The prognostic value of biomarkers after a premature myocardial infarction

Abstract

Background Intravascular thrombogenesis is influenced by a complex interplay of factors related to a procoagulant state, fibrinolysis, endothelial damage/dysfunction and inflammation. We hypothesised that abnormalities of these biological systems would contribute to outcome of coronary artery disease presenting at a young age. Methods We performed a prospective study of 142 subjects presenting with acute myocardial infarction (AMI) at a young age (defined as age ≤ 45 years), to determine the clinical and laboratory predictors of cardiovascular events during 36 months of follow-up. We assessed conventional risk factors and abnormalities of thrombophilia [total homocysteine (tHcy), lipoprotein (a) [Lp(a)], antiphospholipid antibodies (APA)], as well as lipid profile (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides), fibrinogen and fibrin D-dimer (as indices of a hypercoagulable state and thrombogenesis), von Willebrand factor (vWF, an index of endothelial damage/dysfunction), tissue plasminogen activator [t-PA antigen] and its inhibitor [PAI-1 antigen] (as indices of fibrinolysis), and C-reactive protein [CRP] (an index of inflammation). Results In a multivariate analysis, the variables independently associated with cardiovascular events at follow-up were levels of homocysteine (OR 3.73, 95% CI (1.54–9.02); p = 0.003), left ventricle systolic dysfunction (OR 3.04, 95% CI (1.00–9.25); p = 0.050), and smoking habit (OR 2.79, 95% CI (1.09–7.14) p = 0.032). Conclusions Prognostic markers associated with cardiovascular events in premature CAD (young AMI subjects) were cigarette smoking and EF < 50% of left ventricle as conventional clinical risk factors, as well as higher levels of homocysteine.