The self-expandable valve was associated to lower prosthesis-patient mismatch (PPM) compared against the balloon expandable valve regardless annular area, according to this study soon to be published in J Am Coll Cardiol Intv. This difference was basically driven by patients with larger body surface area (>1.83m²).

Prosthesis mismatch has been associated to increased mortality after transcatheter aortic valve replacement (TAVR) and also after surgical valve replacement (SAVR).

Until recently there were no precise data on PPM frequency, let alone a comparison between supra-annular (self-expandable) and intra-annular (balloon expandable) valves. 

For this analysis, researchers included 757 patients between 2007 and 2017 treated with a self-expandable valve (CoreValve, Evolut R) and a balloon expandable valve (SAPIEN THV/XT/3).

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The mismatch was classified −according to discharge effective orifice area indexed to body surface area−  into severe (<0.65 cm²/m²) or moderate (0.65 to 0.85 cm²/m²) for the general population and into severe (<0.60 cm²/m²) or moderate (0.60 to 0.90 cm²/m²) for the obese population (body mass index ≥30kg/m²).

Propensity score was used to compare both populations, with 224 pairs of patients with similar baseline characteristics.

At discharge, the self-expandable prosthesis presented a much lower mismatch incidence compared against the balloon expandable valve (mismatch 33.5% vs. 46.9%, p=0.004; severe mismatch 6.7% vs. 15.6%, p=0.003). This difference in the general population was far more marked in the obese population. When considering only the non-obese population, the difference is no longer significant, which is why the general population results are tainted at the expense of the obese. 

At least at one year, the mismatch had no impact in cardiovascular mortality, or functional class.

Conclusion

The self-expandable valve was associated to lower mismatch rate vs. the balloon expandable valve regardless annulus area. This difference was basically driven by the group of larger patients with greater body surface (body mass >1.83 m²).

Original Title: Prosthesis-Patient Mismatch Following Transcatheter Aortic Valve Replacement With Supra-Annular and Intra-Annular Prostheses.

Reference: Taishi Okuno et al. J Am Coll Cardiol Intv 2019, article in press.

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