Recent evidence suggests that postischemic myocardial dysfunction ("stunning") may be mediated by oxygen free radicals. Various studies have reported the beneficial effects of antioxidants in ischemia-reperfusion injury. The aim of this study was to assess the effect of N-acetylcysteine (NAC) treatment on oxidative stress, infarct size, and left ventricular (LV) function, as adjunct therapy in myocardial infarction (MI). Patients with acute MI received either 15 g NAC infused over 24 h (n = 15) or no NAC (n = 15), combined with streptokinase. Peripheral venous blood was serially sampled to measure creatine kinase (CK)-MB levels. Plasma malondialdehyde (MDA) level was measured at admission and after 4 and 24 h. Echocardiography was performed within 3 days of MI and after 3 months. At admission, plasma MDA levels were not different between the groups. In the NAC-treated patients plasma MDA levels decreased, whereas in the nontreated NAC patients MDA levels increased at 4 and 24 h (P < 0.01 and P < 0.001, respectively). Left ventricular ejection fraction was higher (P < 0.05) and LV end-systolic and end-diastolic diameters were lower (P < 0.001 and P < 0.001) in patients receiving NAC on day 3. Left ventricular wall motion score index was significantly lower in patients treated with NAC on day 3 (P < 0.05). Left ventricular diastolic parameters were not different whether patients were treated with NAC or not. No difference in reduction of infarct size was detected between the groups according to CK-MB levels. It was thus demonstrated that administration of NAC in combination with streptokinase significantly diminished oxidative stress and improved LV function in patients with acute MI. These encouraging results would justify the performance of a larger controlled study.

Chronic heart failure is a common, disabling disorder with high mortality. Oxidative stress may have both functional and structural effects on the myocardium, leading to myocardial decompensation. In this study, the authors examined the relationship of oxidative stress and functional capacity in patients with varying degrees of heart failure. Fifty-one patients with chronic heart failure and 31 control subjects were studied. The functional capacity of patients was determined. Plasma malondialdehyde, vitamin E, and beta-carotene levels were measured. The malondialdehyde levels were significantly different between control subjects and heart failure patients (p=0.03). There was a positive correlation between patients' malondialdehyde levels and New York Heart Association functional class (r=0.59; p<0.0001). There was a negative correlation between the functional class and vitamin E and beta-carotene levels (r=20.43; p<0.0001 and r=20.25; p<0.01, respectively). These data demonstrate that oxidative stress is increased systemically in patients with chronic heart failure. It seems that this increase correlates with functional class. (c)2001 CHF, Inc.

Our study shows gradually increased lipid and protein oxidation and total SA and gradually decreased antioxidant status when the conditions advance from UA to STEMI. These results indicate that these markers may be useful both in understanding plaque destabilization and in determination of risk stratification of patients. Also, measurement of these markers may provide a noninvasive window to study atherosclerotic lesions.

The aim of this study was to investigate the possible relationship between serum total sialic acid (TSA) concentration, recently shown to be a cardiovascular risk factor, and lipid and protein oxidation and antioxidant status and the severity of coronary artery disease (CAD) according to the obstructive vessel number in patients. The study was carried out on a total of 200 patients (142 men and 58 women) who were hospitalized for elective coronary angiographic evaluation with complaint of typical angina pectoris. According to the results of angiography, 150 patients had angiographically proven CAD (CAD group) and 50 patients had a history suggestive of angina pectoris but normal coronary angiograms (control group). The CAD group was further divided into single-, double- and triple-vessel disease groups according to the number of vessels involved. Lipid parameters were determined by routine laboratory methods. Plasma malondialdehyde (MDA) and vitamin E concentrations were determined by high-performance liquid chromatography. TSA and other oxidant and antioxidant parameters were studied spectrophotometrically. Our results demonstrated significant increases both in TSA levels and in indicators of oxidative stress in the patients with CAD compared with the controls. However, antioxidant parameters were decreased in the patients with CAD. We found strong positive correlations between TSA and plasma MDA, Delta-MDA which represents the degree of oxidative modification of apolipoprotein B-containing lipoproteins, serum protein carbonyls and apolipoprotein B and weak correlations between TSA and low density lipoprotein cholesterol, triacylglycerol, paraoxonase, glutathione peroxidase (GPx), vitamin C and vitamin E. In conclusion, TSA is related to markers of lipid and protein oxidation, paraoxonase and GPx activities, vitamin C and E levels and the severity of CAD.

In summary plasma IL-6 and hs-CRP levels were increased in obese patients. Orlistat-induced weight reduction was associated with decreasing levels of both IL-6 and hs-CRP in obese subjects. Because inflammatory mediators may be directly involved in atherogenesis, this would suggest that interventions to reduce IL-6 and CRP levels could be cardioprotective.