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ATLANTA, GA — Younger, low-risk patients with aortic stenosis who need aortic valve replacement may now be able to consider a less invasive transcatheter approach rather than surgical aortic valve replacement (SAVR), as results of a randomized trial have shown no significant difference in outcomes between the two after 1 year of follow-up.

The DEDICATE-DZHK6 trial included 1404 patients aged 65 and older with severe aortic stenosis and randomly assigned them to either transcatheter aortic valve implantation (TAVI) or SAVR and found no statistically significant difference between the two, said Moritz Seiffert, MD, professor of cardiology at BG University Hospital Bergmannsheil Bochum, Ruhr University Bochum in Bochum, Germany.

For all-cause death or stroke a year after the procedure, the primary study endpoint, the rates were 10% for SAVR and 5.4% for TAVI vs an assumed overall event rate of 6.2% at the outset of the study. The hazard ratio between the two was 1.14, conferring a small 14% relative risk to SAVR, he said.

"The study adds to the current evidence that TAVI in a low-to-intermediate-risk patient population that mirrors clinical routine is safe and noninferior to SAVR for the timeframe of 1 year," Seiffert told theheart.org | Medscape Cardiology. "In fact, event rates were substantially lower for the primary outcome and some key secondary outcomes for TAVI compared to SAVR."

Seiffert reported the trial results on April 8 at the annual meeting of the American College of Cardiology, and they were published simultaneously online in the New England Journal of Medicine.

The study enrolled patients with low-to-intermediate operative risk on the basis of the heart team assessment, Siefert said. They had their procedures at 38 heart centers throughout Germany. The average age of the patient population was 74.3 years in the TAVI arm and 74.6 years in the SAVR arm. The percentage of male patients was 56% and 57.3%, respectively.

The study also split out all-cause death and stroke separately. For the former, the rates were 6.2% in the SAVR arm and 2.6% in the TAVI patients. The stroke rates were 4.7% and 2.9%, respectively.

The study also looked at a host of secondary endpoints, with no significant difference seen between most with the following exceptions:

• Vascular access complications, 0.7% for SAVR vs. 7.9% for TAVI, a more than 10-fold difference.
• Bleeding, 17.2% and 4.3%, respectively, a 76% lower risk with TAVI.
• New-onset left bundle branch block, 17.5% and 32%, a twice greater risk for TAVI.
• New-onset atrial fibrillation, 30.8% and 12.4%, a 64% lower risk with TAVI.
• New permanent pacemaker implantation, 6.7% and 11.8%, which is almost twice the risk with TAVI.

Echocardiography findings between the two groups were also similar after 1 year. The aortic valve mean gradient was 470 and 561 in the SAVR and TAVI arms, respectively.

"Several key secondary endpoints and components of the primary outcome were significantly lower in the TAVI compared to the SAVR groups — for example, all-cause mortality, cardiovascular mortality, disabling stroke," Seiffert said. "This was substantial. Consistent with previous studies, vascular complications and pacemaker implantation occurred more often after TAVI; bleeding and new-onset atrial fibrillation occurred more often after SAVR."

Seiffert said these patients will be followed for 5 and 10 years to get a better idea of the longer-term implications of one procedure vs the other.

"More than half of the patients were 75 years or younger," he said. "Particularly for these patients, it will be important to assess valve durability to gain insights on lifetime management of aortic valve stenosis. Hence, a 5- and 10-year follow-up will be essential to approach these open questions."

Entré for Shared Decision-Making

This study validates the need for shared decision-making for lower-risk patients with aortic stenosis, Kimberly Guibone, DNP, structural heart coordinator and clinical program manager at Beth Israel Deaconess Medical Center in Boston, Massachusetts, said.

"With this low- and intermediate-risk patient population, they are generally more savvy, and they're more consumer-oriented as opposed to years back when we had patients who were truly destined because they had no other option; they were just told that the one-time risk of SAVR was the only solution," she told Medscape Medical News.

This study at least introduces TAVI into the conversation of options for those patients, who may be younger than the typical patients decades ago and need a second procedure later in life, Guibone said.

"All of this falls under the true concept of shared decision-making, in which the patient has the right to have all the information, has the right to declare their values and preferences, and has the right to put their faith in what their final decision-making is," she said.

While she said at this point "there is no right answer," having the 5- and 10-year data Seiffert said the DEDICATE researchers are pursuing will be critical, she said. "Do you do surgery now and TAVI later, or do you do TAVI now and surgery later, or do you do TAVI-TAVI, or do you do surgery-surgery? So what is the right combination, and is it right for everybody, or case-by-case? We just don't know."

In an editorial accompanying the NEJM publication, Pinak B. Shah, MD, from the Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, wrote that, "Given the more rapid return to normal activity associated with TAVI, these results are a win for TAVI among patients at low surgical risk, even according to the noninferiority trial design."

"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," Shah concluded. "However, with each passing year, the unknowns are becoming knowns, and the future of TAVI appears to be bright."

The study was independently supported. Seiffert disclosed financial relationships with Amgen, AstraZeneca, Bristol Myers Squibb/Pfizer, Boston Scientific, Daiichi Sankyo, Edwards Lifesciences, Inari Medical, Medtronic, and Siemens Healthineers. Guibone disclosed relationships with Abbott Laboratories and Medtronic.

Richard Mark Kirkner is a medical journalist based in the Philadelphia area.