Diagnostic efficacy of myeloperoxidase to identify acute coronary syndrome in subjects with chest pain

Figures & data

Table I. Clinical characteristics of the study groups.

	NCA	SAP	ACS
n (males/females)	219 (102/117)	242 (160/82)^‡‡‡	242 (160/82)
Age (years)	65.7 (59.6–71.7)	65.9 (57.0–75.3)	66.0 (56.5–76.5)
Body mass index (kg/m^2)	26.8 (24.2–29.8)	26.5 (23.8–29.0)	25.5 (23.3–28.1)**
Hypertension	146 (66.7)	163 (67.2)	172 (71.1)
Previous myocardial infarction	0 (0)	153 (63.2)^‡‡‡	83 (34.4)*** ^†††
Smoking
Never	120 (54.9)	92 (38.1)	97 (40.0)
Ex-smoker	34 (15.6)	59 (24.3)	60 (24.6)
Current smoker	65 (29.5)	91 (37.7)	86 (35.4)
Medication use
Aspirin	176 (80.4)	220 (90.9)	233 (96.3)** ^†
β-Blocker	176 (93.1)	206 (93.6)	195 (84.8)** ^††
ACE inhibitor/AT 1 receptor blocker	106 (48.4)	116 (47.9)	134 (44.6)
Statin
In previous use	194 (88.6%)	222 (91.7%)	161 (66.5%)*** ^†††
Initiated in hospital, before study enrollment	0 (0%)	2 (0.8%)	26 (10.7%)*** ^†††
Not in use before study enrollment	1 (0.5%)	5 (2.1%)	45 (18.6%)*** ^†††
Use not known before study enrollment	24 (11.0%)	13 (5.4%)^‡‡‡	10 (4.1%)***

ACE = angiotensin-converting enzyme; ACS = acute coronary syndrome; Apo = apolipoprotein; AT = angiotensin; CRP = C-reactive protein; HDL = high-density lipoprotein; LDL = low-density lipoprotein; NCA = normal coronary artery; oxLDL = oxidized low-density lipoprotein; PON1 = paraoxonase-1; SAP = stable angina pectoris; sPLA2 = secretory phospholipase A2.

Data are presented as medians (interquartile ranges) or numbers (frequencies).

*P < 0.05, **P < 0.01, ***P < 0.001 for difference between groups NCA versus ACS.

^†P < 0.05, ^††P < 0.01, ^†††P < 0.001 for difference between groups SAP versus ACS.

^‡P < 0.05, ^‡‡P < 0.01, ^‡‡‡P < 0.001 for difference between groups NCA versus SAP.

Table II. Biochemical characteristics of the study groups.

	NCA	SAP	ACS
Total cholesterol (mmol/L)	4.21 (3.76–4.77)	4.02 (3.59–4.58)^‡	4.22 (3.66–4.93)^†
LDL cholesterol (mmol/L)	2.15 (1.77–2.77)	2.14 (1.79–2.61)	2.31 (1.89–2.93)^††
HDL cholesterol (mmol/L)	1.18 (0.95–1.51)	1.10 (0.85–1.36)^‡‡	0.99 (0.82–1.17)*** ^††
Non-HDL cholesterol (mmol/L)	2.86 (2.50–3.54)	2.86 (2.48–3.41)	3.15 (2.64–3.83)** ^†††
Triglycerides (mmol/L)	1.18 (0.90–1.73)	1.12 (0.87–1.60)	1.24 (0.93–1.65)
LDL particle size (nm)	26.7 (25.8–27.2)	26.6 (25.7–27.2)	26.6 (26.1–27.2)
ApoA-I (mg/dL)	134.0 (120.4–150.2)	127.8 (112.9–143.0)^‡‡‡	115.2 (105.9–126.0)*** ^†††
ApoB (mg/dL)	75.8 (64.7–92.9)	76.6 (66.7–90.9)	77.6 (65.5–90.9)
ApoB/ApoA-I	0.57 (0.46–0.71)	0.60 (0.51–0.74)^‡‡	0.68 (0.56–0.80)*** ^†††
Lipoprotein(a) (mg/L)	284.2 (138.3–540.5)	419.6 (205.5–783.0)^‡‡‡	321.6 (170.6–606.2)^††
Leukocyte count (E^9/L)	6.1 (85.2–7.2)	6.1 (5.2–7.2)	7.1 (6.0–8.6)*** ^†††
High-sensitivity CRP (mg/L)	1.14 (0.51–2.60)	1.07 (0.44–3.10)	4.49 (1.39–23.1)*** ^†††
sPLA2 (pg/mL)	480 (298–834)	591 (367–1020)^‡‡	770 (471–1155)*** ^†
Myeloperoxidase (ng/mL)	29.5 (23.5–40.8)	29.4 (23.1–41.0)	69.7 (46.7–100.8)*** ^†††
OxLDL (U/L)	46.3 (36.0–60.7)	46.9 (37.6–58.2)	50.2 (38.6–64.6)* ^†
PON1 concentration (μg/mL)	18.50 (12.41–27.11)	14.45 (9.27–22.02)^‡‡‡	13.54 (9.36–19.90)***
TroponinT (ng/L)	–	–	166 (39–620)

ACE = angiotensin-converting enzyme; ACS = acute coronary syndrome; Apo = apolipoprotein; AT = angiotensin; CRP = C-reactive protein; HDL = high-density lipoprotein; LDL = low-density lipoprotein; NCA = normal coronary artery; oxLDL = oxidized low-density lipoprotein; PON1 = paraoxonase-1; SAP = stable angina pectoris; sPLA2 = secretory phospholipase A2.

Data are presented as medians (interquartile ranges) or numbers (frequencies).

*P < 0.05, **P < 0.01, ***P < 0.001 for difference between groups NCA versus ACS.

^†P < 0.05, ^††P < 0.01, ^†††P < 0.001 for difference between groups SAP versus ACS.

^‡P < 0.05, ^‡‡P < 0.01, ^‡‡‡P < 0.001 for difference between groups NCA versus SAP.

Table III. Association of biomarkers with acute coronary syndrome (ACS) when compared to subjects with normal coronary artery (NCA) and stable angina pectoris (SAP).^a.

	Model 1: ACS versus NCA				Model 2: ACS versus SAP
	OR	1/OR	SE	P value	OR	1/OR	SE	P value
Total cholesterol (mmol/L)	0.93	1.07527	0.13	0.624	0.98	1.02041	0.13	0.885
LDL cholesterol (mmol/L)	1.09	0.91743	0.19	0.634	1.01	0.99010	0.17	0.962
HDL cholesterol (mmol/L)	0.12	8.33333	0.05	< 0.00001	0.33	3.03030	0.12	0.003
Non-HDL cholesterol (mmol/L)	1.20	0.83333	0.18	0.217	1.15	0.86957	0.16	0.292
Triglycerides (mmol/L)	1.00	1	0.16	0.985	0.97	1.03093	0.11	0.762
LDL particle size (nm)	1.02	0.98039	0.11	0.835	1.08	0.92593	0.10	0.450
ApoA-I (mg/dL)	0.96	1.04167	0.01	< 0.00001	0.97	1.03093	0.01	< 0.00001
ApoB (mg/dL)	0.99	1.01010	0.01	0.407	0.99	1.01010	0.01	0.044
ApoB/ApoA-I	6.93	0.14430	5.26	0.011	0.88	1.13636	0.20	0.579
Lipoprotein(a) (mg/L)	1.00	1	0.00	0.462	1.00	1	0.00027	0.016
Non-HDL/HDL cholesterol	1.28	0.78125	0.13	0.016	0.99	1.01010	0.02	0.745
Leukocyte count (E^9/L)	1.30	0.76923	0.09	< 0.001	1.16	0.86207	0.07	0.010
High-sensitivity CRP (mg/L)	1.13	0.88496	0.03	< 0.00001	1.06	0.94340	0.01	< 0.00001
sPLA2 (pg/mL)	1.00	1	0.000038	0.362	1.00	1	0.000011	0.408
Myeloperoxidase (ng/mL)	1.04	0.96154	0.01	< 0.00001	1.03	0.97087	0.0046	< 0.00001
OxLDL (U/L)	1.01	0.99010	0.01	0.262	1.00	1	0.01	0.725
PON1 concentration (μg/mL)	1.00	1	0.000010	0.125	1.00	1	0.000010	0.743

ACS = acute coronary syndrome; Apo = apolipoprotein; HDL = high-density lipoprotein; hsCRP = high-sensitivity C-reactive protein; LDL = low-density lipoprotein; NCA = normal coronary artery; oxLDL = oxidized low-density lipoprotein; PON1 = paraoxonase-1; SAP = stable angina pectoris; sPLA2 = secretory phospholipase A2.

^aEach biomarker was tested individually with a logistic regression model adjusting for background variables: sex, body mass index, hypertension, previous myocardial infarction (model 2), smoking, and the use of β-blockers, aspirin, and statins.

Figure 1. Risk discrimination of acute coronary syndrome (ACS) by receiver-operating characteristic curve. Models have been adjusted for sex, body mass index, hypertension, smoking, and the use of β-blockers, aspirin, and statins. CAD = coronary artery disease; MPO = myeloperoxidase; AUC = area under curve.

Figure 2. Risk discrimination of acute coronary syndrome (ACS) by receiver-operating characteristic curve. Models have been adjusted for hypertension, smoking, previous myocardial infarction and the use of β-blockers, aspirin, and statins. CAD = coronary artery disease; MPO = myeloperoxidase; AUC = area under curve.