Determination of mitral valve area with echocardiography, using intra-operative 3-dimensional versus intra- & post-operative pressure half-time technique in mitral valve repair surgery

BACKGROUND: We hypothesized that mitral valve areas (MVAs) with echocardiography, using 3D planimetry technique (measured at one point at maximal opening of mitral valve) versus pressure half-time technique (PHT, measured during entire diastolic phase) in mitral valve repair surgery (MVR) would be different. METHODS: Patients who had undergone MVR were retrospectively reviewed, and two different observers measured the MVAs using PHT and 3D planimetry technique. The MVAs derived from recorded medical data, using PHT and 3D planimetry technique were abbreviated to MVA-PHT1 and MVA-3D1, and data from the PHT and 3D planimetry techniques by observer A and observer B were determined as MVA-PHT2 and MVA-3D2, and MVA-PHT3 and MVA-3D3, respectively. The MVA derived by post-operative transthoracic echocardiography using the PHT technique was determined as MVA-TTE. RESULTS: Intraclass correlation coefficients were 0.90 for the intra-operative PHT technique and 0.78 for the intra-operative 3D planimetry technique. MVA-3D1 (2.91 ± 0.65 cm2), MVA-3D2 (3.00 ± 0.63 cm2) and MVA-3D3 (2.97 ± 0.88 cm2) were significantly larger than MVA-TTE (2.40 ± 0.59 cm2), but intra-operative MVAs-PHT were not. The biases and precisions were larger, and the correlation coefficients were lower in 3D planimetry technique compared with PHT technique. CONCLUSIONS: MVA measured by 3D planimetry technique with TEE at the intra-operative post-MVR period was seemed to be larger than that measured by the PHT technique with TTE at the post-operative period. However, it did not mean that the 3D planimetry technique was inaccurate but needs cautions at determination of MVA using different techniques.