Fate of Bioresorbable Vascular Scaffold Metallic Radio-Opaque Markers at the Site of Implantation After Bioresorption.

revascularization are needed. We also agree with Conti’s opinion that, unless ischemia is present, collaterals do not appear angiographically; if the collateral provides excellent blood flow to ischemic myocardium, the collaterals will remain (2). Werner et al. (3) reported that even collaterals that appear well developed on angiography are not able to fully replace anterograde blood flow; therefore, restoring flow reserve does little to prevent myocardial ischemia. Our hypothesis was that well-developed collateral flow in patients with stable CTO lesions may partially protect the myocardium and the revascularization may allow complete maintenance of viable myocardium (4), and we identified longterm survival benefits of aggressive revascularization compared with medical therapy in our study. Unfortunately, because we did not routinely perform contralateral injections after successful revascularization of CTO in our practice, we could not identify the existence or disappearance of collaterals after CTO revascularization, as mentioned in Conti’s letter. However, we agree with his hypothesis that the change of collateral flow after CTO revascularization in coronary angiography might correlate with whether ischemia of viable myocardium occurs or not. This hypothesis requires further detailed study. As stated by Barbato and Wijns (1), our study might have reported a higher rate of successful percutaneous coronary intervention (PCI) or coronary bypass grafting (CABG) compared to previous studies of CTO revascularization. However, remarkable developments in the survival benefits posed by CTO revascularization are rapidly becoming a reality because CTO PCI techniques have improved and the experience of CABG has also increased. We anticipate that the survival benefits of aggressive reduction of remnant ischemia by revascularization or intensive medication in patients with CTO lesions will be verified by future large-scale randomized trials.