Interobserver, intraobserver and intrapatient reliability scores of myocardial strain imaging with 2-d echocardiography in patients treated with anthracyclines.

Abstract

Myocardial strain imaging with 2-D echocardiography is a relatively new noninvasive method to assess myocardial deformation. To determine the interobserver, intraobserver and intrapatient reliability scores, we evaluated myocardial strain measurements of 10 asymptomatic survivors of childhood cancer. Ten patients were selected randomly out of a follow-up cohort of childhood cancer survivors. All 10 patients underwent a transthoracic echocardiographic examination. Two-dimensional gray scale images were made in parasternal apical four-chamber, apical two-chamber, midcavity short-axis and basal short-axis views. Offline analysis was performed using software for echocardiographic quantification (Echopac 6.1.0, GE Medical Systems, Horten, Norway). All echocardiographic studies were analyzed offline by three observers, separately (A.M., G.W., M.P.). A custom-made software package was designed for averaging the strain curves of three consecutive cardiac cycles. Values of peak systolic strain, time-to-peak strain and time-to-end systole of the different segments of the left ventricle were used for statistical analysis. Interobserver, intraobserver and intrapatient reliability were expressed as intraclass correlation coefficients (ICCs). Interobserver ICCs of peak strain, time to peak strain and time to aortic valve closure (AVC) were generally good to very good in all views and segments, except for in the two-chamber view. Intraobserver ICCs were rated as very good for almost all segments, except for the longitudinal peak strain values of the two-chamber view. Intrapatient ICCs were generally good for the two-chamber, four-chamber and midcavity short-axis views, but fair to moderate for the segments of the basal short-axis view (SaxMV). We recommend use of the four-chamber view for longitudinal peak strain values, and the basal and midcavity short-axis views for radial and circumferential peak strain values. Furthermore, we strongly recommend using the average of three cardiac cycles for peak strain values in clinical studies.