Low protein Z plasma level is a risk factor for acute myocardial infarction in coronary atherosclerosis disease patients.

Objectives: To examine plasma protein Z (PZ) levels in acute myocardial infarction (AMI) and chronic coronary atherosclerosis disease (CCAD) patients without history of AMI and explore its potential clinical significance.

Methods: Plasma PZ concentrations were measured in 90 AMI patients (Group A), 87 CCAD patients without AMI history who remained free of major clinical events at least one year (Group B), and 88 clinically healthy controls (Group C).

Results: PZ was found to be significantly lower (P<0.001) in Group A (1508.5±486.2ng/mL) compared with Group B (1823.0±607.8ng/mL) and C (2001.7±733.0ng/mL) and in Group A+B compared with Group C (Group A+B 1663.1±570.0 ng/mL, P<0.001). No statistically significant difference was reached between Group B and C (P=0.081). PZ level was significantly correlated with concentration of creatine kinase MB, high sensitive-cardiac troponin T, high sensitive C reactive protein, D-dimer and coagulation factor II and may be a useful predictor for AMI (OR: 1.38, 95% CI: 1.13-1.77, P=0.03). Subgroup analysis showed PZ concentration below the lowest tertile (<1398ng/mL) had a significantly increased risk for AMI and CCAD (OR: 3.39; 95% CI: 1.12-10.31; P=0.03 and OR: 7.39; 95% CI: 2.62-20.79; P<0.001 respectively).

Conclusions: PZ deficiency is found in AMI patients and could potentially reflect the myocardium injury, local coagulation activation and inflammation response during the acute phase of coronary atherosclerosis disease.