Quantitative measurements of aortic valve coaptation by three-dimensional transesophageal echocardiography in patients with aortic regurgitation without primary leaflet disease

Abstract

Aortic regurgitation (AR) without primary leaflet disease (functional AR) is known to occur as a result of loss of coaptation due to sinotubular junction (STJ) dilatation. However, the characteristics of change in the aortic valve coaptation length (AVCL) in 3 cusps in patients with functional AR are, as yet, unclear. The aim of this study was to measure the AVCL in 3 cusps in patients with functional AR by three-dimensional transesophageal echocardiograph (3D TEE). Thirteen patients with functional AR with or without aortic dilatation (trivial to mild AR [group A] and moderate to severe AR [group B]) and 7 controls without AR (group N) were examined. We measured the AVCL between the left coronary cusp (LCC) and right coronary cusp (RCC), the LCC and non coronary cusp (NCC), the RCC and NCC, and we also measured the cusp projection area, STJ arc length, leaflet tip-Valsalva wall distance and inter-commissural distance in each cusp by 3D TEE. The average AVCL was significantly shorter in group B than in groups N and A (P<0.001). Particularly, in group B, there was a significant difference in AVCL in the 3 cusps (P=0.043). Moreover, although there were no significant differences in the size of cusps in groups N and A, there was disproportion in the size of those cusps in group B with the largest in RCC. Cusp enlargement was not uniform and was greatest in the RCC, and the loss of coaptation between the 3 cusps was also not uniform, with predominant reduction in the coaptation between the RCC and the other 2 cusps.