Traditional Tricuspid Annuloplasty vs. Pledget Assisted Suture Tricuspid Annuloplasty for Repair of Functional Tricuspid Regurgitation – a Hemodynamic Study in an ex vivo Pulsatile Heart Model

Abstract

Objective: Functional tricuspid regurgitation (FTR) is a common valvular lesion caused by annular dilatation, right ventricular (RV) enlargement and dysfunction in patients with left-side heart disease, atrial fibrillation, or pulmonary hypertension. New transcatheter techniques have been emerging to treat FTR patients, however, their efficacy in correcting FTR and their impact on surrounding ventricular structures is unknown. In this study, we sought to compare the hemodynamic outcomes of two procedures, traditional tricuspid annuloplasty (TTA) and pledget assisted suture tricuspid annuloplasty (PASTA) procedure, for FTR. Methods: A right heart pulsatile flow simulator was developed using intact hearts explanted from swine (Fig 1A). Five hearts (n=5) were studied at an RV pressure of 40 mmHg, 3L/min cardiac output at 70 beats/min. After obtaining baseline data, FTR was induced by elevating RV afterload that instantaneously dilated the RV. PASTA procedure and TTA (26mm MC3) were performed in each heart in a randomized manner (Fig.1-3B, C). Tricuspid valve kinematics were measured with echocardiography, and hemodynamics were measured with flow probes. Results: RV area was 1949±182mm 2 at baseline and increased to 2402±176mm 2 in the setting of FTR (23.2% increase, p=0.009) (Fig. 1D), resulting in a mean regurgitant fraction of 59.0±18.7%. A mean regurgitant fraction of 48.9±19.84% was achieved after PASTA and 37.85±31.05% after TTA. Annular diameter increased 29.3% from baseline to FTR (41.44±2.1mm vs 53.58 ±1.8mm, p=0.0055), and was then reduced to 25.16±2.3mm (p<0.0001 vs baseline) after TTA, and 33.52±2.6mm (p<0.0001 vs baseline) after PASTA (fig.2-3D). Tenting area increased by 501% in FTR from baseline (80±17mm 2 vs. 482±31mm 2 , p=0.0009), and then reduced to 252±98mm 2 (p<0.0001 vs. base-line) after TTA and 164±58mm 2 (p<0.0001 vs. baseline) after PASTA (Fig 4-5D).