Data from a large trial of the Sapien line of replacement heart valves made by Edwards Lifesciences (NYSE:EW) are slated to be used to back bids for expanded indications in intermediate-risk patients.
Presented over the weekend at the American College of Cardiology’s annual meeting in Chicago, results from the Partner II trial involving the Sapien XT and Sapien 3 transcatheter aortic valve replacements compared the TAVR treatments with traditional open surgery in the intermediate-risk cohort (both of the Edwards valves are already approved in the U.S. for high-risk patients).
Sapien XT non-inferior to surgery at 2 years
For the 2nd-generation Sapien XT, approved by the FDA back in June 2014, the study followed 2,032 patients for 2 years. There were no significant difference between the groups for the primary endpoint, death from any cause or disabling stroke, according to the study, which was also published in the New England Journal of Medicine.
“The main results from the Partner II cohort A randomized trial involving intermediate-risk patients can be summarized as follows. First, TAVR, performed in experienced centers, with the use of a lower-profile, next-generation device, was non-inferior to surgery with respect to outcomes at 2 years (death from any cause or disabling stroke). Second, bioprosthetic-valve gradients were lower and the areas were greater with the Sapien XT valve, as compared with surgical valves, whereas the incidence of paravalvular aortic regurgitation was higher after TAVR than after surgery. Third, several benefits with regard to secondary end points were associated with TAVR, including lower risks of bleeding events, acute kidney injury, and new-onset atrial fibrillation, as well as more rapid early recovery that resulted in shorter durations of stay in the ICU and hospital,” the researchers wrote.
“The Partner II trial is unique in its size, distinctive in rigor of execution and exceptional in patient outcomes, making it 1 of the most important trials in the history of our field,” senior author & co-principal investigator Dr. Craig Smith, of the New York’s Columbia University Medical Center, said in prepared remarks.
“With this 2nd-generation valve, TAVR, certainly from a statistical standpoint, was noninferior [to surgery], and in every 1 of the analyses, the point estimate favored TAVR vs. surgery,” added co-principal investigator Dr. Martin Leon, also of the Columbia University Medical Center. “And when you do the subgroup analyses in the transfemoral cohort, which was 76% of the patients, it was significantly better than surgery for the primary endpoint of death and significant stroke.
“If you are a candidate for transfemoral, that’s good. If you are not a candidate, we can’t discern any benefit [of TAVR] other than [it being a] lower risk, beating-heart procedure. We can’t discern any particular hard-endpoint, clinical benefit compared to open surgery.” That said, the overall lower rate of acute kidney injury, major bleeding, and atrial fibrillation and the shorter ICU stay are “are meaningful,” Leon told TCTMD.
The secondary endpoint, rate of disabling stroke, despite FDA-mandated neurological assessment.
“That meant that every patient in both groups had to be seen by a neurologist before the procedure, after the procedure, before discharge, and at follow-up, and the ascertainment of stroke is always much higher when you do that,” Leon told the website. “So the fact that the absolute stroke rates were actually numerically less than the earlier Partner trial, even in the setting of neurology oversight, suggests that the frequency is probably going down.”
Sapien 3 fares well after 1 year
For the Sapien 3 device, which won a nod from the FDA in June 2015, Partner II studied 1,077 patients for 1 year. The results, published in The Lancet, compared the Sapien 3 outcomes with a surgically treated cohort.
All-cause mortality for the Sapien 3 group was 7.4%, compared with 13.0% for the surgical arm. The cardiovascular death rate was 4.5% for the TAVR arm and 8.1% for the surgical arm; rates of stroke were also lower for the transcatheter group, both in terms of all strokes (4.6% for TAVR, 8.2% for surgical) and disabling stroke (2.3% to 5.9%). The combined all-cause death & disabling stroke rate was 8.4% for TAVR with Sapien 3 and 16.6% for the surgery arm.
“TAVR with Sapien 3 in intermediate-risk patients with severe aortic stenosis is associated with low mortality, strokes, and regurgitation at 1 year. The propensity score analysis indicates a significant superiority for our composite outcome with TAVR compared with surgery, suggesting that TAVR might be the preferred treatment alternative in intermediate-risk patients,” the researchers wrote.
“Results from the Partner II trial presented at ACC should establish the Sapien 3 valve as the new benchmark for the treatment of intermediate-risk patients with severe, symptomatic aortic stenosis,” co-principal investigator Dr. Vinod Thourani, of the Emory University School of Medicine, said in prepared remarks. “The size and rigor of this 3,000-patient Partner II trial provide powerful evidence in favor of this therapy for the treatment of patients with aortic stenosis.”
