Diagnostic accuracy of two-dimensional and three-dimensional transesophageal echocardiography in detecting pannus and thrombus in left mechanical valve obstruction

Aims: The aim of this study was to determine the accuracy of two-dimensional and three-dimensional transesophageal echocardiography (TEE) in the detection of pannus and thrombus in left mechanical valve obstruction (LMVO) compared with surgical and histopathology findings. Materials and methods: Patients with suspected LMVO on transthoracic echocardiography were enrolled consecutively. All patients underwent two-dimensional and three-dimensional TEE, and open-heart surgery to replace obstructed valves. Macroscopic and microscopic analysis of the excised masses was used as the gold standard for the diagnosis of thrombus and/or pannus. Results: Forty-eight patients [34 women (70.8%), age 49±13 years, New York Heart Association II: 68.8%, New York Heart Association III: 31.2%] were enrolled. In the diagnostic of thrombus, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of three-dimensional TEE were 89.2, 72.7, 85.4, 91.7, and 66.7%, respectively, compared with those of two-dimensional TEE (42.2, 66.7, 43.8, 95, and 7.1%, respectively). In the diagnosis of pannus, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of three-dimensional TEE were 53.3, 100, 85.4, 100, and 82.5%, respectively; compared with those of two-dimensional TEE (7.4, 90.5, 43.8, 50, and 43.2%, respectively). Receiver operating characteristic curves depict that the area under the curves of three-dimensional TEE was higher than the area under the curves of two-dimensional TEE in both diagnoses of thrombus and pannus (0.8560 vs. 0.7330, P =0.0427 and 0.8077 vs. 0.5484, P =0.005, respectively). Conclusions: This study indicated that three-dimensional TEE had a higher diagnostic value than two-dimensional TEE in the detection of thrombus and pannus in patients with LMVO, and can be a reliable imaging modality to identify the causes of LMVO.