Titanium-nitride-oxide-coated bioactive stents: A novel evolution of stent technology

Abstract

With great interest, we read the article Long-term clinical outcome with titanium-nitride-oxide-coated stents and paclitaxeleluting stents for coronary revascularization in an unselected population by Karjalainen PP, et al. [1]. Recently, the introduction of bioactive stents has been one form of the natural evolution of stent technology. The safety of the titanium-nitride-oxide-coated bioactive stent (Titan2®, Hexacath, Paris, France) has been confirmed in reallife unselected populations [2,3]. Interestingly, bioactive stents have demonstrated an even 'better' outcome as compared with paclitaxeleluting stents in the real-world setting of high-risk patients and complex (type B and C) coronary lesions [4], as well as in patients presenting with acute myocardial infarction [5]. Yet, to the best of the author's knowledge, this article presented one of the longest periods of follow-up (3 years) for a prospective trial comparing the outcome of bioactive stents with that of paclitaxel-eluting stents. The salient point highlighted by the authors was the significantly lower incidence of major adverse cardiac events with bioactive stents at 3-years follow-up, as compared with paclitaxel-eluting stents, chiefly driven by a significantly lower incidence of myocardial infarction [1]. Currently, the use of drug-eluting stents is the state-of-the-art means of reducing in-stent restenosis. Nevertheless, after years of real-life experience with drug-eluting stents, the improvement of restenosis rate was not translated into a reduction of the hard endpoints: death and myocardial infarction. Additionally, recent worrisome data have raised concerns about a significant increase of such serious events with the use of drug-eluting stents in predetermined clinical scenarios and/or lesion or procedural characteristics, chiefly due to late and very late stent thrombosis [6]. Since the birth of percutaneous coronary interventions, it was well-known that in-stent restenosis is a soft non-life-threatening complication; otherwise, it would have been impossible for coronary angioplasty to widely replace surgical coronary bypass. Therefore, in our endeavor to discover a therapeutic strategy that effectively reduces in-stent restenosis, we cannot accept any increase (even if minimal) in hard endpoints as a prepaid tax to achieve such a target. The gold standard in trial design for comparing two strategies is the prospective, randomized, controlled trial. Propensity-matched comparisons, by definition, contain differences in group characteristics, since treatment choice is usually determined by measurable variables (risk factors and coexisting illnesses) and immeasurable variables (emotional factors, socioeconomic conditions, and the preference of the patient or physician). No adjustment, whatever meticulous, can correct for this, often subtle, selection bias. On the other hand, a welldesigned prospective randomized controlled trial, through its design, circumvents this problem. In this sense, a prospective randomized trial comparing the immediate and long-term outcome of bioactive stents with that of drug-eluting stents is highly recommended. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology [7, 8].