Adiponectin--its potential to predict and prevent coronary artery disease.

BACKGROUND: Recent evidence suggests that epicardial adipose tissue may contribute locally to the pathogenesis of coronary artery disease (CAD). We investigated how local and systemic adiponectin, an adipokine with anti-inflammatory and insulin sensitizing properties, is related to the presence of CAD and cardiovascular risk factors. METHODS: Serum and adipose tissue samples from subcutaneous and pericoronary depots were collected from sixty consecutive patients with CAD who required coronary artery bypass grafting or patients without CAD who underwent cardiac surgery for aortic valve replacement. Western blot, ELISA and PCR were used to detect and determine the adiponectin concentrations and expression in the samples. RESULTS: Adiponectin concentrations in the serum and pericoronary fat of patients without CAD were significantly higher than in patients with CAD ( P < 0.01). However, the expression of adiponectin mRNA did not differ in any instances. Male gender, BMI > 30 and type 2 diabetes were significantly correlated to decreased serum adiponectin ( P < 0.03). CONCLUSION: Pericoronary fat specifically secretes metabolically active adiponectin. Its local and systemic concentrations are inversely correlated to the presence of coronary artery disease, indicating its anti-atherogenic effects. As for patients with CAD, adiponectin might be a promising marker for intra-individual monitoring of cardiovascular risk factors and thus a course of secondary prevention. Further evaluation is necessary to elucidate whether a novel therapeutic option could be derived against the onset and progression of CAD.

Effect of closed minimized cardiopulmonary bypass on cerebral tissue oxygenation and microembolization.

OBJECTIVE: Coronary artery bypass grafting with cardiopulmonary bypass carries a risk for neurologic complications because of cerebral hypoperfusion and microembolization. The basic goals of a novel closed minimized extracorporeal circulation are to prevent excessive hemodilution and to avoid blood-air interface. The aim of this prospective randomized study was to determine the effect of using the minimized extracorporeal circulation system compared with open conventional extracorporeal circulation on cerebral tissue oxygenation and microembolization. METHODS: Forty patients undergoing coronary artery bypass grafting (20 in each group) were continuously monitored for changes in cerebral oxygenated hemoglobin and tissue oxygenation index by using near-infrared spectroscopy. Total microembolic count and gaseous embolic count in both median cerebral arteries were monitored with multifrequency transcranial Doppler instrumentation. RESULTS: In the conventional extracorporeal circulation group there was a highly significant reduction in both cerebral oxygenated hemoglobin and tissue oxygenation index from the start to the end of cardiopulmonary bypass (P < .01). The rate of decrease in cerebral oxygenated hemoglobin after aortic cannulation was faster in the conventional extracorporeal circulation group (F test = 9.03, P < .001). No significant changes with respect to cerebral oxygenated hemoglobin or tissue oxygenation index occurred in the minimized extracorporeal circulation group, except at the beginning of rewarming (P < .01). Total embolic count, as well as gaseous embolic count, in the left and right median cerebral arteries was significantly lower in the minimized extracorporeal circulation group (all P < .05). Postoperative bleeding was greater (P < .05) and the transfusion rate was higher (P < .05) in the conventional extracorporeal circulation group. CONCLUSIONS: Use of closed minimized cardiopulmonary bypass compared with conventional open cardiopulmonary bypass preserves cerebral tissue oxygenation and reduces cerebral microembolization.

Effect of acute brain death on release of atrium and B-type natriuretic peptides in an animal model.

INTRODUCTION: Atrium and B-type natriuretic peptides (ANP and BNP) and big endothelin (ET)-1 are markers for severity of heart failure and may be used in the quality assessment of donor hearts. Elevated cardiac troponins predict early graft failure after heart transplantation. This study evaluated the effects of acute brain death (BD) on the release of ANP, BNP, big ET-1, and cardiac troponins in an animal model. MATERIALS AND METHODS: Pigs were randomized into a BD group (n=5) and a control group (n=5). In the first group, acute BD was induced, and anesthesia was stopped. In the control animals, a sham operation was performed, and anesthesia was continued. Parameters were measured at baseline and for 13 hours postoperatively. RESULTS: After acute BD, there were significant hemodynamic changes. In the control group, the BNP level was higher than in the BD group and decreased over time (P =0.016). There was no significant change in BNP release in the BD group up to 13 hours (P =0.1). ANP release remained stable over time in the control group (P =0.35) but decreased in the BD group (P =0.043). The big ET-1 levels were not different between groups. Cardiac troponin I was elevated in the BD group 5 hours after BD (P< 0.05) but remained under 1.5 mg/L throughout the study. CONCLUSION: Acute BD did not lead to an increase of BNP and ANP levels. Moreover, intact brain function seems to augment the release of natriuretic peptides from the myocardium. Further clinical evaluation of prognostic values of natriuretic peptides for the assessment of donor hearts is necessary. Cardiac troponins are a useful additional tool in the evaluation of donor hearts.