Thoratec Laboratories Completes TLC-II Component Validation; Resumes Shipping Devices to Europe; Company Hopes to Resume U.S. Clinical Trial in Second Quarter.

Business Editors/Health & Medical Writers

PLEASANTON, Calif.--(BW HealthWire)--March 22, 2000

Thoratec Laboratories Corporation (Nasdaq:THOR), a medical device company, said today it has completed the validation process for a new component for its TLC-II(TM) Portable VAD (Ventricular Assist Device) Driver.

Subsequently, the technical files have been updated and the declaration of conformity authorizing CE Marking of the device has been completed. As a result, the company intends to resume shipments to Europe within the next 30 days. Thoratec has also submitted an IDE supplement containing the validation data to the FDA and hopes to gain approval to replace the component and resume its U.S. clinical trial in the next 60 days.

In October 1999, Thoratec announced it had put a voluntary hold on further patient enrollment in the U.S. clinical trial initiated in April 1999, and on shipments of the device to new centers in Europe -- where it has been approved for sale for two years -- pending completion of a component upgrade.

"We have achieved the reliability results we require, thus resolving this component issue," said D. Keith Grossman, president and chief executive officer of Thoratec. "The developments we are announcing today are very positive for the company and its efforts to increase the market presence of the Thoratec VAD System. Interest in and demand for the device continue to be strong in both Europe and at our clinical sites in the U.S., reflecting the enthusiastic response by surgeons and patients to the TCL-II's design, which is intended to enhance a patient's mobility, and thus improve quality of life and potentially reduce cost of care," he added.

"We are hopeful that we will receive FDA approval to replace this component and ship new product to the clinical program sites within the next several weeks. Given that we have already accumulated a large portion of the patient days required in our trial protocol, we believe we will be in a position to file a PMA supplement on the device later this year. In the meantime, we are delighted to be resuming sales in Europe," he continued.

The TLC-II is a small, lightweight device used to power Thoratec's VAD which pumps blood to the body in heart failure patients awaiting transplants or recovery from open heart surgery. The TLC-II is designed to enable patients to leave the intensive care unit of the hospital and to be discharged to managed-care facilities or to their homes. It is currently the only portable cardiac assist device that can treat patients by providing left, right or biventricular support.

Thoratec Laboratories Corporation is engaged in the research, development, manufacture and marketing of medical devices for circulatory support and vascular graft applications, all of which incorporate its proprietary biomaterial, Thoralon. For additional information about Thoratec, visit the company's Web site at http://www.thoratec.com.

The portions of this news release that relate to future plans, events or performance are forward-looking statements. Investors are cautioned that all such statements involve risks and uncertainties, including risks related to the government regulatory approval process, the results of clinical trials, announcements by the company's competitors, rapidly changing technology, an intensely competitive market and market acceptance of new products. These factors, and others, are discussed more fully in the company's Form S-3 filed on March 17, 2000, and the company's other filings with the Securities and Exchange Commission. Actual results, events or performance may differ materially. These forward-looking statements speak only as of the date hereof. The company undertakes no obligation to publicly release the results of any revisions to these forward-looking statements that may be made to reflect events or circumstances after the date hereof, or to reflect the occurrence of unanticipated events.