Sep 18, 2003
Guidant Announces Additional Findings of Key Study In Emerging Field of Heart Attack Prevention

Vulnerable Plaque Study Shows Correlation Between Lipid-Rich Plaques and Heart Attacks in Cath Lab Patients

Indianapolis, Ind. - Guidant Corporation (NYSE: GDT), a world leader in the treatment of cardiac and vascular disease, today announced additional findings of a study utilizing optical coherence tomography (OCT) to examine highly detailed images of complex coronary lesions in patients with coronary artery disease. OCT is a new coronary imaging technology that provides resolution 10 times greater than intravascular ultrasound. Results of the Guidant-supported study, which was conducted at Massachusetts General Hospital (MGH) in Boston, Mass., were presented by Dr. Ik-Kyung Jang today at the annual Transcatheter Cardiovascular Therapeutics (TCT) conference in Washington, D.C.

Traditional medical knowledge holds that heart attacks are caused by arteries that become narrow over time, as atherosclerosis progresses within the artery wall. However, evidence suggests that many heart attacks may be triggered by complex vulnerable lesions - vulnerable plaque - that suddenly rupture, causing blood to clot and occlude the artery.

Dr. Jang today reported that lipid-rich plaque and thrombus as detected by OCT occur more frequently in patients with an acute coronary syndrome, including patients who present with heart attack and unstable angina, than occur in patients with stable angina. These statistically significant findings are the first that confirm previously published findings from human autopsies correlating the prevalence of lipid and thrombus in plaques of patients dying of acute coronary syndromes.

"These findings are significant in that they demonstrate that we can detect characteristics common to vulnerable plaques in our current cath lab population. The study identifies key plaque characteristics that will guide the development of a series of clinical trials that will bring us closer to identifying a cause-and-effect relationship between vulnerable plaque and the risk of heart attack," said Dana G. Mead, Jr., president, Vascular Intervention, Guidant Corporation. "Guidant is dedicated to supporting further research that may one day lead to therapies that may prevent many of the 1.1 million heart attacks Americans suffer each year."

Last year Dr. Jang presented preliminary data from the MGH-Guidant study, which demonstrated that OCT is able to successfully detect morphological characteristics of coronary lesions that have been associated with heart attacks, including lipid pools and their thin fibrous caps that are susceptible to rupture. To date, Dr. Jang has successfully used OCT in 88 patients with no procedure-related complications.

"In the past, our knowledge of the pathophysiology of coronary artery disease has been principally based on pathology studies, because, before OCT, there was no reliable method for studying minute details of coronary plaques in living persons," said Ik-Kyung Jang, M.D., Ph.D., interventional cardiologist at MGH, associate professor of medicine at Harvard Medical School, and principal investigator for the study. "OCT has the most extensive clinical experience of all the invasive modalities being studied today for vulnerable plaque. Now that we are detecting lesion-structure differences in different patient subsets, we will want to move on to prospective studies, such as a natural history study."

"OCT has now been shown to detect the features of plaques that may cause heart attacks. These findings support the concept that OCT could be used to identify such plaques before they rupture. This could make prevention of heart attacks a reality," said James E. Muller, M.D., director of the Center for Integration of Medicine and Innovative Technology (CIMIT) vulnerable plaque program at MGH and the Harvard Medical School. "A natural history study is the single most important development needed to move the vulnerable plaque field forward. What we learn from that may someday enable cardiologists to detect in the cath lab signals of those lesions with the highest risk of rupture."

The OCT system used in the study was developed at Wellman Laboratories of Photomedicine, based at Massachusetts General Hospital within the Department of Dermatology at Harvard Medical School. The co-principal investigators of the study were Brett Bouma, Ph.D., and Guillermo Tearney, M.D., Ph.D., assistant professors at Massachusetts General Hospital conducting research at Wellman Laboratories.

Guidant Corporation pioneers lifesaving technology, giving an opportunity for better life today to millions of cardiac and vascular patients worldwide. The company, driven by a strong entrepreneurial culture of more than 11,000 employees, develops, manufactures and markets a broad array of products and services that enable less invasive care for some of life''s most threatening medical conditions. For more information visit www.guidant.com.

This release includes forward-looking statements concerning the development of therapies relating to the treatment of vulnerable plaque. The statements are based on assumptions about many important factors, including progress in the additional studies and trials described in the release, as well as sustained clinical and regulatory progress and other factors identified on Exhibit 99 to the company''s most recent 10-Q. Actual results may differ materially. The company does not undertake to update these forward-looking statements.