麻豆传媒

NEW ORLEANS -- Trials showing the benefits of transcatheter aortic valve replacement (TAVR) in low-risk patients were greeted with loud standing ovations, as the question now shifts to who is still a candidate for open-heart surgery.

TAVR met non-inferiority to surgical aortic valve replacement (SAVR) in the CoreValve Low Risk Trial and superiority in PARTNER 3, with fewer strokes and no significant uptick in paravalvular regurgitation among patients with severe aortic stenosis in either study.

Eugene Braunwald, MD, of Brigham and Women's Hospital in Boston, said it was an "historic moment" here at the American College of Cardiology (ACC) annual meeting. "The fact that two separate groups using two separate valves have come to very similar conclusions, this not only doubles the acceptability, but it quadruples it."

The implications for the healthcare system are great if TAVR becomes an option for many more patients; many expect FDA approval for an expanded indication to low-risk patients based on these data.

"We do TAVR; we take half the time. Nobody goes to the ICU unless there's something totally unexpected," according to cardiac surgeon Michael Reardon, MD, of Houston Methodist Hospital and co-principal investigator of the . "And once they're up on the floor, we're not spending any significant hospital money, [it's] just the opportunity lost to put somebody else in that bed. I would 100% bet that if we do the financials of these trials, TAVR is going to be the cost-saver in a huge way."

"Finally, it is here," commented interventionalist Danny Dvir, MD, of University of Washington Medical Center in Seattle. "Seventeen years after the first TAVR procedure, we have solid clinical data on the main population with severe aortic valve stenosis: those considered at low risk for open heart surgery. That was a long journey with numerous studies, utilizing many platforms. However, now it is clear -- TAVR can result [in] better meaningful clinical outcomes,"

Now that both studies have found less stroke with TAVR compared with SAVR in low-risk patients, "the challenge now seems to be understanding not what is the position of TAVR, but what would be the remaining patient population best treated with open heart surgery," Dvir said.

To that end, patient age and aortic valve anatomy may have a significant role.

Patients who are ages 50-65 may still have a survival advantage with mechanical valves rather than tissue valves, which is not an option in TAVR, according to cardiac surgeon Thoralf Sundt, MD, of Massachusetts General Hospital in Boston.

"The concern is for younger and younger patients for whom issues like durability become increasingly important. We worry about overuse of this technology," Sundt told 麻豆传媒. "Even in the angioplasty versus coronary bypass literature, it's only 10 years out that you see a meaningful difference."

Payors and regulators should insist on 10-year follow-up, he emphasized, as there is no amount of "statistical gymnastics" that can substitute for looking at what the actual long-term outcomes are.

"I would be very cautious about assuming across the board that TAVR is the way to go," agreed heart surgeon Timothy Gardner, MD, of University of Pennsylvania Perelman School of Medicine in Philadelphia.

"The issue remains the durability of the TAVR valve and what happens in terms of risk to the patient if there is a need to reoperate," Gardner commented. "Many advocates of TAVR say 'Well, if they have a large enough TAVR valve inserted the first time, they can have valve-in-valve.' And we'll see. I'm sure the valve-in-valve approach will be refined."

Patients with bicuspid valve anatomy may not get the same benefits from TAVR as they had been excluded from both PARTNER 3 and CoreValve Low Risk trials that evaluated the safety and efficacy of the balloon-expandable Sapien 3 and self-expanding CoreValve devices, respectively.

Others who may still need surgery include those with coronary artery disease (who may do better with coronary artery bypass grafting and valve replacement surgery together), and those who can't get transfemoral access for their procedure, said interventionalist Martin Leon, MD, of Columbia University Medical Center/New York-Presbyterian Hospital in New York City and the Cardiovascular Research Foundation, at an ACC press conference. Leon is co-principal investigator of the trial.

In addition, two concerns and "moderate" downsides of TAVR are the higher incidence of paravalvular leakage with both valves, and the pacemaker rate for the self-expanding valve, according to Gardner.

Ultimately, "if I were a 50-year-old patient and I understood all the positives and negatives about TAVR, and understood the appropriate concerns of surgery, I would hope that my physicians and surgeons would advise me carefully -- not just take whatever appears to be the short-term easier option, but the procedure that is more likely to be durable for the rest of my life," he said.

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