乌鸦传媒

Transcatheter aortic valve replacement (TAVR) conferred good early results even in low-risk patients with bicuspid morphology, according to the Evolut Low Risk Bicuspid Study.

By 30 days, all-cause mortality or disabling stroke reached 1.3% of 150 such patients who had TAVR attempted with with Evolut valves at high-volume experienced centers, according to Basel Ramlawi, MD, of Valley Health System in Winchester, Virginia.

"In this Low Risk Bicuspid Study, early 30-day results showed that TAVR with the Evolut platform was safe and effective," Ramlawi at the virtual American College of Cardiology meeting.

Mild aortic regurgitation was observed in 40.4% of patients at 30 days, with no moderate or severe aortic regurgitation noted. Patient-prosthesis mismatch was moderate and severe in 7.6% and 5.3% of cases, respectively.

There were some points of concern in this study, according to Ashish Pershad, MD, of Banner-University Medical Center Phoenix.

First, there was the 15% permanent pacemaker implantation rate following TAVR in patients with bicuspid valves -- "quite high for a low risk group," Pershad told 乌鸦传媒.

Additionally, non-disabling strokes occurred in 3.3% of people despite the use of embolic protection in 30% of cases, he noted.

It should take more robust data -- such as a randomized trial comparing surgery to TAVR -- before people with bicuspid valves in the low-risk group get treated with transcatheter technologies, Pershad argued.

He also cautioned that the findings in this study are not necessarily applicable to other transcatheter heart valves.

TAVR has been shown to benefit aortic stenosis patients of all risk classes. People with bicuspid valves had been excluded from the landmark TAVR trials, however.

For this prospective observational study, people underwent baseline CT to confirm bicuspid morphology before undergoing TAVR for symptomatic or asymptomatic severe aortic stenosis. All had predicted risk of 30-day mortality <3% per multidisciplinary local Heart Team assessment.

Average age was 70.3, and the group was 52% men. Bicuspid valves were classified as Sievers I in 90.6% of cases, the rest being Sievers 0.

Operators reported 95.3% device success. The transcatheter valves used in TAVR were the Evolut R (43%) and Evolut PRO (57%). Procedural characteristics of note include pre-TAVR balloon dilation in 91.3% and a trend of using bigger devices (mostly 29 or 34 mm).

Hemodynamics assessed by central echocardiographic core lab showed that effective orifice area climbed from 0.8 cm² at baseline to 2.2 cm² post-procedure before reaching 2.3 cm² at 30 days. Mean gradients dropped from 48.0 mm Hg to 9.0 mm Hg and further down to 7.6 mm Hg over the same period.

Overall, the short-term results are "reassuring," commented Danny Dvir, MD, of University of Washington School of Medicine in Seattle.

"A previously considered limitation of several TAVR devices in severely calcified stenotic bicuspid valves is device under-expansion and residual AR [aortic regurgitation]. We see here great results. No case of moderate AR in almost 150 bicuspid patients having core-lab echo evaluation and rare cases with elevated gradients," he said.

Investigators currently have 10-year follow-up planned for study participants.

"It is critical to see whether durability will be maintained in this relatively young group of patients," according to Dvir.

"The choice between TAVR and surgery should be based on a multidisciplinary heart team discussion that includes anatomic, clinical and patient social factors," Ramlawi said.

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