The aim of this study was to assess prosthesis/annulus discongruence and its impact
on the occurrence of significant aortic regurgitation (AR) immediately after transcatheter
aortic valve implantation (TAVI).
Paravalvular AR might occur after TAVI, but its determinants remain unclear.
Comprehensive echocardiographic examinations were performed in 74 patients who underwent
TAVI with a balloon expandable device. Congruence between annulus and device was appraised
with the cover index: 100 x (prosthesis diameter - transesophageal echocardiography
annulus diameter)/prosthesis diameter.
At baseline aortic valve area was 0.67 +/- 0.2 cm(2), and mean gradient was 50 +/-
15 mm Hg. The TAVI used transfemoral approach in 46 patients (62%) and transapical
access in 28 (38%). Prosthesis size was 23 mm in 24 patients (34%) and 26 mm in 50
patients (66%). After TAVI, paravalvular AR was absent in 5 patients (7%), graded
1/4 in 53 (72%), 2/4 in 12 (16%), and 3/4 in 4 (5%). Occurrence of AR >or=2/4 was
related to greater patient height, larger annulus, and smaller cover index (all p
< 0.002) but not to ejection fraction, severity of stenosis, or prosthesis size. AR
>or=2/4 was never observed in patients with aortic annulus <22 mm or with a cover
index >8%. Significant improvements were observed from the first 20 cases (AR >or=2/4,
40%) to the last 54 (AR >or=2/4, 15%) (p = 0.02). In multivariate analysis, independent
predictors of AR >/=2/4 were low cover index (odds ratio: 1.22; per confidence interval:
1.03 to 1.51 per 1% decrease, p = 0.02) and first versus last procedures (odds ratio:
2.24; 95% confidence interval: 1.07 to 5.22, p = 0.03).
Our study shows that the occurrence of AR >or=2/4 is related to prosthesis/annulus
discongruence even after adjustment for experience. Hence, to minimize paravalvular
AR, appropriate annular measurements and prosthesis sizing are critical.