According to a commentary, the first generation of drug-eluting stents had good results in clinical trials using surrogate angiographic outcomes but their increased thrombogenicity, in combination with limited experience about optimum stenting techniques and suboptimum antithrombotic strategies, meant that the initial enthusiasm for drug-eluting stents led to increased risk of early and late stent thrombosis, which was linked to increased mortality. The new generations of stents with more biocompatible and bioresorbable polymers, lower doses of antiproliferative agents, and thinner stent struts with preserved radial strength, have led to better stent performance and improved short-term and long-term clinical outcomes. The FIREHAWK stent is a new-generation cobalt-chromium stent designed to minimise polymer burden and reduce the concentration of drug delivered to the coronary arterial wall by use of a biodegradable polylactic acid polymer, with sirolimus released from abluminal grooves in the stent. The manufacturer has developed the stent and done feasibility studies with angiographic and clinical endpoints in China.
The commentary congratulates the Chinese manufacturer for having concluded a large and well conducted RCT in Europe, with clinical endpoints and a medium (12 months) duration of follow-up, in accordance with the recommendations of the European Society of Cardiology task force on the evaluation of coronary stents in Europe. It adds, however, that while the primary non-inferiority clinical endpoint was met, the clinical need for a new drug-eluting stent might be questioned given that:
• the deliverability of the FIREHAWK appeared to be worse than that of the XIENCE stent• angiographic endpoints tended to favour XIENCE• at 86 μm, the strut thickness of the FIREHAWK is slightly larger than that of the XIENCE stent (81 μm) and larger than many other new-generation drug-eluting stents• the technical success rate in the intention-to-treat population was lower in the FIREHAWK group than in the XIENCE group• significantly more lesions could not be treated with the study stent compared with the XIENCE stent• angiographic follow-up at 13 months showed slightly greater stent late lumen loss with FIREHAWK than with XIENCE and numerically more in-stent restenosis, although these differences were not significant.• rate of definite stent thrombosis with FIREHAWK was not significantly different from that of comparator stent but was higher than that seen in other trials and registries of stents with thinner struts.
It concludes that these points might limit the clinical applicability of this stent and the attraction to using this particular stent of the many well performing new-generation drug-eluting stents already available, at least on the European market.