1. JACC Cardiovasc Imaging. 2009 Sep;2(9):1093-9.

Myeloperoxidase, subclinical atherosclerosis, and cardiovascular disease events.

Wong ND, Gransar H, Narula J, Shaw L, Moon JH, Miranda-Peats R, Rozanski A, Hayes
SW, Thomson LE, Friedman JD, Berman DS.

Division of Cardiology, University of California, Irvine, California, USA.

Comment in:
    JACC Cardiovasc Imaging. 2009 Sep;2(9):1100-2.

OBJECTIVES: We evaluated whether myeloperoxidase (MPO) predicts future
cardiovascular disease (CVD) events in asymptomatic adults and whether
subclinical atherosclerosis may affect this relation. BACKGROUND: Myeloperoxidase
is a leukocyte-derived enzyme-generating reactive oxidant species that has been
shown to predict risk of CVD in selected populations. METHODS: We studied 1,302
asymptomatic adults (mean age 59 years, 47% women) without known CVD who were
followed for 3.8 years. We measured MPO by the use of immunoassay. Coronary
artery calcium (CAC), a measure of subclinical atherosclerosis, was measured by
computed tomography with the Agatston score categorized as none/minimal (0 to 9),
mild (10 to 99), and moderate/significant (> or = 100). Cox regression, adjusted 
for age, sex, and other risk factors, examined the relation of CAC and/or MPO
with incident CVD events. RESULTS: Persons with MPO levels at or above compared
with below the median (257 pM) were more likely (p < 0.05 to p < 0.001) to be
women, have a higher body mass index, greater low-density lipoprotein
cholesterol, greater systolic and diastolic blood pressure, and lower
high-density lipoprotein cholesterol. Mean MPO levels increased according to CAC 
categories (p trend = 0.02). Incident CVD events were more likely in those at or 
above versus below the median MPO level (4.6% vs. 2.3%, p = 0.02), even after
adjustment for age, sex, CAC, and risk factors (hazard ratio [HR]: 1.9, 95%
confidence interval: 1.0 to 3.6, p = 0.04). Combining CAC and MPO categories, CVD
incidence ranged from 0.6% in those with a CAC score of 0 to 9 to 7.1% (adjusted 
HR: 9.2, p < 0.001) in those with CAC scores of > or = 100 and MPO below the
median and 14.0% (adjusted HR: 19.5, p < 0.0001) in those with CAC scores of > or
= 100 and MPO at or above the median. CONCLUSIONS: Our study suggests persons
with both increased levels of both MPO and CAC are at an increased risk of CVD
events. Imaging of subclinical atherosclerosis combined with assessment of
biomarkers of plaque vulnerability may help improve CVD risk stratification.

PMID: 19761988 [PubMed - indexed for MEDLINE]