Demographical parameters
First of all,a total of 9 participants were included for the detection of 1000 cytokines .There were 3 healthy controls,3 HFrecEF patients and 3 HFrEF patients. Participants in these three groups were all females and they were matched in age. Dilated cardiomyopathy is the underlying disease in all patients with heart failure. There was no significant difference in clinical complications(Table 1).
Table 1
Clinical characteristics of 3 HFrEF patients,3HFrecEF patients and 3 healthy controls
|
HFrecEF
|
HFrEF
|
Control
|
|
Variables
|
(n = 3)
|
(n = 3)
|
(n = 3)
|
P value
|
Age, mean ± SD,yr
|
68.0 ± 11.4
|
63.3 ± 5.8
|
65.7 ± 2.5
|
0.758
|
Female sex,No.(%)
|
3(100.0)
|
3(100.0)
|
3(100.0)
|
–
|
Body mass index, mean ± SD,kg/m2
|
24.1 ± 2.4
|
24.2 ± 1.3
|
23.6 ± 3.1
|
0.953
|
NYHA class III or IV,No.(%)
|
3(100)
|
2(66.7)
|
–
|
1.000a
|
Dilated cardiomyopathy,No.(%)
|
3(100)
|
3(100)
|
–
|
–
|
Hypertension,No.(%)
|
2(66.7)
|
2(66.7)
|
3(100.0)
|
1.000a
|
Diabetes,No.(%)
|
1(33.3)
|
2(66.7)
|
1(33.3)
|
1.000a
|
Atrial fibrillation,No.(%)
|
0(0.0)
|
1(33.3)
|
0(0.0)
|
1.000a
|
Baseline LVEF,mean ± SD,%
|
29.7 ± 4.5
|
22.3 ± 8.7
|
63.3 ± 2.9*#
|
< 0.001
|
Follow-up LVEF,mean ± SD,%
|
50.0 ± 5.0
|
31.0 ± 6.1
|
–
|
0.014
|
Hemoglobin, mean ± SD,g/L
|
132.3 ± 11.0
|
113.7 ± 8.3
|
141.0 ± 13.5#
|
0.058
|
eGFR,mean ± SD,mL/min/1.73 m2
|
87.3 ± 25.4
|
72.8 ± 6.2
|
96.0 ± 23.4
|
0.421
|
NT-proBNP,median(IQR),pg/mL
|
813(170,2330)
|
2077(312,2653)
|
–
|
0.7
|
*P < 0.05 vs HFrecEF |
#P < 0.05 vs HFrEF |
aFisher's Exact Test |
Abbreviations: HFrecEF, heart failure with recovered ejection fraction; HFrEF, heart failure with reduced ejection fraction; SD,standard deviation;No,number;NYHA,New York Heart Association;LVEF,left ventricular ejection fraction;eGFR,estimated glomerular filtration rate;NT-proBNP,N-terminal pro-B-type natriuretic peptide;IQR, interquartile range |
Then,a total of 79 participants were included for further detection. There were 10 healthy controls,22 HFrecEF patients and 47 HFrEF patients. The basic diseases of patients with heart failure included coronary heart disease,dilated cardiomyopathy, rheumatic heart disease, hypertension, etc.Most patients with heart failure were accompanied by hypertension, some patients with diabetes mellitus and atrial fibrillation.The healthy controls were the youngest among all participants.HFrEF patients had the highest proportion with coronary heart disease and old myocardial infarction, and the poorlist renal function. Clinical characteristics of the 79 paticipants are shown in Table 2.
Table 2
Clinical characteristics of 47 HFrEF patients,22HFrecEF patients and 10 healthy controls
|
HFrecEF
|
HFrEF
|
Control
|
|
Variables
|
n = 22
|
n = 47
|
n = 10
|
P value
|
Age, mean ± SD, yr
|
64.6 ± 17.9
|
70.3 ± 11.4
|
58.3 ± 7.9#
|
0.023
|
Female sex,No.(%)
|
13(59.1)
|
17(36.2)
|
6(60.0)
|
0.126
|
NYHA class III or IV,No.(%)
|
16(88.9)
|
34(77.3)
|
–
|
0.486
|
Body mass index, mean ± SD, kg/m2
|
25.4 ± 5.2
|
25.3 ± 4.2
|
24.8 ± 2.9
|
0.928
|
Coronary heart diasease,No.(%)
|
8(36.4)
|
32(68.1)
|
–
|
< 0.001
|
Acute myocardial infarction,No.(%)
|
5(22.7)
|
5(10.6)
|
–
|
0.162
|
Old myocardial infarction,No.(%)
|
2(9.1)
|
23(48.9)
|
–
|
< 0.001
|
Dilated cardiomyopathy,No.(%)
|
10(45.5)
|
12(25.5)
|
–
|
0.098
|
Rheumatic heart disease,No.(%)
|
1(4.5)
|
2(4.3)
|
–
|
1.000a
|
Hypertension,No.(%)
|
16(72.7)
|
32(68.1)
|
6(60.0)
|
0.519
|
Diabetes ,No.(%)
|
4(18.2)
|
15(31.9)
|
3(30.0)
|
0.488
|
Atrial fibrillation ,No.(%)
|
5(22.7)
|
11(23.4)
|
0(0.0)
|
0.245a
|
Baseline LVEF,mean ± SD,%
|
30.3 ± 6.3
|
29.0 ± 7.6
|
63.5 ± 2.4#*
|
< 0.001
|
Follow-up LVEF,mean ± SD,%
|
55.3 ± 5.0
|
29.5 ± 6.6
|
–
|
< 0.001
|
Hemoglobin, mean ± SD, g/dL
|
132.4 ± 34.0
|
129.2 ± 20.7
|
143.6 ± 17.3
|
0.258
|
eGFR,mean ± SD, mL/min/1.73 m2
|
82.5 ± 26.5
|
69.9 ± 23.3*
|
107.6 ± 24.5*#
|
< 0.001
|
NT-proBNP,median(IQR), pg/mL
|
1848 (711,3548)
|
1711(294,4878)
|
–
|
0.564
|
*P < 0.05 vs HFrecEF |
#P < 0.05 vs HFrEF |
aFisher's Exact Test |
Abbreviations: HFrecEF, heart failure with recovered ejection fraction; HFrEF, heart failure with reduced ejection fraction; SD,standard deviation;No,number;NYHA,New York Heart Association;LVEF,left ventricular ejection fraction;eGFR,estimated glomerular filtration rate;NT-proBNP,N-terminal pro-B-type natriuretic peptide;IQR, interquartile range |
Analysis of antibody microarrays
A total of 1000 known proteins (e.g. cytokines, chemokines, adipokine,growth factors, angiogenic factors, proteases, soluble receptors and soluble adhesion molecules) were measured in the sera of 3 HFrecEF patients, 3 HFrEF patients and 3 healthy controls.
The results demonstrated that 52 proteins had significantly different expressions between HFrecEF group and control group (Appendix Table 1). Serum mixture samples were arranged by similarities in the abundance of these 52 markers in the sera clustering algorithm, which produced two clusters that contained HFrEF and HFrecEF individuals (Fig. 1A).
There are 40 proteins had significantly different expressions between HFrEF group and control group(Appendix Table 2). Serum mixture samples were arranged by similarities in the abundance of these 40 markers in the sera clustering algorithm, which produced two clusters that contained HFrEF and HFrecEF individuals (Fig. 1B).
There are 26 proteins had significantly different expressions between HFrecEF group and HFrEF group (Appendix Table 3). Serum mixture samples were arranged by similarities in the abundance of these 26 markers in the sera clustering algorithm, which produced two clusters that contained HFrEF and HFrecEF individuals (Fig. 1C).
Table 3
Difference of 11 cytokines in the 3 groups
|
HFrecEF vs HFrEF
|
HFrecEF vs control
|
HFrEF vs control
|
Cytokines
|
P value
|
FC
|
P value
|
FC
|
P value
|
FC
|
CDO1
|
0.01
|
0.79
|
0
|
0.62
|
0.05
|
0.78
|
GDF-8
|
0.03
|
0.52
|
0.04
|
0.4
|
0.5
|
0.76
|
Angiopoientin-4/ANG-4
|
0.61
|
1.28
|
0.36
|
0.51
|
0.17
|
0.4
|
B4GALT1
|
0.5
|
1.14
|
0.98
|
0.99
|
0.6
|
0.87
|
Flt-3L
|
0.27
|
1.22
|
0.98
|
0.99
|
0.39
|
0.82
|
GALECTIN-4
|
0.16
|
0.87
|
0.92
|
0.98
|
0.35
|
1.14
|
KELL
|
0.13
|
1.36
|
0.65
|
0.87
|
0.1
|
0.64
|
HO-1
|
0.09
|
0.76
|
0.53
|
0.86
|
0.56
|
1.13
|
TPP1
|
0.77
|
1.05
|
0.64
|
0.89
|
0.46
|
0.84
|
TSLP
|
0.48
|
0.68
|
0.41
|
0.51
|
0.71
|
0.76
|
BAI1
|
0.56
|
0.72
|
0.73
|
0.75
|
0.96
|
1.04
|
Abbreviations: HFrEF, heart failure with reduced ejection fraction; HFrecEF, heart failure with recovered ejection fraction; FC, foldchange; CDO1, Cysteine dioxygenase type 1 ; GDF-8, Growth/differentiation factor 8; B4GALT1, Beta-1,4-galactosyltransferase 1; Flt-3L, Fms-related tyrosine kinase 3 ligand; KELL, Kell blood group glycoprotein ;HO-1, Heme oxygenase 1; TPP1, Tripeptidyl-peptidase 1; TSLP, Thymic stromal lymphopoietin; BAI1, Brain-specific angiogenesis inhibitor 1 |
According to the signal strength, fold changes, clinical significance and Venn diagram analysis, we hypothesized 11 specific HFrecEF biomarkers include cysteine dioxygenase type 1(CDO1), growth-differentiation factor 8(GDF-8), Angiopoientin-4/ANG-4, beta-1,4-galactosyltransferase 1(B4GALT1), fms related receptor tyrosine kinase 3 ligand(Flt-3L), GALECTIN-4, kell blood group glycoprotein(KELL), heme oxygenase 1(HO-1), tripeptidyl peptidase 1(TPP1), thymic stromal lymphopoietin(TSLP) and brain specific angiogenesis inhibitor 1(BAI1) for further detection. A chip containing 11 proteins mentioned aboved was customized to test in 47 HFrEF patients,22 HFrecEF patients and 10 healthy controls. Serum levels of were selected to be measured. Among the 11 proteins, CDO1 and GDF-8 were found to be differentially expressed in patients with HFrecEF and HFrEF(Table 3 and Fig.2).
Analysis of sensitivity and specificity of serum biomarkers for HFrecEF
To validate whether CDO1 and GDF-8 may be used as biomarkers for predicting HFrecEF, ROC curves were used to analyze sensitivity and specificity. AreaunderROCcurve values for CDO1 was 0.663(95%CI:0.517–0.808)(Fig. 3A), which was statistically significant (P = 0.031). AreaunderROCcurve values for GDF-8 was 0.581 (95%CI: 0.414–0.747) (Fig. 3B), which was not statistically significant (P = 0.282). So CDO1 was deemed suitable biomarkers for the prediction of HFrecEF. CDO1 had a sensitivity of 77% and specificity of 54%. The correct diagnostic index corresponding to the cut-off point 10198.5 is the largest.
Clinical end-point and survival analyses
69 patients enrolled were followed-up by 57(20,69) months, all cause death was recorded in 17 patients (24.6%), cardiovascular death was recorded in 15 patients(21.7%). Kaplan-meier survival curves showed significantly lower risk of all-cause death (P = 0.011) and cardiovascular death (P = 0.004) in HFrecEF patients than in HFrEF patients (Fig. 4A,Fig. 4B).
Although the survival rate in patients with low baseline CDO1 levels (< 10198.5) seemed to be higher, we failed to find high baseline CDO1 levels (≥ 10198.5) as a significant predictor of all-cause death and cardiovascular death in the longer term follow-up duration by using the cut-off value based on ROC curve analysis(Fig. 4C,Fig. 4D).