Bilirubin and its oxidative metabolite biopyrrins in patients with acute myocardial infarction.

This study aimed to assess the involvement of bilirubin and its oxidative metabolite biopyrrin in patients with acute myocardial infarction (AMI) and to determine the responsible organs that overproduce these molecules. One hundred thirteen consecutive patients hospitalized for AMI were analyzed. Levels of serum bilirubin, plasma and urinary biopyrrins were measured on the day of admission, day 2, 3, 7 and 14. Expressions of biopyrrins and heme oxygenase-1 (HO-1), a stress-responsive bilirubin-producing enzyme, in heart, aorta, kidney, liver and lung were immunostained with autopsied specimens. Serum bilirubin, plasma and urinary biopyrrins were increased within 24 hr, formed a peak on day 3 and then decreased by day 14. These three parameters were well correlated to each other. The maximum biopyrrin elevation was higher in death cases and associated with impaired left ventricular function. Immunohistochemical analyses revealed biopyrrin accumulation and HO-1 expression in the infracted myocardium. Immunoreactive HO-1 and biopyrrins were also observed in renal tubular cells, aortic wall and lung. Serum bilirubin and its metabolite biopyrrins were elevated in patients with AMI. Plasma and urinary biopyrrin elevation were associated with mortality and morbidity. Induction of anti-oxidative enzyme HO-1 seemed to be involved in the activation of bilirubin/biopyrrin pathway.

High serum erythropoietin level is associated with smaller infarct size in patients with acute myocardial infarction who undergo successful primary percutaneous coronary intervention.

OBJECTIVES: We investigated whether a higher serum erythropoietin (EPO) level in patients with acute myocardial infarction (MI) subjected to successful primary percutaneous coronary intervention (PCI) can predict a smaller infarct size determined by creatine kinase (CK) release. BACKGROUND: Erythropoietin has been shown to protect cardiomyocytes from ischemia-reperfusion injury in rodents. METHODS: We prospectively studied 101 patients with first MI who received successful primary PCI within 12 h from the onset of MI. Blood samples were collected to examine the serum EPO level after the primary PCI and within 24 h from the onset of MI. RESULTS: The peak CK level and cumulative CK release were significantly lower in the above-median EPO group than in the below-median EPO group. Thrombolysis In Myocardial Infarction (TIMI) grades and collateral grades before PCI, infarct-related coronary arteries, time to the successful reperfusion from the onset of MI, and serum creatinine levels were similar in the two EPO groups. A stepwise multiple regression analysis revealed that the absolute serum EPO level (mU/ml) as well as TIMI grades after PCI and preinfarction angina was an independent predictor for the cumulative CK release. CONCLUSIONS: These data suggest that a high endogenous EPO level can predict a smaller infarct size in patients with acute MI subjected to successful primary PCI. This might be attributed to the potentially protective effect of endogenous EPO against ischemia-reperfusion injury in humans.