NMT Medical, Inc. (Nasdaq: NMTI) announced today that it has received conditional approval from the U.S. Food and Drug Administration (FDA) for modifications the Company requested to its current investigational device exemption (IDE) for its pivotal PFO (patent foramen ovale)/migraine clinical study, MIST II. The changes are supported by the Company's previous trials -- MIST and BEST (BioSTAR(R) Evaluation STudy). The FDA granted approval to adjust the primary endpoint for the study from resolution to reduction of migraine headaches and to upgrade the implant used in the study from STARFlex(R) to NMT's new bioabsorbable implant, BioSTAR(R). MIST II's modified design will evaluate the safety and effectiveness of NMT's proprietary catheter-based implant technology for the treatment of migraine headaches in patients with a PFO.

A PFO is a common heart defect that may be a potential risk factor for migraine headaches in some patients. The PFO allows venous blood, unfiltered and unmanaged by the lungs, to enter the arterial blood circulation. The unfiltered venous blood may contain elements that can trigger migraines in some patients.

John E. Ahern, NMT's President and Chief Executive Officer, said, "The approved clinical trial changes represent an important milestone for NMT and will benefit patients and our clinical partners in several ways. First, we believe patients participating in the MIST II study will benefit from the advantages of our latest PFO closure technology, BioSTAR(R), including faster healing and more complete closure.

"Second, the MIST II clinical research team and the patients they enroll will participate in the only PFO/migraine clinical trial designed to reflect clinical evidence from a predicate PFO/migraine study, MIST. Completed earlier this year, NMT's MIST trial in the United Kingdom is the only prospective study that showed a PFO/migraine connection and a positive treatment effect.

"Lastly, we believe that the MIST II changes extend the Company's leadership position in PFO clinical research and technology. We provided the FDA with real-time data from our recently completed BEST study and clinical evidence from our randomized, double-blinded MIST study. As a result, we have transformed MIST II into a stronger, U.S.-based PFO/migraine study with a clinically relevant primary endpoint."

MIST II is a prospective, randomized, multi-center, controlled study. The double-blinded trial is designed to randomize approximately 600 migraine patients with a PFO to either PFO closure with NMT's implant technology or a control arm. More than 40 leading migraine headache specialists and interventional cardiologists have committed to participate in MIST II.

MIST II will employ the bioabsorbable BioSTAR(R) implant. As reported in NMT's recently completed BEST study, BioSTAR(R) achieved a post implant complete closure rate of 92% at 30 days and 96% at six months. Over time, 90% to 95% of the BioSTAR(R) implant is absorbed and replaced with the patient's native tissue providing a more natural, biological closure of their PFO.

Stewart Tepper, MD and Mark Reisman, MD are the co-principal investigators of the MIST II clinical trial. Dr. Tepper is Director of The New England Center for Headache in Stamford, Connecticut. Dr. Reisman is Director of Cardiovascular Research at Swedish Medical Center, Seattle, Washington.

Ahern concluded, "The MIST II modifications are a considerable achievement and reflect a tremendous amount of collaborative work from our strong clinical and regulatory partnerships and our dedicated employees."

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 cardiac sources of migraine headaches, stroke and other potential brain attacks through minimally invasive, catheter-based procedures. NMT Medical is investigating the potential connection between a common cardiac defect called a PFO and brain attacks such as migraine headaches, stroke and transient ischemic attacks (TIAs). A PFO 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 21,000 PFOs have been closed 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 500,000 Americans experience a TIA.

The Company also serves the pediatric interventional cardiologist with a broad range of cardiac septal repair implants delivered with nonsurgical catheter techniques. For more information about NMT Medical, please visit nmtmedical.

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 amount of patient enrollment and outcome of the Company's MIST II trial, as well as its BioSTAR(R) program, expansion of the Company's cardiovascular business and market opportunities, including migraines and any other new applications for the Company's technology or products, regulatory approvals for the Company's products in the United States and abroad, 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, a potential delay 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 "Certain Factors That May Affect Future Results" included in Management's Discussion and Analysis of Financial Condition and Results of Operations in the Company's Annual Report on Form 10-K for the year ended December 31, 2005, Quarterly Report on Form 10-Q for the period ended June 30, 2006, and subsequent filings with the U.S. Securities and Exchange Commission.

NMT Medical, Inc.
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