At the meeting, Dr. Feldman presented two analyses of the 2-year data. The first was an intention-to-treat analysis, in which any mitral valve surgery following percutaneous repair was considered an end-point event.
The second analysis was a comparison of treatment strategies, in which MV surgery following unsuccessful in-hospital percutaneous repair was not considered an end point event. In the latter analysis, subsequent surgery within 90 days of the percutaneous procedure was still considered a “success” for the MitraClip.
The composite primary efficacy end point was freedom from death, MV surgery for valve dysfunction (for device patients) or reoperation (for surgery patients), and mitral regurgitation greater than 2+ at 12 months.
In the intention-to-treat analysis, the primary composite end point was met at 2 years by 52% of the percutaneous group and by 66% of the surgery group; in the 1-year analysis, these figures were 55% and 73%, respectively.
More patients receiving the clip later had MV surgery (22%), compared with the few patients in the surgery arm who required reoperation (3.6%). There was no significant difference in mortality or recurrent mitral regurgitation.
In the second analysis, there was no statistical difference in the effectiveness end point between the two arms of the study.
“When subsequent surgery within 90 days on device patients is considered a success, we see similarly stable results at 1 and 2 years,” he noted.
In this analysis, the primary end point was met at 2 years by 63% of the percutaneous group and by 66% of the surgery group.
When the subsequent need for MV surgery is removed as an end-point event, 6.2% of the percutaneous group and 3.6% of the surgery group had MV surgery or reoperation.
There was no difference in the Kaplan-Meier mortality plot for the intention-to-treat analysis at any time point, he stressed. At 1 year, 95% of the patients in each arm were alive; at 2 years, 91% of the surgery arm and 90% of the percutaneous arm were still alive.
The Kaplan-Meier plot for freedom from MV surgery/reoperation, however, favored the surgical arm: 96% versus 78% at 2 years.
The “need for surgery in patients in the clip group was almost entirely in the first several months after therapy, and after 6 months the curves overlapped at 1 and 2 years,” he observed.
“Importantly, 78% of device patients are free from MV surgery at 2 years,” noted Dr. Feldman.
When these early failures were excluded, there were no differences in the need for MV surgery or for reoperation.
At the press conference, Dr. Feldman explained that the two analyses “answer different questions.”
“The intention-to-treat analysis gives the patient the odds of success with the clip at the end of the year,” he explained. “It tells them that 78% will be free of the need for surgery at 2 years, and 97% will have NYHA functional class I or II.”
The second analysis answers the question, “What if I am in the 20% needing surgery?” That analysis counts the combined strategy of the clip, with surgery as needed.
'Stability is the major message in the examination of 2-year outcomes' of percutaneous repair.
Source DR. FELDMAN