DEDICATE-DZHK6 Trial in Germany Compares TAVR and SAVR in Low-Risk Patients

April 8, 2024—The DEDICATE-DZHK6 trial compared transcatheter aortic valve replacement (TAVR) versus surgical aortic valve replacement (SAVR) in 1,414 patients who underwent valve replacement procedures at 38 centers in Germany. The study was funded by the German Center for Cardiovascular Research with financial support by the German Heart Foundation.

The background of the study is that guidelines in the United States recommend TAVR versus open heart SAVR for older patients and those patients with high cardiovascular risk. However, previous studies and different countries’ guidelines have varied when it comes to determining the optimal approach for younger and lower-risk patients.

In DEDICATE-DZHK6, TAVR was found to bring no increased risks and was associated with substantial decreased rates of death or stroke at 1 year in low-risk patients, compared with SAVR.

The study data were presented by Moritz Seiffert, MD, at ACC.24, the American College of Cardiology’s Annual Scientific Session held April 6-8 in Atlanta, Georgia. The data were simultaneously published online by Stefan Blankenberg, MD, et al in The New England Journal of Medicine.

“We can now provide strong data that in this low-risk patient population, you could very safely offer TAVR versus SAVR,” commented Dr. Seiffert in the press release from ACC. “TAVR is less invasive; it’s usually performed under local anesthesia, lasting 30-60 minutes, and the convalescence is shorter than with open chest surgery. [These findings offer] a strong argument toward catheter-based treatment, at least for the one-year timeframe of this study, in these patients.”

Dr. Seiffert is a professor of cardiology at BG University Hospital Bergmannsheil, Ruhr University Bochum in Bochum, Germany.

As summarized in the ACC press release, all patients enrolled in the trial were eligible for either TAVR or SAVR and had similar characteristics in terms of the severity of aortic stenosis and a similar balance of risks and benefits expected with either type of procedure.

The average age of patients was 74 years and 43% were women. The study excluded patients with bicuspid valves, previous heart surgery, or additional coronary or valvular diseases requiring further treatment.

The investigators randomly assigned half of the patients to undergo TAVR and the other half to SAVR.

Additionally, because the trial was intended to mirror real-world conditions, many decisions were left to the local heart teams at each study site, rather than strict predetermined study protocols. Local interdisciplinary heart teams determined which patients were eligible to participate in the study based on broad inclusion criteria. Operators selected which replacement valve to use and followed their own center’s standard practices for performing the procedures.

The coprimary safety endpoint was designed to assess whether TAVR was noninferior to SAVR as indicated by an absolute increase of no more than 1% in the composite rate of death or stroke at 1 year.

The trial met this endpoint, showing that people who underwent TAVR were 47% less likely than those undergoing SAVR to experience death or stroke at 1 year. Event rates for several secondary endpoints, including all-cause death or disabling stroke, were also significantly lower in patients undergoing TAVR compared with those undergoing SAVR at 1 year.

Dr. Seiffert stated, “Although we primarily tested for noninferiority, the magnitude of the difference surprised us. 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.”

Investigators 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, noted the ACC press release.

The investigators stated that the findings are likely generalizable to patient populations and health care environments across many developed countries.

“What it really adds to previous trials is that it mirrors clinical routine,” concluded Dr. Seiffert in the press release. “It’s completely industry independent, not focused on one particular device but comparing a catheter-based strategy to a surgical strategy overall. That makes it more applicable and aligned with the types of decisions physicians are making in their daily medical work.”

The ACC press release advised that the investigators will continue to track outcomes for at least 5 years. Future analyses will include additional metrics for assessing clinical superiority as well as quality of life outcomes. In addition, investigators plan to examine whether certain subgroups appear to derive specific risks or benefits from one approach or the other.