For Congenital Heart Disease, SAVR With Bioprosthetic Valve Still Reigns

NEW ORLEANS, LA—Among the contemporary population of young and middle-aged adults undergoing aortic valve replacement, bioprosthetic valves are most often used and TAVR is rare but increasing, according to a new analysis. Moreover, about one-sixth of this population is made up of those with congenital heart disease.

“Congenital patients are unique but challenging to triage because certain characteristics favor TAVR while others caution against it,” said Jennifer Nelson, MD (Nemours Children's Hospital, Orlando, FL), who presented the findings in a plenary session at the annual meeting of the Society of Thoracic Surgeons (STS) on Monday. “In this population, a prospective trial is needed to refine optimal patient selection and match patients to the most appropriate valve type. In the meantime, ongoing harmonization of variables across STS databases, establishing clear criteria to define adult congenital heart disease, and evaluating center-level characteristics including case volume and experience will be valuable efforts.”

SAVR vs TAVR

For the study, chosen as the J. Maxwell Chamberlain Memorial Paper for Congenital Heart Surgery at the meeting, Nelson and colleagues looked at administrative data of 45,753 patients undergoing aortic valve replacement from both the STS Adult Cardiac Surgery Database (n = 44,173) and Congenital Heart Surgery Database (n = 1,580) between 2013 and 2018.

Of the total cohort, 16% had congenital heart disease. These patients tended to be younger and were twice as likely to have a prior sternotomy.

Overall, more than half the cohort had prior hypertension, 15% had active endocarditis, and 11% had a prior MI at the time of AVR. Comparing the congenital and noncongenital groups, the former had fewer preoperative comorbid conditions.

Bioprosthetic valves were most commonly used among the entire cohort (55%), with the remainder made up of mechanical valves (42%), homograft valves (1.2%), TAVR (1.0%), autograft valves (0.6%), and Ozaki valves (0.4%). Mechanical valves were most heavily favored in the congenital group (51%), followed by bioprosthetic valves (44%), autograft valves (2.9%), homograft valves (1.3%), and TAVR (0.5%). Over the study period, bioprosthetic valve use rose by 54% while TAVR use increased by 167%.

Notably, 46% of patients had isolated AVR, while others had concomitant aortic (22%), mitral (15%), CABG (13%), root (8%), and annular enlargement (6%) procedures.

Total 30-day mortality was highest among those who received homograft valves (9.6%) followed by Ozaki (6.6%), TAVR (3.8%), bioprosthetic (3.7%), mechanical (3.3%), and autograft (0.7%) valves. Those who underwent isolated AVR and patients with congenital disease each had lower 30-day mortality and morbidity compared with patients who had concomitant procedures and without congenital heart disease, respectively. The one exception was that TAVR led to higher morbidity in the congenital subgroup.

Comparing isolated SAVR to isolated TAVR overall, the stroke rate was lower (0.9% vs 2.4%; P = 0.002) and 30-day mortality was slightly better (1.9% vs 2.9%). However, TAVR was associated with a shorter hospital length of stay (4 vs 6 days; P < 0.001).

On multivariate analysis, larger implanted valves reduced the odds of mortality (OR 0.892; 95% CI 0.870-0.915) and the use of nonmechanical vales increased it (OR 1.212; 95% CI 1.080-1.360). For morbidity, both bioprosthetic (OR 0.921; 95% CI 0.876-0.968) and homograft valves (OR 0.697; 95% CI 0.560-0.868) were protective, as was larger valve type (OR 0.962; 95% CI 0.953-0.972).

Defining the Landscape

Discussing the study following the presentation, Emile Bacha, MD (NewYork-Presbyterian Morgan Stanley Children's Hospital, NY), said: “This is actually an important subject because there’s not much data known about this—the real-time results with aortic valve replacements in this patient population of young adults. There’s also no doubt that TAVR has been a disruptive force in the congenital arena as well.”

He asked why the mortality rates observed were higher than what was seen for both TAVR and SAVR in the PARTNER trial.

“First, it’s important to point out that the PARTNER trial was conducted in a highly selected population where bicuspid aortic valves were excluded,” Nelson responded. “In this study, which was not selected, there are risk factors that can come into play as well as factors that were not accurately assessed or measured in the PARTNER trial. It is also true that we were unable to [identify] reasons for valve selection and it's possible that TAVR was selected due to patient factors—for example, the perception that patients were perhaps sicker.”

While this study also did not collect information on procedural factors, Nelson highlighted that it “spans the era over which there’s been development and improvements in the technology related to TAVR devices, . . . and it’s possible that our results just captured the average experience.”

Asked about her opinion on the role of TAVR in young and middle-aged adults, she said it’s important to understand that surgery can “virtually restore a patient to their normal life expectancy and that [it] remains still an excellent option for patients in general less than perhaps 40 years of age.” Also, for patients younger than 55 years, the evidence shows a survival advantage with mechanical valves. “That said, I think there are important lifestyle considerations to factor into valve choice as well,” she observed. “In general, I think including patients and including congenital surgeons and congenital cardiologists in the conversation as part of the heart team will be important as we plan for upcoming prospective trials.”

In a press conference, moderator Robbin Cohen, MD (University of Southern California, Los Angeles), said: “Dr. Nelson and her associates have done a beautiful job of defining the landscape for aortic valve replacement in younger patients and also initiating the conversation regarding the application of transcatheter aortic valve replacement to not only younger patients but to some patients who might have congenital heart disease.”

I think bottom line is the heart team needs to expand. Jennifer Nelson

Cohen called TAVR a “disruptive technology” for patients with aortic stenosis, as “nobody can compete with the excellent short-term results, routine hospital stays of 24 hours in many centers, and a procedure that’s practically incisionless and, hence, virtually painless. Why wouldn’t all patients want it and why wouldn’t we want to give that to them?”

However, it’s important that operators remember that SAVR results are “excellent and sometimes superior to TAVR” in younger patients, Cohen said. Additionally, many younger patients may not be amenable to receiving TAVR due to aortic insufficiency, he continued, and the durability of TAVR in younger patients is an important issue “because bioprostheses are known to degenerate more rapidly, resulting in the potential need for multiple valve replacements in a patient's lifetime. To complicate matters more, I don’t think that we really know what the treatment of failed TAVR is going to be.”

Looking forward, Cohen said “no one doubts that the role of TAVR will increase with increased clinical experience and the evolution of the devices. But having said that, I think the young patient cohort is going to be the one that really calls for increased patience among not only physicians but increased reason among surgeons and potentially even parents [of pediatric patients] until we really have some long-term data that tells us not only the long-term results, but how we’re going to treat them when they fail.”

‘Meaningful’ Outcomes

During the discussion in the main session, audience member Charles Fraser, MD (The University of Texas at Austin), said, “There’s an ongoing debate and evolution about what are the most meaningful outcomes and measures for patients with congenital heart disease. Your study of course is really telling us what’s going on in the acute setting, but I can imagine that we're going to need to know if you’re a young person who has a TAVR with other complex congenital heart disease, what’s life like for you going forward?”

Incorporating a quality-of-life measure into future prospective trials will be “extremely important,” Nelson replied. “There’s a great appeal and allure for TAVR for younger patients given the anticipated faster recovery time, no scar, and short hospital stay. However, it if leads to increased numbers of repeat interventions or salvage surgery, that will be important to recognize. I think the most important thing to focus on is including congenital heart surgeons and cardiologists in the conversation early to plan out these trials responsibly. I think bottom line is the heart team needs to expand.”