Abstract 17687: Comparison of Two-dimensional Echocardiography and Cardiac Magnetic Resonance for the Assessment of Left Ventricular Volume and Systolic Functions in Patients With Non-ischemic Cardiomyopathy: Impact of Myocardial Fibrosis
Background: The accuracy of echocardiographic assessment of LV size and function is limited due to underlying geometric assumptions of LV shape. In patients with non-ischemic cardiomyopathy (NICM) these measurements may be inaccurate, particularly in patients with focal regional dysfunction due to the presence of myocardial fibrosis (MF). We sought the accuracy of LV size and function using echocardiography, compared with cardiac MRI (CMR) in NICM with and without MF.
Methods: 81 consecutive patients (49% male; age = 50 ± 16 y) with NICM who had both echo and CMR study within 30 days were studied. Echocardiography-derived LV ejection fraction (LVEF) and LV volumes were measured by Simpson’s biplane method. CMR derived LVEF and LV volumes were measured using summation of discs methodology. Pearson’s correlation coefficient and paired t-tests were used to compare CMR and echo measures. Bland-Altman analysis was used to determine the bias and 95% limits of agreement (LOA).
Results: LVEF measured by echo and MRI were not statistically different (29.5+11 vs 28.8+12, p=0.388). There was modest correlation between the two methods (R2=0.49, p<0.001). CMR derived LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) are significantly higher than echocardiography-derived LV volume (LVEDV 280.1+105.6 mL Vs 203.2+101.9 mL. p<0.001, LVESV 206.8 +105.7 Vs 144.6+98.2,P<0.001). Echocardiography-derived LVEF in patients without MF showed significantly higher correlation with CMR than in patients with MF (R2= 0.68 Vs R2= 0.34, p=0.029). In patients with MF, the mean differences was 1.46 units with 95% LOA of +13.11 units. In patients with MF the mean differences was -1.95 units with LOA of +21.11 units. (Figure)
Conclusion: The accuracy of echocardiography-derived LVEF is significantly lower in NICM patients with MF as compared to the group without scar. This may, in part, related to altered LV geometry and/or focal regional wall motion abnormalities.
- © 2013 by American Heart Association, Inc.