The Warfarin and Antiplatelet Therapy in Heart Failure Trial (WATCH): rationale, design, and baseline patient characteristics

The Dilemma of Use of Anticoagulation in Patients With Heart Failure With Reduced Ejection Fraction and Sinus Rhythm: A Case Report and Literature Review

Heart failure results in significant morbidity and mortality. Heart failure with reduced ejection fraction (HfrEF) in the absence of atrial fibrillation has been increasingly considered an independent risk factor for ischemic stroke, partly because of the development of left ventricular thrombus and subsequent cardioembolic stroke and partly because of hemodynamic impairment. Here, we present a case of a 60-year-old male with heart failure with reduced ejection fraction, who presented with cardioembolic ischemic stroke. In the investigation to localize the source, he was found to have slow intra-ventricular blood flow, which over shorter periods of follow up lead to the development of left ventricle intra-mural thrombi. Meanwhile, the patient also developed hemorrhagic conversion in the ischemic stroke, which further complicated the choice of anticoagulation. To date, no consensus has been developed on the choice of anticoagulation and clinical criteria for the use of anticoagulation in patients having HfrEF and sinus rhythm. This case brings forth a need for further research on whether anticoagulation would be beneficial in patients with HfrEF and sinus rhythm.

Left Atrial Dilatation and Reduced Left Ventricular Ejection Fraction Are Associated With Cardioembolic Stroke

Objective: Left atrial (LA) dilatation and heart failure are independent risk factors for ischemic stroke. The goal of this study is to evaluate the association between LA dilatation and reduced left ventricular ejection fraction (EF) with cardioembolic stroke. Methods: Four hundred fifty-three patients with ischemic stroke admitted to the University of California, Irvine between 2016 and 2017 were included based on the following criteria: age >18 and availability of echocardiogram. Stroke was categorized into cardioembolic and non-cardioembolic. EF was categorized into normal: 52-72% (male), 54-74% (female), mildly abnormal: 41-51% (male), 41-53% (female), moderately abnormal: 30-40%, and severely abnormal: <30%. LA volume was categorized into normal (≤34 ml/m²) vs. enlarged (≥35 ml/m²). Other variables included gender, hypertension [systolic blood pressure (SBP) ≥ 140 or diastolic blood pressure (DBP) ≥ 90], and known history of atrial fibrillation (Afib). Results: Two hundred eighteen patients had cardioembolic, and 235 had non-cardioembolic stroke. Among patients with cardioembolic stroke, 49 (22.4%) and 142 (65%) had reduced EF and enlarged LA, respectively, as compared with 19 (8.1%) and 65 (27.7%) patients with non-cardioembolic stroke (p < 0.0001). The odds of cardioembolic stroke were 2.0 (95% CI: 0.1-6.0) and 8.8 times (95% CI: 1.9-42.3) higher in patients with moderately and severely reduced EF, respectively, than in patients with normal EF. The odds of cardioembolic stroke was 2.4 times (95% CI: 1.5-3.9) higher in patients with enlarged LA than in patients with normal LA size. Compared with patients with normal LA and EF, patients with combined enlarged LA and reduced EF had significantly higher rates of Afib (43.4 vs. 9.0%, p < 0.0001) and cardioembolic stroke (78.3 vs. 43.4%, p < 0.0001). Conclusions: LA dilatation along with reduced EF is a reliable predictor of Afib and cardioembolic stroke. Further studies are warranted to determine the benefit of anticoagulation for secondary stroke prevention in such patient population.

Non-vitamin K antagonist oral anticoagulants for heart diseases

Non-vitamin K antagonist oral anticoagulants (NОАСs) are highly effective drugs that prevent venous thrombosis and stroke in atrial fibrillation. Their use has difficulties that are associated with the need for laboratory control and with the influence of many factors on the activity of these medications. The emerged direct oral anticoagulants have some advantages over NOACs. Nevertheless, there are a number of pathological conditions, in which NOACs remain first-line drugs. These include prosthetic mechanical heart valves, a glomerular filtration rate less than 60 mL/min/1.73 m2, and left atrial thrombus.

Thromboembolic risk stratification of patients hospitalized with heart failure in sinus rhythm: a nationwide cohort study

AIMS

Patients with heart failure in sinus rhythm are at an increased risk of thromboembolic complications. So far, validated risk stratification tools are lacking for such patients, which makes the decision to initiate anti-thrombotic treatment difficult.

METHODS AND RESULTS

We included 136,545 patients admitted with heart failure in sinus rhythm from national registries from 1999 to 2012. Patients receiving oral anticoagulants were omitted from the study. First, we investigated if the CHA2DS2-VASc score could identify heart failure patients in sinus rhythm with high rates of thromboembolic complications. Second, we investigated if any single CHA2DS2-VASc risk factor carried a greater prognostic value with regard to thromboembolism. The risk of thromboembolism increased more than ninefold (hazard ratio 9.2, 95% confidence interval 6.8-12.5) in patients with all CHA2DS2-VASc risk factors compared with those with heart failure alone. The incidence rates of thromboembolism were clinically significant, averaging 6.0 (95% confidence interval 5.98-6.02) events per 100 patient years during the first year following diagnosis. Risk factors such as diabetes, age, vascular disease, and especially previous thromboembolism, conferred an independent risk of future thromboembolism.

CONCLUSION

The CHA2DS2-VASc risk stratification scheme was able to provide prognostic information on future thromboembolic events in patients with heart failure in sinus rhythm. The CHA2DS2-VASc scale could be easily implemented as an aid to clinicians in risk stratifying heart failure patients in sinus rhythm, for thromboembolism.

Anticoagulation in Heart Failure: a Review

Heart failure (HF) with reduced left ventricular function inflicts a large and growing burden of morbidity and mortality in the US and across the globe. One source of this burden is stroke. While it appears that HF itself may impose some risk of stroke, it is in the presence of other risk factors, like atrial fibrillation, that the greatest risks are observed. Therapeutic anticoagulation is the mainstay of risk reduction strategies in this population. While warfarin was the only available therapy for anticoagulation for many decades, there are now four direct oral anticoagulants available. In three of these four, outcomes in the specific subgroup of patients with heart failure have been examined. In this review, we provide some pathophysiologic basis for the risk of stroke in heart failure. In addition, the available therapeutic options for stroke risk prevention in heart failure are described in detail including how these options are incorporated into relevant professional society guidelines.

Vitamin K antagonists in heart disease: current status and perspectives (Section III). Position paper of the ESC Working Group on Thrombosis--Task Force on Anticoagulants in Heart Disease

Oral anticoagulants are a mainstay of cardiovascular therapy, and for over 60 years vitamin K antagonists (VKAs) were the only available agents for long-term use. VKAs interfere with the cyclic inter-conversion of vitamin K and its 2,3 epoxide, thus inhibiting γ-carboxylation of glutamate residues at the amino-termini of vitamin K-dependent proteins, including the coagulation factors (F) II (prothrombin), VII, IX and X, as well as of the anticoagulant proteins C, S and Z. The overall effect of such interference is a dose-dependent anticoagulant effect, which has been therapeutically exploited in heart disease since the early 1950s. In this position paper, we review the mechanisms of action, pharmacological properties and side effects of VKAs, which are used in the management of cardiovascular diseases, including coronary heart disease (where their use is limited), stroke prevention in atrial fibrillation, heart valves and/or chronic heart failure. Using an evidence-based approach, we describe the results of completed clinical trials, highlight areas of uncertainty, and recommend therapeutic options for specific disorders. Although VKAs are being increasingly replaced in most patients with non-valvular atrial fibrillation by the new oral anticoagulants, which target either thrombin or FXa, the VKAs remain the agents of choice for patients with atrial fibrillation in the setting of rheumatic valvular disease and for those with mechanical heart valves.

Anticoagulation in Patients With Left Ventricular Systolic Dysfunction and Sinus Rhythm

Left ventricular (LV) systolic dysfunction and chronic systolic heart failure (HF) predispose to intraventricular thrombus formation and embolization resulting in stroke. Current guideline recommends the use of oral anticoagulants in patients with atrial fibrillation and history of previous thromboembolism. However, anticoagulant treatment in patients with LV systolic dysfunction with sinus rhythm and without history of previous thromboembolism is still on debate. Recent epidemiologic date has reported increased stroke rate in patients with systolic HF shortly after diagnosis. This review focuses on the possible causes of increased stroke rate shortly after the diagnosis of HF and subsequently suggests a rationale for the use of oral anticoagulant in these patient groups.

Antithrombotic therapy in heart failure

Patients with congestive heart failure have a significant risk of stroke due to thromboembolism from the dilated left ventricle. Two relatively small trials suggest that oral anticoagulation with vitamin-K antagonists may reduce this risk when compared with placebo, aspirin or clopidogrel. However, more studies are eagerly awaited. So far, physicians seeing patients with heart failure should decide who needs antithrombotic prophylaxis on a case-by-case basis, especially since most heart failure patients have significant comorbidity precluding the use of oral anticoagulant.

Prevention of cardioembolic stroke

Cardiac causes of ischemic stroke lead to severe neurological deficits from large intracranial artery occlusion compared to small vessel ischemic stroke. The most common cause of cardioembolic stroke is atrial fibrillation (AF), which has an increasing incidence with age. AF stroke trials demonstrate that anti-coagulation is superior to anti-platelet therapy in terms of ischemic stroke prevention. Recently, warfarin was compared with dabigatran, an oral, direct thrombin inhibitor, and was found to be at least equally effective in reducing ischemic stroke with less intracranial bleeding risk. Future research is investigating other direct thrombin inhibitors as potential alternatives to warfarin, which has a narrow therapeutic index, requires frequent blood monitoring, has multiple drug interactions, and a higher rate of intracranial bleeding. Other causes of cardioembolic stroke include myocardial infarction, left ventricular thrombus, reduced ejection fraction, valvular abnormalities, and endocarditis. Patent foramen ovale is a common finding on echocardiograms in patients with and without stroke (up to 20% of the population), and it is a controversial source of cryptogenic stroke. The best way to prevent cardioembolic stroke remains early detection and treatment of AF, and treating the underlying stroke mechanism. Cardiac magnetic resonance imaging is an emerging technology and reveals some sources of cardiac embolism missed by echocardiography, and might provide an additional diagnostic tool in investigating cardioembolic stroke.

[Neurology and cardiology: points of contact]

Strokes resulting from cardiac diseases, and cardiac abnormalities associated with neuromuscular disorders are examples of the many points of contact between neurology and cardiology. Approximately 20-30% of strokes are related to cardiac diseases, including atrial fibrillation, congestive heart failure, bacterial endocarditis, rheumatic and nonrheumatic valvular diseases, acute myocardial infarction with left ventricular thrombus, and cardiomyopathies associated with muscular dystrophies, among others. Strokes can also occur in the setting of cardiac interventions such as cardiac catheterization and coronary artery bypass procedures. Treatment to prevent recurrent stroke in any of these settings depends on the underlying etiology. Whereas anticoagulation with vitamin K antagonists is proven to be superior to acetylsalicylic acid for stroke prevention in atrial fibrillation, the superiority of anticoagulants has not been conclusively established for stroke associated with congestive heart failure and is contraindicated in those with infective endocarditis. Ongoing trials are evaluating management strategies in patients with atrial level shunts due to patent foramen ovale. Cardiomyopathies and conduction abnormalities are part of the spectrum of many neuromuscular disorders including mitochondrial disorders and muscular dystrophies. Cardiologists and neurologists share responsibility for caring for patients with or at risk for cardiogenic strokes, and for screening and managing the heart disease associated with neuromuscular disorders.

Guidelines for the prevention of stroke in patients with stroke or transient ischemic attack: a guideline for healthcare professionals from the american heart association/american stroke association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of ischemic stroke among survivors of ischemic stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches for atherosclerotic disease, antithrombotic treatments for cardioembolism, and the use of antiplatelet agents for noncardioembolic stroke. Further recommendations are provided for the prevention of recurrent stroke in a variety of other specific circumstances, including arterial dissections; patent foramen ovale; hyperhomocysteinemia; hypercoagulable states; sickle cell disease; cerebral venous sinus thrombosis; stroke among women, particularly with regard to pregnancy and the use of postmenopausal hormones; the use of anticoagulation after cerebral hemorrhage; and special approaches to the implementation of guidelines and their use in high-risk populations.

Dilated cardiomyopathy and role of antithrombotic therapy

BACKGROUND

There is no consensus as to whether anticoagulation has a favorable risk:benefit in reducing thromboembolic events in patients with heart failure (HF) secondary to dilated cardiomyopathy who do not suffer from atrial fibrillation or primary valvular disease.

METHODS AND RESULTS

The literature reviewed on this topic included most recent and ongoing studies that assessed the use of anticoagulation for this population. Several large retrospective studies showed an increased risk of thromboembolic events among patients with depressed left ventricular function. The relative risk of stroke in individuals with HF from all causes was found to be 4.1 for men and 2.8 for women, but confounding comorbidities (such as atrial fibrillation and coronary artery disease) were commonly present. Currently, there are no randomized prospective trials to guide the use of antithrombotics for these patients, and the risk of bleeding secondary to anticoagulation has limited the use of oral anticoagulants for prevention of thrombosis. Among patients with HF, increasing age directly correlates with both major bleeding and thromboembolic events, with a 46% relative risk of bleeding for each 10-year increase in age older than 40 years.

CONCLUSIONS

To date, there is no agreement on appropriate antithrombotic treatment (if any) for primary thromboembolism prophylaxis in patients with dilated cardiomyopathy with sinus rhythm. In recent years, several promising prospective trials were terminated prematurely due to inadequate enrollment. The Warfarin Aspirin-Reduced Cardiac Ejection Fraction trial may provide evidence regarding the use of anticoagulation for patients with decreased myocardial function.

Resource use and costs of treatment with anticoagulation and antiplatelet agents: results of the WATCH trial economic evaluation

BACKGROUND

The Warfarin and Antiplatelet Therapy in Chronic Heart Failure (WATCH) trial revealed no significant differences among 1587 symptomatic heart failure patients randomized to warfarin, clopidogrel, or aspirin in time to all-cause death, nonfatal myocardial infarction, or nonfatal stroke. We compared within-trial medical resource use and costs between treatments.

METHODS AND RESULTS

We assigned country-specific costs to medical resources incurred during follow-up. Annualized rates of hospitalizations, inpatient and outpatient procedures, and emergency department visits did not differ significantly between groups. Annualized total costs averaged $5901 (95% confidence interval [CI], $4776-$7520) for the aspirin group, $5646 (95% CI, $4903-$6584) for the clopidogrel group, and $5830 (95% CI, $4838-$7400) for the warfarin group.

CONCLUSIONS

Consistent with clinical findings, our analyses did not identify significant cost differences between treatments.

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.

Stroke prevention in atrial fibrillation and other major cardiac sources of embolism

The frequency of cardioembolic stroke is expected to rise as the general population ages. Much of the increase may be attributed to atrial fibrillation, the most common cause of cardioembolic stroke and one that plays a substantial role in aging adults. Other sources of cardioembolic stroke may include ventricular thrombus from myocardial infarction, heart failure, structural heart defects such as patent foramen ovale (PFO), atrial septal aneurysm, proximal aortic atheroma, valvular heart disease, and endocarditis. Diagnostic studies, such as neuroimaging, ECG, and echocardiography, are helpful in uncovering cardioembolic sources of stroke. Medical therapy is predicated on the underlying mechanism. For example, warfarin may be indicated in certain patients who have atrial fibrillation, atrial, or ventricular thrombi, and PFO with atrial septal aneurysm and cryptogenic stroke in select young patients to prevent stroke. Newer diagnostic technologies, including multidetector CT and cardiac MRI, may be useful to diagnose cardiac causes of stroke when transesophageal echocardiography is indeterminate or cryptogenic stroke is present.

Randomized Trial of Warfarin, Aspirin, and Clopidogrel in Patients With Chronic Heart Failure

Background— Chronic heart failure remains a major cause of mortality and morbidity. The role of antithrombotic therapy in patients with chronic heart failure has long been debated. The objective of this study was to determine the optimal antithrombotic agent for heart failure patients with reduced ejection fractions who are in sinus rhythm.

Methods and Results— This prospective, randomized clinical trial of open-label warfarin (target international normalized ratio of 2.5 to 3.0) and double-blind treatment with either aspirin (162 mg once daily) or clopidogrel (75 mg once daily) had a 30-month enrollment period and a minimum of 12 months of treatment. We enrolled 1587 men and women ≥18 years of age with symptomatic heart failure for at least 3 months who were in sinus rhythm and had left ventricular ejection fraction of ≤35%. The primary outcome was the time to first occurrence of death, nonfatal myocardial infarction, or nonfatal stroke. For the primary composite end point, the hazard ratios were as follows: for warfarin versus aspirin, 0.98 (95% CI, 0.86 to 1.12; P =0.77); for clopidogrel versus aspirin, 1.08 (95% CI, 0.83 to 1.40; P =0.57); and for warfarin versus clopidogrel, 0.89 (95% CI, 0.68 to 1.16; P =0.39). Warfarin was associated with fewer nonfatal strokes than aspirin or clopidogrel. Hospitalization for worsening heart failure occurred in 116 (22.2%), 97 (18.5%), and 89 (16.5%) patients treated with aspirin, clopidogrel, and warfarin, respectively ( P =0.02 for warfarin versus aspirin).

Conclusion— The primary outcome measure and the mortality data do not support the primary hypotheses that warfarin is superior to aspirin and that clopidogrel is superior to aspirin.

Heart failure and chronic obstructive pulmonary disease: diagnostic pitfalls and epidemiology

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) are global epidemics incurring significant morbidity and mortality. The combination presents many diagnostic challenges. Clinical symptoms and signs frequently overlap. Evaluation of cardiac and pulmonary function is often problematic and occasionally misleading. Echocardiography and pulmonary function tests should be performed in every patient. Careful interpretation is required to avoid misdiagnosis and inappropriate treatment. Airflow obstruction, in particular, must be demonstrated when clinically euvolaemic. Very high and very low concentrations of natriuretic peptides have high positive and negative predictive values for diagnosing HF in those with both conditions. Intermediate values are less informative. Both conditions are systemic disorders with overlapping pathophysiological processes. In patients with HF, COPD is consistently an independent predictor of death and hospitalization. However, the impact on ischaemic and arrhythmic events is unknown. Greater collaboration is required between cardiologists and pulmonologists to better identify and manage concurrent HF and COPD. The resulting symptomatic and prognostic benefits outweigh those attainable by treating either condition alone.

Adverse drug reactions in patients with cardiovascular disease

Adverse drug reactions (ADRs) occur frequently in modern medical practice, increasing morbidity and mortality and inflating the cost of care. Patients with cardiovascular disease are particularly vulnerable to ADRs due to their advanced age, polypharmacy, and the influence of heart disease on drug metabolism. The ADR potential for a particular cardiovascular drug varies with the individual, the disease being treated, and the extent of exposure to other drugs. Knowledge of this complex interplay between patient, drug, and disease is a critical component of safe and effective cardiovascular disease management. The majority of significant ADRs involving cardiovascular drugs are predictable and therefore preventable. Better patient education, avoidance of polypharmacy, and clear communication between physicians, pharmacists, and patients, particularly during the transition between the inpatient to outpatient settings, can substantially reduce ADR risk.

Predictors of short term mortality in heart failure - insights from the Euro Heart Failure survey

OBJECTIVE

To identify factors associated with short term mortality in hospitalised patients with heart failure.

BACKGROUND

Hospitalisation is frequent in patients with heart failure and is associated with a high mortality.

METHODS

The Euro Heart Failure survey collected data from patients with suspected heart failure. We searched this data for predictors of short term mortality.

RESULTS

Of 10,701 patients, 1404 (13%) died within 12 weeks of admission. On univariate analysis, increasing age, hyponatraemia, renal impairment, hyperkalaemia, anaemia, severe mitral regurgitation, severe LV systolic dysfunction(LVSD), increasing QRS and female sex carried adverse prognosis. ACEI, beta-blockers, nitrates, anti-thrombotic and lipid lowering drugs were associated with a better prognosis. On multivariable analysis the following provided independent prognostic information: increasing age (OR per SD=1.5, 95% CI 1.4-1.6), severe LVSD (1.8, 1.5-2.1), serum creatinine (1.2, 1.2-1.3), sodium (0.9, 0.8-0.9), Hb (0.9, 0.8-0.9) and treatment with ACEI (0.5, 0.5-0.6), beta-blockers (0.7, 0.6-0.8), statins (0.6, 0.5-0.7), calcium channel blockers (0.7, 0.6-0.8), warfarin (0.5, 0.4-0.6), heparin (1.7, 1.4-1.9), anti-platelet drugs (0.6, 0.5-0.6) and need for inotropes (5.5, 4.6-6.6). A simple risk score (range 0-11) identified cohorts with a 12 week mortality ranging from 2% to 44%.

CONCLUSIONS

Simple and readily available clinical variables and a risk score based on medical history and routine tests that all patients admitted with heart failure have, can identify patients with good, intermediate and high short term mortality.

The Role for Anticoagulation with Warfarin in Patients with Systolic Heart Failure and Normal Sinus Rhythm

Objective:

To evaluate the role of anticoagulation with warfarin in patients with systolic heart failure (HF) and normal sinus rhythm (NSR).

Data Sources:

Literature was accessed through MEDLINE (1950–December 2007) and the American College of Cardiology Annual Scientific Session (2004) using the terms heart failure, warfarin, and anticoagulation.

Study Selection and Data Extraction:

All articles in English identified via the searches were evaluated. We excluded trials that evaluated the use of anticoagulation in patients with atrial fibrillation (AF) or valvular disorders.

Data Synthesis:

Patients with systolic HF are considered to be in a prothrombotic state. Studies have demonstrated a decreased incidence of thromboembolic events with anticoagulation therapy in patients with HF and concomitant AF, valvular dysfunction, or hypercoagulable disorders, but there are limited data supporting the role of anticoagulation in patients with HF and NSR. There are 3 prospective clinical trials and 1 ongoing trial designed to assess the efficacy of warfarin in patients with HF and NSR. These trials compare warfarin with antiplatelet therapy or no antithrombotic therapy. Warfarin did not show a benefit in the primary clinical composite outcome of death, myocardial infarction, or stroke, but was associated with more adverse events. However, these trials were underpowered to detect a difference between treatment arms.

Conclusions:

There is no objective evidence to support the need for anticoagulation with warfarin in patients with systolic HF and NSR. Additional large randomized, controlled trials need to be completed to determine the efficacy and safety of anticoagulation with warfarin in such patients.

The primary and secondary prevention of coronary artery disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

The following chapter devoted to antithrombotic therapy for chronic coronary artery disease (CAD) is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do or do not outweigh risks, burden, and costs. Grade 2 suggests that individual patient values may lead to different choices (for a full understanding of the grading see the "Grades of Recommendation" chapter by Guyatt et al in this supplement, CHEST 2008; 133[suppl]:123S-131S). Among the key recommendations in this chapter are the following: for patients with non-ST-segment elevation (NSTE)-acute coronary syndrome (ACS) we recommend daily oral aspirin (75-100 mg) [Grade 1A]. For patients with an aspirin allergy, we recommend clopidogrel, 75 mg/d (Grade 1A). For patients who have received clopidogrel and are scheduled for coronary bypass surgery, we suggest discontinuing clopidogrel for 5 days prior to the scheduled surgery (Grade 2A). For patients after myocardial infarction, after ACS, and those with stable CAD and patients after percutaneous coronary intervention (PCI), we recommend daily aspirin (75-100 mg) as indefinite therapy (Grade 1A). We recommend clopidogrel in combination with aspirin for patients experiencing ST-segment elevation (STE) and NSTE-ACS (Grade 1A). For patients with contraindications to aspirin, we recommend clopidogrel as monotherapy (Grade 1A). For long-term treatment after PCI in patients who receive antithrombotic agents such as clopidogrel or warfarin, we recommend aspirin (75 to 100 mg/d) [Grade 1B]. For patients who undergo bare metal stent placement, we recommend the combination of aspirin and clopidogrel for at least 4 weeks (Grade 1A). We recommend that patients receiving drug-eluting stents (DES) receive aspirin (325 mg/d for 3 months followed by 75-100 mg/d) and clopidogrel 75 mg/d for a minimum of 12 months (Grade 2B). For primary prevention in patients with moderate risk for a coronary event, we recommend aspirin, 75-100 mg/d, over either no antithrombotic therapy or vitamin K antagonist (Grade 1A).

The role of aspirin in cardiovascular prevention: implications of aspirin resistance

Aspirin is well recognized as an effective antiplatelet drug for secondary prevention in subjects at high risk of cardiovascular events. However, most patients receiving long-term aspirin therapy still remain at substantial risk of thrombotic events due to insufficient inhibition of platelets, specifically via the thromboxane A2 pathway. Although the exact prevalence is unknown, estimates suggest that between 5.5% and 60% of patients using this drug may exhibit a degree of "aspirin resistance," depending upon the definition used and parameters measured. To date, only a limited number of clinical studies have convincingly investigated the importance of aspirin resistance. Of these, few are of a sufficient scale, well designed, and prospective, with aspirin used at standard doses. Also, most studies do not sufficiently address the issue of noncompliance to aspirin as a frequent, yet easily preventable cause of resistance to this antiplatelet drug. This review article provides a comprehensive overview of aspirin resistance, discussing its definition, prevalence, diagnosis, and therapeutic approaches. Moreover, the clinical implications of aspirin resistance are explored in various cardiovascular disease states, including diabetes mellitus, hypertension, heart failure, and other similar disorders where platelet reactivity is enhanced.

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.

Residual platelet reactivity is associated with clinical and laboratory characteristics in patients with ischemic heart disease undergoing PCI on dual antiplatelet therapy

A residual platelet reactivity (RPR) on antiplatelet therapy in patients with ischemic heart disease (IHD) has been reported to be associated with adverse clinical events by some Authors. However, scarce data are present on the clinical parameters associated with this phenomenon. No study, at our knowledge, was designed with the specific aim to examine the relationship between clinical characteristics and RPR. We sought to evaluate the clinical and laboratory characteristics associated with RPR in patients with IHD undergoing coronary revascularization on dual (aspirin plus clopidogrel) antiplatelet therapy. We included in the study 868 patients undergoing a coronary angiography: 386 with acute coronary syndromes undergoing a primary coronary revascularization and 482 IHD patients scheduled to undergo an elective coronary angiography. We measured platelet function by both platelet aggregation with two agonists [0.5 mg/mL arachidonic acid (AA); 2 and 10 microM adenosine 5'-diphosphate (ADP)] and a point-of-care assay (PFA-100) on venous blood samples collected within 24 h from the end of the procedure. In patients with acute coronary syndromes and elective PCI diabetes is independently associated with RPR [group A: OR=2.9 (1.5-5.7) by 10 microM ADP, OR=5.3 (1.1-27.8) by PFA-100; group B: OR=4.0 (1.6-10.0) by 10 microM ADP]; reduced left ventricular systolic function [OR=3.7 (2.2-6.5) by AA-PA, OR=2.7 (1.6-4.6) by PFA-100], chronic use of aspirin [OR=0.2 (0.1-0.4) by AA-PA, OR=0.3 (0.2-0.5) by PFA-100] and loading dose of clopidogrel [OR=0.2 (0.06-0.5) by 10 microM ADP] were independent variables significantly associated with RPR in patients undergoing elective PCI. In addition, inflammatory status was found to be significantly associated with RPR in both groups of patients. These results provide indications for the selection of patients for whom the evaluation of platelet reactivity could be useful.

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.

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.

Guidelines for the prevention, detection and management of people with chronic heart failure in Australia 2006

Chronic heart failure (CHF) is found in 1.5%-2.0% of Australians. Considered rare in people aged less than 45 years, its prevalence increases to over 10% in people aged >/= 65 years. CHF is one of the most common reasons for hospital admission and general practitioner consultation in the elderly (>/= 70 years). Common causes of CHF are ischaemic heart disease (present in > 50% of new cases), hypertension (about two-thirds of cases) and idiopathic dilated cardiomyopathy (around 5%-10% of cases). Diagnosis is based on clinical features, chest x-ray and objective measurement of ventricular function (eg, echocardiography). Plasma levels of B-type natriuretic peptide (BNP) may have a role in diagnosis, primarily as a test for exclusion. Diagnosis may be strengthened by a beneficial clinical response to treatment(s) directed towards amelioration of symptoms. Management involves prevention, early detection, amelioration of disease progression, relief of symptoms, minimisation of exacerbations, and prolongation of survival.

Current developments in anti-platelet therapy

Platelets play a life-saving role in hemostasis and blood clotting at sites of vascular injury and consequently are similarly involved in the pathological counterpart, namely thrombosis. Thus, anti-platelet therapy has become a mainstay in treatment and/or prophylaxis of conditions like myocardial infarction, stroke and other cardiovascular diseases. Acetyl-salicylic acid (ASA, aspirin) is still the most widely used agent and considered as the prototype antiplatelet drug. Since platelet activation occurs via several pathways that are not influenced by ASA, several other compounds have been developed to add to its beneficial effect. Currently four main classes of antiplatelet agents are available for clinical use: acetyl-salicylic acid (ASA), phosphodiesterase (PDE) inhibitors, thienopyridines and the intravenous GPIIb/IIIa antagonists. This article gives a concise review of these four classes of anti-platelet agents, using ASA as the reference standard.

Warfarin versus aspirin in patients with reduced cardiac ejection fraction (WARCEF): rationale, objectives, and design

BACKGROUND

Warfarin is widely prescribed for patients with heart failure without level 1 evidence, and an adequately powered randomized study is needed.

METHODS AND RESULTS

The Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction study is a National Institutes of Health-funded, randomized, double-blind clinical trial with a target enrollment of 2860 patients. It is designed to test with 90% power the 2-sided primary null hypothesis of no difference between warfarin (International Normalized Ratio 2.5-3) and aspirin (325 mg) in 3- to 5-year event-free survival for the composite endpoint of death, or stroke (ischemic or hemorrhagic) among patients with cardiac ejection fraction < or =35% who do not have atrial fibrillation or mechanical prosthetic heart valves. Secondary analyses will compare warfarin and aspirin for reduction of all-cause mortality, ischemic stroke, and myocardial infarction (MI), balanced against the risk of intracerebral hemorrhage, among women and African Americans; and compare warfarin and aspirin for prevention of stroke alone. Randomization is stratified by site, New York Heart Association (NYHA) heart class (I vs II-IV), and stroke or transient ischemic attack (TIA) within 1 year before randomization versus no stroke or TIA in that period. NYHA class I patients will not exceed 20%, and the study has a target of 20% (or more) patients with stroke or TIA within 12 months. Randomized patients receive active warfarin plus placebo or active aspirin plus placebo, double-blind.

CONCLUSION

The results should help guide the selection of optimum antithrombotic therapy for patients with left ventricular dysfunction.

Clopidogrel Is Associated With a Lesser Increase in NT-proBNP When Compared to Aspirin in Patients With Ischemic Heart Failure

BACKGROUND

Aspirin has been associated with adverse heart failure outcomes, probably because of a blunting interaction with angiotensin-converting enzyme (ACE) inhibitors. Therefore, we hypothesized that clopidogrel when compared with aspirin would be associated with a slower progression of heart failure as determined by levels of amino-terminal pro-brain natriuretic peptide (NT-proBNP).

METHODS AND RESULTS

In an open-label, randomized, 2-treatment, 2-period crossover study, 18 patients with ischemic heart failure (14 post-myocardial infarction, left ventricular ejection fraction 0.32 +/- 0.08), median age 73, New York Heart Association class II (11 patients) or III (7 patients), all taking ACE inhibitors were included. Patients were randomized to 8 weeks of aspirin 100 mg/day followed by 8 weeks of clopidogrel 75 mg/day, or the reversed sequence. Blood levels of NT-proBNP were measured using sandwich immunoassay. Patients on aspirin experienced an 8-times greater increase in log-transformed values of NT-proBNP compared with patients on clopidogrel (average change 4.757% versus 0.597%; P = .0395 for intervention, P = .4453 for period, P = .4046 for sequence). We observed no change in functional class, 6-minute walking test, creatinine levels, or electrolytes.

CONCLUSION

Aspirin is associated with a greater increase in natriuretic peptides (log-transformed NT-proBNP levels), implying that aspirin therapy is associated with a more progressive course of heart failure.

[Cardiomyopathies. I: classification of cardiomyopathies--dilated cardiomyopathy]

Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).