Authors birthdate: 29.06.1993

Abstract character count (including spaces): 2913

Background

Concomitant moderate/severe mitral regurgitation (MR) is observed in 17-35% of patients undergoing transcatheter aortic valve implantation (TAVI) and contributes to worse prognosis. The decrease in afterload due to the elimination of outflow obstruction after TAVI can lead to a reduction of MR severity in some patients. Larger studies analysing outcomes of TAVI treated patients with concomitant MR of different etiologies are rare and data on the unique and underrecognized etiology of atrial FMR in this context are absent.  

Objective

To address this gap in knowledge, we aimed to analyse mortality, outcome predictors, long-term MR severity development and symptomatic improvement of patients with atrial FMR (aFMR) compared to ventricular FMR (vFMR) and PMR patients following TAVI.

Methods and results

All consecutive patients with at least moderate MR undergoing TAVI between 01/2013 and 12/2020 at the Munich University Hospital were analysed. Characterization of MR etiology was performed by detailed individual echocardiographic assessment. 3-year-mortality, changes in MR severity and NYHA class at follow-up were assessed.

Out of 3,474 patients undergoing TAVI, 631 patients showed MR ≥2+ (172 with aFMR, 296 with vFMR and 163 with PMR, respectively). Procedural characteristics and endpoints according to the VARC-3 criteria were comparable between groups. Mean time to echocardiographic follow-up was 561 ±682 days and there was no difference in time to echocardiographic follow-up between the three groups (p=0.40). Estimated 3-year survival rates did not differ between the different MR etiologies (p=0.57). However, MR severity before TAVI (HR 1.34, 95%CI [1.02, 1.78], p=0.037) and MR persistence at follow-up (HR 1.49, 95%CI [1.04, 2.11], p=0.027) were associated with higher mortality. This was mainly driven by the subgroup of PMR patients (Figure 1). The rate of MR improvement was highest in aFMR patients (80.2%) and significantly higher compared to both other groups (vFMR: 69.4%, p=0.03; PMR: 40.8%, p<0.001). Additionally, the presence of PMR was identified as an independent predictor for MR persistence following TAVI (OR 2.73, 95% CI [1.6, 4.8], p≤0.001). In terms of symptomatic development after TAVI, NYHA class improved significantly in all groups. However, in patients with baseline MR ≥3+, the PMR etiology was associated with the lowest MR improvement, the lowest survival rates and least symptomatic improvement.

Conclusion

TAVI reduces MR severity and symptoms in patients with aFMR, vFMR and – less pronounced - PMR. Therefore, for patients with severe AS and FMR (aFMR and vFMR), a “watchful waiting” strategy seems preferable, as MR severity and symptoms have a high potential for improvement. In contrast, in PMR patients, a dual valve intervention might be an option in selected patients, since sufficient MR reduction after TAVI is most probably not expectable.


Figure 1