Comparison of the proximal flow convergence method and the jet area method for the assessment of the severity of tricuspid regurgitation

Aims To compare the value of the proximal flow convergence method and the jet area method for the determination of the severity of tricuspid regurgitation. Methods and Results The proximal isovelocity surface area radius and the jet area/length were measured in 71 consecutive patients with angiographically graded (grade O/I-III) tricuspid regurgitation. Rank correlation coefficients with the angiographic grade were 0.71 (P<0.001) for the proximal isovelocity surface area radius (aliasing border of 28 cm. s(-1)), 0.66 (P<0.001) for the jet area, and 0.63 (P<0.001) for the jet length. The proximal isovelocity surface area radius was significantly correlated with the jet area/length (correlation coefficients 0.82/0.77, P<0.001). Correct differentiation between mild to moderate (grade I-II) and severe (grade III) tricuspid regurgitation was achieved in 62 of 71 patients (87%) by means of the proximal isovelocity surface area radius, in 61 of 71 (86%) by the jet area, and in 62 of 71 (87%) by the jet length. Grade III tricuspid regurgitation was not identified in five of 21 patients (24%) by means of the proximal isovelocity surface area radius, in six of 21 (29%) by the jet area, and in seven of 21 (33%) by the jet length. Conclusion The flow convergence method and the jet area method are of similar value for the determination of the severity of tricuspid regurgitation. Both methods differentiated mild to moderate from severe tricuspid regurgitation in most patients. However, underestimation of severe tricuspid regurgitation in 20-30% of the cases represents a serious limitation of both methods.