Leaflet Thickening and Immobility in Evolut Low Risk

Leaflet thickening and immobility caused by thrombosis have been reported for both surgical and transcatheter bioprostheses.

This phenomenon is diagnosed through hypoattenuation, thickening, and lack of motion, as observed through computed tomography (CT) imaging.

The incidence and, especially, the clinical implications of this phenomenon remain unclear, but they are of great interest, particularly in a low-risk population for whom device durability may be affected.

This work is an Evolut Low Risk sub-study that includes patients who were not receiving anticoagulant agents and who were assessed through CT at 30 days and 1 year after transcatheter aortic valve replacement (TAVR) or surgery.

The primary endpoint was the incidence of leaflet thickening at 30 days and 1 year. Imaging scans were analyzed by an independent committee using standardized definitions. Secondary endpoints included reduced leaflet motion, mean aortic gradient, and clinical events.

Read also: Virtual ACC 2020 | First Results of Evolut in Low-Risk Bicuspid Valves.

At 30 days, the rate of thickening was 17.3% for transcatheter valves and 16.5% for surgically-implanted valves. Reduced motion was observed in 14.6% and 14.3% of patients, respectively.

After 1 year, its rate doubled in both patient groups. The rate of thickening in transcatheter valves was 30.9%, compared with 28.4% for surgically-implanted valves, and the rate of reduced motion was 31%, compared with 27%, respectively.

Gradients were not influenced by the presence or severity of thickening and reduced motion at any time during follow-up.

Read also: Meta-Analysis of Large TAVR Studies on Low-Risk: Evidence is Consistent.

The rates for both phenomena observed through CT were similar with supra-annular, self-expanding transcatheter, and surgical bioprostheses.

Conclusion

The presence of CT imaging abnormalities in aortic bioprostheses was frequent, but it did not affect any hemodynamic parameters, at least at 1 year. A longer follow-up is required (particularly in this low-risk population) to determine whether thickening could impact prosthesis durability.

Original Title: Leaflet Thickening or Immobility Following Aortic Valve Replacement: Results from the Evolut Low Risk Sub-study.

Reference: Philipp Blanke et al. Journal of the American College of Cardiology. Journal Pre-proof. https://doi.org/10.1016/j.jacc.2020.03.022.

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