Background: Severe aortic valve stenosis is the most prevalent clinically relevant valvular heart disease in the elderly. Transcatheter aortic valve implantation (TAVI) has become the standard of care in patients ≥70 years. Contemporary TAVI prostheses with optimized hemodynamic performance may not only relieve left ventricular outflow obstruction but also favorably influence concomitant functional mitral regurgitation (MR), which is frequently present in this population. This study investigated the impact of modern TAVI prosthesis generations on the course of MR and evaluated their potential role as an indirect therapeutic strategy.
Methods: In this retrospective single-center study, 2856 transthoracic echocardiograms obtained between January and June 2025 at the Heart Center Schwerin were analyzed. Patients with severe aortic stenosis and at least mild functional MR without prior interventional valve therapy were included. Following interdisciplinary heart team assessment, 130 patients with an indication for TAVI were identified. Of these, 117 underwent TAVI (TAVI group), Self-Expandable Valve ( SEV n= 80 ) and Balloon-Expandable Valve (BEV n=33 ) while 13 received conservative management after declining TAVI (conservative group). Echocardiography was assessed at two time points in both groups. In the TAVI cohort, examinations were performed pre- and post-intervention (mean interval 5 days), whereas in the conservative group the mean interval between the two examinations was 20.7 months. The primary endpoint was change in MR severity. Secondary endpoints included changes in Pmean (mean pressure gradient), of the aortic valve, left ventricular ejection fraction (LVEF), and glomerular filtration rate (GFR). MR severity was analyzed using the Wilcoxon signed-rank test; categorical changes were assessed by chi-square test. Continuous variables were compared using paired t-tests. A subgroup analysis compared MR changes between balloon-expandable and self-expanding prostheses (unpaired t-test). Statistical significance was defined as p < 0.05.
Results: In the TAVI group, MR severity improved in 59% of patients, remained stable in 34%, and worsened in 7%. Both ordinal and categorical analyses demonstrated a significant reduction in MR severity (p < 0.0001). Pmean of the aortic valve decreased significantly (p < 0.0001), while LVEF (p = 0.5845) and GFR (p = 0.1782) remained unchanged.
In contrast, the conservative group showed significant progression of MR: twelve of 13 patients exhibited worsening MR, and six developed new-onset MR; median MR severity increased by one grade (p = 0.0005). Aortic valve gradients showed a slight decrease (p ≈ 0.03), whereas LVEF (p = 0,8921) and GFR (p = 0,6547) remained unchanged.
Subgroup analysis revealed significant MR reduction with both prosthesis types (p < 0.0001 each), without a statistically significant difference between them (p = 0.38), although numerically greater reduction was observed in the balloon-expandable cohort.
Conclusions: TAVI using last prosthesis generations is associated with significant improvement or stabilization of functional MR, whereas conservative management is linked to MR progression. No significant difference in MR reduction was observed between prosthesis types. Beyond effective relief of aortic stenosis and marked hemodynamic improvement, TAVI may serve as an indirect therapeutic option for functional MR in appropriately selected patients.
