The Warfarin/Aspirin Study in Heart failure (WASH): a randomized trial comparing antithrombotic strategies for patients with heart failure. Dicumarol prophylaxis of thromboembolic disease in congestive heart failure. Efficacy of antithrombotic therapy in chronic heart failure: the HELAS study. The effect of dicumarol upon the mortality and incidence of thromboembolic complications in congestive heart failure.
Heart failure is commonly associated with vascular disease and a high rate of athero-thrombotic events, but the risks and benefits of antithrombotic therapy are unknown.
                The current study was an open-label, randomized, controlled trial comparing no antithrombotic therapy, aspirin (300 mg/day), and warfarin (target international normalized ratio 2.5) in patients with heart failure and left ventricular systolic dysfunction requiring diuretic therapy. The primary objective was to demonstrate the feasibility and inform the design of a larger outcome study. The primary clinical outcome was death, nonfatal myocardial infarction, or nonfatal stroke.
                Two hundred seventy-nine patients were randomized and 627 patient-years exposure were accumulated over a mean follow-up time of 27 +/- 1 months. Twenty-six (26%), 29 (32%), and 23 (26%) patients randomized to no antithrombotic treatment, aspirin, and warfarin, respectively, reached the primary outcome (ns). There were trends to a worse outcome among those randomized to aspirin for a number of secondary outcomes. Significantly (P =.044) more patients randomized to aspirin were hospitalized for cardiovascular reasons, especially worsening heart failure.
                The Warfarin/Aspirin Study in Heart failure (WASH) provides no evidence that aspirin is effective or safe in patients with heart failure. The benefits of warfarin for patients with heart failure in sinus rhythm have not been established. Antithrombotic therapy in patients with heart failure is not evidence based but commonly contributes to polypharmacy. nan It is not clear if long-term antithrombotic treatment has a beneficial effect on the incidence of thromboembolism in chronic heart failure (CHF). The HELAS study (Heart failure Long-term Antithrombotic Study) is a multicentre, randomised, double-blind, placebo-controlled trial to evaluate antithrombotic treatment in patients with CHF.
                197HF patients (EF <35%) were enrolled. Patients with Ischaemic Heart Disease were randomised to receive either aspirin 325mg or warfarin. Patients with Dilated Cardiomyopathy (DCM) were randomised to receive either warfarin or placebo.
                Analysis of the data from 312 patient years showed an incidence of 2.2 embolic events per 100 patient years, with no significant difference between groups. The incidence of myocardial infarction, hospitalisation, exacerbation of heart failure, death and haemorrhage were not different between the groups. No peripheral or pulmonary emboli were reported. Echocardiographic follow-up for 2years showed an overall increase in left ventricular ejection fraction from 28.2+/-6 to 30.3+/-7 p<0.05, which was most obvious in patients with DCM taking warfarin (EF 26.8+/-5.3 at baseline, 30.7+/-10 at 2 years, p<0.05).
                (1) Overall embolic events are rare in heart failure regardless of treatment. (2) Treatment does not seem to affect outcome. nan
Based on the two major randomised trials (HELAS 2006; WASH 2004), there is no convincing evidence that oral anticoagulant therapy modifies mortality or vascular events in patients with heart failure and sinus rhythm. Although oral anticoagulation is indicated in certain groups of patients with heart failure (for example atrial fibrillation), the data available does not support its routine use in heart failure patients who remain in sinus rhythm. A large randomised trial of warfarin in heart failure patients in sinus rhythm is currently in progress and data from this trial will be a useful addition to this topic.