Efficacy and safety of warfarin vs. antiplatelet therapy in patients with systolic heart failure and sinus rhythm: a systematic review and meta-analysis of randomized controlled trials
- Conflicts of interest: Dr. Aaron Liew has received educational and research support from AstraZeneca, BI, BMS, MSD, Novo Nordisk, Novartis, Sanofi Aventis and Medtronic. Dr. John Eikelboom has received honoraria and research support from Bayer, BI, BMS, Johnson and Johnson, and Pfizer. Dr. Stuart Connolly has received honoraria and research support from Bayer, BI, BMS, Johnson and Johnson, and Pfizer. Dr. Martin O'Donnell has received an unrestricted education grant from BI and honoraria from BI and Sanofi Aventis. Dr. Robert Hart has no conflict of interest.
- Funding: None.
Background and purpose
Heart failure is an independent risk factor for stroke. Anticoagulation is effective for prevention of cardio-embolic stroke secondary to atrial fibrillation or mechanical heart valves but is of uncertain benefit in heart failure patients. We performed this meta-analysis to obtain the best estimates of the efficacy and safety of warfarin as compared with antiplatelet therapy in patients with systolic heart failure who are in sinus rhythm.
Methods and results
A systematic search was performed using PubMed and Central Register of Controlled Trials databases for all randomized controlled trials, which compare warfarin with antiplatelet therapy given for at least one-month in heart failure patients with sinus rhythm and report at least one of the following outcomes: ischemic stroke, death, myocardial infarction, hospitalization due to worsening heart failure, intracranial hemorrhage, and major hemorrhage. Four randomized controlled trials involving adjusted-dose warfarin (4187 subjects) were included. When compared with antiplatelet therapy, warfarin reduced ischemic stroke by 0·74% per year (RR 0·49; 95% CI: 0·32–0·73: P = 0·0006; Number needed to treat = 135) but increased major hemorrhage by 0·99% per year (RR 2·15; 95% CI: 1·55–2·99: P < 0·00001; Number needed to harm = 101). Warfarin did not significantly affect the risk of death, myocardial infarction, hospitalization due to heart failure or intracranial hemorrhage as compared with antiplatelet therapy.
Warfarin as compared with antiplatelet therapy reduces risk of ischemic stroke, does not significantly affect death, myocardial infarction, hospitalization due to heart failure or intracranial hemorrhage and increases major hemorrhage in heart failure patients who are in sinus rhythm.