Antiplatelet agents versus control or anticoagulation for heart failure in sinus rhythm: a Cochrane systematic review

BACKGROUND: Heart failure predisposes to stroke and thromboembolism, which in turn contribute to the high mortality and morbidity in heart failure. OBJECTIVES: To determine the effect of antiplatelet agents, compared to placebo or anticoagulant therapy, on death and/or major thromboembolic events in adults with heart failure who are in sinus rhythm. DESIGN: Systematic review of randomized parallel group placebo or controlled trials comparing oral antiplatelet therapy with control or anticoagulation therapy in adults with chronic heart failure in sinus rhythm. DATA SOURCES: Reference lists of papers resulting from this search, electronic database searching (MEDLINE, EMBASE, DARE), and abstracts from national and international cardiovascular meetings were studied to identify unpublished studies. Relevant authors of these studies were contacted to obtain further data. SELECTION CRITERIA: These included duration of treatment of at least 1 month, and adults with heart failure due to any underlying cause. To assess any adverse effects, cohort study and non-randomized controlled studies were assessed. Inclusion decisions were duplicated, disagreement resolved by discussion or a third party. No meta-analyses were performed, as no data were available from randomized comparisons. RESULTS: One randomized controlled trial of warfarin vs. aspirin vs. no antithrombotic therapy was found, but no definitive data have yet been published. Three retrospective, non-randomized cohort studies from large trials examining the role of ACE inhibitors have examined the role of aspirin therapy with and without anticoagulant therapy in patients with heart failure and/or left ventricular systolic dysfunction were identified, but the results from these trials were conflicting. A possible interaction with ACE inhibitors may reduce the efficacy of aspirin, although this evidence is from retrospective analyses of trial cohorts. CONCLUSIONS: At present there is no evidence from long term RCTs to recommend use of aspirin to prevent thromboembolism in patients with heart failure in sinus rhythm. There is also no evidence to indicate superior effects from oral anticoagulation, when compared to aspirin, in patients with heart failure in sinus rhythm.