TAVR was found to bring no increased risks and was associated with substantially decreased rates of death or stroke at one year in low-risk patients, compared with surgical aortic valve replacement (SAVR), according to results from the DEDICATE-DZHK6 study presented during a Late-Breaking Clinical Trial session at ACC.24 in Atlanta and simultaneously published in the New England Journal of Medicine.

Researchers randomized 1,414 patients (mean age 74 years, 57% men) to TAVR (n=701) or SAVR (n=713) at 38 sites in Germany. Their median Society of Thoracic Surgeons risk score was 1.8%. Local interdisciplinary heart teams determined which patients were eligible to participate in the study based on broad inclusion criteria, although patients with bicuspid valves, previous heart surgery or additional coronary or valvular diseases requiring further treatment were excluded. Operators selected which replacement valve to use and followed their own center's standard practices for performing the procedures.

Results showed that the primary composite outcome of death from any cause or fatal or nonfatal stroke at one year in this noninferiority trial was 47% lower with TAVR vs. SAVR. The primary outcome occurred in 5.4% of the TAVR group and 10.0% of the SAVR group (hazard ratio [HR], 0.53; 95% CI, 0.35-0.79; p<0.001 for noninferiority).

The incidence of death from any cause was 2.6% in the TAVR group and 6.2% in the SAVR group (HR, 0.43; 95% CI, 0.24-0.73) and the incidence of stroke was 2.9% and 4.7% respectively (HR, 0.61; 95% CI, 0.35-1.06). Procedural complications occurred in 1.5% of patients who underwent TAVR and 1.0% of patients who underwent SAVR.

"Although we primarily tested for noninferiority, the magnitude of the difference surprised us," said Moritz Seiffert, MD, one of the study authors. "Valve prosthesis selection based on individual patients' anatomical and medical considerations may have played a role. In addition, the COVID-19 pandemic might have amplified the surgical risk. In fact, the relative difference was comparable to previous studies, but the overall higher event rates and larger patient population may have led to these significant results."

Researchers plan to further investigate some factors that set the trial apart from previous studies and may have contributed to the substantially reduced risk in the TAVR group, including the relatively high proportion of females in the study group. The data were consistent among the subgroups tested so far. Outcomes in the study population will be followed for at least five years.

In an accompanying editorial comment, Pinak Bipin Shah, MD, FACC, wrote that "Although the early favorable outcomes of TAVI that were seen in the current trial are encouraging, heart teams will continue to need to balance patient preference with the current reality of the unknowns regarding the long-term outcomes of TAVI when deciding on a treatment pathway with patients. However, with each passing year, the unknowns are becoming knowns, and the future of TAVI appears to be bright."