The first international registry of patients undergoing transcatheter mitral interventions after transcatheter aortic valve implantation (TAVI) has shown that a staged interventional strategy is feasible, safe, and associated with significant improvement in mitral regurgitation grade and New York Heart Association functional class in these patients.
The retrospective international registry study, published in JACC: Cardiovascular Interventions, authored by Guy Witberg (Rabin Medical Center, Petach-Tikva, Israel) and colleagues, sought to describe the baseline characteristics, periprocedural and mid-term outcomes in patients undergoing transcatheter mitral valve interventions after TAVI, using data taken from 23 TAVI centres worldwide.
Researchers reported data from 106 of 24,178 patients (0.43%) who underwent mitral interventions post-TAVI (100 staged, 6 concomitant), at the 23 sites, most common of which was percutaneous edge-to-edge mitral valve repair (PMVR). The median interval of the interventions post-TAVI was 164 days. Patients had a mean age of 79.5±7.2 years and mitral regurgitation (MR) was >moderate in 97.2%.
The reported technical success was 99.1%, and the 30-day device success rate was 88.7%. In total there were 18 periprocedural complications (16.9%) including four deaths, and during a median follow-up of 464 days, the cumulative risk for three-year mortality was 29%.
MR grade and New York Heart Association (NYHA) functional class improved dramatically, the study team reported; at one year, MR was moderate or less in 90.9% of patients (mild or less in 69.1%), and 85.9% of patients were in NYHA functional class I/II. Staged PMVR was associated with lower mortality versus medical treatment (57.5% vs. 30.8%) in a propensity-matched cohort (n=156), but this was not statistically significant (hazard ratio: 1.75; p=0.05).
The study team concluded that for patients who continue to have significant MR, remain symptomatic post-TAVI, and are anatomically suitable for transcatheter interventions, these interventions are feasible, safe, and associated with significant improvement in MR grade and NYHA functional class.
Discussing the findings, Witberg and colleagues note: “Our results show that the prevalence of TMVR/r [transcatheter mitral valve repair] procedures post-TAVR is 0.43%, and that the use of these procedures in the TAVR population is growing; in this selected population, these interventions can be carried out with a high procedural success rate (98.1%) and low periprocedural morbidity and mortality. In terms of clinical benefit, these interventions were associated with a dramatic improvement in MR grade that resulted in 85.9% of patients maintaining a favourable NYHA functional class (I/II) through 1 year of follow-up.”
Speaking to Cardiovascular News, Witberg said: “Although our data show that under current/recent clinical practice, the use of staged TMVR/r post TAVI is very infrequent, one major cause for this underutilisation is that many patients are not anatomically suitable for TMVR/r—this may not be the case in the very near future given the increase in clinical experience with TMVR/r and the availability of more dedicated devices of transcatheter treatment of mitral regurgitation.”
The study team notes that while the analysis can only be treated as hypothesis-generating, the results suggest that for those who remain symptomatic post-TAVI and are anatomically-suited to percutaneous edge-to-edge mitral valve repair, a staged intervention may be associated with a reduction in mid-term mortality.