Boston Scientific Corporation has announced two-year follow-up data from the pivotal Platinum Workhorse trial comparing the safety and effectiveness of the Promus Element Everolimus-Eluting Platinum Chromium (PtCr) Coronary Stent System to the Promus (Xience V) Everolimus-Eluting Coronary Stent System.

The outcomes reported at 12 months for the Promus Element Stent and the Promus (Xience V) Stent remained comparable at two years. However, an additional landmark analysis of outcomes from year one to year two demonstrated superior efficacy of the Promus Element Stent as compared to the Promus (Xience V) Stent during this 12-month period of follow-up.

Results were presented at the American College of Cardiology Annual Scientific Sessions by Gregg W Stone, MD, Professor of Medicine and Director of Research and Education at the Centre for Interventional Vascular Therapy at Columbia University Medical Centre/New York-Presbyterian Hospital and Global Principal Investigator of the trial.

“The Promus Element Platinum Chromium Stent continues to demonstrate excellent safety and effectiveness with low rates of cardiac death, myocardial infarction, stent thrombosis and repeat revascularization,” said Dr Stone.  “These long-term results confirm that this device is an effective option for treating patients with coronary artery disease. Of particular note, a statistically significant reduction in recurrent ischemia requiring repeat revascularization procedures was present between the first and second year with the platinum chromium stent. This finding is potentially important, but must be confirmed by longer-term follow-up.”

The trial reported a two-year target lesion failure (TLF) rate of 4.4 per cent for the Promus Element Stent compared to 5.8 per cent for the Promus (Xience V) Stent (p=0.32). The Promus Element Stent demonstrated numerically lower but not statistically different event rates than the Promus (Xience V) Stent in TLF components at two years, including cardiac death related to the target vessel (0.9 per cent vs. 1.1 per cent, respectively, p=0.98), myocardial infarction (MI) related to the target vessel (1.2 per cent vs. 2.1 per cent, p=0.28) and ischemia-driven target lesion revascularization (TLR, 2.4 per cent vs. 4.0 per cent, p=0.12). Low rates of target vessel revascularization (TVR, 4.2 per cent vs. 5.6 per cent, p=0.30) and stent thrombosis (ARC definite/probable, 0.5 per cent vs. 0.7 per cent, p=0.99) were observed at two years for both stents.

In a landmark analysis of event rates from year one to year two, the Promus Element Stent demonstrated statistically significant differences in TLF (1.2 percent vs. 3.0 percent, p=0.04, 56 percent relative reduction), and TLR (0.7 percent vs. 2.2 percent, p=0.02, 67 percent relative reduction) compared to the Promus (Xience V) Stent, showing superior efficacy of the Promus Element Stent from 12 months to two years.

Trial results also confirmed a previously reported significant reduction in unplanned (bail-out or emergency) stenting with the Promus Element Stent (5.9 percent vs. 9.8 percent, p=0.004), including a significantly lower rate of inadequate lesion coverage or 'geographic miss' (1.4 percent vs. 3.4 percent, p=0.01).  These clinical observations reflect the results of comparative bench and animal studies, which have demonstrated the enhanced visibility and deliverability of the Promus Element Stent relative to the Promus (Xience V) Stent.

The prospective, multi-centre, randomized PLATINUM Workhorse trial enrolled 1,530 patients with up to two de novo lesions at 132 clinical sites worldwide.  The trial met its primary endpoint of 12-month target lesion failure demonstrating non-inferiority for the platinum chromium Promus Element Stent compared to the cobalt chromium Promus (Xience V) Stent.  The comprehensive PLATINUM clinical program is evaluating the safety and effectiveness of the Promus Element Stent in six multi-center studies totaling more than 1,900 patients, including single-arm studies evaluating small vessels, long lesions, pharmacokinetics, and quantitative coronary angiography and intravascular ultrasound data.

“With its exceptional deliverability and visibility, the Promus Element Stent offers interventional cardiologists a true next-generation stenting option for patients with coronary artery disease.  We are excited by these data from the landmark analysis, which exhibited superior efficacy of the Promus Element Stent,” said Kevin Ballinger, president of the Cardiology Division at Boston Scientific. “We are pleased that the internally manufactured Promus Element Stent platform is now approved in every major market worldwide and continues to meet our high expectations.”

The Promus Element Stent, used in the Promus Element Stent System and the Promus Element Plus Stent System, employs a proprietary PtCr alloy designed specifically for coronary stenting, which enables enhanced visibility, less recoil, excellent conformability and higher radial strength. The Promus Element Plus Stent System employs an advanced low-profile delivery system to facilitate precise delivery of the stent across challenging lesions.

The Company received CE Mark approval for the Promus Element Stent System in 2009 and for the Promus Element Plus Stent System in 2011. In the US, the Promus Element Plus Stent System was approved by the Food and Drug Administration in 2011. Xience V is a trademark of the Abbott Laboratories group of companies. The Promus Stent is a private-labeled Xience V Stent manufactured by Abbott and distributed by Boston Scientific.

Boston Scientific is a worldwide developer, manufacturer and marketer of medical devices that are used in a broad range of interventional medical specialties.