mid to long-term echocardiographic follow-up of patients undergoing transcatheter tricuspid valve-in-valve replacement for degenerated bioprosthetic valves: first single-center report from iran

Background: transcatheter tricuspid valve-in-valve (ttviv) replacement has become an alternative treatment in high-risk patients with bioprosthetic valve degeneration. this is the first report on the mid to long-term echocardiographic findings of patients who underwent ttviv replacement in a cardiac referral center in iran. methods: data of 12 patients, consisting of 11 women and 1 man, who underwent ttviv replacement between 2015 and 2021 were reviewed retrospectively. the patients underwent echocardiography before the procedure and at a mean follow-up time of 3.17±1.75 years. results: all the patients had new york heart association (nyha) function class iii/iv before ttviv. six patients had tricuspid regurgitation, 1 had tricuspid stenosis, and 5 had both. all the patients had successful ttviv. the mean time from the initial valve surgery to ttviv was 6.25±2.45 years. at follow-up, 2 patients had died: 1 due to covid-19 pneumonia and 1 without a known cause. the remaining 10 patients experienced improvements in the nyha functional class. echocardiographic measures showed significant improvements. transvalvular mean gradient pressure decreased from 7.08±1.98 mm hg to 5.29±1.63 mm hg (p=0.028), tricuspid valve pressure half time decreased from 245.00±49.46 ms to 158.64±57.41 ms (p=0.011), tricuspid regurgitation gradient decreased from 39.91±7.31 mm hg to 26.72±8.99 mm hg, and left ventricular ejection fraction increased from 47.71±4.70% to 49.79±4.58% (p=0.046). there was no significant paravalvular or transvalvular leakage at follow-up. conclusion: this is a single-center report on the mid and long-term echocardiographic follow-up of patients after ttviv replacement. our study showed that ttviv was a safe and efficient method in treating high-risk patients with degenerated bioprosthetic tricuspid valves and had favorable echocardiographic and clinical results.