Association between high-sensitivity C-reactive protein and coronary atherosclerosis in a general middle-aged population.

Despite abundant knowledge about the relationship between inflammation and coronary atherosclerosis, it is still unknown whether systemic inflammation measured as high-sensitivity C-reactive protein (hsCRP) is associated with coronary atherosclerosis in a general population. This study aimed to examine the association between hsCRP and coronary computed tomography angiography (CCTA)-detected coronary atherosclerosis in a population-based cohort. Out of 30,154 randomly invited men and women aged 50 to 64 years in the Swedish Cardiopulmonary Bioimage Study (SCAPIS), 25,408 had a technically acceptable CCTA and analysed hsCRP. Coronary atherosclerosis was defined as presence of plaque of any degree in any of 18 coronary segments. HsCRP values were categorised in four groups. Compared with hsCRP below the detection limit, elevated hsCRP (≥ 2.3 mg/L) was weakly associated with any coronary atherosclerosis (OR 1.15, 95% CI 1.07-1.24), coronary diameter stenosis ≥ 50% (OR 1.27, 95% CI 1.09-1.47), ≥ 4 segments involved (OR 1.13, 95% CI 1.01-1.26 ) and severe atherosclerosis (OR 1.33, 95% CI 1.05-1.69) after adjustment for age, sex and traditional risk factors. The associations were attenuated after further adjustment for body mass index (BMI), although elevated hsCRP still associated with noncalcified plaques (OR 1.16, 95% CI 1.02-1.32), proposed to be more vulnerable. In conclusion, the additional value of hsCRP to traditional risk factors in detection of coronary atherosclerosis is low. The association to high-risk noncalcified plaques, although unlikely through a causal pathway, could explain the relationship between hsCRP and clinical coronary events in numerous studies.

Arginase 1 is upregulated at admission in patients with ST-elevation myocardial infarction.

BACKGROUND: The mechanisms underlying rupture of a coronary atherosclerotic plaque and development of myocardial ischemia-reperfusion injury in ST-elevation myocardial infarction (STEMI) remain unresolved. Increased arginase 1 activity leads to reduced nitric oxide (NO) production and increased formation of reactive oxygen species due to uncoupling of the NO-producing enzyme endothelial NO synthase (eNOS). This contributes to endothelial dysfunction, plaque instability and increased susceptibility to ischemia-reperfusion injury in acute myocardial infarction. OBJECTIVE: The purpose of this study was to test the hypothesis that arginase gene and protein expression are upregulated in patients with STEMI. METHODS: Two cohorts of patients with STEMI were included. In the first cohort (n = 51), expression of arginase and NO-synthases as well as arginase 1 protein levels were determined and compared to a healthy control group (n = 45). In a second cohort (n = 68), plasma arginase 1 levels and infarct size were determined using cardiac magnetic resonance imaging. RESULTS: Expression of the gene encoding arginase 1 was significantly elevated at admission and 24-48 h after STEMI but not 3 months post STEMI, in comparison with the control group. Expression of the genes encoding arginase 2 and endothelial NO synthase (NOS3) were unaltered. Arginase 1 protein levels were elevated at admission, 24 h post STEMI and remained elevated for up to 6 months. No significant correlation between plasma arginase 1 protein levels and infarct size was observed. CONCLUSION: The markedly increased gene and protein expression of arginase 1 already at admission indicates a role of arginase 1 in the development of STEMI.