PLC Plc Systems,

Pioneering Study Indicates CO2 TransMyocardial Revascularization Combined with Gene Therapy Enhances Angiogenic Response and Improves Myocardial Function Innovative Animal Research Published In The Journal of Thoracic and Cardiovascular Surgery FRANKLIN, Mass., June 9 /PRNewswire-FirstCall/ -- PLC Systems Inc. (AMEX:PLC), the leader in carbon dioxide (CO2) TransMyocardial Revascularization (TMR) technology used to treat severe angina, or heart pain, today announced that a study published in the May 2005 issue of The Journal of Thoracic and Cardiovascular Surgery reports an increase in angiogenesis within the heart as a result of a combination of revascularization therapies: CO2 transmyocardial laser revascularization plus matrix adenoviral fibroblast growth factor-2 (FGF-2) gene therapy. "Prior studies and clinical use have demonstrated that CO2 TMR can be a positive influence on treating ischemic myocardium. Other investigations have evaluated gene therapies as treatments for ischemic heart disease," said Dr. Keith A. Horvath, lead author of the study and Chief, Cardiothoracic Surgery Branch, National Heart, Lung and Blood Institute, NIH. "We believe the principal mechanism of action for both CO2 TMR and gene therapy is the stimulation of angiogenesis. With this study we have demonstrated that the combination of a growth factor formulated in a collagen-based matrix and CO2 TMR will lead to enhanced neovascularization and most importantly, improved myocardial function." The study entitled, "Improvement of Myocardial Contractility in a Porcine Model of Chronic Ischemia using a Combined Transmyocardial Laser Revascularization and Gene Therapy Approach," is a pre-clinical animal study that had four treatment groups -- CO2 TMR alone, adenoviral FGF-2 in a collagen-based matrix alone, adenoviral FGF-2 in a collagen-based matrix combined with CO2 TMR, and saline-formulated adenoviral FGF-2. The study demonstrated that a matrix adenoviral FGF-2 combined with CO2 TMR treated areas had a 105 percent increase in arteriolar development versus either alone treatment. In addition, the matrix adenoviral FGF-2 combined with CO2 TMR treated areas had a 390 percent increase compared with saline-formulated adenoviral FGF-2. Contractility was significantly improved in matrix adenoviral FGF-2 plus CO2 TMR treated areas as measured by myocardial wall thickening. This functional improvement was confirmed by cine magnetic resonance imaging, in which a 90 percent increase in the contractility of the treated area after matrix adenoviral FGF-2 plus CO2 TMR. The other treatments provided significantly less restoration of myocardial function. "The research results published in this study are very promising," stated PLC Systems' CEO and President Mark R. Tauscher. "Gene therapies and biologics are cutting-edge, emerging research areas that have a significant level of interest and investment by academia, healthcare providers and leading biotech companies. We believe this study demonstrates that CO2 TMR can enhance the angiogenic response of a gene therapy or biologic. As the research and development continues to evolve we hope to demonstrate that CO2 TMR should be the preferred therapy to complement or enhance gene therapies, autologous cells or biologics within the heart." PLC Systems is a medical technology company specializing in innovative technologies for the cardiac and vascular markets. Headquartered in Franklin, Mass., PLC pioneered the CO2 Heart Laser System that cardiac surgeons use to perform CO2 transmyocardial revascularization (TMR) to alleviate symptoms of severe angina. Edwards Lifesciences (NYSE:EW) is the exclusive U.S. marketer and distributor of PLC's next-generation CO2 Heart Laser 2 systems. To date, more than 13,000 cardiac patients have been treated with a CO2 Heart Laser. Additional company information can be found at http://www.plcmed.com/. This press release contains "forward-looking" statements. For this purpose, any statements contained in this press release that relate to prospective events or developments are deemed to be forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "will" and similar expressions are intended to identify forward-looking statements. Our statements of our objectives are also forward looking statements. While we may elect to update forward-looking statements in the future, we specifically disclaim any obligation to do so, even if our estimates change, and you should not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this press release. Actual results could differ materially from those indicated by such forward-looking statements as a result of a variety of important factors, including the animal study identified above may not prove indicative of actual clinical results with humans, we may be unable to successfully develop or manufacture products under our agreements with Edwards; Edwards may decide not to pursue or continue the sales and marketing activities for these products; Edwards may be unsuccessful in distributing these products, operational changes, competitive developments may affect the market for our products, regulatory approval requirements may affect the market for our products, we may be unable to convince health care professionals and third party payers of the medical and economic benefits of the CO2 Heart Lasers and there can be no assurance that all payers will reimburse health care providers who perform TMR procedures or that reimbursement, if provided, will be adequate, and additional risk factors described in our Report on Form 10-K for the year ended December 31, 2004, and our other SEC reports. PLC Systems, PLC Medical Systems, PLC and CO2 Heart Laser are trademarks of PLC Systems Inc. Edwards Lifesciences, and Edwards are trademarks of Edwards Lifesciences. Contact: John Jordan Director of Investor Relations 508-541-8800, ext. 145 DATASOURCE: PLC Systems Inc. CONTACT: John Jordan, Director of Investor Relations of PLC Systems, +1-508-541-8800, ext. 145 Web site: http://www.plcmed.com/

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