Viral hepatitis: Croatian consensus statement

There has been a dramatic improvement in diagnostic procedures and therapy of viral hepatitis in the last 20 years. Improvements in therapy caused an increase in actual cost, however, with significant long-term savings through a decreased cost of treatment of advanced liver disease including liver transplantation. The Croatian National Board for Viral Hepatitis has decided to initiate the organization of consensus conference on viral hepatitis enabling the leading experts in the country to give the best possible recommendations for the diagnosis, prophylaxis and therapy in our circumstances. The Consensus Conference took place in Zagreb in June 2004, with update in March 2005, organized by the Croatian National Board for Viral Hepatitis, Reference Centers of the Ministry of Health for Chronic Liver Diseases, Infectious Diseases and AIDS, Croatian Society of Gastroenterology--Hepatology Section, Croatian Society for Nephrology, Dialysis and Transplantation, and Croatian Institute for Health Insurance. Invited experts provided written reports on the respective subjects that appear in this issue and their recommendations resulting in this consensus statement.     

Reduction in oxidative stress and modulation of heart failure subsequent to myocardial infarction in rats

BACKGROUND:

Patients surviving myocardial infarction (MI) are at a heightened risk for the development of congestive heart failure. This clinical syndrome has been associated with an antioxidant deficit and elevated oxidative stress in the myocardium. Effects of dietary vitamin E, a lipid-soluble antioxidant, on myocardial anti-oxidant enzyme activities, oxidative stress and hemodynamic function, were examined separately in the viable left ventricle (LV) and right ventricle (RV) of rats at 16 weeks post-MI.

METHODS AND RESULTS:

Animals were fed either a basal diet or a diet enriched with 1500 U of vitamin E/kg beginning two weeks before MI-inducing surgery and continued 16 weeks post-MI. In the MI animals on the basal diet, LV systolic pressure (LVSP) and RVSP were significantly depressed and LV end-diastolic pressure (LVEDP) and RVEDP were significantly elevated. These hemodynamic alterations were accompanied by clinical signs of heart failure including dyspnea, lethargy and cyanotic limbs. Supplementation of MI animals with dietary vitamin E resulted in complete normalization of RVSP and RVEDP. An increase in LVSP and a decrease in LVEDP was observed in the vitamin E-supplemented MI animals, although mild residual LV dysfunction remained. The myocardial enzymatic antioxidants catalase and glutathione peroxidase declined substantially in each of the ventricles of unsupplemented MI animals. Myocardial levels of vitamin E were reduced by 33% in the LV and no change was observed in the RV of the MI animals. Vitamin E-supplemented control animals and MI animals showed a significant increase in vitamin E levels in both ventricles. Myocardial oxidative stress, as assessed by lipid peroxidation and the ratio of reduced to oxidized glutathione, was significantly increased in each of the respective ventricles of untreated MI animals. Supplementation with dietary vitamin E resulted in a substantial increase in the myocardial activities of catalase and glutathione peroxidase in both the LV and RV. Furthermore, an increase in the ratio of reduced to oxidized glutathione concomitant with significantly less lipid peroxidation was also observed in each of the respective ventricles of MI animals supplemented with vitamin E. No overt clinical signs of heart failure were evident in these vitamin E-supplemented animals.

CONCLUSIONS:

An improved myocardial redox state and endogenous antioxidant reserve with vitamin E therapy, coupled with the modulation of the development of heart failure, lend strong support in favour of a pathophysiological role for increased oxidative stress in the pathogenesis of heart failure, at least in experimental animals. Association between an increase in oxidative stress and cardiac events in patients requires further examination.