Quick, easy, and safe? On the use of low-molecular-weight heparins in cardioversion of atrial fibrillation

Abstract

Low-molecular-weight heparins (LMWHs) are gradually replacing unfractionated heparin (UFH) in several settings in cardiology and internal medicine. In most studies, LMWHs were either as effective as UFH or superior and had the additional advantage of the greater ease of subcutaneous application. Although earlier studies focused on the use of LMWHs in the venous vasculature, more recent studies have demonstrated some clinical advantages compared with UFH also in the arterial bed, e.g. in patients with unstable angina pectoris.1 Another clinical entity with the risk of arterial thrombo-embolism is atrial fibrillation (AF), an arrhythmia which not only shows a rising prevalence in recent years but is also associated with increased morbidity and mortality mainly due to thrombo-embolic events. Several studies in the late 1980s and early 1990s have demonstrated that inhibition of plasmatic coagulation is more effective than antiplatelet drugs in preventing thrombo-embolic events in patients with chronic AF. This has been underscored by more recent data showing that even combined antiplatelet therapy with acetylic salicylic acid plus clopidogrel is less effective than oral anticoagulation in this setting.2 Mainly because of their mode of application (intravenous or subcutaneous route), the role of heparins in AF is confined to short-term anticoagulation, such as the initiation of anticoagulation before the full effect of oral anticoagulants is reached, e.g. before cardioversion of AF. The results of the ACUTE trial have demonstrated … Corresponding author. Tel: +49 5215813401; fax: +49 5215813498. E-mail address : christoph.stel: brink{at}sk-bielefeld.de