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Balloon-expandable TAVR safe in bicuspid aortic valves
NEW ORLEANS — Patients with bicuspid aortic valves who underwent transcatheter aortic valve replacement with a balloon-expandable valve had similar rates of death and stroke at 1 year, compared with patients with tricuspid aortic valves, according to new data highlighted at the American College of Cardiology Scientific Session.
At 30 days, there were no differences in mortality. However, the bicuspid group had a higher rate of stroke than the tricuspid group.
“Based on this study, patients with bicuspid aortic valve stenosis who are at intermediate or high risk for open-heart surgery can be safely treated by balloon-expandable TAVR with an acceptable risk,” Raj Makkar, MD, associate director of Cedars-Sinai Heart Institute and a member of the Cardiology Today’s Intervention Editorial Board, who presented the data at the American College of Cardiology Scientific Session, said in a press release. “Our study supports the notion that carefully selected patients with bicuspid aortic stenosis can avoid surgery and be treated with this less invasive option.”
Growing population
Makkar said during a presentation that as many as 50% of younger patients who require surgical AVR have bicuspid valves, and more of these patients will undergo TAVR as its use expands into lower-risk populations, but patients with bicuspid valves have been excluded from pivotal trials of TAVR devices.
Makkar and colleagues analyzed 2,726 patients with bicuspid valves (mean age, 73 years; 60% men) and 79,096 patients with tricuspid valves (mean age, 81 years; 55% men) who were at intermediate or high risk for surgery and underwent TAVR with the balloon-expandable valve (Sapien 3, Edwards Lifesciences) from June 2015 to November 2018 and were listed in the Society of Thoracic Surgeons/ACC Transcatheter Valve Therapy registry.
After propensity matching based on 25 covariates, the researchers compared 2,691 patients with bicuspid valves and 2,691 with tricuspid valves. In the matched cohort, both groups averaged 73 years of age, the bicuspid group had 60% men vs. 61% for the tricuspid group, and differences in baseline STS Predicted Risk of Mortality, carotid stenosis, atrial fibrillation, prior CABG and kidney function were no longer evident.
The primary endpoints were death and stroke at 30 days and 1 year.
The bicuspid group had more conversion to open surgery and annulus rupture, but other procedural outcomes did not differ, Makkar said.
Death and stroke outcomes
At 30 days, all-cause mortality was 2.6% in the bicuspid group and 2.5% in the tricuspid group (P = .82), while stroke occurred in 2.4% of the bicuspid group and 1.6% of the tricuspid group (P = .02), according to the researchers.
New pacemakers were more common in the bicuspid group at 30 days (P = .03), but there were no differences in life-threatening bleeding, major vascular complications or aortic valve reinterventions, Makkar said.
At 1 year in the matched cohort, there was no difference in mortality (HR = 0.9; 95% CI, 0.73-1.1), stroke (HR = 1.28; 95% CI, 0.91-1.79) or the combination of the two (HR = 0.97; 95% CI, 0.81-1.16), he said, noting most strokes occurred within the first 3 days and the bicuspid group had a higher rate of periprocedural stroke.
There was no significant difference in paravalvular leak at discharge (P = .08), 30 days (P = .17) or 1 year (P = .44), nor were there differences in hemodynamic parameters at any point, according to the researchers.
Both groups showed similar improvement in NYHA HF class and Kansas City Cardiomyopathy Questionnaire overall summary score, Makkar said.
“The results indicate that survival, stroke and valve function were very acceptable and similar to tricuspid aortic stenosis, which is the more common type of aortic stenosis,” Makkar said in the release. “Using a CT scan prior to the procedure to predict which bicuspid valves should be triaged to surgery rather than TAVR is a crucial area of research.” – by Erik Swain, with additional reporting by Katie Kalvaitis
Reference:
Makkar R, et al. Joint American College of Cardiology/New England Journal of Medicine Late-Breaking Clinical Trials. Presented at: American College of Cardiology Scientific Session; March 16-18, 2019; New Orleans.
Disclosures: The statistical analyses were performed by Edwards Lifesciences and are not endorsed by the STS or ACC. Makkar reports he receives consultant fees/honoraria and research/grant support from Abbott, Boston Scientific, Edwards Lifesciences and Medtronic, and holds equity in Entourage Medical.
Perspective
Back to TopThe researchers investigated a cohort of patients with bicuspid valves who had favorable anatomy for TAVR. Bicuspid valves are the most common manifestation of congenital heart disease; its prevalence is approximately 2%. Approximately 50% of people younger than age 60 who need surgery on their aortic valve have a bicuspid valve. There is also a high correlation between having a bicuspid valve and having conditions that lead to aortic dissection.
This analysis isolated patients that had favorable anatomy, morphology and hemodynamics for TAVR. These patients had severe aortic stenosis but not aortic regurgitation or any autopathy. This cohort was patients who had severe aortic stenosis and a tricuspid valve. These patients were younger and thus already qualified to be in the low- to intermediate-risk range. The Society of Thoracic Surgeons Predicted Risk of Mortality was 4.6%. Because the bicuspid cohort was younger and had fewer comorbidities, the analysis was performed via propensity matching.
The conclusion is that TAVR may be a favorable option for patients with bicuspid aortic valves, but careful assessment of the valve in terms of morphology, hemodynamics and absence of autopathy is important before we perform TAVR in this population.
Perspective
Back to Top
Early-generation TAVR valves did not perform very well in patients with bicuspid valves, but indications are the newer generations are better. What Dr. Makkar and his team did was look at patients with bicuspid valves treated with Sapien 3, a later generation of the balloon-expandable valve. They found that patients with bicuspid valves did just as well as patients with tricuspid valves. Jeffrey J. Popma, MD, and colleagues previously used the same registry to show the same thing for the Evolut (Medtronic), a later-generation self-expanding valve.
The thing to bear in mind is that all these patients have been selected by their implanting physicians, who have determined that this is a bicuspid valve on which they are comfortable performing TAVR. We don’t know how many have been screened out by the implanting teams, although I think it’s a relatively small number.
We are already treating patients with bicuspid valves with TAVR if they are at intermediate risk or high risk for surgery. We feel very comfortable treating bicuspid valves in those populations. The patients who we decide are better off with surgery tend to have aneurysms that are getting borderline large or other anatomic characteristics.
I am study chair of a nonrandomized trial that is underway looking at TAVR in low-risk patients with bicuspid valves. It would be great to do a randomized trial, but I think at this point it’s not pragmatically possible, now that data from the large randomized trials showing the benefit of TAVR in low-risk patients are available. We expect to produce the early results of that study by the end of the year. We want to see how endpoints such as paravalvular leak, stroke and mortality are at 30 days. The truth is, if you are doing OK at 30 days, you will probably do OK long-term. If the valve works anatomically, it will continue to work.
In the intermediate- and high-risk bicuspid populations, we are already saying that if a patient can have either TAVR or surgery, they get TAVR. If they are not anatomically suitable for TAVR, they get surgery. If you see a patient who is a candidate for a bioprosthetic surgical valve, you have to talk them about TAVR as a potential option or you are not giving them complete informed consent. That does not mean they have to have TAVR, but it needs to be part of the conversation.
This is a seismic shift because 80% of the population has bicuspid valves. Not all of them are going to be candidates for TAVR, but at least 50% of them, if not more, would be bioprosthetic candidates.
