Background:

Edge-to-edge (TEER) transcatheter mitral valve repair (M-TEER) has shown safety and efficacy in reducing mitral regurgitation (MR) and led to the development of TEER for tricuspid regurgitation (TR). We hypothesized that T-TEER procedural outcomes are directly impacted by M-TEER experience.

Methods:

We retrospectively analyzed intraprocedural reduction of secondary MR and TR after release of a valve specific device, in the time frame between 2018, when M-TEER was implemented in our center, through November 2020, when T-TEER procedures started, and up to the end of 2022 (Figure 1A). Within this period, we compared results between the 55 T-TEER procedures performed so far (2020-2022) and 3 M-TEER cohorts: the very first 55 M-TEER (2018-2019), the 55 M-TEER before implementation of T-TEER (2020), and the very last 55 M-TEER (2022). 

For secondary MR, a 4-grade classification (I/IV to IV/IV) was used, as III/IV was defined by an effective regurgitation orifice area (EROA) of 20-39mm², coupled with regurgitation fraction ³50%, while IV/IV was present if EROA ³40mm². Secondary TR was evaluated using the latest 5-grade (I/V to V/V) classification. Considering that a 5-grade TR reduction from V/V to 0/V is either not possible or not desirable, the extent of regurgitation reduction for both valves was set on a scale from 1- to 4-grade reduction. Also, optimal results were defined as residual MR 0+ (none or trace) or TR I+ (mild or mild to moderate), while acceptable results were considered MR I+ (mild or mild to moderate) and TR II+ (moderate or moderate to severe). 

Results:

In all 4 TEER groups, regurgitation was successfully and significantly reduced within-group (Figure 1B), with the exception of 2 T-TEER cases with coaptation gaps of 15mm. MR reduction to optimal or acceptable levels increased over time from 60% at M-TEER program start to 78% after 12-18 months (p=0.039), and 84% (p=0.005) after approximately 3 years. Accordingly, the extent of regurgitation reduction significantly improved between the first 2 M-TEER cohorts (p=0.016), as well as the first and the last 55 M-TEER (p=0.045), with no significant change from the second to the third population (p=0.267) (Figure 2).

In comparison, T-TEER achieved 84% optimal or acceptable residual TR (Figure 1B), better than initial (p=0.005) and similar to the middle (p=0.466) and last M-TEER cohorts (p=1.000). In terms of extent of regurgitation reduction (Figure 2), T-TEER also performed better than the 1^st (p=0.025) and similar to the 2^nd (p=0.645) and 3^rd M-TEER cohorts (p=0.076), despite higher mean effective regurgitant orifice area (78.5±32.2mm² vs  44.8±16.1mm² in all MR patients, p<0.001), more complex anatomy, more challenging imaging, and sicker patients (mean-EuroSCORE II 8.8±6.6% vs 6.4±5.3% in all MR patients, p<0.001). 

TEER safety aspects were excellent, counting only 4 complications during M-TEER, of which only one device related being a case of single leaflet attachment (SLA) (0.6%). Equally, T-TEER led to one single SLA (1.8%). All patients were discharged, on average after 5.3±4.3 (M-TEER) vs 6.1±5.3 days (T-TEER), p=0.277.

Conclusions:

TEER is safe and effective in reducing secondary MR and TR. In our center, gain in knowledge and experience, coupled with technological advances, have significantly impacted procedural M-TEER success over time and allowed similar successful implementation of a T-TEER program.