Ross Procedure Again Surpasses Bioprosthetic AVR: Toronto Experience

Adults who undergo the Ross procedure will fare far better over the next two decades than those treated with bioprosthetic aortic valve replacement (AVR), according to a propensity-matched comparison from Toronto General Hospital in Canada.

The findings add to accumulating reports favoring the Ross procedure, wherein a patient’s aortic valve is removed and then replaced with their own pulmonary valve. The latter is then replaced with a donor valve.

“In the last 10 years, the literature around the Ross has really skyrocketed, and more and more data are being published,” the study’s senior author, Maral Ouzounian, MD, PhD (Toronto General Hospital), told TCTMD. “The message is always the same: Ross seems to be the only aortic valve replacement operation that restores patient survival, perhaps not completely to that of the general population but really very close.” Complication rates are also “extremely low” with Ross, she added.

This latest study, published Monday in the Journal of the American College of Cardiology, follows an earlier report by their group comparing Ross favorably to mechanical AVR. What they’ve learned, said Ouzounian, is that it’s crucial to “follow patients long enough to see what happens to their valve and what happens to their survival and valve-related complications.”

Here, the mean follow-up duration was 14.5 years, and, thanks to propensity matching, “we’ve made the groups as close together as they can be,” she said, acknowledging that there will always be unmeasured confounders in nonrandomized data. But what’s clear in looking at the data is that it takes many years “to start seeing the adverse effects of structural valve deterioration and reintervention,” she noted.

Joseph A. Dearani, MD (Mayo Clinic, Rochester, MN), immediate past president of the Society of Thoracic Surgeons, described himself as a “big fan” of the Ross procedure. His practice involves a mix of pediatric and adult congenital heart surgery, which he said has given him a unique perspective.

“My enthusiasm and passion for the Ross stems from it being the primary operation in children when aortic valve replacement is needed, since it’s just so superior to the other options,” Dearani explained. With growing knowledge about the Ross procedure and evolutions in surgical techniques, it’s become “clear that it also has a very important role in adult patients,” he said. “I’m very fortunate because I get to do this operation in a 1 year old, or a 10 year old, or a 30 year old, and as a result, it’s gotten to be . . . one of the procedures that I’ve gained a substantial amount of experience with in my career.”

Both Dearani and Ouzounian pointed out to TCTMD that the zeal for bioprosthetic valves needs to be tempered, especially given the creep of transcatheter aortic valve interventions into lower age brackets.

Without considering the durability of the various treatment options, Ouzounian said, “I really think we’re doing a disservice to younger patients who have to live with the choice of their valve implantation for decades. If you’re 70 years old, or 75, does it really matter what kind of prosthesis you have? Likely not. But if you’re 30 or 35 years old, or have a life expectancy of 15 or more years, then I think it does matter.”

Mortality Risk Cut by 65%

For their study, with lead author Amine Mazine, MD (Toronto General Hospital), the investigators analyzed results for patients ages 16 to 60 years who underwent either the Ross procedure or bioprosthetic AVR surgery between 1990 and 2014.

At the end of the day, the techniques around the Ross are very teachable, very doable by an aortic root surgeon. Maral Ouzounian

Propensity-score matching identified 108 pairs of patients with similar baseline characteristics. Nearly all of the Ross procedures (97%) were performed by surgeon Tirone E. David, MD, who also performed 60% of the AVRs. Median age was 41 years, and 69% of patients were male. Indications for surgery were aortic stenosis (49%), aortic insufficiency (32%), and mixed pathology (19%). Three-quarters had a bicuspid aortic valve.

No patients died during their surgeries, and the frequency of early complications didn’t differ between the Ross and AVR groups.

Over the long term, all-cause mortality was lower with the Ross procedure (HR 0.35; 95% CI 0.14-0.90). Twenty-eight deaths occurred, in seven Ross patients and 21 AVR patients. At 10 years, the mortality rates were 3.1% after the Ross procedure and 9.7% after bioprosthetic AVR. By 20-year follow-up, the gap had widened: mortality rates were 9.6% and 25.1%, respectively.

With death as a competing risk, Ross also was linked to fewer reinterventions (HR 0.21; 95% CI 0.10-0.41), instances of valve deterioration (HR 0.25; 95% CI 0.14-0.45), thromboembolic events (HR 0.15; 95% CI 0.05-0.50), and permanent pacemaker implantations (HR 0.22; 95% CI 0.07-0.64).

Late mortality in the Ross group was valve-related in one patient (14%) and noncardiac in six patients (86%). For bioprosthetic AVR, late mortality was valve-related in 16 patients (76%), cardiac but not valve-related in four patients (19%), and noncardiac in one patient (5%). By 20 years, the cumulative incidence of valve-related death was 1.3% for Ross and 17.2% for AVR (HR 0.05; 95% CI 0.01-0.37).

“In specialized centers with sufficient expertise, the Ross procedure should be considered the primary option for young and middle-aged adults undergoing AVR,” the researchers conclude.

Why the Skepticism?

Some physicians still have reservations about the Ross procedure.

Ouzounian said there are two main reasons for this reluctance: “Either they haven’t critically looked at the data and examined their own biases, or they function in a center where Ross is just not available anywhere nearby.”

This isn’t to say the Ross procedure is easy, she stressed. “It is certainly technically more demanding than aortic valve replacement, for sure. It also incorporates techniques on the right side of the heart, including harvesting the autograft, that adult cardiac surgeons are not typically trained to do. And so it does require dedication and focus to develop the expertise to offer the Ross procedure. But at the end of the day, the techniques around the Ross are very teachable, very doable by an aortic root surgeon.”

Dearani, for his part, said clinicians’ concerns stem from lack of familiarity with Ross’ role and benefits. The skeptics tend to be people who don’t do the surgery themselves, he said. “It’s not an operation for every cardiac surgeon; it’s [a niche procedure] done by a short list of surgeons. The ones that do it a lot are the ones that are enthusiastic, passionate, and supportive of it, because they’re very aware of the current literature and advantages of it.”

The most-common argument against the Ross procedure, said Dearani, is the notion that “a patient starts out with single-valve disease and you leave them with two-valve disease: why would you want to jeopardize another valve that now needs lifelong surveillance, too, when you’re starting out with only one valve that’s involved?”

It’s true, he acknowledged, that deterioration of one or both valves does develop over time, but if reoperation (or percutaneous reintervention) is done in a timely fashion, the risk of the procedure should be low. Today, though, the need for reoperation or reintervention is lower after Ross than it once was, since reinforcement modifications are now applied at the time of the Ross procedure, said Dearani, noting that no alternative valve replacement therapy carries a reintervention rate of zero.

Centers of Excellence

Writing in an editorial, Ismail El-Hamamsy, MD, PhD (Mount Sinai Hospital, New York, NY), and colleagues draw parallels between the Ross procedure and mitral valve repair, a comparison also made by Dearani and Ouzounian.

“Much like mitral valve repair two decades ago, access to the Ross procedure remains limited. In addition to important geographic and socioeconomic barriers for patients, the Ross procedure is without a doubt a more complex operation than conventional AVR,” the editorialists note. “Although operative risk is higher when performed in low-volume centers, there is no additional risk associated with the operation in a high-volume setting. Thus, this begs the question: has the time come for Ross Centers of Excellence?”

Yes, they say, arguing that criteria should be set for “case volumes, operative mortality, echocardiographic outcomes, and longitudinal follow-up, all information that should be accessible to the public.”

If a young adult wants to live until they’re in their 80s, they have a statistically greater chance of doing so if they have a Ross procedure now compared to mechanical or tissue AVR. Joseph A. Dearani

Dearani agreed that this concept is sorely needed. With the Ross procedure, outcomes are dependent on the surgeon, the team, and the institution, he said. “It requires a multidisciplinary team to know how to do the imaging, it requires proper interpretation of the imaging, it requires factoring in other patient medical conditions that may or may make it appropriate to advise the Ross, and then it requires a surgical team that has experience with the procedure—all of these things are important.”

Cardiologists who are less familiar with Ross but recognize the importance of surgical expertise “should not feel that they need to apologize for referring their patient outside of their institution to get access to this operation. The degree of difficulty of this operation is above a standard aortic valve replacement. It’s not realistic for all cardiac surgeons to be able to do it well if they’re only going to be doing it once in a while—it should be done by a surgeon who’s doing it all the time,” he urged.

According to Dearani, it’s time to spread the word in the medical community that bioprosthetic valves, whether surgical or percutaneous, are not a good option for young adults less than 40 years old.

The Ross procedure “needs to be an option for these younger patients for a long list of reasons,” he said. “But the most important reason is the survival benefit of the Ross. If a young adult wants to live until they’re in their 80s, they have a statistically greater chance of doing so if they have a Ross procedure now compared to mechanical or tissue AVR.”

Dearani said that patients and their families also should be made aware of their alternatives. “The internet has become a very powerful educational tool for the patient community. They go online, they search, they read, they learn, they ask questions,” he noted. Fortunately, with most aortic valve disease, “almost all the operations are nonemergent, so it allows the patients and their families and the physicians to ‘shop around,’ investigate and look, and decide.”