treatment of patients with chronic stable ischemic heart disease .

In the case presented by Talanas and Garbo , the patient experienced dyspnea with moderate physical efforts, without symptoms of angina, and had anomalies in left ventricular kinetics with preserved ejection fraction. The recanalization of the ISR-CTO of the RCA would appear to be logical; the opening of an occluded artery which irrigates a dysfunctional myocardium could improve the dysfunction, changing the symptoms and prognosis of the patient. However, successful recanalization of an ISR-CTO is not always associated with reduced mortality. In fact, several studies have failed to demonstrate that PCI improves the prognosis . In a meta-analysis, Stergiopoulos and colleagues demonstrated that the 5-year outcomes (death, nonfatal MI, unplanned revascularization, and angina) of patients with stable coronary artery disease and objectively documented myocardial ischemia were similar among those treated with PCI plus medical therapy and those treated with medical therapy alone . In addition, the clinical outcomes of 1192 patients from the CREDO-Kyoto registry with successful CTO-PCI have been compared to the clinical outcomes of 332 registry patients with failed CTO-PCI; after a 3-year follow-up period, successful therapy was not associated with reduced total or cardiac mortality .

Moreover, in the case presented by Talanas and Garbo , the treatment was associated with extensive secondary stenting (multiples, longs, and overlapping stents), which is a risk factor for lesion recurrence, late stent thrombosis, and worsening prognosis.

Therefore, we believe that patients with ISR-CTO treated by PCI should be selected very carefully for revascularization, especially if the patient is asymptomatic or has very few symptoms. Sometimes, the “enthusiasm” for revascularization can trigger further ischemic events, resulting in the readmission of the patient to the catheterization laboratory with the same or worse problem.