A pooled analysis of interventional studies assessing the feasibility, efficacy and clinical outcomes of transcatheter repair of tricuspid regurgitation (TR) has concluded that a percutaneous repair strategy for severe TR appears to be feasible, effective, and is associated with improved clinical outcomes at mid-term follow-up.
Published in JACC: Cardiovascular Interventions, the analysis by Claudio Montalto (Fondazione IRCCS Policlinico San Matteo, Pavia, Italy), senior author Antonio Mangieri (GVM care and research, Maria Cecilia Hospital, Cotignola, Italy) and colleagues brought together data from seven studies of patients undergoing transcatheter tricuspid valve repair to assess echocardiographic results and functional improvements from the procedures.
The study team sourced data from several electronic databases from interventional studies involving percutaneous repair of TR, using devices such as: Cardioband (Edwards Lifesciences), FORMA (Edwards Lifesciences), MitraClip (Abbott), PASCAL (Edwards Lifesciences) and Trialign (Mitralign). Outcomes included in the final analysis were successful implantation, residual severe TR, post procedural New York Heart Association (NYHA) functional class III‒IV, six-minute walking test and echocardiographic parameters.
Within the seven eligible studies identified, data were available for 454 patients undergoing transcatheter tricuspid valve repair. Of these, 95% had at least severe TR and 91% were in NYHA functional class III–IV, and successful implantation was achieved in 86% of patients. At the longest follow-up available (weighted mean 265 days), 9% died, the study team reports. When compared to baseline, a significantly lower proportion of patients had at least severe TR (Relative Risk [RR] 0.38; 95% Confidence Interval [CI]: 0.2‒0.7; p=0.004) and were in NYHA functional class III‒IV (RR 0.23; 95% CI: 0.2-0.3; p<0.001). Patients also experienced an increase in their six-minute walking test capacity (+64.6 meters; p<0.001) and a significant reduction in tricuspid valve annulus diameter (-3mm; p<0.001), while left and right ventricular function did not change significantly.
Discussing the findings, Montalto and colleagues note that currently, robust data supporting the use of transcatheter tricuspid valve replacement are limited, meaning that current guidelines only advocate for the surgical correction of TR. However, they add that an interventional strategy to treat severe TR has been shown to reduce mortality and rates of hospitalisation in comparison to conventional pharmacological therapy.
The authors write: “Irrespective of the advanced clinical condition, our pooled analysis confirmed the feasibility and the high successful implantation rates of TTVr [transcatheter tricuspid valve repair] with a low mortality rate at mid-term follow-up. These findings compare favourably against prior cohorts consisting solely of medically managed patients and especially when considering that a learning-curve effect might have been observed in the earliest phase of patients treated with TTVr. Moreover, TTVr was effective since patients experienced a significant reduction in TR, as assessed semi-quantitatively and quantitatively. These changes were also accompanied by clinical improvements, both in terms of a lower proportion of patients in NYHA functional class III‒IV and with an increase in 6MWT [six-minute walking test] capacity.”
Montalto and colleagues note that the study has several limitations, including that the pooled analysis included only single-arm interventional studies, and that therefore no comparison was present. Additionally, devices for transcatheter tricuspid valve replacement feature different mechanisms, and the majority of subjects received edge-to-edge plasty “which might account for a large part of the observed positive effects”. Furthermore, as the population analysed was advanced both clinically and in terms of echocardiographic parameters, they write, the results may not be applicable to a wider population with less severe clinical conditions.
In conclusion, they write: “Our pooled analysis revealed that TTVr with current devices is feasible and effective in reducing TR in high risk patients with severe symptomatic TR. Moreover, patients treated with TTVr exhibit favourable outcome[s] with improved functional capacities. Further studies are required to confirm the positive effects of transcatheter therapies on patient’s prognosis and functional status at long term follow-up.”