Abbott to Acquire Evalve; MitraClip's EVEREST Data Presented at TCT

September 10, 2009—Abbott Vascular (Santa Clara, CA) announced a definitive agreement to acquire the outstanding equity of Evalve, Inc. (Menlo Park, CA). Evalve's minimally invasive, catheter-based MitraClip system is approved in Europe for nonsurgical mitral valve repair for patients with mitral regurgitation (MR). The MitraClip system is an investigational device in the United States and is currently in clinical trials.

The transaction is expected to close in the fourth quarter of 2009, Abbott stated.

On September 22, Evalve announced that data were presented from the company's EVEREST (Endovascular Valve Edge-to-Edge Repair Study) registries studying reduction in MR at 12 months after percutaneous mitral valve repair with the MitraClip. The data were presented at the Transcatheter Cardiovascular Therapeutics (TCT) 2009 scientific symposium in San Francisco. Ted Feldman, MD, is principal investigator of the EVEREST studies, including the EVEREST I feasibility study and the EVEREST II pivotal study.

Scott Lim, MD, presented 12-month data from a subset of the initial registry cohort of the EVEREST studies. The data showed that sustained reduction of MR after mitral valve repair with the MitraClip system in patients with degenerative MR or functional MR (FMR) led to heart function improvements.

This subset of the initial EVEREST registry cohort was comprised of 79 patients with moderate-to-severe (grade 3+) or severe (grade 4+) MR who had discharge MR reduction to grade 2+ or less. Of the 79 patients, 73% had degenerative MR and 27% had FMR, and 49 patients continued with a MitraClip device with MR less than or equal to grade 2+ at 12 months. Matched core laboratory echocardiographic data was available at baseline and 12 months. Mean MR grade reduced from 3.1 ± 0.7 at baseline to 1.4 ± 0.5 at 12 months. Multiple indices of left ventricle (LV) function improved significantly (LV volumes, LV mass, LV sphericity, and forward stroke volume), and there was no significant change in annular dimensions.

Also at TCT, Evalve announced that Renu Virmani, MD, presented a subset of data from the EVEREST study that showed that the mechanical integrity of the MitraClip device for repair of the mitral valve was maintained for up to 5 years and with complete healing. The data also showed complete fibrous encapsulation of the MitraClip device with organized, endocardial tissue growth demonstrating complete healing and incorporation of the implant within the native mitral valve. Additionally, no significant stenosis or inflammation was observed beyond 300 days.

In the EVEREST study, 16 MitraClip devices were explanted more than 300 days after implantation. During explant surgery, the fibrous capsule often requires dissection in order to perform surgical repair of the valve. Dr. Virmani reported on three MitraClip explants with minimal tissue disturbance. In these three MitraClip explants, a fibrous tissue bridge with a mean thickness of 10.01 ± 2.09 mm was observed over and between the MitraClip device arms resulting in tissue continuity between the two valve leaflets. Tissue growth over the MitraClip device arms had a mean thickness of 0.82 ± 0.74 mm. There was no (or minimal) inflammation and no evidence of infection or stenosis. None of the 16 long-term MitraClip implants studied demonstrated any evidence of wear, component fracture, or corrosion for up to 5 years.

Also at TCT, Evalve announced that Saibal Kar, MD, presented 12-month data from the EVEREST II high-risk registry arm. In the data, high-risk patients with FMR after valve repair with the MitraClip system showed a reduction in mitral annular dimension, improvement in heart function, and a reduction in hospitalization for congestive heart failure. This data included 34 patients from the high-risk registry with moderate-to-severe (3+) or severe (4+) FMR who received a MitraClip device and had matched core laboratory echocardiographic data at baseline and 12 months. Results included a mean MR grade reduction from 3.2 ± 0.5 at baseline to 1.8 ± 0.9 at 12 months. In addition to the reduction of MR, there was significant reduction in the systolic and diastolic septolateral mitral annular diameter as well as a significant reduction in left ventricular end diastolic and systolic volumes. LV ejection fraction did not change significantly from baseline, although forward stroke volume improved, indicating improved cardiac efficiency, the company stated.