Examination of the Morphological Change of the Tricuspid Valve Complex in Functional Tricuspid Regurgitation

Objective: We examined the morphological change in functional tricuspid regurgitation (FTR) of each TR severity by 3DCT and echocardiographic data. Methods: 17 patients underwent 3DCT and echocardiography (TR grade: 1 severe, 2 moderate, 5 mild, and 9 trivial). We measured tricuspid annulus area (TAA), tricuspid annulus circumference (TAC), right ventricular volume (RVV, end-diastolic [EDRVV] and end-systolic [ESRVV]), the coefficient that divided various data by body surface area (BSA), and distance between each papillary muscles by 3DCT, and TR grade, vena contracta (VC), jet area (JA), tricuspid annular plane systolic excursion (TAPSE), functional area change (FAC), tricuspid annulus diameter (TA, 4ch, end-diastolic), right ventricular pressure (RVP), and inferior vena cava diameter (IVC) by echocardiography. We divided into trivial group (n=9), and mild-severe group (n=8), and considered whether each data point was significantly different between groups. Then, we examined the correlation of TR grade and each data point with 3DCT. Finally, we examined the cut-off level with ROC curve for TAA, TAC, RVP, and TA, using TAPSE<17mm showing right ventricle functional failure. Results: Comparing between two groups, TAA/BSA (p=0.034, 95% confidence interval[CI] 0.268-5.966), VC (p=0.041, [CI] 0.061-2.430), and RVP (p<0.01, [CI] 9.131-20.175) showed significant differences. There was a positive correlation between TR grade and TAA, and the correlation became stronger in TAA/BSA (TAA: R20.453, and TAA/BSA: R20.608). Similarly, TAC and RVV had positive correlation (TAC: R20.394, TAC/BSA: R20.548, EDRVV: R20.630, EDRVV/BSA: R20.609, ESRVV: R20.612, and ESRVV/BSA: R20.641). Distance between papillary muscles did not have correlation. The cut-off level with ROC curve using TAPSE was 15.37cm2 at TAA, 9.63 at TAA/BSA, 142.20mm at TAC, 89.06 at TAC/BSA, 167.60 ml at EDRVV, 113.97 at EDRVV/BSA, 96.90ml at ESRVV, 65.62 at ESRVV/BSA, and 32.00mm at TA. Conclusions: TR grade had positive correlations with TAA, TAC, and RVV. It was thought that we can consider intervention timing for FTR using these cut-off levels with 3DCT.