T cell activation and enhanced apoptosis in non-ST elevation myocardial infarction

Association of Neutrophil to Lymphocyte Ratio With Plaque Rupture in Acute Coronary Syndrome Patients With Only Intermediate Coronary Artery Lesions Assessed by Optical Coherence Tomography

Objectives

Plaque vulnerability and rupture rather than plaque size are the major cause of clinical events in patients with intermediate coronary lesions. Therefore, the present study was aimed to explore potential markers associated with plaque rupture in acute coronary syndrome (ACS) patients with intermediate coronary lesions.

Methods

A total of 82 ACS patients presenting with only intermediate coronary lesions (40–70% stenosis demonstrated by quantitative coronary angiography) and no severe stenosis in other main coronary arteries [median age 63 years, 53 male and 29 female] were enrolled. Plaque morphology were assessed by optical coherence tomography (OCT). Hematological indices were assayed by automated hematological analyzer.

Results

Plaque rupture was identified in 14 patients by OCT. Neutrophil to lymphocyte ratio (NLR) in patients with plaque rupture (n = 14) was significantly higher than that in patients with non-plaque rupture (n = 68) [3.85 (3.28, 4.77) vs. 2.13 (1.40, 2.81), p < 0.001]. Multivariate logistic regression analysis revealed that NLR was one of the independent risk factors for plaque rupture in intermediate coronary artery lesions (odds ratio 1.64, 95% confidence intervals 1.18–2.29, p = 0.003). ROC curve analysis found a cutoff point of NLR > 2.94 for plaque rupture with 93.8% sensitivity and 77.9% specificity.

Conclusion

NLR, an inflammatory biomarker, is closely associated with plaque rupture in intermediate coronary artery lesions. Monitoring NLR may be useful in risk stratification and management for intermediate coronary artery lesions.

Novel human immunomodulatory T cell receptors and their double-edged potential in autoimmunity, cardiovascular disease and cancer

In the last decade, approaches based on T cells and their immunomodulatory receptors have emerged as a solid improvement in treatments for various types of cancer. However, the roles of these molecules in the therapeutic context of autoimmune and cardiovascular diseases are still relatively unexplored. Here, we review the best known and most commonly used immunomodulatory T cell receptors in clinical practice (PD-1 and CTLA-4), along with the rest of the receptors with known functions in animal models, which have great potential as modulators in human pathologies in the medium term. Among these other receptors is the receptor CD69, which has recently been described to be expressed in mouse and human T cells in autoimmune and cardiovascular diseases and cancer. However, inhibition of these receptors individually or in combination by drugs or monoclonal antibodies generates a loss of immunological tolerance and can trigger multiple autoimmune disorders in different organs and immune-related adverse effects. In the coming decades, knowledge on the functions of different immunomodulatory receptors will be pivotal for the development of new and better therapies with less harmful side effects. In this review, we discuss the roles of these receptors in the control of immunity from a perspective focused on therapeutic potential in not only cancer but also autoimmune diseases, such as systemic lupus erythematosus, autoimmune diabetes and rheumatoid arthritis, and cardiovascular diseases, such as atherosclerosis, acute myocardial infarction, and myocarditis.

Routinely measured hematological parameters and prediction of recurrent vascular events in patients with clinically manifest vascular disease

Background and aims

The predictive value of traditional risk factors for vascular events in patients with manifest vascular disease is limited, underscoring the need for novel biomarkers to improve risk stratification. Since hematological parameters are routinely assessed in clinical practice, they are readily available candidates.

Methods

We used data from 3,922 vascular patients, who participated in the Second Manifestations of ARTerial Disease (SMART) study. We first investigated associations between recurrent vascular events and 22 hematological parameters, obtained from the Utrecht Patient Oriented Database (UPOD), and then assessed whether parameters associated with outcome improved risk prediction.

Results

After adjustment for all SMART risk score (SRS) variables, lymphocyte %, neutrophil count, neutrophil % and red cell distribution width (RDW) were significantly associated with vascular events. When individually added to the SRS, lymphocyte % improved prediction of recurrent vascular events with a continuous net reclassification improvement (cNRI) of 17.4% [95% CI: 2.1, 32.1%] and an increase in c-statistic of 0.011 [0.000, 0.022]. The combination of lymphocyte % and neutrophil count resulted in a cNRI of 22.2% [3.2, 33.4%] and improved c-statistic by 0.011 [95% CI: 0.000, 0.022]. Lymphocyte % and RDW yielded a cNRI of 18.7% [3.3, 31.9%] and improved c-statistic by 0.016 [0.004, 0.028]. However, the addition of hematological parameters only modestly increased risk estimates for patients with an event during follow-up.

Conclusions

Several hematological parameters were independently associated with recurrent vascular events. Lymphocyte % alone and in combination with other parameters enhanced discrimination and reclassification. However, the incremental value for patients with a recurrent event was limited.

Systemic inflammatory response following acute myocardial infarction

Acute cardiomyocyte necrosis in the infarcted heart generates damage-associated molecular patterns, activating complement and toll-like receptor/interleukin-1 signaling, and triggering an intense inflammatory response. Inflammasomes also recognize danger signals and mediate sterile inflammatory response following acute myocardial infarction (AMI). Inflammatory response serves to repair the heart, but excessive inflammation leads to adverse left ventricular remodeling and heart failure. In addition to local inflammation, profound systemic inflammation response has been documented in patients with AMI, which includes elevation of circulating inflammatory cytokines, chemokines and cell adhesion molecules, and activation of peripheral leukocytes and platelets. The excessive inflammatory response could be caused by a deregulated immune system. AMI is also associated with bone marrow activation and spleen monocytopoiesis, which sustains a continuous supply of monocytes at the site of inflammation. Accumulating evidence has shown that systemic inflammation aggravates atherosclerosis and markers for systemic inflammation are predictors of adverse clinical outcomes (such as death, recurrent myocardial infarction, and heart failure) in patients with AMI.

Postischemic revascularization: from cellular and molecular mechanisms to clinical applications

After the onset of ischemia, cardiac or skeletal muscle undergoes a continuum of molecular, cellular, and extracellular responses that determine the function and the remodeling of the ischemic tissue. Hypoxia-related pathways, immunoinflammatory balance, circulating or local vascular progenitor cells, as well as changes in hemodynamical forces within vascular wall trigger all the processes regulating vascular homeostasis, including vasculogenesis, angiogenesis, arteriogenesis, and collateral growth, which act in concert to establish a functional vascular network in ischemic zones. In patients with ischemic diseases, most of the cellular (mainly those involving bone marrow-derived cells and local stem/progenitor cells) and molecular mechanisms involved in the activation of vessel growth and vascular remodeling are markedly impaired by the deleterious microenvironment characterized by fibrosis, inflammation, hypoperfusion, and inhibition of endogenous angiogenic and regenerative programs. Furthermore, cardiovascular risk factors, including diabetes, hypercholesterolemia, hypertension, diabetes, and aging, constitute a deleterious macroenvironment that participates to the abrogation of postischemic revascularization and tissue regeneration observed in these patient populations. Thus stimulation of vessel growth and/or remodeling has emerged as a new therapeutic option in patients with ischemic diseases. Many strategies of therapeutic revascularization, based on the administration of growth factors or stem/progenitor cells from diverse sources, have been proposed and are currently tested in patients with peripheral arterial disease or cardiac diseases. This review provides an overview from our current knowledge regarding molecular and cellular mechanisms involved in postischemic revascularization, as well as advances in the clinical application of such strategies of therapeutic revascularization.

Differentiating ischemic from non-ischemic chest pain using white blood cell-surface inflammatory and coagulation markers

Chest pain is one of the most common complaints seen in emergency departments (ED), up to 5-8 % of all ED visits. About 50-60 % of chest pain patients presenting to the ED are hospitalized. Seventy percentage of those patients not discharged from the ED are subsequently shown to not have acute cardiac disease. It has been estimated that emergency physician miss 2-6 % of acute coronary syndrome (ACS) that present to ED. While admitting a non-ACS patient is a financial burden on the medical system, releasing to home an undiagnosed ACS patient has life-threatening consequences. This study used flow cytometry to evaluate a panel of mononuclear cells, neutrophils, cytokines and fibrinolytic activation markers in patients presenting in ED with acute chest pain. The goal was to add diagnostic tools to the differentiation between true ischemic cardiac and non-ischemic chest pain in the process of triage. The study population consisted of 74 consecutive patients presenting with acute chest pain to the emergency department of Ziv Medical Center and were admitted to Intensive Cardiac Care Unit or Internal Wards of our hospital during the period September 2009 to February 2010. ACS has been clearly associated with a decrease in CD89+/CD62L+ population, an increase in percentage of cytotoxic T-cell subset, and an increase in platelet marker. Differences in thrombin receptor surface expression were also noted. The combination of multiple biomarkers may help to enhance diagnostic accuracy.

Post-chemotherapy T-cell recovery is a marker of improved survival in patients with advanced thoracic malignancies

Background:

There is increasing interest in combining chemotherapy with immunotherapy. However, the effects of chemotherapy on the human immune system are largely unknown.

Methods:

Longitudinal changes in peripheral T-cell subsets in 40 patients with malignant mesothelioma (MM) or advanced non-small cell lung cancer (NSCLC) receiving platinum-based chemotherapy were assessed by flow cytometry and evaluated for associations with clinical outcome.

Results:

Proliferating T cells of all subsets were almost entirely depleted at day 8 following chemotherapy, but rapidly recovered above baseline levels. Regulatory T cells (Treg) were most profoundly depleted at this time point. A greater increase in CD8⁺ T-cell proliferation following one treatment cycle was associated with improved overall survival in univariate (hazard ratio (HR)=0.40; P<0.05) and multivariate (HR=0.17; P<0.01) analyses. A greater increase in the ratio of CD8⁺ T cell to Treg proliferation was also predictive of better prognosis.

Conclusion:

Chemotherapy potentially provides a favourable environment for the development of anti-tumour immunity through transient Treg depletion and regeneration of the T-cell pool. Change in CD8⁺ T-cell proliferation after one cycle of chemotherapy may represent a useful prognostic indicator in patients with MM and NSCLC.

Non-ST elevation myocardial infarction: a new pathophysiological concept could solve the contradiction between accepted cause and clinical observations

Non-ST elevation myocardial infarction (NSTEMI) and ST elevation infarction have many differences in their appearance and prognosis. A comprehensive search made us form a new hypothesis that a further cause also existsin NSTEMI: an acute, critical increase in the already existing high microvascular resistance in addition to the subtotal coronary artery occlusion. Various findings and studies can be interpreted only by our hypothesis: hemodynamic findings, ECG changes, autopsy reports and clinical observations (different long-time prognosis and different result of acute revascularization therapy in NSTEMI, similarities of NSTEMI with other clinical symptoms where increased microvascular resistance can be supposed without coronary artery disease).

OBJECTIVE

Despite similarities in the underlying pathologic mechanism non-ST elevation myocardial infarction(NSTEMI) and ST elevation infarction (STEMI) have many differences in their clinical presentation and prognosis.

METHOD

A systematic review of the literature about NSTEMI and the blood supply of the myocardium made us form a hypothesis that a further cause also exists in addition to the accepted cause of NSTEMI (subtotal coronaryartery occlusion): an acute, critical increase in an already existing high intramyocardial microvascular resistance.

EVIDENCE

Knowledge about microcirculation disturbances in ischemic heart disease and development of microcirculation damage can be fitted in our hypothesis. Various findings and studies can be interpreted only by our hypothesis: hemodynamic findings, ECG changes, autopsy reports and clinical observations about NSTEMI. The latest ones involve the different long-time prognosis and different result of acute revascularization therapy in STEMI and NSTEMI. Regarding the repolarization changes on the ECG NSTEMI shows similarities with other clinical symptoms where increased intramyocardial microvascular resistance can be supposed without coronary artery disease: false positive exercise stress test, supraventricular tachycardia, left ventricular strain and conduction disturbances.

CONCLUSION

The acute treatment of NSTEMI should aim to improve the blood inflow to the stiff myocardiumand/or impaired microvascular system and decrease the high microvascular resistance.

Therapeutic implications of low lymphocyte count in non-ST segment elevation acute coronary syndromes

BACKGROUND

Low lymphocyte count (LLC), a surrogate for inflammation, has emerged as a potential risk factor for cardiovascular outcomes, especially new ischemic events. To identify patients with non-ST segment elevation acute coronary syndromes (NSTEACS) who benefit from an invasive revascularization strategy remains a challenge. We sought to determine if patients with high-risk NSTEACS who exhibited LLC have a greater reduction in long-term post-discharge myocardial infarction (MI) when managed under a revascularization invasive strategy (RIS) as compared with conservative strategy (CS).

METHODS

Nine hundred seventy two consecutive patients with high-risk NSTEACS were treated under two revascularization strategies (RS): 1) CS, from January 2001 to October 2002 (345 patients; 35.5%) and 2) RIS, from November 2002 to May 2005 (627 patients; 64.5%). LLC was defined as lymphocytes count < or =1200 cells/ml (1 vs. 2-4 quartiles). The association between the type of RS and MI was stratified by lymphocyte count status and assessed by Cox regression adapted for competing events.

RESULTS

At 3-year follow-up, 145 deaths (14.9%), 135 MI (13.9%) and 76 revascularization procedures (7.8%) were registered. In a multivariable setting, LLC patients exhibited a greater MI risk reduction when managed under RIS (HR: 0.40; 95% CI=0.22-0.72, p=0.003). Conversely, when LLC was not present, no difference in the rate of MI was detected between the two RS.

CONCLUSIONS

LLC identifies a subgroup of patients with greater reduction in the risk of postdischarge MI when a RIS is applied.

Relationship between low lymphocyte count and major cardiac events in patients with acute chest pain, a non-diagnostic electrocardiogram and normal troponin levels

OBJECTIVE

Risk stratification of patients with acute chest pain, non-diagnostic electrocardiogram and normal troponin (ACPneg) remains a challenge, partly because no standardized set of biomarkers with prognostic ability has been identified in this population. Lymphopenia has been associated with atherosclerosis progression and adverse outcomes in cardiovascular diseases; although its prognostic value in ACPneg is unknown. We sought to determine the relationship between the lymphocyte count obtained in the Emergency Department (ED) and the risk of the long-term all-cause mortality or myocardial infarction (MI) in patients with ACPneg.

METHODS

We analyzed 1030 consecutive patients admitted with ACPneg in our institution. Lymphocyte count was determined in the ED as a part of a routine diagnostic workup to rule out an acute coronary syndrome. Patients with inflammatory, infectious diseases, or active malignancy were excluded (final sample=975). The independent association between lymphocyte count and the composite endpoint (death/MI) was assessed by survival analysis for competing risk events (revascularization procedures).

RESULTS

During a median follow-up of 36 months, 139 (14.3%) patients achieved the combined endpoint, with rates increasing monotonically across lymphocyte quartiles (6.2%, 10%, 20.6% and 24.1% for Q4, Q3, Q2 and Q1 (p<0.001), respectively). In a multivariable analysis, patients in lymphocytes' Q1 and Q2 as compared with those in Q4 had an increased risk for the combined endpoint: HR=2.45 (CI 95% 1.25-4.79, p=0.008) and HR=2.56 (CI 95% 1.30-5.07, p=0.007), respectively.

CONCLUSION

In patients with ACPneg, low lymphocytes count was associated with an increased risk for developing the combined endpoint of death or MI.

Uncontrolled immune response in acute myocardial infarction: unraveling the thread

Recently, the theory that hyperinflammation is the body's primary response to potent stimulus has been challenged. Indeed, a deregulation of the immune system could be the cause of multiple organ failure. So far, clinicians have focused on the last steps of the inflammatory cascade. However, little attention has been paid to lymphocytes, which play an important role as strategists of the inflammatory response. Experimental evidence suggests a crucial role of T lymphocytes in the pathophysiology of atherosclerosis and acute myocardial infarction (AMI). In summary, from the bottom of an imaginary inverted pyramid, a few regulatory T-cells control the upper parts represented by the wide spectrum of the inflammatory cascade. In AMI, a loss of regulation of the inflammatory system occurs in patients with a decreased activity of regulatory T-cells. As a consequence, aggressive T-cells boost and anti-inflammatory T-cells drop. A pleiotropic proinflammatory imbalance with damaging effects in terms of left ventricular performance and patient outcome is the result of this uncontrolled immune response. It is needed to unravel the thread of the inflammatory cells to better understand the pathophysiology as well as to open innovative therapeutic options in AMI.