(April 12, 2005) -- Boston Scientific Corporation (NYSE: BSX) today announced that enrollment has begun in its clinical trial known as SYNTAX, which will compare the performance of drug-eluting stents with cardiac surgery in the most complex patient subsets: those with coronary artery disease in all three coronary arteries, in the left main coronary artery, or both. This randomized, controlled clinical trial is designed to compare 12-month outcomes of percutaneous coronary intervention (PCI) using the Company's TAXUS® Express²™ paclitaxel-eluting coronary stent system with coronary artery bypass graft (CABG) treatment. SYNTAX is a multi-center, prospective trial that will involve over 4,200 patients at up to 90 sites in Europe and the United States.

In recent years, the outcomes and risks of both CABG and less-invasive PCI treatments have been substantially improved through new treatment strategies, patient monitoring and technologies such as drug-eluting stents. Previous studies comparing CABG and PCI using bare-metal or drug-eluting stents have been limited to highly selected patient populations. For the most severe form of coronary artery disease involving all three coronary arteries, the left main artery, or both, the optimal treatment strategy remains undetermined.

The SYNTAX trial uses an innovative enrollment methodology that enrolls consecutive patients without significant exclusion criteria. Based on an initial assessment, the treating cardiothoracic surgeon and interventional cardiologist will jointly decide whether a patient meets the eligibility requirements for both treatment approaches (CABG and PCI). Patients who are eligible for both treatment options will be enrolled in the randomized arm comparing CABG to PCI, which will include approximately 1,500 patients. Patients determined to be eligible for only one treatment option will be enrolled in one of two “nested