“MASTER I” STUDY IDENTIFYING PATIENTS IN GREATEST NEED OF IMPLANTABLE CARDIAC DEFIBRILLATORS

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Unique Non-Invasive Technology Will Stratify Risk of Sudden Cardiac Arrest among 1,800 Post-Heart-Attack Patients at 50 Leading Medical Centers Worldwide

The MASTER Study (Microvolt T-Wave AlternanS Testing for Risk Stratification of Post MI Patients) will target post-myocardial infarction (MI) patients whose hearts have been damaged by previous heart attacks. About one in every ten heart-attack patients who are left with poor heart pumping function will die of heart-rhythm abnormalities within two years, according to the American College of Cardiology. Results of the recent MADIT II clinical trial, published in the New England Journal of Medicine, showed that implantable defibrillators improve survival in this group by 31 percent. If members of this high-risk group can be stratified more precisely through a non-invasive test conducted in a clinic or doctor’s office, ICD implantations can be more cost-effective and reduce mortality rates still further for this population.

The Study, to be conducted in conjunction with a leading medical technology company, will take place at up to 50 leading medical centers around the world. Each of the 655 patients enrolled in the study was implanted with a currently marketed Medtronic ICD met MADIT II criteria (post heart attack and 30% or less ejection fraction). Another 1,200 patients, with slightly better pumping function (ejection fraction 30% to 40%) will be evaluated in a related registry. Results of the study are expected to be available in late 2005.