Background: Patients undergoing transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS) are often diagnosed with concomitant mitral regurgitation (MR). The frequency and extent to which MR improves after TAVR remains unclear due to very limited clinical data. In addition, there is a lack of evidence-based guidelines on how to proceed in patients with persistently severe, symptomatic MR after TAVR. One possible treatment option for these high-risk patients is transcatheter edge-to-edge repair (TEER)  using the MitraClip® system. The extent to which patients benefit from this additional interventional procedure is currently not known.

Objective: The aim of this single-center retrospective study was to evaluate the impact of TAVR in patients with combined mitroaortic disease in terms of one-year and overall survival compared to guideline-directed medical therapy (GDMT), as well as the effect on MR severity. Moreover, we examined the clinical outcome after TEER in patients with persistent severe MR after TAVR. 

Methods: 208 patients who were diagnosed with high-grade AS and MR >2 at the Heidelberg University Hospital were enrolled between December 2008 – March 2021. Of these, n = 142 received TAVR and n = 66 were treated conservatively (GDMT). Patients with a history of mechanical valve replacement and endocarditis were excluded.

Results: Among 208 patients (median age 82.6 years), 108 (51.9%) were female and the median EuroSCORE II was 11.2% (TAVR: 10.7%; conservative: 12.1%). One patient died during the TAVR procedure and was not included in further statistical analysis. At 1 year, there were 41 deaths (29.1%) in the TAVR and 40 deaths (60.6%) in the conservative group. We observed a significant difference in one-year (P < 0.001) and overall-mortality (P < 0.001, median follow-up 187 [IQR 31-582] days) with inferiority of the conservatively treated patients. Regarding the secondary outcomes, TAVR was associated with a significant improvement of the MR directly after intervention (59/100 patients MR ≤2; P < 0.001), however no changes were observed later in the course. Self-expandable valves were inferior to balloon-expandable valves regarding the MR-severity after intervention (P = 0.017). After TAVR, persistent MR was detected in n = 45 patients (median follow-up 49 [IQR 8-150] days). Of these, n = 12 subsequently received TEER. Those patients had a significantly worse prognosis than non-TEER-patients (P = 0.022). Furthermore, TAVR-patients benefited significantly regarding the New York Heart Association (NYHA) functional status (P < 0.001), whereas patients with persisting moderate-severe symptomatic MR who received additional TEER  did not. Neither age, left ventricular ejection fraction, E/e´ ratio, systolic pulmonary artery pressure (sPAP), NYHA status prior intervention nor MR aetiology emerged as an independent prognostic risk factor for persistent MR after TAVR. 

Conclusion:  Patients with high-grade AS and concomitant moderate-severe MR benefit from TAVR procedure, both in terms of survival and clinical status. In case of persistent significant MR after TAVR, TEER appears to be more detrimental in terms of survival and clinical outcome regarding the NYHA status. Prospective multicenter clinical trials are indicated to consolidate or refute these findings and determine the clinical benefit from catheter-based double-valve intervention.