Elevated carbonylated proteins are associated with major cardiovascular events in patients with chronic coronary syndrome: A cohort study.

Abstract

Protein carbonylation is reported in atherosclerosis, but its predictive value is unknown. We evaluated plasma carbonylated protein (PC) levels in association with clinical outcomes in coronary artery disease (CAD) in long-term follow-up. In patients with advanced stable CAD, we assessed plasma PC content along with fibrin clot properties, i.e., permeability (Ks) and clot lysis time, and its determinants: plasminogen activator inhibitor-1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor. We recorded a composite of myocardial infarction, ischemic stroke, systemic embolism, and cardiovascular death during a follow-up of 8.3 (1.8) years. The analysis involved 178 patients aged 64.0 (57.0-70.0) years. The baseline PC content was 2.9 (2.2-3.7) nmol/mg protein and was elevated above the reference value obtained for a control group (2.03 nmol/mg protein) in 82.6% of patients. In linear regression models, high PC adjusted for age was associated with lower Ks, longer clot lysis time, and elevated PAI-1 and thrombin-activatable fibrinolysis inhibitor. Baseline PC was 48% higher in patients with the composite endpoint (n = 67, 37.6%) compared with others (P <0.001). Patients with PC in the highest quartile (3.7-5.1 nmol/mg protein) were more likely to develop the composite endpoint compared to the lowest quartile (hazard ratio [HR] 4.9; 95% confidence interval, 2.1-11.3; P <0.001). This is the first study showing that in CAD the extent of protein carbonylation, in part via its antifibrinolytic effects, predisposes to cardiovascular events in long-term follow-up, highlighting the role of persistent oxidative protein modifications in atherosclerotic vascular disease.