Baseline characteristics
Out of 1,024 patients enrolled in the CorLipid trial, 707 (69.8%) were excluded, and the current analysis involved 316 (30.2%) patients with comorbid DM. Of included patients, 176 (55.7%) underwent coronary angiography due to ACS [62 (19.6%) patients due to ST-Elevation Myocardial Infarction (STEMI), 59 (18.7%) patients due to Non-ST-Elevation Myocardial Infarction (NSTEMI), and 55 (17.4%) patients due to unstable angina], and 140 due to CCS (44.3%)[24]. Baseline demographical, clinical and laboratory characteristics of patients included in the present analysis are shown by the presence of acute or chronic coronary syndrome in Table 1. Comparison of all measured novel biomarkers between patients with ACS and CCS is summarized in Table 2.
In general, the baseline characteristics between the two groups were well-matched. The mean age of patients was 67 ± 11 years and the majority of patients were males (70.3%). Patients with ACS were more likely to smoke, have a history of chronic kidney disease and have a lower mean left-ventricular ejection fraction. Peak values of HsTnT were also much higher in the ACS group, while mean high-density lipoprotein values were significantly lower. Regarding clinically novel biomarkers, apoA1 was significantly lower in patients with ACS, and these patients also had a higher ApoB/ApoA1 ratio compared to patients with CCS.
Table 1
Baseline clinical and demographic characteristics and comorbidities in the CorLipid population by the presence of coronary syndrome
|
All diabetic patients
(n = 316)
|
Diabetic patients with ACS
(N = 176)
|
Diabetic patients with CCS
(N = 140)
|
P-value
|
Clinical characteristics, No. (%)
|
|
|
|
|
Male Gender
|
222 (70.3)
|
129 (73.3)
|
93(66.4)
|
0.18
|
STEMI
|
62 (19.6)
|
62 (35.2)
|
0 (0)
|
-
|
NSTEMI
|
59 (18.7)
|
59 (33.5)
|
0 (0)
|
-
|
Unstable angina
|
55 (17.4)
|
55 (31.3)
|
0 (0)
|
-
|
Smoking
|
129 (40.8)
|
87 (49.4)
|
42 (30)
|
< 0.01
|
Clinical parameters [mean (± SD) /
median (IQR Q3-Q1)]*
|
|
|
|
|
Age (years)
|
67 (11)
|
66 (13)
|
67 (10)
|
0.60
|
Body mass index (kg/m2)
|
29.4 (5.1)
|
28.8(4.9)
|
29.3 (5)
|
0.40
|
Estimated glomerular filtration rate by CKD-EPI (mL/min/1.73m2)
|
90 (39.3)
|
89 (40.7)
|
92.3 (36.9)
|
0.46
|
Left Ventricular Ejection Fraction (%)
|
50 (10)
|
50 (11)
|
55 (9)
|
< 0.01
|
Total cholesterol (mg/dL)
|
155 (44)
|
156 (45)
|
155 (45)
|
0.86
|
Triglycerides (mg/dL)
|
166 (174)
|
168 (171)
|
165 (179)
|
0.90
|
High density lipoprotein (mg/dL)
|
41 (12)
|
40 (12)
|
44 (14)
|
0.02
|
Low density lipoprotein (mg/dL)
|
82 (36)
|
85 (38)
|
82 (35)
|
0.43
|
Fasting glucose (mg/dl)
|
127 (416)
|
128 (399)
|
126 (380)
|
0.62
|
Glycated hemoglobin A1c (%)
|
7.3 (1.6)
|
7.1 (1)
|
7.2 (1.4)
|
0.34
|
Peak high-sensitivity cardiac troponin (ng/L)
|
530(1249)
|
943(9996)
|
53(197)
|
< 0.01
|
Medical Histories, No. (%)
|
|
|
|
|
Hypertension
|
237 (75)
|
127 (72.2)
|
110 (78.6)
|
0.19
|
Dyslipidemia
|
155 (49.1)
|
80(45.5)
|
75 (53.6)
|
0.15
|
Heart failure
|
9 (2.8)
|
7 (11.4)
|
2 (4.3)
|
0.17
|
Chronic kidney disease
|
26 (8.2)
|
20 (4.6)
|
6 (2.9)
|
0.02
|
Peripheral vascular disease
|
22 (7)
|
12 (6.8)
|
10 (7.1)
|
0.91
|
Atrial fibrillation
|
32 (10.1)
|
18 (10.2)
|
14 (10)
|
0.94
|
Prior stroke
|
12 (3.8)
|
5 (2.8)
|
7 (5)
|
0.31
|
Positive family history of CAD
|
47 (14.9)
|
29 (16.6)
|
18 (12.9)
|
0.35
|
Statin medication
|
185 (58.5)
|
97 (55.1)
|
88 (63.8)
|
0.12
|
Oral anticoagulant medication
|
45 (14.2)
|
31 (17.6)
|
14 (10.1)
|
0.061
|
*Mean values and standard deviations for parametric variables, median values and interquartile range (IQR) for non-parametric variables |
Table 2
Baseline comparison of measured novel biomarkers in the CorLipid population by the presence of coronary syndrome
|
All diabetic patients
(n = 316)
|
Diabetic patients with ACS
(N = 176)
|
Diabetic patients with CCS
(N = 140)
|
P-value
|
Clinical parameters [mean (± SD) /
median (IQR range Q3-Q1)]*
|
|
|
|
|
Acylcarnitine C4
|
41.01 (736)
|
40.62 (422)
|
37.21 (735)
|
0.87
|
Acylcarnitine C18:2
|
58 (264)
|
54.9 (263)
|
61.3 (151)
|
0.20
|
Acylcarnitine ratio C4/C18:2
|
0.71 (12.5)
|
0.75 (12.5)
|
0.69 (3.4)
|
0.41
|
Apolipoprotein (Apo)B
|
84.5 (412)
|
87.2 (412)
|
81.1 (152)
|
0.53
|
ApoA1
|
97.9 (193)
|
89.2 (185)
|
113 (168)
|
< 0.01
|
ApoB/ApoA1 ratio
|
0.79 (6.9)
|
0.84 (6.9)
|
0.70 (3.2)
|
0.02
|
Ceramide C24:0
|
7.4 (32.7)
|
7.4 (28.7)
|
7.1 (32.7)
|
0.80
|
Ceramide C24:1
|
3.2 (12.5)
|
3.4 (6.7)
|
3.1 (12.5)
|
0.08
|
Ceramide ratio C24:1/C24:0
|
0.44 (1.75)
|
0.45 (1.75)
|
0.41 (1.71)
|
0.18
|
Adiponectin
|
162 (215)
|
162 (207)
|
160 (214)
|
0.81
|
*Mean values and standard deviations for parametric variables, median values and interquartile range (IQR) for non-parametric variables |
Clinical outcomes
After a median 2-year follow up period (IQR = 0.7 years), 36 of 316 (11.4%) study participants died. Of deaths, 30 (86.7%) were attributed to CV causes. The primary composite outcome occurred in 69 (21.8%) patients. This included 7 major bleeding events, 3 myocardial infarction, 4 strokes, 30 CV-related hospitalizations and 11 repeat unplanned coronary revascularization procedures. Univariable analyses yielded that acylcarnitine ratio C4/C18:2, apoB, HsTnT and HbA1c were associated with higher risk of the composite primary outcome in patients with CAD.
These biomarkers were then forced into the multivariable Cox regression model along with clinically relevant baseline covariates which were invariably significant (presence of ACS, age > 65, history of HF, history of peripheral artery disease). According to this multivariable analysis, higher levels of acylcarnitine ratio C4/C18:2 (aHR = 1.89 [1.09, 3.29]; p < 0.01), and apoB (aHR = 1.02 [1.01, 1.04]; p = 0.01), as well as history of HF (aHR = 1.28 [1.01, 1.41]; p = 0.02), age > 65 (aHR = 1.04 [1.01, 1.05]; p = 0.04) and presence of ACS (aHR = 1.12 [1.05–1.21]; p = 0.01) were independent predictors of more frequent MACCE/repeat revascularization/cardiovascular hospitalization occurrence (Fig. 1). The ROC analysis for the prediction of the primary outcome in patients with CAD according to the developed model is depicted in Fig. 2 (area under the curve [AUC]: 0.76, 95% CI: 0.60–0.87).
Sub-analysis in patients with ACS showed that history of HF (aHR = 1.08 [1.00, 1.11], p = 0.04), age > 65 (aHR = 1.01 [1.00, 1.02], p = 0.04), higher levels of acylcarnitine ratio C4/C18:2 (aHR = 1.59 [1.04, 2.18], p = 0.02) and apoB (aHR = 1.01 [1.00, 1.01], p = 0.02) as well as higher levels of peak HsTnT (aHR = 1.01 [1.01–1.02], p = 0.02) were independently associated with the primary outcome. In patients with CCS, acylcarnitine ratio C4/C18:2 (aHR = 2.01 [1.65, 3.39]; p < 0.01), apoB (aHR = 1.06 [1.02, 1.09]; p < 0.01), history of HF (aHR = 1.39 [1.09, 1.67]; p < 0.01), and age > 65(aHR = 1.11 [1.06, 1.19]; p = 0.03) predicted independently the occurrence of the primary composite outcome (Fig. 1).
As far as CAD complexity is concerned, univariable linear regression analyses showed that higher levels of acylcarnitine C4, acylcarnitine ratio C4/C18:2 and ceramide ratio C24:1/C24:0, age > 65, and history of HF were significantly associated with higher SYNTAX score, whereas higher ApoA1 levels were associated with decreased SYNTAX score. The developed multivariable regression model, detailed in Fig. 3, demonstrated that ceramide ratio C24:1/C24:0 (adjusted β = 7.36 [5.74, 20.47]; p = 0.02), acylcarnitine ratio C4/C18:2 (adjusted β = 3.02 [0.09 to 6.06]; p = 0.04), history of peripheral artery disease (β = 3.02 [0.09, 6.06];p = 0.04), and age > 65 (β = 2.02 [0.09, 6.06];p = 0.04) were independently and positively associated with the SYNTAX score, while ApoA1 (adjusted β= -0.65 [-1.31, -0.02]; p = 0.04) independently predicted decreased SYNTAX score. The ROC analysis performed for the model set to predict CAD complexity is shown in Fig. 4 (AUC: 0.71; 95% CI: 0.60–0.83).
Sub-analyses in ACS group showed that acylcarnitine ratio C4/C18:2 (β = 2.89 [0.09, 6.06]; p = 0.04), ceramide ratio C24:1/C24:0 (8.02 [6.29, 17.45]; p = 0.02), history of peripheral artery disease (β = 3.42 [0.18, 4.94]; p = 0.02), and age > 65 (β = 1.59 [0.02, 8.06]; p = 0.04) still predicted independently the SYNTAX score, whereas ApoΑ1 (-0.36 (-1.21, -0.01); p = 0.40) was an independent predictor of decreased SYNTAX score. Acylcarnitine ratio C4/C18:2 (β = 3.12 [0.09, 6.06], p = 0.04), ceramide ratio C24:1/C24:0 (β = 6.98 [4.03, 23.08], p = 0.02), history of peripheral artery disease (β = 2.98 [0.03, 8.48], p = 0.04), age (β = 3.00 [0.27, 5.06], p = 0.04), and ApoA1 (β= -0.69 [-1.41, -0.12]; p = 0.03) were also independent predictors of CAD complexity in patients with CCS.