Randomized trial for evaluation of mortality and morbidity of coronary revascularization with drug-eluting stent versus bare metal stent

The Norwegian Coronary Stent Trial (NorStent) is a randomized controlled trial including 9013 patients with coronary heart disease. The objective of the trial is to compare the long-term risks and benefits after implantation of coronary drug-eluting stents (DES) versus conventional bare-metal stents (BMS). Lipid deposits in coronary arteries may cause narrowing of the arteries so that the blood flow to the heart is impaired. Such impairement may cause angina, heart attack, or sudden death. The narrowing may be removed by implantation of a metal stent that restores blood flow to the heart. Two different types of stents are in use. One type of stent releases drugs to the vessel wall (drug eluting stent - DES)whereas the other type of stent does not release drugs (bare metal stent - BMS). Current data are insufficient to determine the long term balance of risk and benefit of DES vs BMS. The NorStent trial was started in 2007. All Norwegian hospitals with invasive coronary intervention units participate. The trial s investigator initiated and sponsored by the Norwegian Research Council, The Regional Health Authorities and other not-for-profit organizations. The primary outcome measures are total mortality, heart attack, and quality of life after five years of follow-up. A total of 9013 patients were recruited between september 2008 and february 2011 and followed up through December 31, 2014. Adjudication of end-points according to pre-specified and standardized criteria is performed by an independent Clinical Event Committee blinded to study assignment. Study results will be published in september 2016. NorStent is the first randomized trial with sufficient statistical power to compare long term effects of DES vs BMS. The study results may influence clinical treatment decisions and guidelines world-wide.

Coronary heart disease (angina pectoris and myocardial infarction) is a frequent cause of disability and death world-wide. The disease is caused by narrowing of the coronary arteries so that blood do not reach the heart muscle. The arteries may be opened by expanding a metal tube (stent) within the artery. Each year more than 12000 patients are treated with stents in Norway. World-wide many million patients have been treated. Drug-eluting stents (DES) were developed to reduce the risk of renarrowing of the arteries after bare-metal stents (BMS). The short-term effect with both stents is good, but the overall long-term balance of benefit and risk of DES vs BMS is not known. Cost-effectiveness is an additional issue since the extra cost of treating all No rwegian patients with DES compared to BMS amounts to NOK 190 mill per year. The present study is the first large scale comparison of the long-term effects on mortality and myocardial infarction of DES versus BMS. A total of 8000 Norwegian men and women with disabling angina pectoris or acute myocardial infarction will be asked to participate. They will be randomized to treatment with DES or BMS. All clinical events occurring during five years after treatment will be registered. The primary efficacy mea sure is the occurrence of death or myocardial infarction, and the trial is powered to detect a 3% absolute risk difference between BMS and DES. The trial will begin January 2008 and will be completed by July 2014. The project is a collaborative projec t iniated and run by Norwegian researchers and doctors at the following hospitals: The Northern Norway University Hospital (Tromsø), St.Olavs University Hospital (Trondheim), Haukeland University Hospital (Bergen), Sørlandet Hospital (Arendal), Ullevål Un iversity Hospital (Oslo), Rikshospitalet (Oslo), and Feiringklinikken (Feiring). The trial will help resolve an important question and will contribute to improved treatment of patients.