The nature of U.S. transcatheter aortic valve replacement (TAVR) shifted dramatically in mid-June when the Food and Drug Administration, in two separate actions timed just days apart, approved marketing of next-generation models for the only two transcatheter aortic valve replacement systems on the U.S. market.
For inoperable or high-risk patients in came the Edwards Sapien 3 and the CoreValve Evolut R systems, and out went the Sapien XT and the original CoreValve. In the process the transcatheter aortic valve replacement (TAVR) procedures available to American patients on a routine basis became smaller – meaning more likely to use transfemoral approaches, less likely to cause substantial paravalvular leak, less likely to cause stroke, and in the case of the Evolut system also became repositionable and less likely to result in the need for a pacemaker.
With approvals of these two latest-generation devices, in both cases based on follow-up data of only 30 days, “we have really expanded the types of patients who can be treated with TAVR in the U.S., and we can do it with better products and get better outcomes. I am thrilled this technology will be available to patients,” said Dr. Jeffrey J. Popma , a lead investigator for the Evolut U.S. pivotal trial and professor of medicine at Harvard University in Boston.
The pair of approvals were also notable as clear demonstration that the FDA was willing to base its decisions on 30-day follow-up data, a step closer to the approval model it applies to heart valves placed using open surgery. Perhaps most attention-grabbing of all, the FDA based its approval of the Evolut system on data from a total of 151 patients, with 60 coming from the ex-U.S. trial designed to secure a CE mark in Europe, and the other 91 patients the first ones enrolled in what was designed to be the U.S. pivotal trial for Evolut, with a planned enrollment of 250 patients that had almost fully filled by mid-June.
“This was a really good week for the FDA,” said Dr. Popma. “The FDA approved devices with reasonable assurance of safety and efficacy but without the burden of requiring 1 or more years follow-up. We are seeing a changed FDA,” he declared in an interview.
Although the full dataset for all 151 patients that the FDA used to approve the self-expanding Evolut system has not yet been released, investigators from the U.S. trial say data from their first 91 patients looked similar to the 60 patients in the CE trial, the results of which appeared in a poster in March at the annual scientific sessions of the American College of Cardiology.
The CE trial enrolled 60 symptomatic extreme- or high-risk patients at six centers in Australia, New Zealand, and the United Kingdom, who averaged 83 years old and had an average Society of Thoracic Surgeons predicted mortality estimate of 7%. Fifty-nine of the 60 patients (98%) had their TAVR done via the transfemoral route, and during 30-day follow-up no patients died and none had a stroke. The researchers identified a moderate or severe paravalvular leak in 3% of patients after 30 days, and 12% of patients had a new need for a pacemaker. By comparison, in the CoreValve pivotal trial for the first-generation version of this self-expanding valve, death occurred in 3% of patients after 30 days, major strokes in 4%, moderate or severe paravalvular leaks occurred in 9%, and 20% of patients by that point had required placement of a new pacemaker ( N. Engl. J. Med. 2014;370:1790-8 ).
The striking reductions in more severe paravalvular leaks and in the need for a pacemaker likely related at least in part to the ability to reposition the Evolut valve during placement as long as the valve was not more than 80% deployed and as long as retrieval was not attempted more than three times.
Repositioning is “huge” said Dr. Mathew R. Williams , chief of adult cardiac surgery and director of interventional cardiology at New York University, and one of two lead investigators on the U.S. CoreValve Evolut R pivotal trial. “We don’t need to use it most of the time, but having that ability reduces stress and helps make the operator more comfortable,” he said in an interview. The more optimized positioning allowed by the recapture feature likely helped minimize both paravalvular leaks and the valve’s ability to trigger an arrhythmia and need for pacing. In the CE trial the operator used the repositioning function in 15 patients (25%) for a total of 22 repositioning events.
Like Dr. Popma, Dr. Williams welcomed the June 17 approval of the Sapien 3 TAVR system, based on 30-day outcomes from all 583 patients enrolled in the U.S. pivotal trial. Results from that study became public last March in a late-breaker report at the American College of Cardiology meeting.
Sapien 3 treatment of high-risk, symptomatic patients, who averaged 83 years old and had a STS predicted mortality rate of 8.6%, resulted in a 2% mortality rate, a 1.5% stroke rate, a 3% rate of moderate or severe paravalvular leaks, and 13% of patients had a new need for a pacemaker, Dr. Susheel Kodali reported when he presented these data in March. Trial investigators were able to place the Sapien 3 aortic valve via a transfemoral approach in 491 of the 583 patients (84%) enrolled in the study. The adverse outcomes with Sapien 3 contrasted with rates for the prior Sapien XT TAVR system of 3.5% for 30-day mortality, 4.3% for strokes, and a 24% rate of moderate or severe paravalvular leak, said Dr. Kodali, director of the heart valve program at Columbia University in New York.
While the Sapien 3 and Evolut systems appeared to produce roughly similar outcomes for parameters like 30-day mortality, stroke, and paravalvular leak rates, with both systems outperforming what they displaced, the Evolut has two important differences, compared with Sapien 3. First, the Evolut is slightly smaller, with the ability to traverse arteries as narrow as 5 mm, whereas the minimum vessel size for Sapien 3 passage is 5.5 mm; second, Evolute is repositionable, while Sapien 3 is not.
The CoreValve Evolut R trials were sponsored by Medtronic. Dr. Popma has received research grants from and served as a speaker on behalf of Medtronic. He has also been a speaker for Abbott Vascular, Boston Scientific, Covidien, Cook Medical, and Direct Flow Medical and has received research support from five other companies. Dr. Williams has been a consultant to and received research support from Medtronic and has also been a consultant to Edwards and Direct Flow Medical. The Sapien 3 trial was sponsored by Edwards. Dr. Kodali has received research support from Edwards, has an equity interest in Thubrikar Aortic Valve, has received honoraria from St. Jude, and has served on the steering committee for trials sponsored by Claret Medical and Meril.
On Twitter @mitchelzoler