The PARTNER-3 and Evolut trials were heralded as a landmark advance in medicine when the 1-year results from the two studies were presented back in 2019. Both trials suggested benefits of the less-invasive TAVR approach over surgery.
But because these low-surgical-risk patients are younger and will likely have a longer lifespan than will higher risk patients for whom the TAVR technique was first established, patient outcomes and information on how the TAVR devices hold up over the long-term are critical to inform clinical decision-making.
Latest results from the two trials show that the initial benefits of TAVR over surgery seen in PARTNER-3 seem to have attenuated over the longer-term, with main outcomes looking very similar in both groups after 5 years.
However, in the Evolut trial, the early benefit in all-cause mortality or disabling stroke seen in the TAVR group is continuing to increase, with current results showing a 26% relative reduction in this endpoint with TAVR vs. surgery at 4 years.
The 5-year results of the PARTNER-3 trial and the 4-year results of the Evolut study were presented Transcatheter Cardiovascular Therapeutics annual meeting sponsored by the Cardiovascular Research Foundation. Both sets of results were simultaneously published online: PARTNER-3 in The New England Journal of Medicine and Evolut in JACC.
Marty Leon, MD, of NewYork-Presbyterian Columbia University Irving Medical Center, who presented the PARTNER-3 results, said in an interview that both trials are good news for TAVR:
“Both trials have clearly reaffirmed clinical and echocardiographic benefits of TAVR as a meaningful alternative therapy to surgery in low-risk severe symptomatic aortic stenosis patients.” Michael Reardon, MD, Houston Methodist Debakey Heart & Vascular Center, who presented the Evolut results, agreed that both trials were positive for TAVR “as TAVR just has to be as good as surgery to be a winner because clearly it is a lot less invasive.”
But Dr. Dr. Reardon added that, “In making that decision for younger lower-risk patients, then the Evolut valve is the only TAVR valve that has shown superior hemodynamics and durability at all time points with excellent outcomes and widening benefits compared with surgery over the first 4 years.”
PARTNER-3
The PARTNER-3 trial randomly assigned 1,000 patients with severe symptomatic aortic stenosis and low surgical risk to undergo either TAVR with the SAPIEN 3 transcatheter heart valve or surgery.
The results at 5 years show no difference in the two primary composite outcomes between TAVR and surgery patients.
The incidence of the composite end point of death, stroke, or rehospitalization related to the valve, the procedure, or heart failure was similar in the TAVR group and the surgery group, occurring in 22.8% of patients in the TAVR group and 27.2% in the surgery group, which is a nonsignificant difference (P = .07).
The incidence of the individual components of the composite end point were also similar in the two groups. Death occurred in 10.0% in the TAVR group and 8.2% in the surgery group; stroke in 5.8% of the TAVR group and 6.4% of the surgery group; and rehospitalization in 13.7% and 17.4%, respectively.
Aortic-valve durability also looked similar in the two groups. The hemodynamic performance of the valve, assessed according to the mean valve gradient, was 12.8 mm Hg in the TAVR group and 11.7 mm Hg in the surgery group. Bioprosthetic-valve failure occurred in 3.3% of the patients in the TAVR group and in 3.8% of those in the surgery group.
Among the secondary end points, atrial fibrillation and bleeding appeared to be less frequent in the TAVR group than in the surgery group, whereas paravalvular aortic regurgitation, valve thrombosis, and pacemaker implantation appeared to be less frequent in the surgery group.
Functional and health-status outcomes assessed according to New York Heart Association class, quality of life scores, and the percentage of patients who were alive and well at 5 years appeared to be similar in the two groups.
“These data are reassuring,” Dr. Leon said. “Cardiovascular mortality occurred at a rate of about 1% per year with both therapies, strokes at the rate of 1% per year with both therapies, and hospitalization for cardiovascular reasons at about 3% per year with both therapies. For patients in their 70s, these are very good numbers.”
Along with showing similar outcomes for TAVR and surgery at 5 years, he added, “the need for re-intervention was particularly low (2%-3%) and equivalent for both approaches. And structural valve deterioration was also very low and equivalent in both groups.”