The landmark PARTNER 3 trial has delivered reassuring 7-year follow-up data showing that transcatheter aortic valve replacement (TAVR) continues to provide equivalent clinical outcomes to surgical aortic valve replacement in low-risk patients with severe aortic stenosis. The results, presented at TCT 2025 and published simultaneously in the New England Journal of Medicine, address critical questions about the long-term durability of the minimally invasive procedure.
Sustained Clinical Equivalence
The international trial followed 1,000 patients (mean age 73.4 years; 70% male) with an STS predicted risk of mortality less than 4% across 71 centers. At 7 years, the primary composite endpoint of death from any cause, stroke, or rehospitalization occurred in 34.6% of TAVR patients compared to 37.2% of surgery patients (HR 0.87; 95% CI 0.70-1.08), a difference that was not statistically significant.
All-cause mortality rates were 16.8% in the TAVR group versus 19.5% in the surgery group (HR 1.17; 95% CI 0.86-1.59). The mortality curves showed an interesting pattern, with TAVR demonstrating early advantages in the first year, followed by surgical outcomes improving from years 1 to 7, ultimately resulting in roughly equivalent outcomes.
"There is catch-up occurring with surgery so that by 7 years things are roughly equal in all components of the primary endpoint," explained coprincipal investigator Michael Mack, MD, from Baylor Scott & White Health.
Valve Durability Concerns Addressed
Perhaps most importantly for the field, the study found no significant difference in bioprosthetic valve failure rates between the two approaches. The rate of all-cause bioprosthetic valve failure was 6.9% in the TAVR group compared to 7.3% in the surgery group. Similarly, aortic valve reintervention rates were nearly identical between the two treatment arms.
"We were all wondering if there was a difference in valve durability and reintervention," said Philippe Généreux, MD, one of the PARTNER 3 investigators from Morristown Medical Center. "This should be very reassuring for patients. We now have data up to 7 years to say that both therapies offer similar results."
The balloon-expandable bioprosthetic valve (Sapien 3; Edwards Lifesciences) demonstrated stable hemodynamic performance throughout the follow-up period. The mean aortic gradient was slightly higher with TAVR than surgery (13.1 vs 12.1 mm Hg; P = 0.02), but both measures remained stable from 1 to 7 years. Paravalvular regurgitation was also stable and appeared to have no impact on all-cause mortality.
Clinical Considerations and Limitations
While the overall outcomes were reassuring, the study did identify some differences between treatments. Clinical valve thrombosis per the VARC-3 definition was higher in the TAVR group at 2.8% compared to 0.5% with surgery. However, this higher rate of valve thrombosis did not translate into increased stroke risk or bioprosthetic valve failure.
Stefan Blankenberg, MD, from the University Heart & Vascular Center in Hamburg, urged caution around the valve thrombosis findings while acknowledging the importance of the long-term durability data for confirming TAVR's sustainability in low-risk populations.
The study faced some methodological challenges, including disproportionate loss to follow-up in the surgical arm. Seven-year follow-up was available for 92.7% of TAVR patients compared to 86.1% of surgery patients. Investigators attempted to address this through a virtual status sweep using publicly available data, which captured additional mortality information but could not account for other endpoints like stroke and rehospitalization.
Implications for Clinical Practice
The findings reinforce TAVR's established role in treating low-risk patients with aortic stenosis, though they may not immediately expand its use to younger populations. Only 7% of PARTNER 3 patients were under 65 years old, limiting conclusions about younger patient outcomes.
"I don't see a reason for this to change practice," Mack noted. "It gives more confidence in both therapies. The question about whether this moves TAVR into younger patients—it doesn't give any evidence because only 7% of the PARTNER 3 patients were under 65."
Benjamin Hibbert, MD, PhD, from Mayo Clinic, suggested that the data support considering definitive trials in younger populations. "Given these very reassuring results, it's time to embark on a definitive trial in a young population," he said. "TAVR has a seat at the table in the discussion of lifetime management in patients with longer expected survival."
The investigators plan to continue following patients to report 10-year outcomes and valve durability data, which will provide even more comprehensive information about the long-term performance of both treatment approaches in this patient population.
