Medtronic Announces Start of Two Clinical Trials Studying Treatment of Thoracic Aortic Aneurysms and Dissections.

VALOR II and VIRTUE Studies Both Evaluating Valiant Thoracic Stent Graft System

MINNEAPOLIS -- Medtronic, Inc. (NYSE:MDT), today announced the first patient enrollments in two separate clinical trials studying the use of the Valiant Thoracic Stent Graft system for treating descending thoracic aortic aneurysms and descending thoracic aortic dissections, respectively. The Valiant device is Medtronic's next generation thoracic endograft designed for minimally-invasive treatment of potentially fatal thoracic aortic conditions that affect tens of thousands of people each year.

The VALOR II clinical trial, which will enroll a maximum of 125 patients at up to 30 investigational sites in the United States, will examine the safety and efficacy of Valiant in treating descending thoracic aortic aneurysms, or dangerous bulges in the descending thoracic aorta. It is anticipated that data from this trial will be used to support application to the U.S. Food and Drug Administration for product approval in the United States. Dr. Joseph Bavaria, site principal investigator at the University of Pennsylvania, enrolled the first patient last week. The national principal investigator for VALOR II is Dr. Ronald Fairman, also at the University of Pennsylvania.

"The Valiant stent graft has quickly become the most widely used thoracic graft outside the United States because it offers precision deployment and expanded sizing options that allow surgeons to treat a large array of patient anatomies," said Dr. Fairman, Chief of the Division of Vascular Surgery, University of Pennsylvania Health System. "We are thrilled to have initiated the VALOR II clinical trial in the United States, as we believe it will advance and refine endovascular therapy in the thoracic aorta."

Dr. Ivan Degrieck, Onze Lieve Vrouw Hospital in Aalst, Belgium, implanted the first patient in the VIRTUE registry. This registry will enroll 100 patients at approximately 20 clinical centers in Western Europe and will evaluate the use of the Valiant graft for the treatment of descending thoracic aortic dissections, also known as Type B dissections. The Valiant Stent Graft has been available outside the U.S. since 2005 for the treatment of thoracic aortic aneurysms, dissections and other lesions. The objective of the VIRTUE registry is to collect additional health economic and clinical performance data on Valiant for the treatment of acute dissections, complicated or expanding sub-acute dissections and expanding chronic dissections. An aortic dissection occurs when the inner surface of the aortic wall separates from the outer surface.

The principal investigator for the VIRTUE registry is Prof. Matt Thompson, St George's Hospital, University of London. "Descending aortic dissection is a potentially fatal condition, and traditional treatment with open surgery or medical management can result in high morbidity and mortality," said Prof. Thompson. "The early use of stent graft therapy in both elective and emergency treatments of Type B dissections has produced very encouraging outcomes, but we need to learn more about the effectiveness of this therapy. Our goal is to offer patients the best treatment option possible, and the VIRTUE study may help us better understand when to use thoracic endograft therapy in the reconstruction of an aortic dissection."

Aneurysms and Dissections

With an aortic aneurysm, the aorta - the body's largest artery - becomes weakened and could burst if left untreated. Patients often have no symptoms before this occurs. Stent graft systems provide a minimally-invasive therapy option as an alternative to riskier open surgery. Many patients who develop aneurysms also have other serious illnesses such as coronary artery disease, emphysema, high blood pressure or diabetes. These conditions make it difficult - if not impossible - for them to survive open surgical repair.

With an aortic dissection, blood flows between the inner and outer layers of the aortic wall, causing pressure on the outer layer of the wall that could result in a potentially fatal rupture. This condition in the descending thoracic aorta affects more than 15,000 people worldwide, mostly among the elderly and often among people with hypertension. Currently, most of these patients receive anti-hypertensive medications or undergo complex surgical procedures, with a prognosis that can include significant risk of paraplegia, stroke or death.

Medtronic has been at the forefront of the stent graft industry in conducting significant clinical research and has a long history as a market leader, with more than 100,000 abdominal aortic aneurysm (AAA) implants dating back to 1996, and an additional 20,000 thoracic graft implants. In addition to Valiant, the company also markets the Talent[TM] Thoracic Stent Graft System outside the United States and the AneuRx[R] AAAdvantage Stent Graft system in the U.S.

"With Talent, Valiant and AneuRx, Medtronic has strong roots in treating patients with aortic disease and the most clinical experience and long-term results of anyone in the industry," said Katie Szyman, vice president and General Manager of the Medtronic endovascular business. "Valiant represents a state-of-the-art system designed to improve device performance and clinical outcomes."

About Medtronic

Medtronic, Inc. (www.medtronic.com), headquartered in Minneapolis, is the global leader in medical technology - alleviating pain, restoring health, and extending life for millions of people around the world.

Caution: In the United States, the Valiant Thoracic Stent Graft is an investigational device and limited to clinical investigation.

Any forward-looking statements are subject to risks and uncertainties such as those described in Medtronic's Annual Report on Form 10-K for the year ended April 28, 2006. Actual results may differ materially from anticipated results.