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.