Reliability of echocardiographic assessment of left ventricular structure and function: the PRESERVE study. Prospective Randomized Study Evaluating Regression of Ventricular Enlargement.

OBJECTIVES The study was done to evaluate reliability of echocardiographic left ventricular (LV) mass. BACKGROUND Echocardiographic estimation of LV mass is affected by several sources of variability. METHODS We assessed intrapatient reliability of LV mass measurements in 183 hypertensive patients (68% men, 65 +/- 9 years) enrolled in the Prospective Randomized Enalapril Study Evaluating Regression of Ventricular Enlargement (PRESERVE) trial after a screening echocardiogram (ECHO) showed LV hypertrophy. A second ECHO was repeated at randomization (45 +/- 25 days later). Two-dimensional (2D)-guided M-mode or 2D linear measurements of LV cavity and wall dimensions were verified by one experienced reader. RESULTS Mean LV mass was similar at first and second ECHO (243 +/- 53 vs. 241 +/- 54 g) and showed high reliability as estimated by intraclass correlation coefficient (RHO) = 0.93. Within-patient 5th, 10th, 90th and 95th percentiles of between-study difference in LV mass were -32 g, -28 g, +25 g and +35 g. Mean LV mass fell less from the first to the second ECHO than expected from a formula to predict regression to the mean (2 +/- 19 vs. 17 +/- 12 g, p < 0.001). Reliability was also high for LV internal diameter (RHO = 0.87), septal (RHO = 0.85) and posterior wall thickness (RHO = 0.83). Substantial or moderate reliability was observed for measures of LV systolic function and diastolic filling (RHO from 0.71 to 0.57). CONCLUSIONS Left ventricular mass had high reliability and little regression to the mean; between-study LV mass change of +/-35 g or +/-17 g had > or = 95% or > or = 80% likelihood of being true change.