Devices FDA Cardiology

 News Release - April 24, 2006

FDA Approves Almost 50% Reduction in Size of WorldHeart's RELIANT Destination Therapy Trial

Trial Reduced From 390 to 208 Patients
Broadened Inclusion Criteria Expected to Significantly Increase Patient Enrollment Rate
Conference Call to Discuss Trial Revisions Set for April 25

OAKLAND, Calif., April 24 (HSMN NewsFeed) -- World Heart Corporation (Nasdaq: WHRT ; TSX: WHT ; WorldHeart), a global technology leader in mechanical circulatory support systems, announced today that the U.S. Food and Drug Administration has given conditional approval of the Company's Investigational Device Exemption (IDE) Supplement for modifications to the RELIANT (Randomized Evaluation of the Novacor® LVAS In A Non-Transplant Population) clinical trial design. The trial design changes include:

* Sample size reduction, from 390 to 208 patients.

This reduction in patient enrollment is expected to significantly reduce the time required to complete the trial. The RELIANT Destination Therapy (DT) trial has already enrolled nearly 20% of the newly required number. The rate of patient enrollment has been increasing and is expected to accelerate as new centers complete the enrollment process. The enrollment rate in the first quarter of 2006 was double the enrollment rate in the prior quarter.

* Broadened patient inclusion criteria and reduced waiting times for high risk patients.

The inclusion criteria are now expanded to include patients in NYHA Class IIIB heart failure as well as currently included NYHA Class IV patients. The Novacor Left Ventricular Assist System (LVAS) will now be available, through the study, to patients who previously did not have access to this potentially life-saving therapy. More timely implantation, before patients develop excessive risk, should improve outcomes. These changes are expected to yield a significant increase in the patient enrollment rate, further accelerating completion of the trial.

* A new group of potential patients, allowing elective implantation of the Novacor LVAS in commercial DT patients needing replacement of a competitor's pump.

The Novacor LVAS is now available, within the trial, to DT patients requiring replacement of a failed Thoratec Corporation's HeartMate® XVE originally implanted outside of the study. As requested by leading clinical centers, replacement with the Novacor adds the advantage of superior pump durability, Thoratec Corporation's ongoing HeartMate II trial similarly allows replacement of failed HeartMate XVEs with HeartMate IIs, which has been announced as a significant source of implants within that trial.

"These trial revisions reflect advances in the field of mechanical circulatory support, allowing us to expand the trial to a broader group of patients more quickly," said Dr. John B. O'Connell, cardiologist and Director of the Center for Heart Failure, Bluhm Cardiovascular Institute and Professor of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. "It is encouraging to see the FDA adopt trial approaches that maintain scientific rigor, are significantly more timely and have the potential to bring important new technologies and therapies to patients. I am pleased to be part of this important trial, and look forward to the expected acceleration of its completion." Dr. O'Connell recently joined the WorldHeart Clinical Executive Committee for the RELIANT trial.

Dr. James W. Long, cardiac surgeon and head of the Artificial Heart Program at LDS Hospital, Salt Lake City, Utah, also a member of the WorldHeart Clinical Executive Committee, said, "We are at an important juncture in the evolution of mechanical circulatory support for long-term use. Even as new technologies enter their introductory phase, there is an essential role for well-established, reliable pulsatile devices. I believe this revised trial will provide valuable information in a more timely way, will set the stage for improving outcomes and potentially will lead to a greater choice of therapeutic options for the treatment of advanced heart failure."

"We are extremely pleased with the collaborative process between the FDA, the RELIANT trial clinical executive committee and WorldHeart, which led to the revised study design," said Jal S. Jassawalla, President and Chief Executive Officer of WorldHeart. "These changes to the RELIANT trial were driven by the experience of leading cardiologists and cardiac surgeons in delivering mechanical circulatory support solutions to their patients. Of course, we are excited that these efforts are expected to significantly accelerate completion of the study and bring us closer to completion of the market approval process of the Novacor LVAS for Destination Therapy. Even more importantly, however, is that we believe these changes to our trial will help advance the adoption of mechanical circulatory assist and heart replacement devices as the standard of care for the many tens of thousands of patients who could potentially benefit from such therapy."

WorldHeart's DT Product Platform

As the only company with both rotary and pulsatile next-generation ventricular assist devices (VADs) under development, WorldHeart is uniquely able to address the full spectrum of patient needs, from partial support, i.e., assist, to full functional support, i.e., replacement. WorldHeart's next-generation, magnetically levitated rotary VAD successfully began human trials in March, 2006, and the Novacor II next-generation pulsatile pump has begun chronic animal trials. Furthermore, WorldHeart's current Novacor LVAS is the most durable and reliable pulsatile VAD in the world today. Combining WorldHeart's broad product portfolio with the significant reduction in size and the broadening of inclusion criteria of the RELIANT Trial, WorldHeart expects its leadership in technology and innovation to translate into leadership in the marketplace as well.

About the RELIANT Trial Design

Under the newly approved IDE supplement, the primary endpoint for the trial, formerly only patient survival, is now a composite of patient survival, device replacement and neurologic events. The use of a composite primary endpoint reduces the required enrollment from 390 to 208 patients. Secondary endpoints include quality of life, adverse events and cost effectiveness. The inclusion criteria are now expanded to all patients in AHA/ACC Stage D (NYHA Class IIIB/IV) heart failure who are not candidates for heart transplantation. Broadened inclusion criteria also include reduction of the total time of heart failure exposure from 60 out of 90 days to 30 out of 60 days, and the early identification of patients at risk. The added patient cohort allows DT patients currently supported by a commercially available HeartMate XVE in need of device replacement to electively receive the Novacor LVAS.

Thirty-eight patients have already been enrolled in the study. These patients will count towards the required enrollment of 208, upon confirmation of poolability. FDA approval of the revised study is conditional upon submission of additional details related to the study's statistical model, the incorporation of additional secondary analyses in the study protocol, and adjustment of the composition of the clinical events review committee.

About the Novacor LVAS

Novacor LVAS is an implanted electromagnetically driven pump that provides circulatory support by taking over part or all of the workload of the heart's left ventricle. Many recipients have lived with their original pumps for more than four years -- results unmatched by any other implanted electromechanical circulatory support device on the market. There have been no patient deaths attributed to device failure in more than 1,700 implants. Novacor LVAS is commercially approved as a bridge to transplantation in the U.S. and Canada. In Europe, the Novacor LVAS has unrestricted approval for use as a bridge to transplantation, an alternative to transplantation and to support patients who may have an ability to recover the use of their natural heart. In Japan, the device is commercially approved for use in cardiac patients at risk of imminent death from non-reversible left ventricular failure for which there is no alternative except heart transplantation.

Conference Call

The company has scheduled a conference call for 8 a.m. Pacific Time tomorrow, Tuesday, April 25th to discuss this news and advances in other WorldHeart programs. To participate in the call, please dial 800-659-2032 or 617-614-2712 at least 10 minute prior to the start of the call, and enter the passcode 9759-5663. A telephonic replay will be available approximately one hour after the conclusion of the call through May 2, 2006. To listen to this replay, please dial 888-286-8010 or 617-801-6888, and enter the passcode 5853-6155. The call will be Webcast, and a Webcast replay will be available from the Company's website, www.WorldHeart.com, under "News and Events."

About WorldHeart

WorldHeart is a global technology leader in mechanical circulatory support systems, dedicated to working with physicians to provide reliable, long-term mechanical circulatory support products and services to the broadest patient population through technology, leadership and innovation. The company is headquartered in Oakland, California, USA with additional facilities in Salt Lake City, Utah and in Heesch, Netherlands. WorldHeart's registered office is Ottawa, Ontario, Canada.

Any forward-looking statements in this release, including statements about the expected acceleration of enrollment in and completion of the RELIANT trial, planned preclinical and clinical studies, breadth of the company's product platform and other statements about the advancements in the adoption of mechanical circulatory assist and heart replacement devices, are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Investors are cautioned that all forward-looking statements involve risk and uncertainties, including without limitation: risk that the FDA might not grant unconditional approval of the revised trial protocol on a timely basis; risks in product development and market acceptance of and demand for the Company's products; possible delays in successful completion of or negative outcomes in current and planned clinical trials and preclinical testing; and other risks detailed in the Company's filings with the U.S. Securities and Exchange Commission, including its Annual Report on Form 10-KSB for the year ended December 31, 2005.

Source: WorldHeart

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