Transcatheter tricuspid valve-in-valve: evolution of tricuspid hydraulic performance and respective changes of right ventricular anatomy and function

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter tricuspid valve-in-valve replacement (TVIV) is an emerging therapy for dysfunctional surgically implanted bioprostheses. There are few data about the evaluation of hydraulic performance of these valves. Purpose Purpose of this single-center study was to evaluate the evolution of the right ventricular anatomy and function and the respective changes of TVIV hydraulics. Methods Six patients who underwent Sapien S3 TVIV (size 29mm) were studied (age 57 ± 11years, 3/6 in sinus rhythm, all in NYHA class III/IV). Inspiratory (insp) and expiratory (exp) TV mean gradients (mGR) , respective heart rate (HR), right ventricular end-diastolic diameter (RVEDd mm), RV fractional area change (FAC%) and RV free wall longitudinal strain (RV strain) were estimated at baseline (B), 1 month (1m) and later than 6 months (>6m). Results NYHA class fell by at least 1 scale at 1m and remained either stable or further improved at 6m. RVEDd increased early at 1m (B: 33.5 ± 5.3mm vs 1m: 41.3 ± 3.3mm, p = 0.018) and remained unchanged at >6m (>6m: 41 ± 4.2mm vs 1m: 41.3 ± 3.3mm, p = ns). FAC improved late at 6m (B: 42.6 ± 2.8% vs 6m: 56 ± 6.2% p = 0.04). RV strain remained unchanged (B: -17 ± 5.5% vs 1m: 16 ± 7% vs >6m: -20 ± 6%, p = ns). The improvement in both mGR-exp and mGR-insp was evident at 1m and remained unchanged afterwards: (mGR-exp: B 9 ± 4mmHg, 1m: 3 ± 2, >6m: 5 ± 1, both p < 0.05 vs B, mGR-insp: B 15 ± 5mmHg, 1m: 6 ± 2, >6m: 8 ± 2, both p < 0.05 vs B). The respective heart rates during measurements at inspiration and expiration were similar (HR-exp: B 72 ± 22bpm, 1m: 81 ± 22bpm, >6m: 65 ± 9bpm, HR-insp: B 75 ± 27bpm, 1m: 79 ± 18bpm, >6m: 69 ± 3bpm) Absolute values for both mGR-insp and mGR-exp, despite progressive improvement, showed variations exceeding the conventional cut-off for TV prosthetic valve dysfunction of 6 mmHg, despite preserved clinical improvement. Variations of mGR were not related with the respective HR. Conclusion Following TVIV, early clinical improvement was related with a concomitant increase in RV volume, whereas RV functional indices showed a delayed response. Conventional echocardiographic hydraulics showed variability, often exceeding threshold for definition of prosthetic valve dysfunction. Thus, the significance of TV gradient after TVIV should be interpreted in the clinical context, taking into account respiratory changes.