“… the development of a device suitable for percutaneous insertion, which is a functional equivalent of the present spring guide but capable of externally controlled concentric expansion over a suitable portion of its length.”
Coronary artery stents were envisioned by two of the founding fathers of coronary artery intervention, Drs. Charles T. Dotter and Melvin Judkins. In 1964, they described a transluminal approach with rigid dilators for the treatment of patients with critical limb ischemia . Dr. Dotter took almost two decades to describe the first percutaneous placement of nitinol coil stents for the nonoperative restoration and maintenance of patency of blood vessels and biliary ducts . Dr. Jacques Puel, however, is credited for the implantation of the first coronary artery stent in March 1986, and the first report, which was published in the same year, on the clinical use of stents for the prevention of occlusion and restenosis after transluminal angioplasty in 19 patients belongs to Drs. Ulrich Sigwart and Jacques Puel . The Cook Inc. Gianturco-Roubin Flex-Stent™ was the first coronary stent approved by the US Food and Drug Administration (FDA) in May 1993 for “chronic placement in a coronary artery or graft to obtain vessel patency in the treatment of acute or threatened closure associated with an interventional procedure.” However, the stent was frequently used for additional nonapproved indications, including the treatment of restenosis, early recoil, high-risk lesions, and the treatment of primary (de novo) lesions in an attempt to improve the clinical outcome in these different settings. After a lengthy seven-year development process by Drs. Julio Palmaz and Richard Schatz, the FDA approved the Palmaz-Schatz® stainless steel stent in August of 1994. In its first year alone, the Palmaz-Schatz stent was implanted in more than 100,000 patients in the United States.
Bare metal stents (BMS) clearly helped reduce the incidence of elastic recoil and restenosis after balloon angioplasty. Two landmark studies, the BElgian NEtherlands Stent study (BENESTENT) and the STent REStenosis Study (STRESS), demonstrated the clear superiority of BMS over balloon angioplasty, and by 1999, BMS were used in 85% of all coronary interventions. However, long-term follow-up revealed a 10–40% incidence of in-stent restenosis with significant morbidity and mortality . It took 15 years after the first stent was deployed and numerous studies with different metals, alloys, drugs, devices, and strategies to find and develop a stent that would have lower restenosis rates. In January 2001, Dr. Eduardo Sousa and colleagues described 30 patients electively treated with 2 different formulations of sirolimus-coated stents. At 4 months angiographic and 8 months clinical follow-up, there were no cases of in-stent restenosis, and in April 2003, the CYPHER® sirolimus-eluting coronary stent was approved by the FDA. Numerous randomized, controlled studies showed a significant reduction in in-stent restenosis and target vessel revascularization compared with BMS. The TAXUS® paclitaxel-eluting stent was approved by the FDA one year later, and several studies confirmed its efficacy against BMS in low-risk patients with noncomplex coronary artery disease.
Although in-stent restenosis, the nemesis of every interventional cardiologist in the late 1990s, seemed to have been finally defeated, drug-eluting stents (DES) did not send BMS to the graveyard of interventional cardiology technology. A high initial list price, uncertainty over the long-term safety, concerns over delayed healing, and very late stent thrombosis associated with high mortality rates led to a significant drop in the use of DES from more than 90% to 64% and a resurgence of the use of BMS in 2007 . Although most of these issues and concerns were eventually discarded with the advent of newer and safer second-generation DES, BMS are still frequently used in our daily practice.
In this issue, Wang et al present the 9 months angiographic and 1 year clinical outcomes of 328 patients treated with 337 OMEGA® (Boston Scientific Corporation, Marlborough, MA) coronary artery stents. The OMEGA BMS is a platinum-chromium, thin-strut (81 μm), balloon-expandable, laser-cut BMS that was approved by the FDA in 2014 and is commercialized as the REBEL™ stent (albeit some structural design changes). OMEGA was a single-arm registry performed in 22 sites in the United States and 15 sites in Europe that enrolled 328 patients between October 2011 and January 2013. As usually seen in these studies, this was a low-risk population with simple coronary artery lesions. Target lesion failure, the primary outcome of the study, was seen in 12.8% of patients at 1 year, mainly driven by an 8.4% target lesion revascularization rate and a 1.9% all-cause mortality rate. These rates seem comparable to those seen with the two other currently commercially available BMS in the United States ( Fig. 1 ) . The slightly higher mortality rate observed in this study (1.8% at 9 months and 1.9% at 12 months) is somewhat concerning, but the relative small sample size is one of the main limitations of the study as clearly stated by Dr. Wang and colleagues. Also, it would have been of great value to understand the rationale for the use of BMS in these patients.
