2.1 Baseline clinical characteristics of the population
A total of 63 patients were ultimately included in the NLP group, and 38 patients in the LP group based on their respective target lesions. Table 1 provides a comprehensive description of contrasting analysis results regarding the baseline clinical data of patients in both the NLP and LP groups. There were statistical differences in DBP between two groups [75.61±13.669 vs. 81.3± 11.377. P<0.026]. In the meanwhile, There are statistical differences in serum Ang2 levels between the LP group and NLP group [(18.97 (15.245-22.12)) vs. (14.79 (12.13-20.28)), P<0.023]. Additionally, There were no significant differences in other baseline characteristics and angiographic characteristics between the two groups(Online Resource 2). The kappa coefficients of inter-observer and intra-observer consistency were 0.88 and 0.94, respectively.
Table 1 Baseline characteristics
|
LP(n=38)
|
NLP(n=63)
|
p Value
|
Age
|
59(51~71.25)
|
58(52~68)
|
0.512
|
Male
|
31(81.6%)
|
51(81%)
|
0.938
|
HR
|
75.868 ± 11.104
|
79.54 ± 13.647
|
0.164
|
SSB
|
119.37 ± 23.697
|
126.3 ±17.585
|
0.096
|
DSB
|
75.61±13.669
|
81.3± 11.377
|
0.026
|
Laboratory findings
|
|
|
|
WBC
|
11.405(8.2975~14.07)
|
10.38(8.59~13.18)
|
0.563
|
Neutrophil
|
0.82(0.7375~0.8725)
|
0.8(0.74~0.86)
|
0.455
|
Hs-CRP
|
4.611(1.14~11.501)
|
3.4575(1.0623~6.549)
|
0.416
|
LDL-C
|
3.0776 ±0.72303
|
3.2121 ±0.789
|
0.398
|
TC
|
4.94243 ±1.107516
|
5.10767 ±1.286
|
0.516
|
TG
|
1.44(1.03~2.72)
|
1.44(0.8~2.49)
|
0.808
|
HDL-C
|
1.08(0.935~1.185)
|
1.07(0.93~1.18)
|
0.889
|
blood glucose
|
7.325(5.26~9.5175)
|
7.28(5.53~9.54)
|
0.883
|
HbA1c
|
6(5.6~6.4)
|
6(5.5~6.9)
|
0.923
|
Creatinine
|
74(68~90)
|
76(68~88)
|
0.828
|
Electrolyte
|
3.9(3.7~4.3)
|
3.9(3.5~4.1)
|
0.381
|
Myoglobin
|
349(67~710.5)
|
268.5(106.5~746.25)
|
0.572
|
Cardiac troponin T
|
267.4(72.94~1033)
|
394.8(111.575~1598)
|
0.445
|
NT-proBNP
|
394(96~1059)
|
367.5(96.25~1617.5)
|
0.785
|
Risk factors
|
|
|
|
Hypertension
|
21(50.8%)
|
32(55.3%)
|
0.663
|
Diabetes mellitus
|
9(23.7%)
|
18(28.6%)
|
0.591
|
Dyslipidemia
|
9(23.7%)
|
26(41.3%)
|
0.072
|
Smoking
|
22(57.9%)
|
46(73%)
|
0.117
|
Clinical presentation
|
|
|
0.617
|
STEMI
|
31(81.6%)
|
48(76.2%)
|
|
Other
|
7(18.5%)
|
15(23.8%)
|
|
Previous MI
|
0(0%)
|
3(4.8%)
|
0.447
|
Previous PCI
|
1(2.6%)
|
7(11.1%)
|
0.251
|
EF
|
48(40~55)
|
47(39~59)
|
0.917
|
Ang2
|
18.97(15.245~22.12)
|
14.79(12.13~20.28)
|
0.023
|
Admission event
|
8(21.1%)
|
6(9.5%)
|
0.104
|
Statin
|
35(92.10%)
|
63(100%)
|
0.051
|
Clopidogry
|
27(71.10%)
|
45(71.40%)
|
0.968
|
Aspirin
|
29(76.30%)
|
49(77.80%)
|
0.865
|
β-blocker
|
31(81.6%)
|
47(74.6%)
|
0.418
|
Diuretic
|
10(26.30%)
|
16(25.40%)
|
0.918
|
Indobufen
|
7(18.40%)
|
13(20.60%)
|
0.787
|
ACEI/ARB
|
28(73.7%)
|
40(63.5%)
|
0.29
|
Mechanical support
|
4(10.50%)
|
2(3.20%)
|
0.194
|
Killip classification
|
|
|
0.21
|
1
|
23(60.5%)
|
43(68.3%)
|
|
2
|
8(21.1%)
|
18(28.6%)
|
|
3
|
1(2.6%)
|
1(1.6%)
|
|
4
|
6(15.8%)
|
1(1.6%)
|
|
Data are showned as the median (interquartile range), mean ± SD, or n (%). HR: heart rate; SSB: systolic blood pressure; DSB: Diastolic blood pressure; WBC: White blood cell count; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; TC: total cholesterol; TG: triglyceride; EF: ejection fraction; NT-proBNP: N-Terminal Pro-Brain Natriuretic Peptide; STEMI: ST-segment elevation myocardial infarction;Ang2:angiopoietin-2; ACEI: angiotensin-converting enzyme inhibitor; ARB: angiotensin receptor blocker
2.2 Characteristics of baseline image data of the study population
Table 2 describes in detail of OCT characteristics between the two groups. The nature of plaque in the LP group is mainly plaque rupture, and it is more likely to be combined with thrombosis, mainly white thrombus. At the same time, the number of microvessels, calcification and macrophages in the LP group was higher than that in the NLP group. However the proportion of lipid arc and thin fibrous cap in the NLP group was larger. In addition, the LP group was in an area with high stenosis rate and greater plaque burden.
Table 2 Optical coherence tomography characteristics
|
LP(n=38)
|
NLP(n=63)
|
p Value
|
Underlying pathology
|
|
|
0.721
|
Plaque rupture
|
26(66.7%)
|
40(58.8%)
|
|
Plaque erosion
|
12(30.8%)
|
26(38.2%)
|
|
None
|
1(2.6%)
|
2(2.9%)
|
|
Fiber cap thick
|
0.14(0.11~0.18)
|
0.13(0.1~0.17)
|
0.18
|
lipid arc
|
248(210~327.1)
|
273.45(211.95~330.375)
|
0.423
|
Lipid length
|
5.1(3.8~7)
|
4.95(3.8~6.1)
|
0.543
|
Thin-cap fibroatheroma
|
18(46.2%)
|
38(55.9%)
|
0.332
|
Microvessels
|
26(66.7%)
|
41(60.3%)
|
0.512
|
Calcification
|
23(59%)
|
29(42.6%)
|
0.104
|
Macrophage
|
33(84.6%)
|
50(73.5%)
|
0.186
|
Thrombus
|
|
|
0.785
|
White thrombus
|
23(59%)
|
38(55.9%)
|
|
Mixed thrombus
|
11(28.2%)
|
19(27.9%)
|
|
Red thrombus
|
3(7.7%)
|
9(13.2%)
|
|
None
|
2(5.1%)
|
2(2.9%)
|
|
MLA
|
1.2(0.71~1.775)
|
1.14(0.745~1.7825)
|
0.763
|
Area stenosis
|
81.2(75.25~87.45)
|
81.1(71.525~86.3)
|
0.585
|
RA
|
3.02(1.33~5.31)
|
2.575(1.08~4.575)
|
0.497
|
Data are expressed as the median (interquartile range) or n (%). MLA: minimum lumen area; RA: reference vessel area.
2.3 Univariate and multivariate Logistic regression analysis of layered plaque of target lesions
Based on the risk factors of patients with ACS and the outcomes of the difference analysis between the two groups (refer to Table 1), in the difference analysis, potential influencing factors with P < 0.2 were incorporated, encompassing Ang2, DSB, HR, Hs-CRP, dyslipidemia, smoking, in admission event, mechanical support, and Stain for univariate analysis( Online Resource 3). In this study, a binary logistic regression model was employed to analyze the effects of each included factor on whether the target lesion was layered Plaque, and the final results revealed as follows: 1) there was a statistical difference in Ang2 concentration and DSB in the univariate analysis (P<0.05); HR, Hs-CRP, dyslipidemia, smoking, in admission event, mechanical support, and Stain were not statistically substantial in univariate analysis. 2) From a professional point of view, factors with P<0.2 in the univariate analysis are brought into the multivariate logistic analysis(Table 3), and the results indicate that serum Ang2 is an independent risk factor of layered Plaque in the target lesions. and the risk of layered Phenotype of target lesions increased by 1.2% with each one-unit increase in concentration (OR: 1.167, 95%CI: 1.051 ~ 1.295, P<0.004).
Table 3 Multivariate analysis for LP
|
multivariate analysis
|
|
|
OR(95%CI)
|
p Value
|
Admission event
|
1.143(0.261~5)
|
0.859
|
HR
|
0.972(0.933~1.013)
|
0.178
|
Mechanical support
|
6.648(0.638~69.244)
|
0.113
|
Ang2
|
1.167(1.051~1.295)
|
0.004
|
Smoking
|
0.4(0.145~1.102)
|
0.076
|
Dyslipidemia
|
0.738(0.271~2.012)
|
0.553
|
DSB
|
0.965(0.927~1.005)
|
0.083
|
Data showed that Ang2 is an independent risk factor for layered Plaque. HR: heart rate; DSB: Diastolic blood pressure;Ang2:angiopoietin-2; OR: odds ratio
2.4 Prediction effect of serum Ang2 concentration on layered Plaque of target lesions
ROC curve analysis (Fig. 3)indicated that the AUC of serum Ang2 concentration for predicting layered plaques was 0.635 (95%CI: 0.523-0.748), and the optimal cut-off value (15.045ng/mL) was determined according to the Yoden index, with sensitivity 0.789 and specificity 0.556. Combined variable 1 (serum Ang2 concentration, DSB, HR, Hs-CRP, Dyslipidemia, Smoking, in Admission event, mechanical support) predicted that the AUC of layered plaques was 0.735 (95%CI: 0.634-0.835).