Automated Functional Imaging by 2D Speckle Tracking Echocardiography Reveals High Incidence of Abnormal Longitudinal Strain in a Cohort of Pediatric Oncology Patients.

BACKGROUND

Automated functional imaging (AFI) was introduced to two-dimensional speckle-tracking echocardiography to facilitate strain assessment in the clinical settings. In patients treated with cardiotoxic anthracyclines, AFI may be helpful in the detection of early myocardial injury when left ventricular ejection fraction (LVEF) remains normal.

METHODS

We retrospectively assessed feasibility of AFI in 143 echocardiograms on 102 subjects aged 0.4-22 years (mean 12.3) obtained over a 12-month period. We computed a Z-score for apical four-chamber longitudinal strain using published normal data to assess for abnormal strain in patients with and without previous exposure to anthracyclines.

RESULTS

AFI was feasible in 95.1% of echocardiograms, with low inter- and intraobserver variability. There was a statistically significant association between abnormal longitudinal strain Z-score (SZ < -2.0) and depressed LVEF (<55%, P < 0.001). However, 46% of echocardiograms with normal LVEF had abnormal SZ; half of which had no prior anthracycline exposure. The correlation between SZ and LVEF was strongest in subjects exposed to anthracyclines (r(2) = 0.12, P < 0.01). Increasing age was associated with decreasing SZ. Total cumulative dose, after adjusting for age, was inversely associated with SZ (r(2) = 0.42, P < 0.001). Time from last dose of anthracycline had no significant association with SZ.

CONCLUSIONS

AFI is highly feasible in the clinical settings. The observed high prevalence of abnormal longitudinal strain in our cohort emphasizes the importance of obtaining baseline measurements prior to anthracycline treatment. The effects of anthracycline on longitudinal strain may be dose and age dependent, with younger children less likely to show abnormalities.