SUPPLEMENTARY INFORMATION
Assessment of 3DE Left Ventricular Volume and Mass
All studies were performed with transthoracic using the Philips IE33 ultrasound system (Philips, Andover, MA, USA) equipped with the X3-1 matrixarray transducer. Volumes were obtained over four cardiac cycles with ECG gating and brief patient breath-hold to minimize stitch artefacts. Care was taken to include the entire LV cavity within the pyramidal 3D scan volume.
3DE datasets were analyzed using commercial software (Philips QLABv8). Pyramidal volume data was displayed in three cross sections that could be modified interactively. Using this convention, we selected the anatomically correct two- and four chamber views with the largest long-axis dimensions. The operator defined the LV apical and mitral valve annular landmarks (septal, lateral, anterior, and inferior) at end-diastole (D) and end-systole (S) to automatically track the endocardial border throughout the frames of the cardiac cycle. Failure to track was manually corrected as found appropriate. Epicardial contours were mainly manually traced to calculate the left ventricle epicardial volumes at D and S. The 3DE LVM was calculated at both D and S. 3DE measurements were made by subtracting the endocardial volume from the epicardial volume and multiplying by 1.05 to correct for the density of cardiac muscle. As the correlation between systolic and diastolic LVM was good (r=0.872, p<0.001), the more repeatable systolic LVM was selected as a final outcome variable as previously reported. 1 LVM was normalized to height (in meters) to the power of 2.7 (LVM index, LVMI) and expressed as g/m2.7. 2Survivor’s LVMI was compared to the study controls and values exceeding +2SDs were consider as LV hypertrophy.
Synchronization Indexes
The LV 3DE model utilized 16, 12, or 6 segments depending on the degree to which more apical segments are excluded from the analysis. The 3DE-derived systolic dyssynchrony index(SDI) is the standard deviation of the time taken to reach the minimum systolic volume, expressed as a percentage of the cardiac cycle length (R-R interval). 3-6
Assessment of cardiac function
Ejection fraction (EF) was calculated according to standard formulas from the 3DE endocardial datasets of LV volumes at D and S. Tissue Doppler imaging (TDI) was performed from the apical four-chamber view with Pulsed Wave Doppler. A sample volume of 4 mm was placed at the basal ventricular septum with theultrasound beam aligned parallel to the longitudinal myocardial wall segment motion. The peak systolic (S`) and early diastolic (E`) tissue velocities were measured as a mean of three cardiac cycles directly on the spectral display. The recognition of each peak velocity was based on the direction and timing (ECG) of the wave. The early inflow diastolic velocity (E) was measured with Pulsed Wave Doppler and E/E’ used as a measure of cardiac diastolic function. 7
Tests for Physical Performance
The tests used were the following: leg-lift, repeated squatting, sit-up and shuttle-run. One physiotherapist performed the tests.
A standard deviation score (SDS) in the physical performance test was calculated for each study subject (survivor and control) individually using the normal values of healthy controls from our previous study (by calculating the difference between the study subject value and the mean value of the oldest (17 to 18 year) healthy control group divided by the SD of the healthy control group). 8The muscle sum score was determined by calculating the mean SDS value for the 5 tests. SDS values were used in the analyses.
Data Analysis
All data is presented as mean±SD. The Mann-Whitney U test and the Fisher’s exact test were used for statistical comparison between survivors and controls as well as between TBI and non-TBI survivor groups. Age and sex were not adjusted for due to matching of the survivor and control groups. We used Spearman’s correlations to select the most descriptive parameter of 3DE echo measures to simple and multiple linear regression analyses with LVMI and LVMI/ESV as dependent variables and survivor/control, triglycerides and 24hSYS as independent variables. A p-value of <0.05 was considered as statistically significant. Analyses were performed using the IBM SPSS statistical software package (version 22).
REFERENCES
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2. de Simone G, Daniels SR, Devereux RB, Meyer RA, Roman MJ, de Divitiis O, et al. Left ventricular mass and body size in normotensive children and adults: assessment of allometric relations and impact of overweight. J Am Coll Cardiol 1992; 20: 1251-1260.
3. Kapetanakis S, Kearney MT, Siva A, Gall N, Cooklin M, Monaghan MJ. Real-time three-dimensional echocardiography: a novel technique to quantify global left ventricular mechanical dyssynchrony. Circulation 2005; 112: 992-1000.
4. Cerqueira MD, Weissman NJ, Dilsizian V, Jacobs AK, Kaul S, Laskey WK, et al. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart. A statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. Int J Cardiovasc Imaging 2002; 18: 539-542.
5. Gimenes VM, Vieira ML, Andrade MM, Pinheiro J,Jr, Hotta VT, Mathias W,Jr. Standard values for real-time transthoracic three-dimensional echocardiographic dyssynchrony indexes in a normal population. J Am Soc Echocardiogr 2008; 21: 1229-1235.
6. Russo C, Jaubert MP, Jin Z, Homma S, Di Tullio MR. Intra- and interobserver reproducibility of left ventricular mechanical dyssynchrony assessment by real time three-dimensional echocardiography. Echocardiography 2012; 29: 598-607.
7. Plana JC, Galderisi M, Barac A, Ewer MS, Ky B, Scherrer-Crosbie M, et al. Expert consensus for multimodality imaging evaluation of adult patients during and after cancer therapy: a report from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. Eur Heart J Cardiovasc Imaging 2014; 15: 1063-1093.
8. Hovi L, Kurimo M, Taskinen M, Vettenranta J, Vettenranta K, Saarinen-Pihkala UM. Suboptimal long-term physical performance in children and young adults after pediatric allo-SCT. Bone Marrow Transplant 2010; 45: 738-745.
Supplementary table 1.Treatment characteristics in survivors of high-risk neuroblastoma.
1.HdTx / 2.HdTx / Local RTPEM+TBI 12Gy/6fr / Orbita and mandibular l.sin 32Gy/19fr
PEM +TBI 10Gy/5fr / ThXI-LII l.dx 18Gy/10fr
PEM+TBI 10Gy/5fr / ThXI-LII l.sin 19.8Gy/11fr and occipitalis l.sin20Gy
PEM+TBI 10Gy/5fr / CVII-ThI and left lung 12.6Gy/8fr
CEM+TBI 10Gy/5fr / No
PEM+TBI 10Gy/5fr, no head / Lumbosacral 18Gy/10fr and orbital.dx 20Gy/10fr
PEM+TBI 12Gy/6fr / Left kidney
PEM+TBI 12Gy/6fr / Retroperitoneum
L-PAM / ETO+Carbo+TT TBI 10Gy/5fr / LI-LII 45Gy/27fr
PEM+TBI 12Gy/6fr / Retroperitoneum
PEM / Retroperitoneum
ETO/Topo+Carbo+TT / Retroperitoneum
L-PAM / Retroperitoneum
L-PAM / ETO+Carbo+TT / ThXI-LV 25Gy/16fr
ETO+Carbo+TT / Retroperitoneum
L-PAM / Mediastinum and clavicula 24Gy
L-PAM / Abdomen 7.2Gy/12fr
L-PAM / Retroperitoneum
L-PAM / Retroperitoneum
Abbreviations: CEM= Carboplatin, etoposide and melphalan; ETO/Topo+Carbo+TT= Etoposide or topotecan, carboplatin and thiotepa; fr= Fractions; L-PAM= Melphalan; PEM= Cisplatin, etoposide and melphalan; TBI= Total body irradiation
Supplementary Table 2.Results of Physical Performance Tests reported as SD-scores in survivors and controls.
Tests / Controls(n=20) / Survivors
(n=19) / p-value / Survivors Non-TBI
(n=9) / Survivors TBI
(n=10) / p-value
Leg-lift / -0.00.7 / -1.01.6 / 0.058 / -0.41.1 / -1.51.8 / 0.111
Repeated squatting / 0.51.0 / -0.41.5 / 0.041 / 0.00.9 / -0.91.8 / 0.346
Sit-up / 0.21.2 / -2.11.8 / <0.001 / -2.41.8 / -1.81.9 / 0.461
Back-extension / 0.30.8 / -0.61.3 / 0.020 / 0.10.9 / -1.3 1.2 / 0.014
Shuttle-run / 0.90.6 / -3.55.3 / <0.001 / -1.51.6 / -5.36.8 / 0.205
Muscle sum score / 0.40.7 / -1.51.9 / <0.001 / -0.80.9 / -2.1 2.4 / 0.191
Results are reported as Mean±SD. Abbreviations: TBI= total body irradiation
Supplementary table 3.Simple and multiple linear regressions of 3DE left ventricular mass, disease and cardiovascular risk factors in survivors and controls.
Dependent / Independent / Simple regression / Multiple regressionAll study subjects / β / p-value / β / p-value / R²
LVMI / Survivor/Control / 5.847 / 0.020 / 3.966 / 0.142 / 0.218
Triglycerides / 3.780 / 0.128 / 1.633 / 0.514
24hSYS / 0.228 / 0.024 / 0.172 / 0.090
LVMI/ESV / Survivor/Control / 0.420 / 0.028 / 0.357 / 0.092 / 0.169
Triglycerides / 0.358 / 0.054 / 0.244 / 0.214
24hSYS / 0.001 / 0.900 / -0.005 / 0.544
Abbreviations: β= regression coefficient; R2= coefficient of determination. LVMI= left ventricular mass index; ESV=end systolic volume; 24hSYS= 24h mean systolic blood pressure