all patients treated with TAVI at our institution were screened for inclusion into this prospective study (n=170; Figure 1). Indication for TAVI was in concordance with the recent consensus statement.18 Data collection was approved by the Institutional Review Board, and all patients signed an informed written consent. Patients with a contraindication to MRI (eg, pre-or post-TAVI pacemakers or MRI incompatible implants) and patients with claustrophobia, severe arrhythmias, or unstable clinical conditions were excluded from the study. Ultimately, a total of 55 consecutive patients treated with TAVI with the use of the 2 currently commercially available bioprostheses (Medtronic CoreValve, Background-Aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) has been associated with poor outcomes, but little is known about how it evolves over time. We evaluated left ventricular (LV) function, remodeling, and the occurrence and evolution of AR after TAVI by using cardiac MRI. Methods and Results-Forty-three patients treated with transfemoral TAVI underwent cardiac MRI 1 week and 6 months after TAVI. LV volumes and function were assessed by using standard cine MRI sequences. Phase-contrast imaging was performed to quantify the degree of AR. The mean age of the evaluated patients was 80 years, and 65% of patients were women. At baseline MRI, the median LV ejection fraction was 58.1%, which improved significantly at follow-up to 63.4% (P<0.0001). A significant reduction of LV end-diastolic volume (149.7±41.4-140.1±43.9 mL; P=0.014) and of LV mass (156.3±32.8-142.7±39.3 g; P<0.001) was observed. Over time, aortic regurgitant fraction increased slightly but significantly from 5.2% to 7.8% (P=0.04). Subgroup analysis revealed that significant changes of LV ejection fraction, volumes, and mass only occurred in patients with no or mild AR at baseline MRI, whereas those parameters remained unchanged in patients with AR more than or equal to grade II. Conclusions-By using cardiac MRI in patients with TAVI, a significant improvement of LV function, volume, and mass can be documented. Mild-to-moderate AR is commonly seen, and AR shows a small increase over time. More-than-mild AR seems to prevent LV functional and structural recovery after TAVI.