Abstract 2761: Intrapatient Variability Is Of Greater Interest Than Absolute Values In Assessment Of Tissue Doppler Imaging In Pediatric Cardiac Transplant Recipients
Tissue Doppler imaging (TDI) is a promising technique for early detection of cardiac rejection in pediatric heart transplant (HTx) recipients. However, few studies have evaluated how to use TDI data in this population.
Methods: We reviewed all echo images from pediatric HTx recipients without coronary disease at our institution in an 18-month period. Data included systolic (LVSF%, contractility index (VCFc), and VCFc z-score) and diastolic (mitral e and a velocities, pressure half time (PHT), IVRT), and mitral annular TDI velocities. We related echo data to cath data obtained within 45 days, including CI, filling pressures, and rejection grade. We analyzed normal data with descriptive statistics. Intrapatient variability was estimated using Mean Square of Regression from one-way ANOVA. Data from rejection episodes was related to population and single patient norms.
Results: We identified 34 eligible subjects (ages 0.4 to 26 years, median 9.8 yrs) with 388 echos and 73 caths during the study period. There were 5 rejection episodes (ISHLT grade > 1a) in 4 subjects. Echo and cath data related to rejection episodes was excluded from normative data. Table 1⇓ describes the normal echo and TDI data. In 2/5 rejection episodes, patients suffered increases in cardiac filling pressures. In these instances, decreased TDI e’ and a’ velocities were the most substantially quantifiable changes detected by echo. When hemodynamic changes were not present, rejection caused no change in a patient’s baseline echo findings.
Conclusions: Although population variability among all echo parameters was substantial (even within age groups), intrapatient variability of TDI values, VCFc, and mitral inflow velocities were comparatively small, suggesting that serial comparison of echos is of greater clinical value than adherence to population norms. With the addition of TDI, echo may be better able to detect changes in diastolic function as detected by catheterization.