Devices FDA Interventional Cardiology Neurology

 News Release - April 23, 2007

NMT Medical Receives FDA Approval for Modifications in Pivotal U.S. PFO/Stroke Trial

CLOSURE I Enrollment Targeted for Completion by Year End

BOSTON, April 23 (HSMN NewsFeed) -- NMT Medical, Inc. (NASDAQ: NMTI ), an advanced medical technology company that designs, develops, manufactures and markets proprietary implant technologies that allow interventional cardiologists to treat structural heart disease through minimally invasive, catheter-based procedures, today announced that it has received conditional approval from the U.S. Food and Drug Administration (FDA) to its revised study hypothesis and statistical plan in the CLOSURE I Patent Foramen Ovale (PFO)/stroke and transient ischemic attack (TIA) trial in the U.S. As part of the revised plan, the Company plans to enroll approximately 800 patients. The original CLOSURE I statistical plan, approved by the FDA five years ago, required an enrollment of 1,600 patients.

On March 2, 2007, NMT participated in a public and private FDA advisory panel meeting to discuss the current status of the ongoing PFO/stroke trials being sponsored by NMT and other companies. At the close of the meeting, both the FDA and advisory panel concurred that only randomized, controlled trials would provide the necessary data to be considered for premarket approval (PMA) for devices intended for transcatheter PFO closure in the stroke and TIA indication. During a private session, NMT provided the FDA and advisory panel with a revised study hypothesis and statistical plan to complete the CLOSURE I study as a randomized controlled trial.

"The FDA's acceptance of our revised plan to complete enrollment in the CLOSURE I study represents an important milestone for NMT and the medical community," said President and Chief Executive Officer John E. Ahern. "The revision is based on the recommendations made at the recently held meeting. As a result of this decision, we believe that we are now much closer to completing enrollment in CLOSURE I and thereby understanding the PFO/stroke and TIA connection and the possibility that treatment with a closure device may reduce the frequency of recurrent events. The stroke and TIA indications, which have a potential market of 250,000 U.S. patients annually, have always been a major focus for the Company. As the leader in the PFO closure space, we are committed to being the first company to complete a randomized controlled trial and to submit a PMA for these indications. I want to acknowledge the tremendous effort put forth by our investigators, our internal team, the clinical community and the FDA in order to develop an appropriate revised plan that accelerates the completion date for patient enrollment in the CLOSURE I study."

Anthony Furlan, M.D., Associate Director Cerebrovascular Center, Neurological Institute, Cleveland Clinic, and the Principal Investigator of CLOSURE I, said, "It is very important to obtain an answer to the stroke/PFO connection based upon a randomized controlled clinical trial. The Executive Committee and investigators are excited about the recent FDA acceptance of a revised statistical plan and the prospects for completing this important study. The answers from CLOSURE I will help determine the best treatment for patients presenting with cryptogenic stroke and TIA that also have a right to left shunt through a PFO."

Ahern concluded, "To date, more than 650 patients have been randomized in CLOSURE I. We are not aware of any other randomized stroke and TIA studies as far along or with as much accumulated clinical information. Based on the revised statistical plan, we currently expect to complete enrollment by year end. Follow-up with the patients will continue to be over a two-year period."

A PFO is a common heart defect that may be a potential risk factor for stroke, migraine, TIA or other brain attacks in some patients. The PFO allows venous blood, unfiltered and unmanaged by the lungs, to enter the arterial blood circulation. CLOSURE I is NMT's pivotal clinical trial designed to evaluate the effectiveness of the STARFlex® technology in preventing recurrent stroke and/or TIA due to a presumed, paradoxical embolism through a PFO.

About NMT Medical, Inc.

NMT Medical is an advanced medical technology company that designs, develops, manufactures and markets proprietary implant technologies that allow interventional cardiologists to treat structural heart disease through minimally invasive, catheter-based procedures. NMT Medical is currently investigating the potential connection between a common heart defect that allows a right to left shunt or flow of blood through a defect like a Patent Foramen Ovale (PFO) and brain attacks such as migraine headaches, embolic stroke and transient ischemic attacks (TIAs). A common right to left shunt can allow venous blood, unfiltered and unmanaged by the lungs, to enter the arterial circulation of the brain, possibly triggering a cerebral event or brain attack. More than 23,000 PFOs have been treated globally with NMT's minimally invasive, catheter-based implant technology.

The prevalence of migraines in the United States is about 10%. Of the 28 million migraine sufferers in America, those who experience aura and have a PFO may represent a three million patient subset. Stroke is the third leading cause of death in the United States and the leading cause of disability in adults. Each year, 750,000 Americans suffer a new or recurrent stroke and an additional 500,000 Americans experience a TIA.

For more information about NMT Medical, please visit www.nmtmedical.com.

This press release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements - including statements regarding the CLOSURE I trial, regulatory approvals for the Company's products, and the Company's investment in product development - involve known and unknown risks, uncertainties or other factors that may cause actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by such forward- looking statements. Factors that may cause such a difference include, but are not limited to, the Company's ability to develop and commercialize new products, potential delays in the regulatory process with the U.S. Food and Drug Administration and foreign regulatory agencies, as well as risk factors discussed under the heading "Risk Factors" included in the Company's Annual Report on Form 10-K for the year ended December 31, 2006 and subsequent filings with the U.S. Securities and Exchange Commission.

Source: NMT Medical

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