Hormone replacement therapy and cardiovascular disease

This year's work on hormone replacement therapy (HRT) and cardiovascular di sease has been remarkable for the publication of the first randomised contr olled trial of HRT use, the Heart Estrogen Replacement Study (HERS). The fi ndings go against not only the trend of previous observational epidemiologi cal studies, but also against findings in the very many studies which have previously shown and continue to show this year a beneficial effect of HRT on a large variety of cardiovascular risk factors, including endothelial fu nction, here reviewed. The aspect of the effect of HRT on clotting variable s is clearly crucial given the increased risk of venous thrombosis, and als o increased number of cardiac events in the first 4 months of the HERS. Pro thrombotic factors increase with age in women, and HRT alters these, partic ularly fibrinogen, factor VII, and PAI (less change with transdermal HRT) a nd antithrombin III. In normal women therefore the balance should be toward s fibrinolysis rather than coagulation. Work has been presented in abstract for clarifying the effects of HRT on coagulation markers and grasping the problem of differences according to its route of administration. The full p ublications on this work are expected shortly. We are still awaiting eviden ce from randomized controlled trials of HRT in primary prevention; one is n ow recruited but will not report until 2005. Curr Opin Lipidol 10:581-587. (C) 1999 Lippincott Williams & Wilkins.