Influence of CoreValve ReValving System implantation on mitral valve function: an echocardiographic study in selected patients.

OBJECTIVES: The purpose of this study is to verify whether transcatheter aortic valve implantation (TAVI) determined changes in mitral valve (MV) function, in terms of mitral regurgitation (MR) and stenosis.
BACKGROUND: Little data is available regarding the effects of TAVI on global MV function, often derived from analysis primarily focused on clinical and aortic related outcomes.
METHODS: From May 2008 to March 2010, 73 patients with severe symptomatic aortic stenosis underwent TAVI with the CoreValve ReValving System. The study population consisted of 58 patients (27 males, mean age 82 ± 7 years) who underwent transthoracic echocardiography at least ≥1 month after implantation (mean follow-up 7.8 ± 5.4 months).
RESULTS: In patients with a left ventricular dysfunction (ejection fraction, EF, <45%) at the baseline, EF significantly increased from 37 ± 6% to 48 ± 7% after TAVI (P = 0.003). Before TAVI, 42 patients had no or mild MR, 13 mild-to-moderate, and 3 moderate or moderate-to-severe. During follow-up, the MR degree was unchanged in the majority of patients (55%), 12% reduced, and 33% worsened. Variables associated with worsening in MR were depth of aortic prosthesis (P = 0.02 for the distance between the ventricular end and the right coronary cusp; P = 0.04 for mean distance right-left coronary cusps) and left atrium area at the baseline (P = 0.02). After TAVI, six patients (10%) developed mild or moderate mitral stenosis, often in a native valve with anterior calcifications.
CONCLUSIONS: In the majority of patients no significant changes occurred in the degree of MR in native valve, but we found that if the aortic valve was deeply implanted in the left ventricle outflow tract, a worsening in MR can be observed. A mitral stenosis development must be sought in patients with heavy calcifications of the anterior leaflet.