OBJECTIVES: 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). Background: Paravalvular AR might occur after TAVI, but its determinants remain unclear.
METHODS: 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.
RESULTS: 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 >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).
CONCLUSIONS: Our study shows that the occurrence of AR >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.