Evaluation of platelets in heart failure: is platelet activity related to etiology, functional class, or clinical outcomes?

Association between blood inflammatory indices and heart failure: a cross-sectional study of NHANES 2009-2018

BACKGROUND

Inflammation plays a pivotal role in the pathogenesis of heart failure (HF). This study was aimed to the potential association between complete blood cell count (CBC)-derived inflammatory biomarkers and HF.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2009-2018 were utilised. We evaluated the associations between HF and five systemic inflammation markers derived from CBC: systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR). Demographic characteristics, physical examinations, and laboratory data were systematically collected for comparative analysis between HF and non-HF individuals. Fitted smoothing curves and threshold effect analysis delineated the relationship. In addition, Spearman correlation and subgroup analyses were further conducted.

RESULTS

A total of 26,021 participants were categorised into HF (n = 858) and non-HF (n = 25,163) groups. After adjusting for confounding variables, SIRI, NLR, and MLR had significant positive correlations with the risk of HF. Participants in the highest quarter groups of SIRI, NLR, and MLR showed a increased risk of developing HF compared to those in the lowest quarter group. Furthermore, subgroup and sensitivity analyses indicated that SIRI, NLR, and MLR had a stronger correlation to HF (all p < 0.05). Smoothing curve fitting highlighted a nonlinear relationship between CBC-derived inflammatory biomarkers and HF.

CONCLUSIONS

Our results illustrated a significant association between elevated levels of SIRI, NLR, and MLR and an increased risk of HF. SIRI, NLR, and MLR could potentially serve as systemic inflammation hazard markers for HF.

The Role of Circular RNA for Early Diagnosis and Improved Management of Patients with Cardiovascular Diseases

Cardiovascular diseases (CVDs) are responsible for approximately 17.9 million deaths every year. There is growing evidence that circular RNAs (circRNAs) may play a significant role in the early diagnosis and treatment of cardiovascular diseases. As regulatory molecules, circular RNAs regulate gene expression, interact with proteins and miRNAs, and are translated into proteins that play a key role in a wide variety of biological processes, including the division and proliferation of cells, as well as the growth and development of individuals. An overview of the properties, expression profiles, classification, and functions of circRNAs is presented here, along with an explanation of their implications in cardiovascular diseases including heart failure, hypertension, ischemia/reperfusion injury, myocardial infarction, cardiomyopathies, atherosclerosis, and arrhythmia.

The platelet to lymphocyte ratio in heart failure: a comprehensive review

Introduction. At the crossroads of heart failure (HF) and systemic inflammation, platelets and lymphocytes are both influenced as well as actively participating in the bidirectional relationship. The platelet to lymphocyte ratio (PLR) could therefore be a marker of severity. This review aimed to assess the role of PLR in HF. Methods. We searched the PubMed (MEDLINE) database using the keywords "platelet", "thrombocyte", "lymphocyte", "heart failure", "cardiomyopathy", "implantable cardioverter defibrillator", "cardiac resynchronization therapy" and "heart transplant". Results. We identified 320 records. 21 studies were included in this review, with a total of 17,060 patients. PLR was associated with age, HF severity, and comorbidity burden. Most studies reported the predictive power for all-cause mortality. Higher PLR was associated with in-hospital and short-term mortality in univariable analysis, however, it was not consistently an independent predictor for this outcome. PLR > 272.9 associated an adjusted HR of 3.22 (95%CI 1.56 - 5.68, p<0.001) for 30-day fatality. During long-term follow-up from 6 months to 5 years, PLR was an independent predictor of mortality in most studies, with cut-off values ranging from > 150 to > 194.97 and adjusted HR from 1.47 (95%CI 1.06 - 2.03, p=0.019) to 5.65 (95%CI 2.47-12.96, p<0.001). PLR > 173.09 had an adjusted OR 2.89 (95%CI 1.17-7.09, p=0.021) for predicting response to cardiac resynchronization therapy. PLR was not associated with outcomes after cardiac transplant or implantable cardioverter-defibrillator. Conclusion: Increased PLR could be an auxiliary biomarker of severity and survival prognosis in HF patients.

Impairment of Anti-Aggregatory Responses to Nitric Oxide and Prostacyclin: Mechanisms and Clinical Implications in Cardiovascular Disease

The propensity towards platelet-rich thrombus formation increases substantially during normal ageing, and this trend is mediated by decreases in platelet responsiveness to the anti-aggregatory nitric oxide (NO) and prostacyclin (PGI₂) pathways. The impairment of soluble guanylate cyclase and adenylate cyclase-based signalling that is associated with oxidative stress represents the major mechanism of this loss of anti-aggregatory reactivity. Platelet desensitization to these autacoids represents an adverse prognostic marker in patients with ischemic heart disease and may contribute to increased thrombo-embolic risk in patients with heart failure. Patients with platelet resistance to PGI₂ also are unresponsive to ADP receptor antagonist therapy. Apart from ischemia, diabetes and aortic valve disease are also associated with impaired anti-aggregatory homeostasis. This review examines the association of impaired platelet cyclic nucleotide (i.e., cGMP and cAMP) signalling with the emerging evidence of thromboembolic risk in cardiovascular diseases, and discusses the potential therapeutic strategies targeting this abnormality.

Platelet Activity and Its Correlation with Inflammation and Cell Count Readings in Chronic Heart Failure Patients with Reduced Ejection Fraction

Background and objectives: There has been an increasing interest in the role of inflammation in thrombosis complications in chronic heart failure (HF) patients. The incidence of thrombosis in HF has been shown to be the highest in patients classified as NYHA IV (New York Heart association). It is stated that inflammation is regulated by platelet-induced activation of blood leukocytes. We aimed to compare the platelet and cell count readings in chronic HF with reduced ejection fraction (HFrEF) patients according to NYHA functional class and to evaluate the correlation between those readings. Materials and methods: A total of 185 patients were examined. The results of heart echoscopy (TEE) testing; fibrinogen, N-terminal pro b-type natriuretic peptide (NT-proBNP), C reactive protein (CRP), and cortisol concentrations; complete blood counts; and a 6 min walking test were assessed and platelet aggregation was determined. Results: Mean platelet volume (MPV) increased with deterioration of a patient’s state (p < 0.005). Lymphocyte count and percentage were the lowest in the NYHA IV group (p < 0.005). Neutrophil and monocyte percentage and count were the highest (p < 0.045) in the NYHA IV group. Adenosine diphosphate (ADP)- and ADR-induced platelet aggregation was higher in the NYHA III group compared to NYHA II and I groups (p < 0.023). NYHA functional class correlated with mean platelet volume (MPV) (r = 0.311, p = 0.0001), lymphocyte count (r = −0.186, p = 0.026), monocyte count (p = 0.172, p = 0.041), and percentage (r = 0.212, p = 0.011). CRP concentration correlated with NT-proBNP (r = 0.203, p = 0.005). MPV correlated with fibrinogen concentration (r = 0.244, p = 0.004). Conclusions: (1) MPV could be considered as an additional reading reflecting a patient’s condition, however the use of MPV to identify patients at risk of hypercoagulable state should be evaluated in more extensive studies; (2) increased neutrophil and monocyte counts could indicate a higher inflammatory state in chronic HFrEF.

Circular RNA Expression Profiles in Plasma from Patients with Heart Failure Related to Platelet Activity

Heart failure (HF) is a deadly disease that is difficult to accurately diagnose. Circular RNAs (circRNAs) are a novel class of noncoding RNAs that might play important roles in many cardiovascular diseases. However, their role in HF remains unclear. CircRNA microarrays were performed on plasma samples obtained from three patients with HF and three healthy controls. The profiling results were validated by quantitative reverse transcription polymerase chain reaction. The diagnostic value of circRNAs for HF was evaluated by receiver operating characteristic (ROC) curves. The expression profiles indicated that 477 circRNAs were upregulated and 219 were downregulated in the plasma of patients with HF compared with healthy controls. Among the dysregulated circRNAs, hsa_circ_0112085 (p = 0.0032), hsa_circ_0062960 (p = 0.0006), hsa_circ_0053919 (p = 0.0074) and hsa_circ_0014010 (p = 0.025) showed significantly higher expression in patients with HF compared with healthy controls. The area under the ROC curve for hsa_circ_0062960 for HF diagnosis was 0.838 (p < 0.0001). Correlation analysis showed that the expression of hsa_circ_0062960 was highly correlated with B-type natriuretic peptide (BNP) serum levels. Some differential circRNAs were found to be related to platelet activity by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The landscape of circRNA expression profiles may play a role in HF pathogenesis and improve our understanding of platelet function in HF. Moreover, hsa_circ_0062960 has potential as a novel diagnostic biomarker for HF.

Platelet indices and outcome after cardiac arrest

BACKGROUND

Platelet variables, including platelet distribution width (PDW) and mean platelet volume (MPV), have been associated with outcome in critically ill patients. We evaluated these variables in patients after cardiac arrest (CA).

METHODS

All adult CA patients admitted to the intensive care unit (ICU) over an 8-year period (2006-2014) and treated with targeted temperature management were included. We retrieved all data concerning CA characteristics as well as platelet count, PDW and MPV on the first 2 days of admission. Unfavorable 3-month neurological outcome was defined as a cerebral performance category score of 3-5.

RESULTS

We included 384 patients (age 62 [52-75] years; 270/384 male): 231 patients (60%) died within 30-days and 246 patients (64%) had an unfavorable 3-month neurological outcome. On admission, platelet count, PDW and MPV were 87 [126-261] *10³cells/mm³, 17 [16.3-17.3]% and 8.3 [7.6-9.2] μm³, respectively. Platelet count decreased significantly over the first 2 days, whereas PDW and MPV did not change significantly. There were no significant differences between the values on admission or time-courses of platelet count, PDW or MPV between survivors and non-survivors or between patients with unfavorable and favorable neurological outcome.

CONCLUSIONS

In our cohort of post-CA patients, PDW and MPV were not associated with outcome.

New Developments in Platelet Cyclic Nucleotide Signalling: Therapeutic Implications

Altered platelet physiology may contribute to the emergence of thrombosis in patients with many forms of cardiovascular disease. Excess platelet activation may reflect increased stimulation of pro-aggregatory pathways. There is, however, increasing evidence that excessive platelet response, due to impaired efficacy of anti-aggregatory autacoids such as nitric oxide (NO) and prostacyclin (PGI₂), may be just as important. For example, diminished platelet response to NO has been documented in acute and chronic myocardial ischaemia, heart failure, aortic valve disease and in the presence of hyperglycaemia. This "NO resistance" has been shown to reflect both the scavenging of NO by reactive oxygen species and dysfunction of its intracellular "receptor", soluble guanylate cyclase. Importantly, these abnormalities of NO signalling are potentially reversible through judicious application of pharmacotherapy. The analogous condition of impaired PGI₂/adenylate cyclase (AC) signalling has received comparatively less attention to date. We have shown that platelet response to prostaglandin E₁ (PGE₁) is frequently impaired in patients with symptomatic myocardial ischaemia. Because the effects of ADP receptor antagonists such as clopidogrel and ticagrelor at the level of the P2Y₁₂ receptor are coupled with changes in activity of AC, impaired response to PGE₁ might imply both increased thrombotic risk and a reduced efficacy of anti-aggregatory drugs. Accordingly, patient response to treatment with clopidogrel is determined not only by variability of clopidogrel bio-activation, but also extensively by the integrity of platelet AC signalling. We here review these recent developments and their emerging therapeutic implications for thrombotic disorders.

Combining patient proteomics and in vitro cardiomyocyte phenotype testing to identify potential mediators of heart failure with preserved ejection fraction

BACKGROUND

Heart failure with ejection fraction (HFpEF) is a syndrome resulting from several co-morbidities in which specific mediators are unknown. The platelet proteome responds to disease processes. We hypothesize that the platelet proteome will change composition in patients with HFpEF and may uncover mediators of the syndrome.

METHODS AND RESULTS

Proteomic changes were assessed in platelets from hospitalized subjects with symptoms of HFpEF (n = 9), the same subjects several weeks later without symptoms (n = 7) and control subjects (n = 8). Mass spectrometry identified 6102 proteins with five scans with peptide probabilities of ≥0.85. Of the 6102 proteins, 165 were present only in symptomatic subjects, 78 were only found in outpatient subjects and 157 proteins were unique to the control group. The S100A8 protein was identified consistently in HFpEF samples when compared with controls. We validated the fining that plasma S100A8 levels are increased in subjects with HFpEF (654 ± 391) compared to controls (352 ± 204) in an external cohort (p = 0.002). Recombinant S100A8 had direct effects on the electrophysiological and calcium handling profile in human induced pluripotent stem cell-derived cardiomyocytes.

CONCLUSIONS

Platelets may harbor proteins associated with HFpEF. S100A8 is present in the platelets of subjects with HFpEF and increased in the plasma of the same subjects. We further established a bedside-to-bench translational system that can be utilized as a secondary screen to ascertain whether the biomarkers may be an associated finding or causal to the disease process. S100A8 has been linked with other cardiovascular disease such as atherosclerosis and risk for myocardial infarction, stroke, or death. This is the first report on association of S100A8 with HFpEF.

A Central Role for Monocyte-Platelet Interactions in Heart Failure

Heart failure (HF) is an increasingly prevalent and costly multifactorial syndrome with high morbidity and mortality rates. The exact pathophysiological mechanisms leading to the development of HF are not completely understood. Several emerging paradigms implicate cardiometabolic risk factors, inflammation, endothelial dysfunction, myocardial fibrosis, and myocyte dysfunction as key factors in the gradual progression from a healthy state to HF. Inflammation is now a recognized factor in disease progression in HF and a therapeutic target. Furthermore, the monocyte-platelet interaction has been highlighted as an important pathophysiological link between inflammation, thrombosis, endothelial activation, and myocardial malfunction. The contribution of monocytes and platelets to acute cardiovascular injury and acute HF is well established. However, their role and interaction in the pathogenesis of chronic HF are not well understood. In particular, the cross talk between monocytes and platelets in the peripheral circulation and in the vicinity of the vascular wall in the form of monocyte-platelet complexes (MPCs) may be a crucial element, which influences the pathophysiology and progression of chronic heart disease and HF. In this review, we discuss the role of monocytes and platelets as key mediators of cardiovascular inflammation in HF, the mechanisms of cell activation, and the importance of monocyte-platelet interaction and complexes in HF pathogenesis. Finally, we summarize recent information on pharmacological inhibition of inflammation and studies of antithrombotic strategies in the setting of HF that can inform opportunities for future work. We discuss recent data on monocyte-platelet interactions and the potential benefits of therapy directed at MPCs, particularly in the setting of HF with preserved ejection fraction.

Correlation between mean platelet volume and B-type natriuretic peptide concentration in emergency patients with heart failure

BACKGROUND

In heart failure patients, mean platelet volume (MPV) may reflect increased platelet activation or increased numbers of large, hyper-aggregable platelets. B-type natriuretic peptide (BNP) concentration in blood is a sensitive and specific marker of heart failure, correlating with the severity and prognosis of illness, in patients presenting with acute dyspnea to the emergency department. This study evaluated the correlation between BNP concentration and MPV.

MATERIAL AND METHODS

Data were collected from 319 patients admitted to the emergency department of a cardiology hospital from January-July 2014. EDTA blood samples drawn at admission were analyzed using automated hematology system, and BNP concentration was measured using a fluorescence immunoassay.

RESULTS

The study included 190 patients with and 129 without acute heart failure (AHF). These groups had BNP concentration of 200-5000 ng/L and 5-98 ng/L, respectively. MPV levels were significantly higher in the AHF group (P<0.001). BNP concentrations were positively correlated with MPV (r=0.41, P<0.001) and neutrophil/lymphocyte ratio (r=0.38, P<0.001).

CONCLUSION

Increased MPV values correlate with BNP concentration, an indicator of HF severity and clinical status, in patients with AHF admitted to the emergency department.

Platelet activation in myocardial ischemic syndromes

Platelets play a central role in the pathogenesis of atherosclerosis and thrombosis. Platelet adhesion and aggregate formation are critical events that occur in unstable coronary syndromes. Platelet activation precedes the formation of homotypic and heterotypic aggregates. In the last 10 years, researchers have described the presence of activated platelets in the systemic circulation in various cardiovascular disease states, particularly acute coronary syndromes. This review describes the evidence for platelet activation in acute myocardial ischemic syndromes, describes the pathophysiology responsible for its occurrence, and discusses how platelet activation and reactivity may affect the use of concomitant drug therapies and patient prognosis.

United States stock market performance and acute myocardial infarction rates in 2008-2009 (from the Duke Databank for Cardiovascular Disease)

We sought to examine the relation between the United States economic decrease in 2008 and cardiovascular events as measured by local acute myocardial infarction (AMI) rates. Mental stress and traumatic events have been shown to be associated with increased risk of MI in patients with ischemic heart disease. This was an observational study of data from the Duke Databank for Cardiovascular Disease and includes patients undergoing angiography for evaluation of ischemic heart disease from January 2006 to July 2009. Patients with AMI occurring within 3 days before catheterization were used to calculate AMI rates. Stock market values were examined to determine the period of severe economic decrease, and time trends in AMI rates were examined over the same period. Time series models were used to assess the relation between United States stock market National Association of Securities Dealers Automated Quotation (NASDAQ) and rates of AMI. Of 11,590 patients included in the study cohort, 2,465 patients had an AMI during this period. Time series analysis showed a significant increase in AMI rates during a period of stock market decrease from October 2008 to April 2009 (p = 0.003), which remained statistically significant when adjusted for seasons (p = 0.02). In conclusion, unadjusted and adjusted analyses of patients in the Duke Databank for Cardiovascular Disease indicated a significant correlation between a period of stock market decrease and increased AMI rates in our local cohort.

Safety and efficacy of sertraline for depression in patients with heart failure: results of the SADHART-CHF (Sertraline Against Depression and Heart Disease in Chronic Heart Failure) trial

OBJECTIVES

The objective was to test the hypothesis that heart failure (HF) patients treated with sertraline will have lower depression scores and fewer cardiovascular events compared with placebo.

BACKGROUND

Depression is common among HF patients. It is associated with increased hospitalization and mortality.

METHODS

The SADHART-CHF (Sertraline Against Depression and Heart Disease in Chronic Heart Failure) trial was a randomized, double-blind, placebo-controlled trial of sertraline 50 to 200 mg/day versus matching placebo for 12 weeks. All participants also received nurse-facilitated support. Eligible patients were age 45 years or older with HF (left ventricular ejection fraction < or =45%, New York Heart Association functional class II to IV) and clinical depression (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition criteria for current major depressive disorder). Those with significant cognitive impairment, psychosis, recent alcohol or drug dependence, bipolar or severe personality disorder, active suicidal ideation, and current antipsychotic or antidepressant medications were excluded. Primary end points were change in depression severity (Hamilton Depression Rating Scale total score) and composite cardiovascular status at 12 weeks.

RESULTS

A total of 469 patients were randomized (n = 234 sertraline, n = 235 placebo). The mean +/- SE change from baseline to 12 weeks in the Hamilton Depression Rating Scale total score was -7.1 +/- 0.5 (sertraline) and -6.8 +/- 0.5 (placebo) (p < 0.001 from baseline, p = 0.89 between groups, mean change between groups -0.4; 95% confidence interval: -1.7 to 0.92). The proportions whose composite cardiovascular score worsened, improved, or was unchanged were 29.9%, 40.6%, and 29.5%, respectively, in the sertraline group and 31.1%, 43.8%, and 25.1%, respectively, in the placebo group (p = 0.78).

CONCLUSIONS

Sertraline was safe in patients with significant HF. However, treatment with sertraline compared with placebo did not provide greater reduction in depression or improved cardiovascular status among patients with HF and depression. (Antidepressant Medication Treatment for Depression in Individuals With Chronic Heart Failure [SADHART-CHF]; NCT00078286).

Acute heart failure: multiple clinical profiles and mechanisms require tailored therapy

Acute heart failure (HF) is the most common diagnosis at discharge in patients aged >65years. It carries a dismal prognosis with a high in-hospital mortality and very high post-discharge mortality and re-hospitalization rates. It is a complex clinical syndrome that cannot be described as a single entity as it varies widely with respect to underlying pathophysiologic mechanisms, clinical presentations and, likely, treatments. It is the aim of this paper to describe some of the main clinical presentations of acute HF. Amongst them, we will consider de novo HF versus acutely decompensated chronic HF, HF caused, and/or worsened, by myocardial ischemia, acute HF with low, normal, or high systolic blood pressure, acute HF caused by lung congestion or fluid retention or fluid redistribution to the lungs, and acute HF with comorbidities (diabetes, anemia, renal insufficiency, etc.). Different pathophysiologic mechanisms and clinical presentations may coexist in the same patient. Identification and, whenever possible, treatment of underlying pathophysiologic mechanisms may become important for acute HF management.

Soluble, platelet-bound, and total P-selectin as indices of platelet activation in congestive heart failure

BACKGROUND

Many complications associated with congestive heart failure (CHF) have a thrombosis-related aetiology. Platelets play an important role in thrombogenesis, but it is not clear whether circulating platelets actively participate in thrombosis-related complications associated with CHF.

OBJECTIVE

To determine whether soluble P-selectin, platelet surface P-selectin, and total platelet P-selectin as indices of platelet activation in CHF patients-compared to 'disease controls' and 'healthy controls'-and to assess their prognostic value in CHF.

METHODS

We measured soluble P-selectin (sP-sel, by enzyme-linked immunosorbent assay, ELISA), total platelet P-selectin (pP-sel, by a novel 'platelet lysate' assay), platelet surface P-selectin (CD62P%G) and platelet surface CD63 (CD63%G) expression by flow cytometry-in 108 patients with stable congestive heart failure (all with left ventricular ejection fraction (LVEF) <50%). Levels were compared with 50 healthy controls and 70 'disease controls' (patients with coronary artery disease with normal left ventricular systolic function).

RESULTS

CHF patients and disease controls had higher sP-sel, CD62P%G and CD63%G than healthy controls. There were no significant correlations between sP-sel, pP-sel, CD62P%G and CD63%G with ejection fraction (all P>0.05). There were no differences in these markers when ischaemic and non-ischaemic aetiologies of CHF were compared. After a median follow-up of 490 days (range 340-535), there were 7 deaths, 15 hospitalizations for worsening heart failure, 1 for cardiac resynchronization therapy, 4 for revascularizations, 4 for myocardial infarctions, and 1 stroke. None of the platelet markers were predictive of the composite end-point at follow-up.

CONCLUSIONS

Patients with stable CHF exhibit evidence of abnormal platelet activation, despite usage of antiplatelet agents. These abnormalities did not determine prognosis and were broadly similar to those seen in 'disease controls' indicating that platelet abnormalities in CHF may simply be related to associated comorbidities.

Aspirin resistance: disparities and clinical implications

Abstract Aspirin is one of the most widely prescribed drugs for the prevention of thrombosis in patients with vascular disease. Yet, aspirin is unable to prevent thrombosis in all patients. The term "aspirin resistance" has been used to broadly define the failure of aspirin to prevent a thrombotic event. Whether this is directly related to aspirin itself through biochemical aspirin resistance or treatment failure, or if it is because of aspirin's inability to overcome the thrombogenic aspects of the disease process itself, has not been elucidated. This can have dramatic clinical implications for a variety of vascular disease subsets and is cause for concern, considering the high prevalence of aspirin use for both primary and secondary prevention. Disparities exist in the rates of aspirin resistance among certain patient populations, such as women, patients with diabetes mellitus, and those with heart failure, and across clinical conditions, such as cardiovascular and cerebrovascular disease. Clinical trial data from studies observing resistance have revealed that regardless of study size, dose of aspirin, control for drug interactions and adherence, or assay used to measure platelet function, aspirin resistance is associated with an increased risk for adverse events. Although the evidence is mounting, there has yet to be a consensus on the appropriate clinical response to aspirin resistance.

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).

Psychobiology of depression/distress in congestive heart failure

Heart failure affects millions of Americans and new diagnosis rates are expected to almost triple over the next 30 years as our population ages. Affective disorders including clinical depression and anxiety are common in patients with congestive heart failure. Furthermore, the presence of these disorders significantly impacts quality of life, medical outcomes, and healthcare service utilization. In recent years, the literature has attempted to describe potential pathophysiologic mechanisms relating affective disorders and psychosocial stress to heart failure. Several potential mechanisms have been proposed including autonomic nervous system dysfunction, inflammation, cardiac arrhythmias, and altered platelet function. These mechanisms are reviewed in this article. Additional novel mechanisms such as mental stress-induced myocardial ischemia are also discussed.

Platelet activation in acute, decompensated congestive heart failure

BACKGROUND

Congestive heart failure (CHF) is associated with increased risk of venous thromboembolism, stroke and sudden death. This may be related to abnormalities of thrombogenesis and platelet activation. A comprehensive assessment of platelet (dys)function in acute decompensated heart failure (AHF) is lacking, and we hypothesised that such patients would show greater abnormalities in platelet indices, compared to stable CHF and healthy controls.

METHODS

We measured soluble P-selectin (sP-sel, by ELISA); platelet surface P-selectin (CD62P%G) and CD63%G expression by flow cytometry; and platelet structural indices [mean platelet volume (MPV), mean platelet mass (MPM) and mean platelet component (MPC)] in 22 patients with AHF (pre- and posttreatment), who were compared to 68 patients with stable congestive heart failure (CHF, all with left ventricular ejection fraction (LVEF) <50%) and 23 healthy controls.

RESULTS

There were significant differences between the 3 study groups in MPV (p<0.001), MPC (p=0.001), platelet surface P-selectin (CD62P%G, p<0.0001) and platelet surface CD63P%G (p=0.017). On post-hoc analyses, AHF patients had higher platelet surface P-selectin (CD62P%G) compared to stable CHF patients and healthy controls (Tukey's test, all p<0.05), whilst CD63%P was similarly high in both disease groups, compared to healthy controls. Platelet surface P-selectin (p=0.032), CD63 (p=0.024) and CD40L (p=0.024) were significantly reduced following treatment of AHF, though platelet morphology and sP-sel levels were not significantly changed.

CONCLUSION

AHF patients demonstrate some abnormalities of platelet activation compared to stable CHF patients and healthy controls. These platelet abnormalities are modified by treatment, raising the possibility that platelets may partly contribute to the pathophysiology of adverse complications associated with AHF.

Why is depression bad for the failing heart? A review of the mechanistic relationship between depression and heart failure

BACKGROUND

Depression is 4 to 5 times as common in heart failure (HF) patients as in the general population, might confer a higher risk of developing HF, and negatively affects prognosis in established HF.

METHODS AND RESULTS

A review was undertaken via Medline (1966-2003) and PsycINFO (1872-2003) searches using the subject headings "depressive disorder" and "heart failure, congestive." Our findings suggest that the link between depression and HF may be due to shared pathophysiology. Depression may augment catecholamine release, arrhythmias, elaboration of proinflammatory cytokines, and platelet activation--processes that may influence prognosis in HF. Depression is also associated with a higher risk of noncompliance and lower levels of social support, which have been shown to worsen prognosis in HF. The impact of pharmacologic or behavioral treatment for depression on physiologic parameters or clinical outcomes in HF remains unclear. Inherent difficulties in recognition of depression in the setting of HF may decrease the likelihood that depressed patients receive the treatment they need.

CONCLUSIONS

Depression is common in HF, may contribute to the development of HF in susceptible populations, and is independently predictive of poor clinical outcomes. Pathophysiologic pathways and psychosocial issues that are shared between the 2 conditions might explain these observations and represent potential therapeutic targets. Vigilant attention to the recognition and treatment of depression in HF patients is warranted.

Antithrombotic therapy for coronary artery disease: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This chapter about antithrombotic therapy for coronary artery disease (CAD) is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients presenting with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS), we recommend immediate and then daily oral aspirin (Grade 1A). For patients with an aspirin allergy, we recommend immediate treatment with clopidogrel, 300-mg bolus po, followed by 75 mg/d indefinitely (Grade 1A). In all NSTE ACS patients in whom diagnostic catheterization will be delayed or when coronary bypass surgery will not occur until > 5 days, we recommend clopidogrel as bolus therapy (300 mg), followed by 75 mg/d for 9 to 12 months in addition to aspirin (Grade 1A). In NSTE ACS patients in whom angiography will take place within 24 h, we suggest beginning clopidogrel after the coronary anatomy has been determined (Grade 2A). For patients who have received clopidogrel and are scheduled for coronary bypass surgery, we recommend discontinuing clopidogrel for 5 days prior to the scheduled surgery (Grade 2A). In moderate- to high-risk patients presenting with NSTE ACS, we recommend either eptifibatide or tirofiban for initial (early) treatment in addition to treatment with aspirin and heparin (Grade 1A). For the acute treatment of NSTE ACS, we recommend low molecular weight heparins over unfractionated heparin (UFH) [Grade 1B] and UFH over no heparin therapy use with antiplatelet therapies (Grade 1A). We recommend against the direct thrombin inhibitors as routine initial antithrombin therapy (Grade 1B). For patients after myocardial infarction, after ACS, and with stable CAD, we recommend aspirin in doses from 75 to 325 mg as initial therapy and in doses of 75 to 162 mg as indefinite therapy (Grade 1A). For patients with contraindications to aspirin, we recommend long-term clopidogrel (Grade 1A). For primary prevention in patients with at least moderate risk for a coronary event, we recommend aspirin, 75 to 162 mg/d, over either no antithrombotic therapy or vitamin K antagonist (VKA) [Grade 2A]; for patients at particularly high risk of events in whom the international normalized ratio (INR) can be monitored without difficulty, we suggest low-dose VKA (target INR, 1.5) [Grade 2A].

Platelet activation in heart transplant recipients

An inappropriate and persistent immune activation has been suggested to contribute to long-term mortality and morbidity after heart transplantation. Several lines of evidence suggest that platelets do not only promote thrombus formation, but also act as inflammatory cells. In the present study, we investigated if long-time survivors of heart transplantation (mean time since transplantation 6.5 yr) were characterized by enhanced platelet activation as assessed by different experimental approaches. Our main findings when comparing heart transplant recipients (n = 52) and age- and sex-matched healthy controls (n = 38) were: (i) platelets from heart transplant recipients showed enhanced expression of both P-selectin and CD63 as assessed by flow cytometry; (ii) platelets from these patients also contained significantly increased levels of soluble CD40 ligand and tended to release higher levels of this cytokine upon SFLLRN stimulation as assessed by enzyme immunoassay; (iii) heart transplant recipients had increased levels of soluble P-selectin in platelet-free plasma; and (iv) the enhanced platelet activation after heart transplantation was most pronounced in those with concomitant hypertension. These findings suggest that long-term survivors of heart transplantation are characterized by enhanced activation of platelets, possibly contributing to the persistent immune activation and clinical complications in these patients.

Effect of angiotensin-converting enzyme inhibitors, beta blockers, statins, and aspirin on C-reactive protein levels in outpatients with heart failure

C-reactive protein (CRP) levels were measured in a cohort of 96 outpatients with heart failure. Baseline angiotensin-converting enzyme inhibitor plus beta-blocker use were associated with lower levels of CRP; no relation was found between CRP levels and aspirin or statin use.