番茄社区

PARIS -- Novel Myval balloon-expandable (BE) valves were as good as contemporary gold standards for transcatheter aortic valve replacement (TAVR or TAVI) -- at least in terms of early safety, based on head-to-head comparisons in the LANDMARK randomized trial.

Tested against Sapien BE valves and Evolut self-expanding (SE) valves in people with severe symptomatic native aortic stenosis (AS), the Myval transcatheter heart valve (THV) showed noninferiority for the primary endpoint combining safety and effectiveness at 30 days (24.7% vs 27.0%, P<0.0001 for noninferiority).

What makes the Indian-made Myval stand out is the availability of intermediate sizes (20 mm, 21.5 mm, 23 mm, 24.5 mm, etc.) to better fit each person's aortic annulus area, according to Patrick Serruys, MD, PhD, of the National University of Ireland in Galway, presenting at the EuroPCR meeting this year.

Indeed, based on effective orifice area (EOA) on echocardiography, Myval recipients in the study showed hemodynamic performance that was superior to Sapien 3 and at least comparable to Evolut at similar valve sizes.

"The availability of intermediate sizes enables precise and appropriate matching of devices to an individual patient's anatomy and was used in 48%," Serruys said. "Continued follow-up to 10 years will unravel whether the documented EOA of the Myval THV series will have a beneficial impact on the long-term patient prognosis and valve durability."

All primary endpoint components individually supported comparable results between the Myval arm and the mixed control group: all-cause mortality, stroke, bleeding, acute kidney injury, major vascular complications, moderate or severe prosthetic valve regurgitation, and conduction system disturbances resulting in new permanent pacemaker implantation.

This endpoint should be interpreted as speaking more to safety than to effectiveness, however, cautioned session discussant Davide Capodanno, MD, PhD, of University of Catania, Italy.

Fellow panelist Martin Leon, MD, of NewYork-Presbyterian Hospital/Columbia University Irving Medical Center in New York City, also urged "much more rigorous comparison" between Myval and other TAVR devices. He cited the ongoing that aims to do just that.

Leon nevertheless called LANDMARK an "important trial because as we begin to evaluate these new devices, I think it's critical that we develop some standard methodologies and practices to compare them, and the LANDMARK trial certainly was a robust effort at doing so with a very interesting new BE device."

Having experience with the valve, panelist Gunasekaran Sengottuvelu, MD, DM, of Apollo Hospitals in Chennai, India, said he personally found Myval "extremely useful particularly in complex anatomies like bicuspid," citing Myval's other design features such as a higher skirt, wide stent frame, and short frame height.

Leon questioned the intermediate sizing aspect as the value proposition of this novel device. TAVR operators are currently able to employ the techniques of oversizing and postdilatation to adjust for intermediate sizing for Sapien and Evolut valves.

"We have to ask ourselves, is there a benefit associated with more valve sizing, which means having more precise nominal sizes, versus other adjustment strategies to account for the intermediate valve sizes? And this really is a resource consumption consideration," Leon stressed. "If you look at Myval, there are nine valve sizes versus four for the other BE and SE systems."

The LANDMARK trial had been conducted at 31 sites in 16 countries, mostly in Europe. The open-label trial design had 768 severe AS patients randomized 1:1 to the Myval or a mixed control group of contemporary valves. Serruys noted that central randomization determined whether controls got Sapien or Evolut valves.

Overall, participants had an average age of 80 years and were roughly split between the sexes. Over half were in New York Heart Association class III or IV, and median STS risk score was 3%.

Baseline echocardiography showed aortic valve gradients averaging 40 mmHg and CT data showed a mean aortic annulus area of 471 mm². People with small annulus accounted for nearly 32% of the group; another 7% had a bicuspid valve.

Beyond Myval's 30-day echo data reported by Serruys, it's more important to show "what those echo differences reflect in terms of late clinical and echocardiographic outcomes during follow-up," Leon said.

"Specific comparisons between Myval and BEV or SEV for the primary endpoint were not displayed, precluding commentary on the individual performance of Myval against each type," Capodanno also commented.

"While such comparisons may lack statistical power and might be fraught with confounding, I think they would be important to offer insights into the relative efficacy of contemporary THVs, especially in potentially differentiating outcomes such as moderate or severe THV regurgitation and permanent pacemaker implantation," he told the audience.

LANDMARK was accepted for publication in the Lancet later this month.

Comment