New Devices May Help Overcome the Issue of Paravalvular Regurgitation After TAVR

Regurgitation can be caused by difficult anatomy as well as malpositioning of the device. “It’s either undersized, you implant it too high or too low or you get incomplete expansion,” said Susheel Kodali, MD, of Columbia University Medical Center in New York, N.Y. Calcium is also a “bad player,” Kodali added, pointing to various studies that show the quantity and asymmetry of calcium deposits are important predictors of paravalvular regurgitation.

In terms of annular sizing, CT seems better than 3D echocardiography, Kodali advised, but “in the end, some sort of 3D imaging is necessary to size the valve appropriately.”

There is no standardized grading system for paravalvular regurgitation. There are a number of qualitative and quantitative parameters that can be useful such as jet density and deceleration, jet width and area and regurgitant volume. A qualitative approach may overestimate leak severity, Kodali said, stressing that “the final assessment really needs to take into account all factors.”

Incidence, management, impact

In a meta-analysis published last year in the Journal of the American College of Cardiology, the incidence of moderate-to-severe aortic regurgitation after TAVR was 16% for CoreValve (Medtronic) and 9.1% for Sapien (Edwards Lifesciences), Kodali reported. Predictors included implantation depth, valve undersizing and Agatston calcium score. Registry data have also shown that use of self-expandable devices and the femoral approach also increase the odds of paravalvular regurgitation. Kodali said that these studies are confounded by bias and by a lack of standardized assessment, as evidenced by the strikingly different rates of the complication in the PARTNER I and II trials.

Post-dilatation is among the best management options for paravalvular regurgitation, though there also seems to be an increase in cerebrovascular events with this technique, Kodali noted.

Importantly, the presence or absence of regurgitation is not consistently linked to negative outcomes, he said. In the PARTNER trial, 2-year mortality was 50.7% in patients with moderate to severe aortic regurgitation vs. 33.4% in those with mild and 26.3% in those with none/trace amounts (P<.001). In CoreValve Extreme Risk, however, only severe paravalvular leak affected mortality. Again, different assessment methods could be at work, Kodali said, concluding, “Impact of [paravalvular regurgitation] on mortality remains controversial and may be device-specific.”

Next-generation systems

Ian Meredith, MBBS, PhD, of Monash Medical Centre Clayton in Melbourne, Australia, said during the same session that next-generation devices may help improve positioning problems inherent to TAVR.

“We’re not marksmen, we’re not archers, we’re not perfect — and occasionally we’ll get it wrong,” Meredith said. “The ability to reposition is important, and you want to be able to do that in a non-traumatic way.”

The newer generation is designed to enable repositioning and retrieval. Devices including Sapien 3 (Edwards Lifesciences) and Lotus (Boston Scientific) have yielded positive results with regard to the problem, Meredith said. As an example, he referred to findings from REPRISE II showing that the Lotus device has only a 1% rate of moderate/severe paravalvular leak at 1 month, substantially lower than seen with earlier devices. True repositioning capabilities also mean that no valve-in-valve procedures would be necessary. Along with repositioning, most modern devices have some sort of cuff, seal or skirt, which also helps reduce leakage.

“Will new generation TAVR devices address [paravalvular leak]? Yes, mostly,” Meredith said. “This is the wave of the future.”

Disclosures:

• Kodali reports receiving grant/research support from Edwards Lifesciences, serving on steering committees for Claret Medical, Edwards Lifesciences and Meril and having equity in Thubrikar Aortic Valve.
•  Meredith reports receiving consulting fees/honoraria from Boston Scientific and Guided Delivery Systems.