A total of 260 patients were evaluated in this study. Patient background information is summarized in Table 1. The findings of physiological examination and a biomarker analysis for each group are summarized in Table 2.
Table 1
Background information of patients in each group
| DCM group | OMI group | NWM group | p-value |
---|
N | 27 | 45 | 188 | |
Age, years (mean ± SD) | 71 ± 11 | 72 ± 11 | 62 ± 16 | 7.24E-06 |
Sex, Female/Male, N | 9/18 | 4/41 | 103/85 | 1.26E-08 |
Medication | | | | |
β-blocker | 22 (81%) | 33 (73%) | 54 (29%) | 1.03E-11 |
ACE-I/ARB | 12 (44%) | 21 (47%) | 77 (41%) | 0.835 |
Calcium-antagonist | 9 (33%) | 13 (29%) | 66 (35%) | 0.7704 |
Digitalis | 2 (7%) | 1 (2%) | 0 | 0.0114 |
Diuretics | 9 (33%) | 20 (44%) | 4 (2%) | 1.03E-14 |
Anti-aldosterone | 9 (33%) | 12 (27%) | 7 (6%) | 5.21E-08 |
α-blocker | 4 (15%) | 4 (9%) | 35 (17%) | 0.3017 |
Nitrate | 0 | 6 (13%) | 3 (2%) | 0.00349 |
Statin | 17 (63%) | 34 (76%) | 89 (47%) | 0.0016 |
ACE-I, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker; DCM, dilated cardiomyopathy; NWM, normal wall motion; OMI, old myocardial infarction; SD, standard deviation |
Table 2
Physiological examination and biomarker data for each group
| DCM group | OMI group | NWM group | p-value |
---|
Echocardiography | | | | |
LVDd (mm) | 57.7 ± 5.4 | 57.8 ± 8.7 | 48.1 ± 4.6 | 5.86E-27 |
LVDs (mm) | 44.1 ± 6.0 | 43.7 ± 10.4 | 29.9 ± 5.0 | 6.12E-39 |
LVEDV (ml) | 127.4 ± 40.1 | 137.5 ± 41.2 | 93.0 ± 28.0 | 8.49E-17 |
LVESV (ml) | 73.1 ± 26.5 | 85.1 ± 34.7 | 36.0 ± 12.8 | 1.46E-40 |
LVEF (%) | 43.5 ± 7.3 | 37.7 ± 11.3 | 61.3 ± 5.4 | 1.31E-61 |
Electrocardiography | | | | |
AF/NSR | 7/20 | 3/42 | 1/187 | 1.12E-06 |
QRS width (ms) | 106.2 ± 19.1 | 106.6 ± 21.2 | 94.9 ± 12.8 | 7.74E-07 |
Biomarker | | | | |
NT-proBNP (pg/ml) | 1,712.7 ± 2,349.7 | 1,155.2 ± 1,147.6 | 121.2 ± 108.9 | 1.56E-19 |
Data are presented as the mean ± standard deviation. |
AF, atrial fibrillation; DCM, dilated cardiomyopathy; LVDd, left ventricular diameter of the diastole; LVDs, left ventricular diameter of the systole; LVEDV, left ventricular end-diastolic volume; LVEF; left ventricular ejection fraction; LVESV; left ventricular end-systolic volume; NSR; normal sinus rhythm; NT-proBNP, N-terminal pro-brain natriuretic peptide; NWM, normal wall motion; OMI, old myocardial infarction |
Representative images of the centroid of the LV in each group are demonstrated in Fig. 1. Firstly, the locus of the centroid that belonged to the NWM group had rapidly moved toward the anterior portion during the early systolic phase; thereafter, it shifted toward the apical direction. Subsequently, it returned to the original position through a diastolic relaxation phase and an atrial contraction stage; during this phase, the centroid moved in the counterclockwise direction on the same sheet frame by frame. Consequently, the locus of the centroid of the NWM group showed a horizontal inverted β shape. In the DCM group, the centroid of the three-dimensional LV showed a box-like shape and rotated clockwise; counterclockwise rotation was observed in the other groups. The locus image of the OMI group showed a crashed inverted β shape.
In the disease groups, the actual locus length of the centroid and the box volume were not significantly different among the groups (Figs. 2a, 2b). These were calculated from the x-, y-, z- transferred distance which the centroid of the three-dimensional LV had moved toward each direction during one cardiac cycle. However, when corrected by the LV end-systolic volume (LVESV), the length of the locus of the centroid of the DCM group (median value: 0.168 mm− 2 [0.150–0.195 mm− 2]) and OMI group (mean value: 0.159 mm− 2 [0.120–0.220 mm− 2]) was significantly shorter than that of the NWM group (median value: 0.379 mm− 2 [0.305–0.493 mm− 2]; p = 7.85e-26) (Fig. 2c). The corrected box volume of the abnormal wall motion groups (median value, DCM group: 0.007 [0.004–0.010]; OMI group: 0.008 [0.004–0.006]) was also smaller than that calculated in the NWM group (median value: 0.011 [0.007–0.015]; p = 1.20e-8) when corrected by LVESV (Fig. 2d).
In the DCM group, the locus length of the centroid for the lateral and antero-posterior directions was longer than that of the NWM group (Figs. 3a, 3b); nevertheless, the length for the longitudinal direction was shorter than that of the NWM group (Fig. 3c). When these data were corrected by LVESV, the lengths were significantly reduced compared with those obtained from the NWM group (Figs. 3d, 3e). The corrected longitudinal length of the abnormal wall motion groups was markedly reduced compared with that of the NWM group (Fig. 3f).
The maximum acceleration of the LV centroid obtained for the DCM group (median value: 698 mm/s2 [547–775 mm/s2]) and OMI group (median value: 724 mm/s2 [565–965 mm/s2]) were reduced compared with that of the NWM group (median value: 878 mm/s2 [713–1112 mm/s2]; p = 7.49e-7) (Fig. 4a). On the other hand, the minimum acceleration of the LV centroid of the abnormal wall motion groups (median value, DCM group: −624 mm/s2 [− 522–−776 mm/s2]; OMI group: −589 mm/s2 [− 507–804 mm/s2]) was higher than that of the NWM group (median value: −826 mm/s2 [− 668–−974 mm/s2]; p = 4.12e-7) (Fig. 4b). When the acceleration values were corrected by LVESV, those of the abnormal wall motion groups were more markedly reduced compared with those of the NWM group (Figs. 4c, 4d).
In the univariate analysis, the transfer distance for the lateral direction, total distance of centroid movement during one cardiac cycle, maximum and minimum accelerations of the LV centroid, QRS duration, and value of the N-terminal pro-brain natriuretic peptide were associated with LVEF (Table 3). However, when the data concerning the distance, volume, velocity and acceleration of the centroid were corrected by LVESV, all data included in Table 3 were related to LVEF. The QRS duration, total distance of centroid movement, maximum velocity, and mean acceleration of the LV centroid were excluded from the multivariate analysis because these data were considered variance inflation factors. Finally, a multiple linear regression analysis with stepwise methods revealed that the N-terminal pro-brain natriuretic peptide and an antero-posterior shift of the LV centroid were strong predictors of the LVEF (multiple R2: 0.6882; adjusted R2: 0.6818; p ≤ 2.2e-16) (Table 4).
Table 3
Univariate analysis for the prediction of LVEF
Factor | β | 95% CI | SE | t-value | p-value |
---|
Lower | Upper |
---|
Log(Transfer distance for the lateral direction of the centroid) | −16.75786 | −26.6021 | −6.913633 | 4.999098 | −3.352177 | 9.22E − 04 |
Log(Transfer distance for the A-P direction of the centroid) | −3.143287 | −14.84097 | 8.5544 | 5.94032 | −0.5291443 | 5.97E − 01 |
Log(Transfer distance for the longitudinal direction of the centroid) | 11.56642 | −0.7904423 | 23.92329 | 6.275064 | 1.843236 | 6.64E − 02 |
Distance of centroid movement during one cardiac cycle | 0.5832442 | 0.008625036 | 1.157863 | 0.2918031 | 1.998759 | 4.67E − 02 |
Log(Total moving box volume of the centroid) | −3.279045 | −8.629779 | 2.071689 | 2.71721 | −1.206769 | 2.29E − 01 |
Mean velocity of the centroid during one cardiac cycle | 0.4976478 | −0.02678432 | 1.02208 | 0.2663172 | 1.868628 | 6.28E − 02 |
Maximum velocity of the centroid during one cardiac cycle | 0.1186465 | −0.02698795 | 0.2642809 | 0.07395609 | 1.604283 | 1.10E − 01 |
Log(Minimum velocity of the centroid during one cardiac cycle) | −3.740764 | −9.106621 | 1.625092 | 2.7248896 | −1.372813 | 1.71E − 01 |
Log(Mean acceleration of the centroid during one cardiac cycle) | 4.566414 | −1.274704 | 10.40753 | 2.966237 | 1.539464 | 1.25E − 01 |
Log(Maximum acceleration of the centroid during one cardiac cycle) | 20.29745 | 10.74705 | 29.84785 | 4.849887 | 4.185139 | 3.91E − 05 |
Log(Minimum acceleration of the centroid during one cardiac cycle) | −21.99373 | −31.09265 | −12.8948 | 4.620616 | −4.7599121 | 3.23E − 06 |
Log(QRS duration) | −52.34276 | −73.98228 | −30.70323 | 10.98898 | −4.763202 | 3.18E − 06 |
Log(NT-proBNP) | −11.59067 | −13.67674 | −9.504603 | 1.059187 | −10.94299 | 4.99E − 23 |
Corrected by LVESV | | | | | | |
Log(Transfer distance for the lateral direction of the centroid/LVESV) | 36.96853 | 31.87738 | 42.05969 | 2.585389 | 14.29902 | 1.50E − 34 |
Log(Transfer distance for the A-P direction of the centroid/LVESV) | 36.40963 | 32.22252 | 40.59674 | 2.126299 | 17.12347 | 2.00E − 44 |
Transfer distance for the longitudinal direction of the centroid /LVESV | 470.58136 | 411.81713 | 529.34559 | 29.841655 | 15.76928 | 1.09E − 39 |
Distance of centroid movement during one cardiac cycle/LVESV | 56.67316 | 50.37252 | 62.97379 | 3.19959 | 17.71263 | 1.76E − 46 |
Log(Total moving box volume of the centroid /LVESV) | 20.89161 | 16.75028 | 25.03295 | 2.103054 | 9.933941 | 6.68E − 20 |
Log(Mean velocity of the centroid during one cardiac cycle/LVESV) | 40.0867 | 36.38057 | 43.79283 | 1.882046 | 21.29953 | 8.86E − 59 |
Log(Maximum velocity of the centroid during one cardiac cycle/LVESV) | 38.39226 | 34.70603 | 42.07848 | 1.8719381 | 20.50936 | 4.14E − 56 |
Log(Minimum velocity of the centroid during one cardiac cycle /LVESV) | 15.65795 | 11.8638 | 19.4521 | 1.926744 | 8.126638 | 1.85E − 14 |
Log(Mean acceleration of the centroid during one cardiac cycle /LVESV) | 18.75454 | 15.38623 | 22.12284 | 1.710494 | 10.9644 | 3.25E − 23 |
Log(Maximum acceleration of the centroid during one cardiac cycle /LVESV) | 30.88431 | 27.51855 | 34.25007 | 1.709201 | 18.069445 | 1.01E − 47 |
Log(Minimum acceleration of the centroid during one cardiac cycle /LVESV) | −30.3035 | −33.56723 | −27.03978 | 1.657384 | −18.283931 | 1.82E − 48 |
A-P, antero-posterior; CI, confidence interval; LCG, locus of the center of gravity; Log; logarithmic; LVEF, left ventricular ejection fraction; LVESV, left ventricular end-systolic volume; NT-proBNP, N-terminal pro-brain natriuretic peptide; SD, standard error |
Table 4
Stepwise multiple linear regression analysis for the prediction of the LVEF
Factor | β | 95% CI | SE | t-value | p-value |
---|
Lower | Upper |
---|
Intercept | 109.73 | 87.16 | 132.29 | 11.45 | 9.58 | 1.20E − 18 |
Log(NT.proBNP) | −5.68 | −7.46 | −3.89 | 0.91 | −6.26 | 1.80E − 09 |
Log(Transfer distance for the A-P direction of the centroid /LVESV) | 23.32 | 15.76 | 30.87 | 3.84 | 6.08 | 4.70E − 09 |
Log(Transfer distance for the lateral direction of the centroid /LVESV) | 13.14 | 7.28 | 23.08 | 4.01 | 3.78 | 1.90E − 04 |
Log(Total moving box volume of the centroid /LVESV) | −10.70 | −16.07 | −5.33 | 2.73 | −3.93 | 1.10E − 04 |
A-P, antero-posterior, CI, confidence interval; Log, logarithmic; LVEF; left ventricular ejection fraction, LVESV; left ventricular end-systolic volume, NT-proBNP; N-terminal pro-brain natriuretic peptide, SE, standard error |