Comparison of Myocardial Deformation by Speckle-Tracking Echocardiography and Cardiac Magnetic Resonance in Patients with Fontan Circulation: Diagnostic Algorithm

BACKGROUND: While the short- and median-term survival has improved considerably in patients with Fontan circulation, cardiac function and exercise capacity are still reduced and may deteriorate over time. Cardiac magnetic resonance (CMR) is the gold standard for the assessment of ventricular volume and function. Speckle-tracking echocardiography (STE) is a myocardial deformation technique to assess ventricular function, with promising results. The aim of our study is to validate STE and conventional echocardiography parameters and to compare them with CMR. Furthermore, we aimed to design a diagnostic algorithm applying some parameters in series for early detection of myocardial dysfunction. MATERIALS AND METHODS: We performed a cross-sectional single-center study in 64 patients with Fontan circulation. Longitudinal and circumferential strain, strain rates, and conventional echocardiographic measurements were registered. Ventricular volumes and ejection fraction (EF) were obtained by CMR. RESULTS: Seven patients presented ventricular dysfunction (EF <45% by CMR), without showing a significant correlation between STE parameters or conventional measures by echocardiography and CMR. After the application of the diagnostic algorithm with the optimal cutoff points (global longitudinal strain – 24.5%, global circumferential strain – 20%, and annular plane systolic excursion – 16.5 mm), we got a sensitivity rate and a negative predictive value of 100%. In 19 patients (40.1%), the absence of ventricular dysfunction was demonstrated without no false-negative cases. CONCLUSIONS: STE should be considered a complementary diagnostic tool in Fontan patients. These suggested parameters applied in series are a useful tool for identifying early ventricular dysfunction and for diagnostic tests improvement with a fewer CMRs in the follow-up of these patients.