Evaluation of aortic regurgitation after transcatheter aortic valve implantation: aortic root angiography in comparison to cardiac magnetic resonance

Aims: Aortic regurgitation (AR) is common after transcatheter aortic valve implantation (TAVI). Intraprocedural assessment of AR relies on aortic root angiography. Cardiac magnetic resonance (CMR) phase-contrast mapping of the ascending aorta provides accurate AR quantification. This study evaluated the accuracy of AR grading by aortic root angiography after TAVI in comparison to CMR phase-contrast velocity mapping. Methods and results: In 69 patients with TAVI for severe aortic stenosis, post-procedural AR was determined by aortic root angiography with visual assessment according to the Sellers classification and by CMR using phase-contrast velocity mapping for analysis of AR volume and fraction. Spearman's correlation coefficient showed a moderate correlation between angiographic analysis of AR grade and CMR-derived AR volume (r=0.41; p<0.01) as well as AR fraction (r=0.42; p<0.01). There was significant overlap between the angiographic Sellers classes compared to CMR-derived AR fractions. Aortic root angiography with cut-off Sellers grade >= 2 had a sensitivity of 71% and a specificity of 98% to detect AR graded as moderate to severe or severe as defined by CMR. Conclusions: There is only a moderate correlation between aortic root angiography and CMR in the classification of AR severity after TAVI. Alternative imaging including multimodality imaging as well as haemodynamic analysis should therefore be considered for intraprocedural AR assessment and guidance of TAVI procedure in cases of uncertainty in AR grading.