Medium-term CT evaluation of stent geometry, integrity, and valve function of the Edwards SAPIEN transcatheter heart valve in the pulmonary position.

OBJECTIVE

Distortion of transcatheter heart valve (THV) stent shape and morphology has been shown to impact on THV function. This study sought to evaluate the relationship between geometrical CT follow-up data and consequent valve function in patients undergoing transcatheter pulmonary valve replacement with the Edwards SAPIEN THV.

METHODS

All patients were enrolled in the COMPASSION trial. Multidetector computed tomography (MDCT) was performed as part of the study protocol at 6 months and yearly thereafter following valve implantation. Prosthesis eccentricity indices, circularity ratios, and expansion ratios (ER) were calculated. Valve function and reintervention rates were correlated with MDCT findings.

RESULTS

Twenty consecutive patients undergoing 58 CT scans were included. Maximum Doppler gradients across the right ventricular outflow tract (RVOT) were significantly reduced following valve implantation (P < 0.001). Geometrical indices and maximum RVOT gradients were compared between the reintervention group (n = 4) and the nonreintervention group (n = 16). Although there was no difference in eccentricity index between the groups, ER [6 months: 90 +/- 12% vs. 69 ± 9%; P = 0.014; at 12 months: 89 ± 14 vs. 69 ± 10%; P = 0.018; at 24 months: 87 ± 14% vs. 70 ± 11%; P = 0.056] and valve area [6 months: 3.98 ± 0.54 vs. 2.86 ± 0.38 P = 0.005; at 12 months: 3.93 ± 0.56 vs. 2.86 ± 0.39 P = 0.006; 24 months: 3.78 ± 0.50 vs. 2.90 ± 0.45 P = 0.019] were lower in the reintervention group compared with the nonreintervention group at all time periods.

CONCLUSION

Geometrical THV measurements as assessed by CT may predict the need for reintervention in patients undergoing transcatheter pulmonary valve replacement with the SAPIEN valve. Valve symmetry is maintained, however under-expansion and smaller valve area are strongly associated with the need for reintervention.