Aortic regurgitation and left ventricular remodeling after transcatheter aortic valve implantation: a serial cardiac magnetic resonance imaging study.

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.