Prediction of paravalvular regurgitation after transcatheter aortic valve implantation by computed tomography: value of aortic valve and annular calcification.

BACKGROUND

The purpose of this study was to quantify and characterize aortic valve leaflet and aortic annular calcification with computed tomography angiography (CTA) and to define whether they predict paravalvular regurgitation (PAR) after transcatheter aortic valve implantation.

METHODS

In all, 94 patients (aged 83.6 years) with severe aortic stenosis underwent CTA. Annular calcification was measured in two planes and defined as "protruding" (depth greater than length), "round," or "adherent" (length less than depth) for the right, left, and noncoronary annulus. Leaflet calcification severity and asymmetry were scored. Transthoracic echocardiography graduation of PAR severity was performed after the procedure (0.5 scale).

RESULTS

Thirty-two percent of patients had no or trivial PAR (grade less than 1) and 68% had mild to severe PAR (≥ 1 [mild 45.7%, moderate 20.2%, moderate to severe 2.1%]). The size of annular calcium was higher in patients with moderate to severe PAR greater than 1 (p = 0.015, p = 0.007, and p = 0.004) and predictive (c = 0.67, 0.71, and 0.711) for noncoronary, left, and total annular calcium size, respectively. Increasing PAR severity was correlated with increasing total calcium size (r = 0.422, p < 0.001). Protruding annular calcification greater than 4 mm (p = 0.02) was more frequently found in moderate to severe PAR greater than 1, and predictive (c = 0.7). Adherent calcium greater than 4 mm did not predict PAR greater than 1 and PAR of 1 or less. There was no association of leaflet calcium severity and asymmetry with PAR severity.

CONCLUSIONS

Protruding annular calcium greater than 4 mm predicts moderate to severe PAR after transcatheter aortic valve implantation. Increasing annular calcium size is another predictor, whereas adherent calcium has a "sealing" effect.