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| Third-generation CoreValve TAVR--Courtesy of Medtronic |
The patients in the successful CE mark trial for Medtronic's ($MDT) third-generation CoreValve TAVR would have had a 7% of chance of dying within 30 days if they received open heart surgery, according to a measure of risk developed by the Society of Thoracic Surgeons. Instead, all 60 patients were alive 30 days after the implantation of the company's CoreValve Evolut R. And there were just two cardiovascular deaths after 6 months.
The data marks a tremendous week for transcatheter aortic valves at the EuroPCR conference in Paris. TAVRs are delivered minimally invasively via catheter in elderly patients who are too frail to withstand the rigors of open heart surgery.
The devices already enable therapy in patients who may have had no options previously, and the latest batch of data from Medtronic and others demonstrates that device companies continue to make improvements on the relatively new paradigm, potentially setting the stage for use of TAVRs in lower-risk patients.
The "R" in CoreValve Evolut R stands for repositioning and retrieval, according to study investigator Dr. Ian Meredith of Australia's MonashHeart medical clinic. "Think of third generation valves as valves that you can put in reverse," he said in an interview.
That's because the latest generation of CoreValve can be retrieved and moved in reverse using its revamped delivery catheter once the valve is initially positioned, allowing cardiologists to make minor adjustments, resulting in fewer complications like paravalvular leak, Meredith said.
After 6 months, 7.4% of the Evolut R's trial patients had moderate paravalvular leak and there were no severe cases. That's partly because of the new retrieval and repositioning feature. It was used in one-fourth of the patients to give the doctor "a second shot at things," Meredith said.
Another highlight was the low rate of pacemaker implantation (13.4% 6 months after implantation), Meredith said.
Other TAVRs including those from Boston Scientific and Direct Flow Medical also reported low mortality rates, and St. Jude Medical's was cleared of safety of concerns that had halted its use for a few months. Meredith singled out Edward's Sapien 3 for its "brilliant" post-market registry results. Edward's Sapien was the first TAVR to market, and only other one to boast FDA approval, making it the CoreValve's fiercest competitor.
There's more than CE mark approval for use in Europe that was at stake in the Evolut R's 60-person trial. The accumulation of positive data has already led TAVRs to be used in lower-risk patients, such as younger heart failure patients.
Meredith said the latest information released at EuroPCR clears the way for further use of TAVRs in lower-risk patients. The gradual shift toward use of TAVRs in slightly lower-risk patients should continue as evidence of the new treatment paradigm's efficacy and safety mounts.
But don't expect 40-years-olds with a long remaining life expectancy to receive them any time soon, for Meredith said that the long-term durability of the valves is not yet known. That's because TAVRs are typically implanted in patients older than 80, and previous postmarket registry data has shown that their one-year mortality rate is close to 25%.