SummaryScarce data exist on the relationship of C-reactive protein (CRP) or plasminogen activator inhibitor-1 (PAI-1) to the occurrence of heart failure (HF) or cardiogenic shock (CS) after acute myocardial infarction (AMI) and on the relationship between these biomarkers and mortality in CS patients. Thus, we compared high-sensitivity CRP and PAI-1 antigen plasma levels on admission among 3 age-and gender-matched AMI patients groups (consisting of 60 patients with CS, 60 with HF, and 60 without HF on admission), after determining that PAI-1 levels did not vary significantly diurnally in these groups by comparing the data among subgroups which were divided according to admission time within the groups. For CS patients, we also conducted regression analyses to examine the relations of these biomarkers to mortality. CRP levels both in CS (P < 0.001) and HF (P < 0.05) patients were significantly higher compared to those without HF, PAI-1 levels in CS patients were significantly higher compared to both those with (P < 0.05) and without HF (P < 0.01), and CRP and PAI-1 were independent predictors of in-hospital (Odds ratio [OR] = 6.12, 95% confidence intervals [95%CI] = 1.47-25.54 and OR = 5.92, 95%CI = 1.31-26.77, respectively) and 1-year mortality (OR = 5.53, 95%CI = 1.21-25.17 and OR = 5.48, 95%CI = 1.09-27.52, respectively) in CS patients. In conclusion, at admission, CRP is associated with the occurrence of CS and HF and PAI-1 is associated with the occurrence of CS after AMI, and they are of prognostic value in CS complicating AMI. (Int Heart J 2009; 50: 33-45)