Antithrombotic therapy is associated with better survival in patients with severe heart failure and left ventricular systolic dysfunction (EPICAL study)

Anticoagulation versus placebo for heart failure in sinus rhythm

BACKGROUND

People with chronic heart failure (HF) are at risk of thromboembolic events, including stroke, pulmonary embolism, and peripheral arterial embolism; coronary ischaemic events also contribute to the progression of HF. The use of long-term oral anticoagulation is established in certain populations, including people with HF and atrial fibrillation (AF), but there is wide variation in the indications and use of oral anticoagulation in the broader HF population.

OBJECTIVES

To determine whether long-term oral anticoagulation reduces total deaths and stroke in people with heart failure in sinus rhythm.

SEARCH METHODS

We updated the searches in CENTRAL, MEDLINE, and Embase in March 2020. We screened reference lists of papers and abstracts from national and international cardiovascular meetings to identify unpublished studies. We contacted relevant authors to obtain further data. We did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing oral anticoagulants with placebo or no treatment in adults with HF, with treatment duration of at least one month. We made inclusion decisions in duplicate, and resolved any disagreements between review authors by discussion, or a third party.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, and assessed the risks and benefits of antithrombotic therapy by calculating odds ratio (OR), accompanied by the 95% confidence intervals (CI).

MAIN RESULTS

We identified three RCTs (5498 participants). One RCT compared warfarin, aspirin, and no antithrombotic therapy, the second compared warfarin with placebo in participants with idiopathic dilated cardiomyopathy, and the third compared rivaroxaban with placebo in participants with HF and coronary artery disease. We pooled data from the studies that compared warfarin with a placebo or no treatment. We are uncertain if there is an effect on all-cause death (OR 0.66, 95% CI 0.36 to 1.18; 2 studies, 324 participants; low-certainty evidence); warfarin may increase the risk of major bleeding events (OR 5.98, 95% CI 1.71 to 20.93, NNTH 17). 2 studies, 324 participants; low-certainty evidence). None of the studies reported stroke as an individual outcome. Rivaroxaban makes little to no difference to all-cause death compared with placebo (OR 0.99, 95% CI 0.87 to 1.13; 1 study, 5022 participants; high-certainty evidence). Rivaroxaban probably reduces the risk of stroke compared to placebo (OR 0.67, 95% CI 0.47 to 0.95; NNTB 101; 1 study, 5022 participants; moderate-certainty evidence), and probably increases the risk of major bleeding events (OR 1.65, 95% CI 1.17 to 2.33; NNTH 79; 1 study, 5008 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Based on the three RCTs, there is no evidence that oral anticoagulant therapy modifies mortality in people with HF in sinus rhythm. The evidence is uncertain if warfarin has any effect on all-cause death compared to placebo or no treatment, but it may increase the risk of major bleeding events. There is no evidence of a difference in the effect of rivaroxaban on all-cause death compared to placebo. It probably reduces the risk of stroke, but probably increases the risk of major bleedings. The available evidence does not support the routine use of anticoagulation in people with HF who remain in sinus rhythm.

Antiplatelet versus anticoagulation treatment for patients with heart failure in sinus rhythm

BACKGROUND

Morbidity in patients with chronic heart failure is high, and this predisposes them to thrombotic complications, including stroke and thromboembolism, which in turn contribute to high mortality. Oral anticoagulants (e.g. warfarin) and antiplatelet agents (e.g. aspirin) are the principle oral antithrombotic agents. Many heart failure patients with sinus rhythm take aspirin because coronary artery disease is the leading cause of heart failure. Oral anticoagulants have become a standard in the management of heart failure with atrial fibrillation. However, a question remains regarding the appropriateness of oral anticoagulants in heart failure with sinus rhythm. This update of a review previously published in 2012 aims to address this question.

OBJECTIVES

To assess the effects of oral anticoagulant therapy versus antiplatelet agents for all-cause mortality, non-fatal cardiovascular events and risk of major bleeding in adults with heart failure (either with reduced or preserved ejection fraction) who are in sinus rhythm.

SEARCH METHODS

We updated the searches in September 2015 on CENTRAL (The Cochrane Library), MEDLINE and Embase. We searched reference lists of papers and abstracts from cardiology meetings and contacted study authors for further information. We did not apply any language restrictions. Additionally, we searched two clinical trials registers: ClinicalTrials.gov (www.ClinicalTrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) Search Portal apps.who.int/trialsearch/) (searched in July 2016).

SELECTION CRITERIA

We included randomised controlled trials comparing antiplatelet therapy versus oral anticoagulation in adults with chronic heart failure in sinus rhythm. Treatment had to last at least one month. We compared orally administered antiplatelet agents (aspirin, ticlopidine, clopidogrel, prasugrel, ticagrelor, dipyridamole) versus anticoagulant agents (coumarins, warfarin, non-vitamin K oral anticoagulants).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed the risks and benefits of antithrombotic versus antiplatelet therapy using relative measures of effects, such as risk ratios (RR), accompanied with 95% confidence intervals (CI). The data extracted included data relating to the study design, patient characteristics, study eligibility, quality, and outcomes. We used GRADE criteria to assess the quality of the evidence.

MAIN RESULTS

This update identified one additional study for inclusion, adding data for 2305 participants. This addition more than doubled the overall number of patients eligible for the review. In total, we included four randomised controlled trials (RCTs) with a total of 4187 eligible participants. All studies compared warfarin with aspirin. One RCT additionally compared warfarin with clopidogrel. All included RCTs studied patients with heart failure with reduced ejection fraction.Analysis of all outcomes for warfarin versus aspirin was based on 3663 patients from four RCTs. All-cause mortality was similar for warfarin and aspirin (RR 1.00, 95% CI 0.89 to 1.13; 4 studies; 3663 participants; moderate quality evidence). Oral anticoagulation was associated with a reduction in non-fatal cardiovascular events, which included non-fatal stroke, myocardial infarction, pulmonary embolism, peripheral arterial embolism (RR 0.79, 95% CI 0.63 to 1.00; 4 studies; 3663 participants; moderate quality evidence). The rate of major bleeding events was twice as high in the warfarin groups (RR 2.00, 95% CI 1.44 to 2.78; 4 studies; 3663 participants; moderate quality evidence). We generally considered the risk of bias of the included studies to be low.Analysis of warfarin versus clopidogrel was based on a single RCT (N = 1064). All-cause mortality was similar for warfarin and clopidogrel (RR 0.93, 95% CI 0.72 to 1.21; 1 study; 1064 participants; low quality evidence). There were similar rates of non-fatal cardiovascular events (RR 0.85, 95% CI 0.50 to 1.45; 1 study; 1064 participants; low quality evidence). The rate of major bleeding events was 2.5 times higher in the warfarin group (RR 2.47, 95% CI 1.24 to 4.91; 1 study; 1064 participants; low quality evidence). Risk of bias for this study can be summarised as low.

AUTHORS' CONCLUSIONS

There is evidence from RCTs to suggest that neither oral anticoagulation with warfarin or platelet inhibition with aspirin is better for mortality in systolic heart failure with sinus rhythm (high quality of the evidence for all-cause mortality and moderate quality of the evidence for non-fatal cardiovascular events and major bleeding events). Treatment with warfarin was associated with a 20% reduction in non-fatal cardiovascular events but a twofold higher risk of major bleeding complications (high quality of the evidence). We saw a similar pattern of results for the warfarin versus clopidogrel comparison (low quality of the evidence). At present, there are no data on the role of oral anticoagulation versus antiplatelet agents in heart failure with preserved ejection fraction with sinus rhythm. Also, there were no data from RCTs on the utility of non-vitamin K antagonist oral anticoagulants compared to antiplatelet agents in heart failure with sinus rhythm.

Anticoagulation versus placebo for heart failure in sinus rhythm

BACKGROUND

Patients with chronic heart failure (heart failure) are at risk of thromboembolic events, including stroke, pulmonary embolism and peripheral arterial embolism, whilst coronary ischaemic events also contribute to the progression of heart failure. Long-term oral anticoagulation is established in certain patient groups, including patients with heart failure and atrial fibrillation, but there is wide variation in the indications and use of oral anticoagulation in the broader heart failure population.

OBJECTIVES

To determine whether long-term oral anticoagulation reduces total deaths, cardiovascular deaths and major thromboembolic events in patients with heart failure.

SEARCH METHODS

We updated the searches in June 2030 in the electronic databases CENTRAL (Issue 6, 2013) in The Cochrane Library, MEDLINE (OVID, 1946 to June week 1 2013) and EMBASE (OVID, 1980 to 2013 week 23). Reference lists of papers and abstracts from national and international cardiovascular meetings were studied to identify unpublished studies. Relevant authors were contacted to obtain further data. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing oral anticoagulants with placebo in adults with heart failure, and with treatment duration at least one month. Non-randomised studies were also included for assessing side effects. Inclusion decisions were made in duplicate and any disagreement between review authors was resolved by discussion or a third party.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed the risks and benefits of antithrombotic therapy using relative measures of effects, such as odds ratio, accompanied by the 95% confidence intervals.

MAIN RESULTS

Two RCTs were identified. One compared warfarin, aspirin and no antithrombotic therapy and the second compared warfarin with placebo in patients with idiopathic dilated cardiomyopathy. Three small prospective controlled studies of warfarin in heart failure were also identified, but they were over 50 years old with methods not considered reliable by modern standards. In both WASH 2004 and HELAS 2006, there were no significant differences in the incidence of myocardial infarction, non-fatal stroke and death between patients taking oral anticoagulation and those taking placebo. Four retrospective non-randomised cohort analyses and four observational studies of oral anticoagulation in heart failure included differing populations of heart failure patients and reported contradictory results.

AUTHORS' CONCLUSIONS

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 those with atrial fibrillation), the available data does not support the routine use of anticoagulation in heart failure patients who remain in sinus rhythm.

Anticoagulation versus placebo for heart failure in sinus rhythm

BACKGROUND

Patients with chronic heart failure (heart failure) are at risk of thromboembolic events, including stroke, pulmonary embolism and peripheral arterial embolism, whilst coronary ischaemic events also contribute to the progression of heart failure. Long-term oral anticoagulation is established in certain groups, including patients with heart failure and atrial fibrillation, but there is wide variation in the indications and use of oral anticoagulation in the broader heart failure population.

OBJECTIVES

To determine whether long-term oral anticoagulation reduces total deaths and/or major thromboembolic events in patients with heart failure.

SEARCH METHODS

We updated the searches in February 2010 on CENTRAL on The Cochrane Library (Issue 1, 2010), MEDLINE (2000 to February 2010) and EMBASE (1998 to February 2010). Reference lists of papers and abstracts from national and international cardiovascular meetings were studied to identify unpublished studies. Relevant authors were contacted to obtain further data. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing oral anticoagulants with placebo in adults with heart failure, and with treatment duration at least one month. Non-randomised studies were also included for assessing side-effects. Inclusion decisions were duplicated, disagreement resolved by discussion or a third party.

DATA COLLECTION AND ANALYSIS

Four review authors independently assessed trials for inclusion and assessed the risks and benefits from antithrombotic therapy using relative measures of effects, such as odds ratio, accompanied with 95% confidence intervals.

MAIN RESULTS

Two RCTs were identified. One compared warfarin, aspirin and no antithrombotic therapy and the second compared warfarin with placebo in patients with idiopathic dilated cardiomyopathy. Three small prospective controlled studies of warfarin in heart failure were also identified, but were over 50 years old with methods not considered reliable by modern standards. In both WASH 2004 and HELAS 2006, there were no significant differences in the incidence of myocardial infarction, non-fatal stroke and death between patients taking oral anticoagulation and placebo. Four retrospective non-randomised cohort analyses and four observational studies of oral anticoagulation in heart failure included differing populations of heart failure patients and reported contradictory results.

AUTHORS' CONCLUSIONS

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.

Anticoagulation in patients with heart failure and normal sinus rhythm

PURPOSE

The evidence evaluating the risk of thrombosis and the efficacy and risk of anticoagulation in patients with systolic heart failure (HF) and normal sinus rhythm is reviewed.

SUMMARY

Although a subject of investigation for over 50 years, use of anticoagulation in patients with HF remains an area of controversy and clinical debate. While early studies reported variable thromboembolism rates in HF (1.9-42.4 events per 100 patient years), the annual rate from larger and more recent trials ranged from 1% to 3%. The trials evaluating the role of oral anticoagulants to reduce thromboembolism and mortality outcomes in patients with a reduced ejection fraction (EF) have provided ambiguous results. Early studies and post hoc analyses of large clinical trials have demonstrated a reduction in thromboembolic events, risk of stroke, and mortality. In contrast, recent underpowered prospective controlled studies found no benefit in the use of warfarin in patients with systolic HF and normal sinus rhythm. The low-to-moderate risk of thromboembolism in patients with HF and the questionable benefit of anticoagulation need to be weighed against the potential for hemorrhagic complications caused by this therapy. The available data collectively suggest that the risk of using warfarin in patients with reduced EF may outweigh any possible benefit, if one exists at all.

CONCLUSION

Anticoagulation therapy in patients with HF and normal sinus rhythm is not supported by the limited evidence. The benefits of anticoagulation in such patients may not compensate for the relatively high risk of major bleeding caused by the treatment.

Thromboembolic risk in the patient with heart failure

Although heart failure is a procoagulant state, the incidence of arterial thromboembolism (peripheral arterial emboli and strokes) is relatively low in the outpatient setting and seems to be higher in those with concomitant atrial fibrillation or recent large anterior myocardial infarction, especially in the presence of a dyskinetic apex. Hospitalized heart failure patients, on the other hand, have an extremely high rate of deep venous thrombosis and pulmonary emboli. Outpatients with heart failure should receive anticoagulation only in the presence of atrial fibrillation or if they have experienced a prior embolic event. Patients with recent large anterior infarction or recent infarction with documented thrombus should be treated with anticoagulation for the initial 3 months after the infarct, whereas those with evidence of a mural thrombus should receive anticoagulation at least until the thrombus has resolved. Heart failure patients with ischemic cardiomyopathy should receive antiplatelet agents for the prevention of myocardial infarction, stroke, or death. Antiplatelet agents should not be prescribed for heart failure patients with nonischemic cardiomyopathy or without other evidence of atherosclerotic vascular disease. All hospitalized heart failure patients who are not taking oral anticoagulants should receive prophylaxis with low molecular weight heparins or factor Xa inhibitors.

Effects of aspirin and clopidogrel on plasma brain natriuretic peptide in patients with heart failure receiving ACE inhibitors

BACKGROUND

By inhibiting prostaglandins, aspirin may be deleterious in heart failure (HF) and/or may counteract angiotensin-converting enzyme (ACE) inhibitor efficacy. Conversely, clopidogrel has no effect on prostaglandin metabolism.

AIM

To investigate the effect of aspirin and clopidogrel on brain natriuretic peptide (BNP) levels in HF patients treated with ACE inhibitors.

METHODS

36 patients with stable HF (65+/-13 years, 24 males/12 females, NYHA class II to IV, ejection fraction <40%, 13 with coronary disease, all treated with ACE inhibitors) were enrolled in this prospective, double-blind study and randomised to aspirin 325 mg/day or clopidogrel 75 mg/day for 14 days. BNP was determined at day 0 and day 14.

RESULTS

19 patients were randomised to aspirin and 17 to clopidogrel. Baseline characteristics were similar in both groups. BNP levels increased in the aspirin group from day 0 to day 14 (107+/-103 to 144+/-149 pg/ml, p=0.04) whereas clopidogrel had no effect (104+/-107 and 97+/-99 pg/ml respectively, p=0.61).

CONCLUSION

This study demonstrates an adverse effect of aspirin 325 mg/day on BNP plasma levels in HF patients treated with ACE inhibitors. In contrast clopidogrel 75 mg/day had no effect.

Viewpoint: The prothrombotic state in heart failure: A maladaptive inflammatory response?

Patients with heart failure (HF) are at an increased risk of stroke, sudden death and venous thromboembolism, which are all linked to thrombus formation (thrombogenesis). The present 'viewpoint' article will discuss how the prothrombotic state in HF may be perpetuated by a chronic inflammatory state that is maladaptive. Indeed, there is considerable evidence that thrombogenesis and endothelial (dys)function can be intimately linked to inflammation in HF.

Antithrombotic therapy in patients with chronic heart failure: rationale, clinical evidence and practical implications

Chronic heart failure (CHF) is traditionally associated with increased risk of thromboembolic complications. Key features of CHF pathophysiology, such as impairment of intracardiac hemodynamics, peripheral blood flow deceleration, neuroendocrine activation, chronic oxidative stress and proinflammatory changes, could explain the predisposition to thromboembolism. However, conclusive epidemiologic data on thromboembolic event incidence in CHF are lacking. Furthermore, the place of antithrombotic therapy in CHF management is still uncertain. Apart from established indications for warfarin (e.g. atrial fibrillation and previous embolic events), there is no robust evidence to support administration of vitamin K antagonists to other patients with CHF, particularly to patients in sinus rhythm. The role of aspirin in preventing thromboembolism in these patients is also controversial. Large randomized trial data on the effectiveness and risks of warfarin and aspirin use in CHF patients with sinus rhythm are forthcoming. This article provides a brief overview of the epidemiologic and pathobiological background of thromboembolism in CHF, and discusses the up-to-date clinical evidence on antithrombotic therapy in detail.

Comparative effect of aspirin and clopidogrel on arterial function in CHF

BACKGROUND

By inhibiting prostaglandins, aspirin may be deleterious in congestive heart failure (CHF) and/or partially counteract the efficacy of angiotensin-converting enzyme inhibitors (ACEI). Conversely, clopidogrel has no effect on prostaglandin metabolism. The aim of this study was to prospectively investigate the effect of aspirin and clopidogrel on arterial functional properties in CHF patients treated with ACEI.

METHODS

Forty-five patients with stable NYHA class II-IV CHF (64.0+/-15.5 years), ejection fraction <40%, were included in this prospective double-blind study and randomized to receive aspirin 325 mg/day or clopidogrel 75 mg/day for 14 days. Reflected wave assessed by radial applanation tonometry and pulse wave velocity (PWV) were measured at day 0 and day 14.

RESULTS

Aspirin resulted in an increase in the augmentation index of the reflected wave (Delta=+3.5+/-5.2%, p=0.005) and the height above the shoulder of the reflected wave (Delta=+1.7+/-3.1 mm Hg, p=0.023), without statistically variation in PWV. Conversely, clopidogrel had no effect on the same parameters (p=0.512, p=0.677 and 0.801, respectively). Overall, variations in the augmentation index of reflected wave significantly differed when compared aspirin with clopidogrel (p=0.0261).

CONCLUSION

This study demonstrates the existence of a negative effect of aspirin 325 mg/day when compared to clopidogrel 75 mg/day on arterial functional properties in CHF patients treated with ACEI.

Antithrombotic therapy for congestive heart failure

Patients with congestive heart failure (CHF) are at increased risk of thromboembolic events. However, there is much debate and uncertainty over the use of antithrombotic therapy in these patients. The evidence for oral anticoagulation is limited, although large randomised trial data are forthcoming. Aspirin may be detrimental for heart failure due to a possible interaction with angiotensin-converting enzyme inhibitors, leading to increased hospitalisations from decompensated heart failure. The objective of this review article is to summarise the available evidence regarding the risk of stroke and thromboembolic events in CHF patients, as well as the effectiveness and risks of antithrombotic therapy in these patients.

Both antiplatelet and anticoagulant therapy may favorably affect outcome in patients with advanced heart failure. A retrospective analysis of the PRIME-II trial

INTRODUCTION

Current guidelines of chronic heart failure (CHF) do not recommend the use of oral anticoagulants (OAC) or antiplatelet therapy (APT). We performed a post-hoc analysis to evaluate the effect of the use of anti-thrombotic therapy with APT and OAC.

PATIENTS AND METHODS

We examined 427 patients with advanced CHF, and assessed the effects of the use of APT or OAC at baseline on mortality. We employed a Cox-proportional hazard model to value the effects of APT or OAC use.

RESULTS

After a mean follow-up of 3.4 years (range 2.0-5.4), 214 patients died (51%). Forty-one (41) percent (95%CI: 29-53%) of the patients on APT died, and 52% (47-57%) of the patients not on APT (P=0.07). Forty-eight (48) percent (42-54%) of the patients on OAC died, and 55% (46-63%) of the patients not on OAC (P=0.20). This effect of OAC was seen both in patients in sinus rhythm and in atrial fibrillation. After adjusting for important prognostic variables, such as age, LVEF, renal function, and NYHA class, both the use of APT (hazard ratio (HR) 0.62, 95% confidence interval (CI) 0.40-0.97; P=0.04) and the use of OAC (HR 0.60, 95%-CI 0.43-0.83; P<0.01) were related to an improved prognosis.

CONCLUSION

This post-hoc analysis suggests that in CHF patients the use of APT or OAC is associated with a higher survival.

Aortic banding in rat as a model to investigate malnutrition associated with heart failure

Heart failure is a severe pathology, which has displayed a dramatic increase in the occurrence of patients with chronic heart disease in developed countries, as a result of increases in the population's average age and in survival time. This pathology is associated with severe malnutrition, which worsens the prognosis. Although the cachexia associated with chronic heart failure is a well-known complication, there is no reference animal model of malnutrition related to heart failure. This study was designed to evaluate the nutritional status of rats in a model of loss of cardiac function obtained by ascending aortic banding. Cardiac overload led to the development of cardiac hypertrophy, which decompensates to heart failure, with increased brain natriuretic peptide levels. The rats displayed hepatic dysfunction and an associated renal hypotrophy and renal failure, evidenced by the alteration in renal function markers such as citrullinemia, creatininemia, and uremia. Malnutrition has been evidenced by the alteration of protein and amino acid metabolism. A muscular atrophy with decreased protein content and increased amino acid concentrations in both plasma and muscle was observed. These rats with heart failure displayed a multiorgan failure and malnutrition, which reflected the clinical situation of human chronic heart failure.

Antiplatelet agents versus control or anticoagulation for heart failure in sinus rhythm

BACKGROUND

Morbidity and mortality in patients with symptomatic chronic heart failure is high, it predisposes to stroke and thromboembolism which in turn contribute to high mortality in heart failure.

OBJECTIVES

To determine effect of antiplatelet agents when compared to placebo or anticoagulant therapy on death and/or major thromboembolic events in adults with heart failure who are in sinus rhythm.

SEARCH STRATEGY

Systematic search of electronic databases (MEDLINE, EMBASE, DARE). Abstracts from cardiology meetings and reference lists of relevant papers were searched. Authors of studies were contacted for further information.

SELECTION CRITERIA

Randomised parallel group placebo or controlled trials comparing antiplatelet therapy with control or anticoagulation in adults with chronic heart failure in sinus rhythm. Treatment for at least 1 month. To assess any adverse effects cohort study & non-randomised controlled studies were assessed. Orally administered antiplatelet agents e.g. non-steroidal anti-inflammatory agents, TICLOPIDINE, CLOPIDOGREL, DIPYRIDAMOLE, ASPIRIN compared with anticoagulant agents e.g. COUMARINS, WARFARIN or placebo.

DATA COLLECTION AND ANALYSIS

Data were extracted by two reviewers independently. No meta-analyses were performed as no data were available from randomised comparisons. The data extracted included data relating to the complexities of the topic area, such as patient characteristics and concomitant treatments, as well as data relating to study eligibility, quality, and outcomes. Non-randomised studies were used to identify side-effects caused by anticoagulants.

MAIN RESULTS

One RCT of warfarin, aspirin versus no antithrombotic therapy was found but no definitive data have yet been published. Three retrospective, non-randomised cohort studies from the V-HeFT, SOLVD and SAVE trials examining the role of ACE inhibitors have examined the role of aspirin therapy +/- anticoagulant therapy in patients with heart failure and/or left ventricular systolic dysfunction. The results from these trials were conflicting.

REVIEWER'S 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. A possible interaction with ACE inhibitors may reduce the efficacy of aspirin, although this evidence is from retrospective analyses of trial cohorts. There is also no evidence to indicate superior effects from oral anticoagulation, when compared to aspirin, in patients with heart failure in sinus rhythm.

Anticoagulation for heart failure in sinus rhythm

BACKGROUND

Patients with chronic heart failure (heart failure) are at risk of thromboembolic events, including stroke, pulmonary embolism and peripheral arterial embolism, whilst coronary ischaemic events also contribute to the progression of heart failure. Long-term oral anticoagulation is established in certain groups, including patients with heart failure and atrial fibrillation but there is wide variation in the indications and use of oral anticoagulation in the broader heart failure population.

OBJECTIVES

To determine whether long-term oral anticoagulation reduces total deaths and/or major thromboembolic events in patients with heart failure, when compared to placebo.

SEARCH STRATEGY

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

Randomised controlled trials (RCTs) comparing oral anticoagulants with control or placebo. Non-randomised studies were included as they may help in assessing side-effects. Duration of treatment at least 1 month, adults with heart failure due to any underlying cause. Inclusion decisions were duplicated, disagreement resolved by discussion or a third party.

DATA COLLECTION AND ANALYSIS

Data were collected by two reviewers independently and where appropriate data from RCTs were meta-analysed.

MAIN RESULTS

One recent pilot RCT compared warfarin, aspirin and no antithrombotic therapy, but no definitive data have yet been published. Three small prospective studies of warfarin in heart failure were also identified, but were over 50 years old with methods not considered reliable by modern standards. Anticoagulation was more efficacious than control for the reduction of all cause death (odds ratio 0.64 95% CI 0.45,0.90) and the reduction of cardiovascular events (0.26 95% CI 0.16, 0.43). Four retrospective non-randomised cohort analyses and three small observational studies of oral anticoagulation in heart failure included differing populations of heart failure patients and reported contradictory results.

REVIEWER'S CONCLUSIONS

Evidence from the RCTs and observational studies found a reduction in mortality and cardiovascular events with anticoagulants compared to control. This evidence needs to be interpreted with caution. Although oral anticoagulation is indicated in certain groups of patients with heart failure (eg 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 data from which will be useful addition to this story.