Author + information
- Susanna L. den Boer, MD,
- Gideon J. du Marchie Sarvaas, MD,
- Liselotte M. Klitsie, MD, PhD,
- Gabriëlle G. van Iperen, MD,
- Ronald B. Tanke, MD, PhD,
- Willem A. Helbing, MD, PhD,
- Ad P.C.M. Backx, MD,
- Lukas A.J. Rammeloo, MD,
- Michiel Dalinghaus, MD, PhD∗ ( and )
- Arend D.J. ten Harkel, MD, PhD
- ↵∗Department of Pediatrics, Division of Pediatric Cardiology, Sophia Children’s Hospital, Erasmus University Medical Center, Dr. Molewaterplein 60, P.O. Box 2060, 3000 CB Rotterdam, the Netherlands
In adults with dilated cardiomyopathy (DCM), it has been demonstrated that global longitudinal and circumferential strain have value in addition to left ventricular ejection fraction (LVEF) in predicting the risk of mortality, heart transplantation, and hospitalization for worsening heart failure (1). Measures that predict disease progression and outcome in children with DCM are needed. Therefore, we aimed to evaluate the predictive value of left ventricular (LV) global peak strain in the outcome in children with DCM.
We prospectively included 75 children (younger than 18 years of age) with DCM (left ventricular end-diastolic dimension [LVEDD] z-score ≥2 for body surface area and fractional shortening [FS] ≤25% on echocardiography) from 7 academic pediatric cardiology centers. Available data for 75 healthy age-matched controls were used (2). A complete 2-dimensional echocardiographic study was performed in a standardized way; measurements (LV dimension, function, and speckle-tracking echocardiography) were performed in a core echocardiography laboratory, as previously described (2). The mean age of all subjects was 7.5 ± 6.3 years. Patients were included at a median time of 1 year (interquartile range [IQR]: 0.1 to 4.0 years) after DCM diagnosis; the mean LVEF was 33 ± 11%, and the mean LVEDD z-score was 5.1 ± 3.0. The mean LV global peak strain in all views was significantly reduced compared with that in control subjects (Figure 1). No specified regions could be identified as more affected than others because all segments were worse in patients than in control subjects (p < 0.001). The 6-segment model (longitudinal 4-chamber view) was feasible in 99% of the patients and the short-axis view in 92% of the patients. The 12-segment model (including the 4- and 2-chamber views) was feasible in 85% and the 18-segment model (including the 4-, 2-, and 3-chamber views) in 64%. The mean global peak strain of the 6-, 12-, and 18-segment models were comparable (13 ± 4%, 13 ± 4%, and 13 ± 5%, respectively). Interobserver variability and intraobserver variability of longitudinal and circumferential strain were good (intraclass correlation coefficients: 0.88 to 0.91) and of radial strain was moderate (0.63).
The median follow-up from echocardiography until an endpoint or censoring was 21 months (IQR: 16 to 31 months); 10 patients (13%) reached a primary endpoint: 8 underwent heart transplantation and 2 died. Using univariable Cox regression analysis, we found that lower mean global longitudinal peak strain of the 4-chamber was significantly associated with a higher risk of an endpoint; each percentage of decrease in strain gave a 1.23 times higher risk of death or heart transplantation (hazard ratio [HR]: 0.81 per percentage of increase in strain, p = 0.04). LVEF (HR: 0.96; p = 0.19), FS (HR: 0.95; p = 0.28), LVEDD z-score (HR: 1.12; p = 0.22), and circumferential peak strain (HR: 0.83; p = 0.07) were not significantly associated with outcome, nor were the 12-segment model (HR: 0.89; p = 0.17) and the 18-segment model (HR: 0.93; p = 0.50) significantly predictive of outcome.
This is the first study to report that, in pediatric DCM, LV global longitudinal strain was predictive of death and heart transplantation. In addition, circumferential strain tended to be significant and had good reproducibility, suggesting that it may be of interest for future studies. According to its feasibility and comparable strain results, in addition to its prognostic value, we advise using the 6-segment model for longitudinal strain.
Our findings are in accordance with adult results (1). Until now, pediatric studies have mainly focused on measures at diagnosis, whereas FS and LVEDD at diagnosis were predictive of death and heart transplantation (3). In the present study, patients had a median time of 1 year after diagnosis. Therefore, our results indicate that in the follow-up of pediatric DCM, LV global longitudinal peak strain may be used to predict outcome.
Please note: Dr. den Boer was financially supported by grants from Stichting Hartedroom, Stichting Spieren voor Spieren, and Zeldzame Ziekten Fonds. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2016 American College of Cardiology Foundation
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