Modeling of mitral chordae’s length in echocardiography as a function of their manual measurement in the operating room

OBJECTIVE: In mitral insufficiency, trans-esophageal echocardiography (TEE) analysis of the mitral valve is an indispensable and irreplaceable examination to establish precisely the type of surgical repair to be performed and the exact length of neo-chordae to be used for an anatomical repair. The aim of our study is to find a predictive model of the Echographic Measurement (EM) variable according to the Manual Measurement (MM) variable of the mitral valve chordae, when the echocardiography measurement is not feasible. PATIENTS AND METHODS: This is a retrospective study on 191 patients undergoing mitral valve repair. The sex ratio (M/F) is 2.13 (130 men and 61 women). The collection of data of mitral chordae measurements performed echographically in preoperatively conditions, and then manually in intraoperatively conditions from January 2008 to December 2016 was made from the medical records of patients at the cardiology and cardiac surgery department of the University Hospital Center of Amiens in Picardy. RESULTS: For this study 191 patients of mean age of 68 ± 13 years were included. The averages of the MM and EM of the mitral chordae were respectively 23 ± 2.5 mm and 24 ± 2.4 mm. The Pearson correlation coefficient was 0.897 (p-value < 10(−4)) showing a strong positive correlation between MM and EM. The results of the linear regression allow us to found the following mathematical model: EM = 0.87 × MM + 4. CONCLUSIONS: When patients have a contraindication to transesophageal echocardiography or when TEE is not feasible, manual measurement is performed during the surgery. By using the values obtained (MM) in the model, it is possible to predict the corresponding echographic measurements. This allows us to achieve the mitral tendinous chordae substitution with a very high precision. Trial registration: Retrospectively registered.