Transcatheter aortic valve replacement (TAVR) in bicuspid anatomy provides outcomes roughly similar to those with tricuspid aortic stenosis among patients at low surgical risk, a large national registry suggests.
“Despite concerns about TAVR in bicuspid anatomy, the procedural success rate was high and intraprocedural complications were low,” Raj Makkar, MD, Smidt Heart Institute at Cedars-Sinai, Los Angeles, said.
In addition, the primary endpoints of all-cause death and stroke at 30 days and 1 year were favorable in low-surgical-risk patients undergoing TAVR for bicuspid aortic stenosis (AS), and similar to those with tricuspid AS.
Almost half of patients undergoing surgery for aortic stenosis, especially in the younger patients, have a bicuspid aortic valve, he noted. Recent pivotal randomized trials have expanded the indication for TAVR to include lower surgical-risk aortic stenosis patients but excluded bicuspid anatomy. As a result, data are scant on TAVR outcomes for low-risk bicuspid patients but crucial to guide their treatment.
To help fill this gap, Makkar and colleagues identified 159,661 patients undergoing TAVR with the Sapien 3 or Sapien 3 Ultra valve (Edwards Lifesciences) between June 2015 and October 2020 in the Society of Thoracic Surgeons/American College of Cardiology (STS/ACC) TVT Registry.
STS/ACC TVT Registry
The analysis focused on those at low risk (STS score <3%) and compared outcomes between 3168 pairs of low-risk patients with bicuspid and tricuspid valves propensity-matched on 29 covariates. Their mean age was 69 years, average STS score was 1.7%, and average ejection fraction was 56.6%.
Although almost 97% of patients in both groups underwent TAVR with transfemoral access, the bicuspid group was significantly less likely to do so under conscious sedation than the tricuspid group (56.9% vs 62.2%) and more likely to receive a 29 mm valve (38.4% vs 29.9%).
Intraprocedural complication rates were 0.5% or less and did not differ between groups for conversion to open heart surgery, annulus rupture, cardiopulmonary bypass, aortic dissection, coronary obstruction, or the need for a second valve, Makkar reported at the virtual Congress of European Association of Percutaneous Cardiovascular Interventions (EuroPCR 2021).
While in hospital, 0.6% of bicuspid patients and 0.4% of tricuspid patients died from any cause, and 1.1% and 0.9%, respectively, experienced a stroke.
Death and stroke rates at 30 days and 1 year “were essentially similar” between the bicuspid and tricuspid cohorts, he said.
30-day death: 0.9% vs 0.8% (P = .55)
30-day stroke: 1.4% vs 1.2% (P = .55)
1-year death: 4.6% vs 6.6% (P = .06)
1-year stroke: 2.0% vs 2.1% (P = .89)
Aortic valve reintervention was similar at 30 days but significantly higher at 1 year in the bicuspid group (1.16% vs 0.43%; P = .02).
The bicuspid and tricuspid groups had similar increases in valve gradients and decreases in valve area at 30 days and 1 year. Moderate or severe paravalvular regurgitation was low but higher in the bicuspid cohort at discharge (0.9% vs 0.3%; P = .0005), 30 days (1.8% vs 1.1%; P = .02), and 1 year (3.5% vs 2.1%; P = .36).
Both cohorts saw almost a 28-point gain in overall Kansas City Cardiomyopathy Questionnaire score, and nearly 95% were in New York Heart Association class 1 or 2 at 30-day or 1-year follow-up.
“Our study findings suggest that TAVR may be a reasonable treatment option in carefully selected patients with bicuspid aortic stenosis who are at low surgical risk,” Makkar concluded.
Heart Team Essential
Nevertheless, during a separate session devoted to bicuspid TAVR/TAVI in which the data were highlighted, he added, “I want to be clear that the outcomes of the analysis cannot be applied in a generalized fashion to all patients with bicuspid aortic stenosis, since these were carefully selected bicuspid AS patients.”
Discussant Eberhard Grube, MD, University Hospital Bonn, Germany, said the data that have been collected in bicuspid patients are biased because of selection criteria, “so we cannot really apply this. The good news is that the outcome in the whole cohort is very good compared to tricuspid.”
He noted that long-term results are lacking and that the jury is still out as to whether or not a randomized trial should be conducted of TAVI in patients with bicuspid stenosis. Like other panelists, he highlighted the need for the heart team and for anatomy to be central to patient selection.
“I wouldn’t judge my decision on which way to go on the low-, intermediate-, or high-risk status, much rather on the anatomy. I think that’s more important,” Grube said. “I think bicuspid is one of the beautiful examples of where the heart team really should be applied to because, in the end, we have to make a decision that’s best for the patients. We shouldn’t force either one and if we have a heart team discussion, we can take the best treatment options in a given case, independent of risk.”
Darren Mylotte, MD, PhD, University Hospital, Galway, Ireland, said TAVI in bicuspid aortic valves is “a different beast” than in tricuspid valves. Along with greater calcification comes differential sinus lengths, more coronary anomalies, aortic root dilation can occur in about 40% of bicuspid cases and increase the risk for aortic dissection, and, very often, fusion and thickening of the commissures and leaflets can lead to difficulty in valve expansion.
“So, we have a range of morphologies and I would suggest certainly as we go into those younger patients that we need to consider very carefully what is the best thing for the patient,” he said. “Is it a TAVI in those more complex anatomies or surgery where the surgeon can remove the leaflets very simply? Or, in those less complex anatomies, I think they’re certainly the ones to start with and where TAVI may have a role relative to surgery in younger patients.”
Surgeon Hendrik Treede, MD, University Hospital Bonn, Germany, said, “the beauty about surgery in bicuspid is you usually have a large landing zone, so you can always implant without enlarging the annulus. You can always implant a large valve.”
Treede also highlighted the lack of long-term data and said younger bicuspid patients are usually good surgical candidates. “I would still opt for surgery because I think we have more experience here and we have also the opportunity to deal with the aortopathy, if there is aortopathy involved, and we can achieve very good long-term results.”
Makkar reported receiving research support and consulting fees/honoraria from Edwards Lifesciences, Abbott, Medtronic, and Boston Scientific, and having a major shareholder/equity interest in Entourage Medical. Grube has been a proctor and served on advisory boards for; and has received speaker honoraria from Medtronic and Boston Scientific. Mylotte is a proctor and consultant for Medtronic and Microport; and is a consultant for Boston Scientific.
Congress of the European Association of Percutaneous Cardiovascular Interventions (EuroPCR 2021). Presented May 18, 2021.
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