Baseline data
The baseline data of the two groups was shown in Table 1
Table1 Baseline clinical charateristics of the two groups and the comparisons of baseline blood lipid profiles and lipoprotein particles between them
Variable
|
PCSK9i+statins(n=54)
|
Statins(n=45)
|
Age (years),mean ± SD
|
60.6± 10.1
|
58.6± 10.6
|
Men, n(%)
|
34(63.0%)
|
30(66.7%)
|
Hypertension, n(%)
|
32(59.3%)
|
26(57.8%)
|
Diabetes, n(%)
|
15(27.8%)
|
10(22.2%)
|
Smoking, n(%)
|
22(41.1%)
|
23(51.1%)
|
BMI (kg/m2)), mean ± SD
|
26±5.0
|
27±5.4
|
STEMI,n(%)
|
10(18.5%)
|
12(26.7%)
|
NSTEMI,n(%)
|
24(44.4%)
|
20(44.4%)
|
UAP,n(%)
|
20(37.0%)
|
13(28.9%)
|
Total cholesterol (mg/dL), mean ± SD
|
214.2±42.4
|
189.7±36.5
|
LDL-C (mg/dL), mean ± SD
|
123.7±32.3
|
103.7±28.1
|
IDL-C (mg/dL), mean ± SD
|
15.5±9.1
|
13.6±7.6
|
VLDL-C (mg/dL), mean ± SD
|
31.9±17.9
|
25.3±15.5
|
HDL-C (mg/dL), mean ± SD
|
43.9±7.8
|
44.3±9.4
|
Lp(a)(nmol/l), median(Q1,Q3)*
|
73.1(13.7,102.3)
|
32.7(8.2,49.1)
|
ApoB (mg/dL),mean ± SD
|
108.7±24.2
|
93.0±20.8
|
LDL-P total (nmol/L), mean ± SD
|
1573.9±375.3
|
1317.8±337.8
|
VLDL-P(nmol/L), mean ± SD
|
237.5±106.0
|
182.8±89.2
|
IDL-P (nmol/L), mean ± SD
|
91.0±47.7
|
88.6±43.3
|
Abbreviations: BMI= Body Mass Index ;STEMI =Stsegment Elevation Myocardial Infarction ;NSTEMI =non–ST-segment elevation myocardial infarction ; UAP=Unstable Angina Pectoris;LDL-C =low-density lipoprotein cholesterol;IDL-C=intermediate-density lipoprotein;VLDL-C = very low-density lipoprotein cholesterol; HDL-C= high-density lipoprotein cholesterol; Lp(a)=Lipoprotein a;ApoB =Apolipoprotein B;LDL-P=low-density lipoprotein particle concentration;VLDL-P = very low-density lipoprotein particle concentration;IDL-P = intermediate-density lipoprotein particle concentration; Q1, Q3 = fifirst and third quartiles; SD = standard deviation
Demographic data, clinical characteristics, baseline blood lipid profiles, and lipoprotein particle concentrations of the 99 participants were shown in Table 1. 63.0% and 66.7% were males in the experimental group and control group, respectively; while 27.8% and 22.2% were diabetic, respectively. No significant difference was found in age, gender, comorbidities including hypertension and diabetes mellitus, and body mass index (BMI) between the two groups(P > 0.05). The comparisons of the prevalence of STEMI, NSTEMI, and UAP revealed no significant difference (P > 0.05). At baseline, the median and interquartile range of LP(a) levels in the two groups were73.1 (13.7, 102.3) and 32.7 (8.2, 49.1), respectively, significantly higher in the experimental group with a P value of 0.032. Other baseline lipid profiles and lipoprotein particle concentrations were comparable between the two groups. The LDL-C concentrations in the experimental and control groups were 123.7 ± 32.3 mg/dL and 103.7 ± 28.1 mg/dL, respectively;and LDL-P concentrations were 1573.9 ± 375.3nmol/L and 1317.8 ± 337.8nmol/L, respectively. Other baseline characteristics of blood lipid profiles and lipoprotein particles were shown in Table 1.
Correlations between NMR spectroscopy and enzymatic method in the measurement of lipid parameters
Pearson correlation analyses were performed to assess the consistency between the NMR spectroscopy and enzymatic method measurements, in terms of the six items that they had in common (triglycerides [TG], total cholesterol [TC], LDL-C, high-density lipoprotein [HDL-C], Apo-A1, and Apo-B). The correlation coefficient was between 0.839 and 0.912, indicating close correlation between the two sets of measurement.
Table 2 Pearson coefficient of correlation in lipid parameters measured by NMR spectroscopy and enzymatic method
|
R values
|
P values
|
TG
|
0.849
|
0.000
|
TC
|
0.912
|
0.000
|
HDL-C
|
0.858
|
0.000
|
LDL-C
|
0.839
|
0.000
|
Apoa1
|
0.865
|
0.000
|
ApoB
|
0.854
|
0.000
|
Changes in lipid profiles after treatment in the two groups
Table 3 Absolute and relative reduction in lipid levels and lipoprotein particle concentration compared to baseline after eight weeks treatment
|
evolocumab+statins
|
statins
|
|
Week8
|
Change from
baseline
|
Percent change from baseline(%)
|
Week8
|
Change from
baseline
|
Percent change from baseline(%)
|
VLDL-C (mg/dl)
Total
|
17.2±7.3
|
14.7±15.4
|
26
|
20.0±12.1
|
5.2±12.9
|
7.9
|
VLDL1
|
6.7±4.6
|
6.1±9.1
|
26.3
|
6.5±4.5
|
3.5±6.6
|
21.6
|
VLDL2+3
|
2.6±1.5
|
2.8±2.7
|
20.4
|
3.6±2.5
|
0.6±2.3
|
-20
|
VLDL4+5
|
1.9±1.3
|
2.2 ±2.5
|
40.9
|
2.9±2.3
|
0.6±1.7
|
2.8
|
IDL-C (mg/dl)
|
5.7±4.1
|
10.0±7.9
|
62.0
|
9.3±4.7
|
4.3±6.4
|
20.7
|
LDL-C (mg/dl)
Total
|
43.8±21.8
|
81.6±28.7
|
65.3
|
80.7±14.8
|
22.9±25.1
|
18.1
|
LDL1+2
|
10.4±4.3
|
9.6±8.5
|
40.4
|
11.3±4.6
|
4.2±5.7
|
21.2
|
LDL3+4
|
7.0±4.9
|
10.2±9.4
|
50.3
|
11.1±4.5
|
2.4±5.9
|
-20.7
|
LDL5+6
|
5.0±5.6
|
21.2±12.7
|
79.5
|
17.6±5.9
|
5.4±7.4
|
6.6
|
HDL-C (mg/dl)
Total
|
46.9±8.3
|
-2.9±6.5
|
-7.6
|
44.8±8.3
|
-0.4±9.0
|
-3.4
|
HDL1+2
|
10.2±4.4
|
0.7±3.6
|
-2.2
|
10.5±4.2
|
0.1±2.6
|
-2.7
|
HDL3+4
|
12.6±5.4
|
-1.9±3.2
|
-82.7
|
11.3±5.3
|
-0.6±4.1
|
27.2
|
TC(mg/dl)
|
109.9±27.9
|
106.0±37.8
|
48.4
|
153.7±18.4
|
35.9±33.7
|
16.9
|
VLDL-P (nmol/l)
|
158.2±56.9
|
80.2±84.8
|
19.1
|
165.5±80.3
|
17.4±79.5
|
-1.2
|
IDL-P (nmol/L)
|
37.4±22.1
|
54.0±45.2
|
53.3
|
60.7±28.8
|
27.8±31.9
|
24.5
|
LDL-P
(nmol/l)
Total
|
463.6±246.7
|
1128.9±374.6
|
71
|
985.2±203.3
|
332.5±32.6
|
21.7
|
LDL1+2
|
113.5±40.1
|
91.4±81.3
|
38.33
|
120.4±45
|
40.5±54.1
|
14.5
|
LDL3+4
|
80.1±52.7
|
119.8±98.9
|
57.3
|
129.5±45
|
32.5±67.3
|
-16.7
|
LDL5+6
|
70.9±76.8
|
304.8±192.1
|
76.8
|
246.4±91.8
|
83.0±99.4
|
13.3
|
Lp(a)(nmol/l)
|
57.5(5.2,72.8)
|
15.6(8.5,29.5)
|
21.1
|
42.6(8.9,62.8)
|
-13.9(-19.2,-0.3)
|
-42.5
|
ApoB
|
42.3±14.8
|
67.5±23.6
|
60.9
|
71.5±14.0
|
21.5±20.2
|
20.8
|
LDL-C:HDL-C ratio
|
0.9±0.4
|
2.0±0.8
|
67.3
|
1.9±0.5
|
0.5±0.7
|
18.3
|
Apo-B:Apo-A1 ratio
|
0.3±0.1
|
0.6±0.2
|
63.3
|
0.6±0.1
|
0.2±0.2
|
21.4
|
LDL-P size
|
20.9±0.5
|
-0.7±0.6
|
-3.6
|
20.2±0.2
|
0.0±0.1
|
0.0
|
In the experimental group, after a combined treatment of evolocumab and moderate statins for eight weeks, benefits in LDL-C concentrations and other blood lipids parameters were revealed with statistical significance (P < 0.05). TC, LDL-C and its subfractions (LDL-1 to -6), VLDL-C and its subfractions (VLDL-1 to -5), and IDL-C significantly decreased compared to baseline (P < 0.001). The decrease in total LDL-C concentrations was mainly due to a decreased concentration of small-sized LDL particles (LDL 5+6). In contrast, a significant increase in HDL-C concentrations was observed (P < 0.05), which could be mainly attributed to an increase in small-sized HDL particles (HDL 3+4). The concentrations of TC, LDL-C, VLDL-C and IDL-C were reduced by 48.4%, 65.5%, 26.3%, and 62.0%, respectively, while the HDL-C concentrations was increased by 7.6%, compared to baseline.
After eight weeks of single moderate statins treatment in the control group, the concentrations of TC, IDL-C, and LDL-C significantly decreased by 16.9%, 20.7%, and 18.1%, respectively(P < 0.05). But the concentrations of VLDL-C and HDL-C did not decrease significantly after treatment(P > 0.05).
After eight weeks treatment, the absolute reduction in the concentrations of TC, LDL-C, VLDL-C, and IDL-C in the experimental and control groups were (14.7 ± 15.4 vs. 5.2 ± 12.9), (81.6 ± 28.7 vs. 22.9 ± 25.1), (14.7 ± 15.4 vs. 5.2 ± 12.9), and (10.0 ± 7.9 vs. 4.3 ± 6.4), respectively, with significant differences between the two groups (P < 0.05).
Changes in lipoprotein particle concentrations after treatment in the two groups
Changes in lipoprotein particle concentrations were presented in Table 3. After eight weeks of combined treatment of evolocumab and moderate statins, statistically significant benefits in the concentrations of LDL-P and other lipoprotein particle concentrations were observed (P < 0.05). VLDL-P, IDL-P, LDL-P and its subfractions (LDL-P1 to 6), ApoB and LP(a) all decreased compared to baseline (P < 0.001). The concentration of total LDL-P before and after treatment was 1573.9 ± 375.3 and 463.6 ± 246.7 respectively, showing a reduction of 71.1% (P < 0.001).The decrease in total LDL-P concentrations was mainly due to a decreased concentration of small-sized LDL particles (LDL 5+6). In this study, LDL-P were further classified into large (LDL-P1+2), medium (LDL-P3+4) and small LDL-P (LDL-P5+6) by the size of the particles. The concentrations of small-sized LDL-P decreased by 76.8%, with a significantly larger extent than medium-sized and large-sized LDL-P (P < 0.001). The concentrations of VLDL-P, IDL-P, LP(a), and apoB decreased by 20%, 53.3%, 21%, and 60.9%, respectively, while the size of LDL-P in the experimental group increased by 3.6% (P < 0.001), as compared to an insignificant change in the control group.
In the control group, after eight weeks of statin monotherapy, IDL-P, LDL-P, and Apo-B concentrations significantly lowered compared to baseline (P < 0.05), but no significant change was found in VLDL-P concentration (P > 0.05). The concentrations of IDL-P, LDL-P and ApoB decreased by 24.5%, 21.7%, and 20.8% compared to baseline. Comparison of LDL-P subfractions(small-sized,medium-sized and large-sized) revealed no significant difference (P > 0.05). LP(a) was seen no significant decrease ,instead an increase in the control group.
After eight weeks treatment, the absolute reductions in the concentrations of VLDL-P, IDL-P, LDL-P and ApoB were significantly different between the experimental and control group (P < 0.05).
The achievement of LDL-C therapeutic target in both groups
After eight weeks treatment, the mean LDL-C concentration in the experimental group decreased from 124mg/dl to 44mg/dl, showing a 65.3% reduction compared to the baseline, in contrast to a 18.1% reduction from 104mg/dl to 81mg/dl in the control group. The difference in the percentage of reduction between the two groups was 47.2%, with an absolute difference of LDL-C concentration of 57mg/dl.
According to the China Cholesterol Education Program (CCEP) Expert Consensus in 2019: for patients at very high risk, the target of LDL-C concentration should be lower than 55mg/dl, or at least a 50% reduction from baseline. After eight weeks treatment, 96.3% patients in the experimental group and 13.3% in the control group had achieved the LDL-C therapeutic target(P < 0.01) (Figure 1).