CHICAGO—At two years, in patients with symptomatic severe aortic stenosis (AS) who were high-risk candidates for surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR) remained equivalent to surgical AVR with similar rates of all-cause and cardiovascular mortality; and symptom improvement was similar in both groups and maintained through two years, based on the longer term PARTNER A results, presented March 26 at the 61st annual American College of Cardiology (ACC) scientific session.
An estimated 5 percent of people age 75 and older have aortic stenosis, which represents approximately 300,000 Americans. Every year, some 50,000 of them undergo SAVR to replace failing gateways, but at least one-third of patients do not undergo treatment despite symptoms because of other medical conditions, age or preference.
Last year, at ACC.11, the PARTNER A trial reported preliminary results comparing SAVR with TAVR in 699 high-risk AS patients were randomly assigned to AVR (351 patients) or TAVR (348 patients) at 25 centers (22 in the U.S.). In this study, of which Susheel K. Kodali, MD, of New York-Presbyterian in New York City, is the lead investigator, all patients were followed for at least two years, with assessment of clinical outcomes and echocardiographic evaluation. The TAVR arm patients received the Edwards Sapien THV valve (Edwards Lifesciences), with 492 patients receiving the valve transfemorally and 207 patients receiving the valve transapically.
“This trial is not powered to examine the differences between the transapical and the transfemoral arms, but PARTNER IIA has a larger cohort, and will hopefully reveal some of explanations,” said Kodali during his presentation.
At two years, the rates of death from any cause were similar in the TAVR and surgery groups, with 33.9 percent in the TAVR group and 35 percent in the surgery group. The frequency of all strokes during follow-up did not differ significantly between the two groups. However, the baseline predictors of mortality were different for TAVR—including body mass index and peripheral vascular disease—and surgery—including STS score and moderate to severe mitral regurgitation. Kodali also reported that adverse procedural events had a significant impact on subsequent mortality, including stroke and major bleeding (for TAVR and SAVR) and major vascular complications (for TAVR).
At 30 days, strokes were more frequent with TAVR than with surgical replacement (4.6 percent vs. 2.4 percent); subsequently, there were eight additional strokes in the TAVR group and 12 in the surgery group.
Strokes were similar in TAVR and surgery patients, despite increased peri-procedural events after TAVR, Kodali added. Also, there was no late (after 30 days) stroke hazard in the TAVR patients.
Improvement in valve areas was similar with TAVR and surgical replacement and was maintained for two years. Paravalvular regurgitation was more frequent after TAVR, and even mild paravalvular regurgitation was associated with increased late mortality.
“TAVR hemodynamic performance was maintained with similar valve gradients and areas compared with surgery; and there was no evidence of structural valve deterioration,” Kodali said.
Study discussant Alan G. Cribier, MD, head of the department of cardiology at the University Hospital Charles Nicolle in Rouen, France, complimented the PARTNER trialists for the “amazing” findings, adding that he was “very interested to discover that there were no differences in the endpoints at two years, with no difference of all-cause mortality.” He pointed this out because the surgeons have far more experience with the surgeries performed in the trial, than do the heart teams who were performing the TAVR procedures, as well as the use of the first-generation TAVR valve. "The valves we have in Europe [where TAVR has been approved since 2007] are far more advanced," Cribier noted.
The trial, which was simultaneously published in the New England Journal of Medicine, was funded by Edwards Lifesciences.