Neutrophilia and congestive heart failure after acute myocardial infarction

Myeloperoxidase as a Promising Therapeutic Target after Myocardial Infarction

Coronary artery disease (CAD) and myocardial infarction (MI) remain leading causes of death and disability worldwide. CAD begins with the formation of atherosclerotic plaques within the intimal layer of the coronary arteries, a process driven by persistent arterial inflammation and oxidation. Myeloperoxidase (MPO), a mammalian haem peroxidase enzyme primarily expressed within neutrophils and monocytes, has been increasingly recognised as a key pro-inflammatory and oxidative enzyme promoting the development of vulnerable coronary atherosclerotic plaques that are prone to rupture, and can precipitate a MI. Mounting evidence also implicates a pathogenic role for MPO in the inflammatory process that follows a MI, which is characterised by the rapid infiltration of activated neutrophils into the damaged myocardium and the release of MPO. Excessive and persistent cardiac inflammation impairs normal cardiac healing post-MI, resulting in adverse cardiac outcomes and poorer long-term cardiac function, and eventually heart failure. This review summarises the evidence for MPO as a significant oxidative enzyme contributing to the inappropriate inflammatory responses driving the progression of CAD and poor cardiac healing after a MI. It also details the proposed mechanisms underlying MPO's pathogenic actions and explores MPO as a novel therapeutic target for the treatment of unstable CAD and cardiac damage post-MI.

Neutrophils facilitate the epicardial regenerative response after zebrafish heart injury

Despite extensive studies on endogenous heart regeneration within the past 20 years, the players involved in initiating early regeneration events are far from clear. Here, we assessed the function of neutrophils, the first-responder cells to tissue damage, during zebrafish heart regeneration. We detected rapid neutrophil mobilization to the injury site after ventricular amputation, peaking at 1-day post-amputation (dpa) and resolving by 3 dpa. Further analyses indicated neutrophil mobilization coincides with peak epicardial cell proliferation, and recruited neutrophils associated with activated, expanding epicardial cells at 1 dpa. Neutrophil depletion inhibited myocardial regeneration and significantly reduced epicardial cell expansion, proliferation, and activation. To explore the molecular mechanism of neutrophils on the epicardial regenerative response, we performed scRNA-seq analysis of 1 dpa neutrophils and identified enrichment of the FGF and MAPK/ERK signaling pathways. Pharmacological inhibition of FGF signaling indicated its' requirement for epicardial expansion, while neutrophil depletion blocked MAPK/ERK signaling activation in epicardial cells. Ligand-receptor analysis indicated the EGF ligand, hbegfa, is released from neutrophils and synergizes with other FGF and MAPK/ERK factors for induction of epicardial regeneration. Altogether, our studies revealed that neutrophils quickly motivate epicardial cells, which later accumulate at the injury site and contribute to heart regeneration.

A Rare Case of Leukemoid Reaction During Mechanical Circulatory Support in a Patient With Severe Heart Failure: An Autopsy Study

The leukemoid reaction (LR) is reported to be caused by severe stress conditions such as infection, malignancies, intoxication, severe hemorrhage, or acute hemolysis; this condition is attributed to a very severe prognosis. Some reports have suggested that the LR was associated with a systemic stress response. A 36-year-old man who required mechanical circulatory support (MCS), including veno-arterial extracorporeal membrane oxygenation and Impella 5.5 due to severe heart failure, was transferred to our hospital. He showed a markedly elevated WBC count and died of multiple organ failure. The autopsy revealed the possibility that leukocytosis might have been due to an LR; however, the cause of the cardiac failure was unknown. To the best of our knowledge, this study is the first to report a rare case of LR in a patient with severe heart failure requiring MCS.

The Impact of the Neutrophil-to-Lymphocyte Ratio on In-Hospital Outcomes in Patients With Acute ST-Segment Elevation Myocardial Infarction

Introduction The neutrophil-to-lymphocyte ratio (NLR) is a significant predictor of cardiovascular diseases, influencing their progression and prognosis. The exact role of the NLR in acute ST-segment elevation myocardial infarction (STEMI) is unclear. We investigated the possible association between peak NLR values within the first three days after STEMI onset and in-hospital outcomes in patients undergoing primary percutaneous coronary intervention (PCI). Methods This retrospective study included 641 patients who were diagnosed with acute STEMI and treated with primary PCI for 18 months at Dr. Siyami Ersek Hospital. The NLR was calculated using the maximum values obtained during the first three days after admission. The patients were divided into quartiles according to their NLR values for further analysis of potential complications during and after hospitalization, up to a follow-up period of three months. Results Significant differences were found in factors such as age, body mass index (BMI), and length of hospital stay among these groups. Specifically, we found that in-hospital mortality rates were significantly higher in the Q4 group, and there were variations in target vessel revascularization (TVR) rates, major adverse cardiac events (MACE) rates, and other clinical outcomes. Some parameters, such as reinfarction rates and certain procedural outcomes, did not show significant differences among the groups. However, despite the differences, most of the patients achieved successful outcomes after PCI, with the best results in the low NLR group and the worst results in the high NLR group. Conclusion Higher NLR values were associated with a higher risk of unfavorable outcomes during hospitalization.

Risk Factors for Death or Cardiovascular Events after Acute Coronary Syndrome in Patients with Myeloproliferative Neoplasms

Patients with myeloproliferative neoplasms (MPNs) are at increased risk of cardiovascular disease (CVD), including acute coronary syndrome (ACS). However, data on long-term outcomes of patients with MPN who have had ACS and risk factors for all-cause death or CV events post-ACS hospitalization are lacking. We conducted a single-center study of 41 consecutive patients with MPN with ACS hospitalization after MPN diagnosis. After a median follow-up of 80 months after ACS hospitalization, 31 (76%) experienced death or a CV event (myocardial infarction, ischemic stroke, or heart failure hospitalization). After multivariable Cox proportional hazards regression, index ACS within 12 months of MPN diagnosis (HR 3.84, 95% CI 1.44-10.19), WBC ≥ 20 K/µL (HR 9.10, 95% CI 2.71-30.52), JAK2 mutation (HR 3.71, 95% CI 1.22-11.22), and prior CVD (HR 2.60, 95% CI 1.12-6.08) were associated with increased death or CV events. Further studies are warranted to improve cardiovascular outcomes in this patient population.

Mitochondrial dysfunction in macrophages promotes inflammation and suppresses repair after myocardial infarction

Innate immune cells play important roles in tissue injury and repair following acute myocardial infarction (MI). Although reprogramming of macrophage metabolism has been observed during inflammation and resolution phases, the mechanistic link to macrophage phenotype is not fully understood. In this study, we found that myeloid-specific deletion (mKO) of mitochondrial complex I protein, encoded by Ndufs4, reproduced the proinflammatory metabolic profile in macrophages and exaggerated the response to LPS. Moreover, mKO mice showed increased mortality, poor scar formation, and worsened cardiac function 30 days after MI. We observed a greater inflammatory response in mKO mice on day 1 followed by increased cell death of infiltrating macrophages and blunted transition to the reparative phase during post-MI days 3-7. Efferocytosis was impaired in mKO macrophages, leading to lower expression of antiinflammatory cytokines and tissue repair factors, which suppressed the proliferation and activation of myofibroblasts in the infarcted area. Mitochondria-targeted ROS scavenging rescued these impairments, improved myofibroblast function in vivo, and reduced post-MI mortality in mKO mice. Together these results reveal a critical role of mitochondria in inflammation resolution and tissue repair via modulation of efferocytosis and crosstalk with fibroblasts. These findings have potential significance for post-MI recovery as well as for other inflammatory conditions.

Long-term prognostic value of inflammatory biomarkers for patients with acute heart failure: Construction of an inflammatory prognostic scoring system

Objective

Systemic inflammation is associated with a poor prognosis in acute heart failure (AHF). This study was to assess the long-term prognostic value of combining the accessible inflammatory markers in relation to all-cause mortality in patients with AHF.

Methods

Consecutive patients with AHF who were hospitalized between March 2012 and April 2016 at the Department of Cardiology of the First Affiliated Hospital of Nanjing Medical University were enrolled in this prospective study. The LASSO regression model was used to select the most valuable inflammatory biomarkers to develop an inflammatory prognostic scoring (IPS) system. Kaplan-Meier method, multivariate COX regression and time-dependent ROC analysis were used to assess the relationship between inflammatory markers and AHF prognosis. A randomized survival forest model was used to estimate the relative importance of each inflammatory marker in the prognostic risks of AHF.

Results

A total of 538 patients with AHF were included in the analysis (mean age, 61.1 ± 16.0 years; 357 [66.4%] men). During a median follow-up of 34 months, there were 227 all-cause deaths (42.2%). C-reactive protein (CRP), red blood cell distribution width (RDW) and neutrophil-to-lymphocyte ratio (NLR) were incorporated into the IPS system (IPS = 0.301×CRP + 0.263×RDW + 0.091×NLR). A higher IPS meant a significantly worse long-term prognosis in Kaplan-Meier analysis, with 0.301 points as the optimal cut-off value (P log-rank <0.001). IPS remained an independent prognostic factor associated with an increased risk of all-cause mortality among patients with AHF in multivariate Cox regression models with a full adjustment of the other significant covariables. Random forest variable importance and minimal depth analysis further validated that the IPS system was the most predictive for all-cause mortality in patients with AHF.

Conclusions

Inflammatory biomarkers were associated with the risk of all-cause mortality in patients with AHF, while IPS significantly improved the predictive power of the model and could be used as a practical tool for individualized risk stratification of patients with AHF.

The neutrophil percentage-to-albumin ratio is associated with all-cause mortality in critically ill patients with acute myocardial infarction

Aim

In this study, we evaluated the utility of neutrophil percentage-to-albumin ratio (NPAR) in predicting in critically ill patients with acute myocardial infarction (AMI).

Methods

The information of patients were collected from Medical Information Mart for Intensive Care III database. Admission NPAR was calculated as neutrophil percentage divided by serum albumin. The endpoints of this study were 30-day, 90-day, 180-day, and 365-day all-cause mortality. Cox proportional hazards models and subgroup analyses were used to determine the relationship between admission NPAR and these endpoints.

Results

798 critically ill patients with AMI were enrolled in. After adjustments for age, race and gender, higher admission NPAR was associated with increased risk of 30-day, 90-day, 180-day, and 365-day all-cause mortality in critically ill patients with AMI. And after adjusting for possible confounding variables, two different trends have emerged. Stratified by tertiles, high admission NPAR was independently associated with 180-day and 365-day all-cause mortality in critically ill patients with AMI (tertile 3 vs. tertile 1: adjusted HR, 95% CI 1.71, 1.10–2.66, p < 0.05; 1.66, 1.10–2.51, p < 0.05). In other hand, stratified by quartiles, highest admission NPAR levels were independently associated with 90-day, 180-day and 365-day all-cause mortality (quartile 4 vs. quartile 1: adjusted HR, 95% CI 2.36, 1.32–4.23, p < 0.05; 2.58, 1.49–4.47, p < 0.05; 2.61, 1.56–4.37, p < 0.05). ROC test showed that admission NPAR had a moderate ability to predict all-cause mortality of critically ill patients with AMI. No obvious interaction was found by subgroup analysis in most subgroups.

Conclusions

Admission NPAR was an independent predictor for 180-day and 365-day all-cause mortality in critically ill patients with AMI.

Leukocyte-Mediated Cardiac Repair after Myocardial Infarction in Non-Regenerative vs. Regenerative Systems

Innate and adaptive leukocytes rapidly mobilize to ischemic tissues after myocardial infarction in response to damage signals released from necrotic cells. Leukocytes play important roles in cardiac repair and regeneration such as inflammation initiation and resolution; the removal of dead cells and debris; the deposition of the extracellular matrix and granulation tissue; supporting angiogenesis and cardiomyocyte proliferation; and fibrotic scar generation and resolution. By organizing and comparing the present knowledge of leukocyte recruitment and function after cardiac injury in non-regenerative to regenerative systems, we propose that the leukocyte response to cardiac injury differs in non-regenerative adult mammals such as humans and mice in comparison to cardiac regenerative models such as neonatal mice and adult zebrafish. Specifically, extensive neutrophil, macrophage, and T-cell persistence contributes to a lengthy inflammatory period in non-regenerative systems for adverse cardiac remodeling and heart failure development, whereas their quick removal supports inflammation resolution in regenerative systems for new contractile tissue formation and coronary revascularization. Surprisingly, other leukocytes have not been examined in regenerative model systems. With this review, we aim to encourage the development of improved immune cell markers and tools in cardiac regenerative models for the identification of new immune targets in non-regenerative systems to develop new therapies.

Effect of interleukin-1 blockade with anakinra on leukocyte count in patients with ST-segment elevation acute myocardial infarction

Leukocytosis is a common finding in patients with ST elevation myocardial infarction (STEMI) and portends a poor prognosis. Interleukin 1-β regulates leukopoiesis and pre-clinical studies suggest that anakinra (recombinant human interleukin-1 [IL-1] receptor antagonist) suppresses leukocytosis in myocardial infarction. However, the effect of IL-1 blockade with anakinra on leukocyte count in patients with STEMI is unknown. We reviewed the white blood cell (WBC) and differential count of 99 patients enrolled in a clinical trial of anakinra (n = 64) versus placebo (n = 35) for 14 days after STEMI. A complete blood cell count with differential count were obtained at admission, and after 72 h, 14 days and 3 months. After 72 h from treatment, anakinra compared to placebo led to a statistically significant greater percent reduction in total WBC count (− 35% [− 48 to − 24] vs. − 21% [− 34 to − 10], P = 0.008), absolute neutrophil count (− 48% [− 60 to − 22] vs. − 27% [− 46 to − 5], P = 0.004) and to an increase in absolute eosinophil count (+ 50% [0 to + 100] vs. 0% [− 50 to + 62], P = 0.022). These changes persisted while on treatment at 14 days and were no longer apparent at 3 months after treatment discontinuation. We found that in patients with STEMI IL-1 blockade with anakinra accelerates resolution of leukocytosis and neutrophilia. This modulation may represent one of the mechanisms by which IL-1 blockade improves clinical outcomes.

Retention of the NLRP3 Inflammasome-Primed Neutrophils in the Bone Marrow Is Essential for Myocardial Infarction-Induced Granulopoiesis

BACKGROUND

Acute myocardial infarction (MI) results in overzealous production and infiltration of neutrophils to the ischemic heart. This is mediated in part by granulopoiesis induced by the S100A8/A9-NLRP3-IL-1β signaling axis in injury-exposed neutrophils. Despite the transcriptional upregulation of the NLRP3 (Nod Like Receptor Family Pyrin Domain-Containing 3) inflammasome and associated signaling components in neutrophils, the serum levels of IL-1β (interleukin-1β), the effector molecule in granulopoiesis, were not affected by MI, suggesting that IL-1β is not released systemically. We hypothesize that IL-1β is released locally within the bone marrow (BM) by inflammasome-primed and reverse-migrating neutrophils.

METHODS

Using a combination of time-dependent parabiosis and flow cytometry techniques, we first characterized the migration patterns of different blood cell types across the parabiotic barrier. We next induced MI in parabiotic mice by permanent ligation of the left anterior descending artery and examined the ability of injury-exposed neutrophils to permeate the parabiotic barrier and induce granulopoiesis in noninfarcted parabionts. Last, using multiple neutrophil adoptive and BM transplant studies, we studied the molecular mechanisms that govern reverse migration and retention of the primed neutrophils, IL-1β secretion, and granulopoiesis. Cardiac function was assessed by echocardiography.

RESULTS

MI promoted greater accumulation of the inflammasome-primed neutrophils in the BM. Introducing a time-dependent parabiotic barrier to the free movement of neutrophils inhibited their ability to stimulate granulopoiesis in the noninfarcted parabionts. Previous priming of the NLRP3 inflammasome is not a prerequisite, but the presence of a functional CXCR4 (C-X-C-motif chemokine receptor 4) on the primed-neutrophils and elevated serum S100A8/A9 levels are necessary for homing and retention of the reverse-migrating neutrophils. In the BM, the primed-neutrophils secrete IL-1β through formation of gasdermin D pores and promote granulopoiesis. Pharmacological and genetic strategies aimed at the inhibition of neutrophil homing or release of IL-1β in the BM markedly suppressed MI-induced granulopoiesis and improved cardiac function.

CONCLUSIONS

Our data reveal a new paradigm of how circulatory cells establish a direct communication between organs by delivering signaling molecules (eg, IL-1β) directly at the sites of action rather through systemic release. We suggest that this pathway may exist to limit the off-target effects of systemic IL-1β release.

The Evolving Roles of Cardiac Macrophages in Homeostasis, Regeneration, and Repair

Macrophages were first described as phagocytic immune cells responsible for maintaining tissue homeostasis by the removal of pathogens that disturb normal function. Historically, macrophages have been viewed as terminally differentiated monocyte-derived cells that originated through hematopoiesis and infiltrated multiple tissues in the presence of inflammation or during turnover in normal homeostasis. However, improved cell detection and fate-mapping strategies have elucidated the various lineages of tissue-resident macrophages, which can derive from embryonic origins independent of hematopoiesis and monocyte infiltration. The role of resident macrophages in organs such as the skin, liver, and the lungs have been well characterized, revealing functions well beyond a pure phagocytic and immunological role. In the heart, recent research has begun to decipher the functional roles of various tissue-resident macrophage populations through fate mapping and genetic depletion studies. Several of these studies have elucidated the novel and unexpected roles of cardiac-resident macrophages in homeostasis, including maintaining mitochondrial function, facilitating cardiac conduction, coronary development, and lymphangiogenesis, among others. Additionally, following cardiac injury, cardiac-resident macrophages adopt diverse functions such as the clearance of necrotic and apoptotic cells and debris, a reduction in the inflammatory monocyte infiltration, promotion of angiogenesis, amelioration of inflammation, and hypertrophy in the remaining myocardium, overall limiting damage extension. The present review discusses the origin, development, characterization, and function of cardiac macrophages in homeostasis, cardiac regeneration, and after cardiac injury or stress.

Inflammatory Cytokines, Immune Cells, and Organ Interactions in Heart Failure

Despite mounting evidence demonstrating the significance of inflammation in the pathophysiological mechanisms of heart failure (HF), most large clinical trials that target the inflammatory responses in HF yielded neutral or even worsening outcomes. Further in-depth understanding about the roles of inflammation in the pathogenesis of HF is eagerly needed. This review summarizes cytokines, cardiac infiltrating immune cells, and extracardiac organs that orchestrate the complex inflammatory responses in HF and highlights emerging therapeutic targets.

Preoperative Leukocytosis Among Female Patients Predicts Poor Postoperative Outcomes Following EVAR For Intact Infrarenal AAA

OBJECTIVES

Elevated white blood count (WBC) can be predictive of adverse outcomes following vascular interventions, but the association has not established using multi-institutional data. We evaluated the predictive value of preoperative WBC after endovascular abdominal aortic aneurysm repair (EVAR) for non-ruptured abdominal aortic aneurysms (AAA) in a nationally representative surgical database.

METHODS

Patients with non-ruptured AAA undergoing EVAR were identified in the vascular-targeted National Surgical Quality Improvement Program (NSQIP) database. Baseline characteristics were compared between patients with WBC < 10 K/μL and WBC ≥ 10 K/μL. Multivariable logistic regression analyses were performed to assess the odds of outcomes. The primary outcome was 30-day mortality. Multiple secondary outcomes including length of stay (LOS) > 1 week, 30-day readmission, lower extremity (LE) ischemia, ischemic colitis, myocardial infarction (MI) and others were assessed based on WBC and patient sex.

RESULTS

A total of 10955 patients were included with a mean WBC 7.7 ± 2.7 K/μL. Patients with WBC ≥ 10 K/μL were younger (71.8 ± 9.5 years versus 74.1 ± 8.7 years; P < .001) and were more likely to be diabetic, on steroids, smokers, functionally dependent and presenting emergently (all P ≤ .009). Aneurysm diameter was larger in WBC ≥ 10 K/μL patients (5.9 ± 1.5 cm versus 5.7 ± 1.5 cm; P < .001). Patients with WBC ≥ 10 K/μL had more mortality (2.4% vs 1.3%), LOS > 1 week (13.5% versus 6.7%), 30-day readmissions (9.8% versus 7.3%), LE ischemia (2.3% vs 1.4%), ischemic colitis (1.2% vs 0.5%), and MI (2.0% vs 1.1% ) (all P ≤ .008). Female patients with WBC ≥ 10 K/μL, compared to male patients with WBC ≥ 10 K/μL had more adverse events including mortality, LOS > 1 week, 30-day readmission, LE ischemia (all P ≤ .025). With each incremental increase in WBC by 1K/μL, the adjusted odds ratio of adverse outcomes for all patient was higher (mortality: 1.05 [95% CI, 1.00-1.10], readmission: 1.03 [95% CI, 1.00-1.06], LOS > 1 week: 1.08 [95% CI, 1.05-1.10] and ischemic colitis: 1.11 [95% CI, 1.05-1.16]; all P < .05). The effect was more pronounced in female patients and statistically significant.

CONCLUSIONS

WBC is a predictor of adverse outcomes in patients undergoing EVAR for non-ruptured AAA. After adjusting for associated risk factors, the effect of increasing WBC was more prominent for female patients. Preoperative WBC should be used as a prognostic factor to predict adverse outcomes among EVAR patients.

Comparative role of hematological indices for the assessment of in-hospital outcome of heart failure patients

Background. The mutual relation between heart failure (HF) and inflammation is reflected in blood cell homeostasis. Neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR) and platelet-lymphocyte ratio (PLR) were linked to HF severity and prognosis. Aims. Our objective was to compare the three ratios for predicting in-hospital outcome of HF patients, in order to establish which is best suited for clinical practice. Methods. Consecutive HF patients admitted to a Cardiology Department from a tertiary hospital were retrospectively evaluated for inclusion. Readmissions and pathologies modifying the hematological indices were excluded. Extended length of hospital stay (LOS) was considered over 7 d. In-hospital all-cause mortality was evaluated. Results: The hematological indices in heart failure (HI-HF) cohort included 1299 patients with a mean age of 72.35 ± 10.45 years, 51.96% women. 2.85% died during hospitalization. 22.17% had extended LOS. In Cox regression for in-hospital mortality alongside parameters from the OPTIMIZE-HF proposed model, all three ratios were independent predictors of mortality. In Cox regression including NT-proBNP, dyspnea at rest, chronic obstructive pulmonary disease (COPD), age and systolic blood pressure, only MLR was an independent predictor of in-hospital mortality (HR 1.68, 95% CI 1.22 - 2.32, p = .002). In multivariable logistic regression, all three ratios independently predicted extended LOS. MLR > 0.48 associated the highest probability (OR 1.76, 95% CI 1.25 - 2.46, p = .001). Conclusions. Hematological indices could be cost-effective and easily available auxiliary biomarkers for in-hospital prognosis of HF patients. We propose MLR > 0.48 as the strongest predictor of in-hospital mortality and prolonged hospitalization.

Nitroxides Mitigate Neutrophil-Mediated Damage to the Myocardium after Experimental Myocardial Infarction in Rats

Reperfusion therapy increases survival post-acute myocardial infarction (AMI) while also stimulating secondary oxidant production and immune cell infiltration. Neutrophils accumulate within infarcted myocardium within 24 h post-AMI and release myeloperoxidase (MPO) that catalyses hypochlorous acid (HOCl) production while increasing oxidative stress and inflammation, thereby enhancing ventricular remodelling. Nitroxides inhibit MPO-mediated HOCl production, potentially ameliorating neutrophil-mediated damage. Aim: Assess the cardioprotective ability of nitroxide 4-methoxyTEMPO (4MetT) within the setting of AMI. Methods: Male Wistar rats were separated into 3 groups: SHAM, AMI/R, and AMI/R + 4MetT (15 mg/kg at surgery via oral gavage) and subjected to left descending coronary artery ligation for 30 min to generate an AMI, followed by reperfusion. One cohort of rats were sacrificed at 24 h post-reperfusion and another 28 days post-surgery (with 4MetT (15 mg/kg) administration twice daily). Results: 3-chlorotyrosine, a HOCl-specific damage marker, decreased within the heart of animals in the AMI/R + 4-MetT group 24 h post-AMI, indicating the drug inhibited MPO activity; however, there was no evident difference in either infarct size or myocardial scar size between the groups. Concurrently, MPO, NfκB, TNFα, and the oxidation marker malondialdehyde increased within the hearts, with 4-MetT only demonstrating a trend in decreasing MPO and TNF levels. Notably, 4MetT provided a significant improvement in cardiac function 28 days post-AMI, as assessed by echocardiography, indicating potential for 4-MetT as a treatment option, although the precise mechanism of action of the compound remains unclear.

Neutrophil-Mediated Cardiac Damage After Acute Myocardial Infarction: Significance of Defining a New Target Cell Type for Developing Cardioprotective Drugs

Significance: Acute myocardial infarction (AMI) is a leading cause of death worldwide. Post-AMI survival rates have increased with the introduction of angioplasty as a primary coronary intervention. However, reperfusion after angioplasty represents a clinical paradox, restoring blood flow to the ischemic myocardium while simultaneously inducing ion and metabolic imbalances that stimulate immune cell recruitment and activation, mitochondrial dysfunction and damaging oxidant production. Recent Advances: Preclinical data indicate that these metabolic imbalances contribute to subsequent heart failure through sustaining local recruitment of inflammatory leukocytes and oxidative stress, cardiomyocyte death, and coronary microvascular disturbances, which enhance adverse cardiac remodeling. Both left ventricular dysfunction and heart failure are strongly linked to inflammation and immune cell recruitment to the damaged myocardium. Critical Issues: Overall, therapeutic anti-inflammatory and antioxidant agents identified in preclinical trials have failed in clinical trials. Future Directions: The versatile neutrophil-derived heme enzyme, myeloperoxidase (MPO), is gaining attention as an important oxidative mediator of reperfusion injury, vascular dysfunction, adverse ventricular remodeling, and atrial fibrillation. Accordingly, there is interest in therapeutically targeting neutrophils and MPO activity in the setting of heart failure. Herein, we discuss the role of post-AMI inflammation linked to myocardial damage and heart failure, describe previous trials targeting inflammation and oxidative stress post-AMI, highlight the potential adverse impact of neutrophil and MPO, and detail therapeutic options available to target MPO clinically in AMI patients.

Emerging roles of neutrophil-borne S100A8/A9 in cardiovascular inflammation

Elevated neutrophil count is associated with higher risk of major adverse cardiac events including myocardial infarction and early development of heart failure. Neutrophils contribute to cardiac damage through a number of mechanisms, including attraction of other immune cells and release of inflammatory mediators. Recently, a number of independent studies have reported a causal role for neutrophil-derived alarmins (i.e. S100A8/A9) in inducing inflammation and cardiac injury following myocardial infarction (MI). Furthermore, a positive correlation between serum S100A8/A9 levels and major adverse cardiac events (MACE) in MI patients was also observed implying that targeting neutrophils or their inflammatory cargo could be beneficial in reducing heart failure. However, contradictory to this idea, neutrophils and neutrophil-derived S100A8/A9 also seem to play a vital role in the resolution of inflammation. Thus, a better understanding of how neutrophils balance these seemingly contrasting functions would allow us to develop effective therapies that preserve the inflammation-resolving function while restricting the damage caused by inflammation. In this review, we specifically discuss the mechanisms behind neutrophil-derived S100A8/A9 in promoting inflammation and resolution in the context of MI. We also provide a perspective on how neutrophils could be potentially targeted to ameliorate cardiac inflammation and the ensuing damage.

2-Arachidonoylglycerol mobilizes myeloid cells and worsens heart function after acute myocardial infarction

AIMS

Myocardial infarction (MI) leads to an enhanced release of endocannabinoids and a massive accumulation of neutrophils and monocytes within the ischaemic myocardium. These myeloid cells originate from haematopoietic precursors in the bone marrow and are rapidly mobilized in response to MI. We aimed to determine whether endocannabinoid signalling is involved in myeloid cell mobilization and cardiac recruitment after ischaemia onset.

METHODS AND RESULTS

Intravenous administration of endocannabinoid 2-arachidonoylglycerol (2-AG) into wild type (WT) C57BL6 mice induced a rapid increase of blood neutrophil and monocyte counts as measured by flow cytometry. This effect was blunted when using cannabinoid receptor 2 knockout mice. In response to MI induced in WT mice, the lipidomic analysis revealed significantly elevated plasma and cardiac levels of the endocannabinoid 2-AG 24 h after infarction, but no changes in anandamide, palmitoylethanolamide, and oleoylethanolamide. This was a consequence of an increased expression of 2-AG synthesizing enzyme diacylglycerol lipase and a decrease of metabolizing enzyme monoacylglycerol lipase (MAGL) in infarcted hearts, as determined by quantitative RT-PCR analysis. The opposite mRNA expression pattern was observed in bone marrow. Pharmacological blockade of MAGL with JZL184 and thus increased systemic 2-AG levels in WT mice subjected to MI resulted in elevated cardiac CXCL1, CXCL2, and MMP9 protein levels as well as higher cardiac neutrophil and monocyte counts 24 h after infarction compared with vehicle-treated mice. Increased post-MI inflammation in these mice led to an increased infarct size, an impaired ventricular scar formation assessed by histology and a worsened cardiac function in echocardiography evaluations up to 21 days. Likewise, JZL184-administration in a myocardial ischaemia-reperfusion model increased cardiac myeloid cell recruitment and resulted in a larger fibrotic scar size.

CONCLUSION

These findings suggest that changes in endocannabinoid gradients due to altered tissue levels contribute to myeloid cell recruitment from the bone marrow to the infarcted heart, with crucial consequences on cardiac healing and function.

Predicting value of white cell count and total bilirubin on clinical outcomes in patients with ST-elevation myocardial infarction following percutaneous coronary intervention: a cohort study

OBJECTIVES

A combined equation based on white cell count (WCC) and total bilirubin (TB) was assessed for its ability to predict adverse clinical outcomes in patients with acute ST-segment elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PCI).

DESIGN

A single-centre, prospective cohort study.

SETTING

The First Affiliated Hospital of Xinjiang Medical University.

METHOD

A total of 615 patients with STEMI postprimary PCI were enrolled. WCC and TB were collected at admission. Logistic regression was used to determine the combined equation. The primary endpoints were in-hospital mortality and major adverse cardiovascular events (MACE), which composed of cardiac death, cardiac shock, malignant arrhythmia (ventricular tachycardia, ventricular fibrillation), severe cardiac insufficiency, non-fatal myocardial infarction, angina pectoris readmission, severe cardiac insufficiency (cardiac III-IV level), stent restenosis and target vessels revascularisation during the hospitalisation and 36 months follow-up period.

RESULT

77 patients occurred in MACE during the hospitalisation (17 in-hospital mortality). WCC and TB were taken as an independent variables to make a category of logistic regression analysis of in-hospital MACE, the logistic regression model was: logit (P)=-8.00+0.265 WCC+0.077 TB, the combination of WCC and TB was more valuable on evaluating the in-hospital mortality (area under the curve 0.804, 95% CI 0.678 to 0.929, p<0.001). Multivariate logistic regression analysis showed that combined detection was an independent risk factor for in-hospital MACE (OR 5.85, 95% CI 3.425 to 9.990, p=0.032). During the follow-up period, 172 patients (29.5%) developed MACE. But the combined detection did not predict the long-term clinical outcome.

CONCLUSION

The combination of WCC and TB is an independent predictor for in-hospital outcomes in patients with STEMI than single detection.

Full blood count as potential predictor of outcomes in patients undergoing cardiac resynchronization therapy

Almost a third of patients fulfilling current guidelines criteria have suboptimal responses following cardiac resynchronization therapy (CRT). Circulating biomarkers may help identify these patients. We aimed to assess the predictive role of full blood count (FBC) parameters in prognosis of heart failure (HF) patients undergoing CRT device implantation. We enrolled 612 consecutive CRT patients and FBC was measured within 24 hours prior to implantation. The follow-up period was a median of 1652 days (IQR: 837–2612). The study endpoints were i) composite of all-cause mortality or transplant, and ii) reverse left ventricular (LV) remodeling. On multivariate analysis [hazard ratio (HR), 95% confidence interval (CI)] only red cell count (RCC) (p = 0.004), red cell distribution width (RDW) (p < 0.001), percentage of lymphocytes (p = 0.03) and platelet count (p < 0.001) predicted all-cause mortality. Interestingly, RDW (p = 0.004) and platelet count (p = 0.008) were independent predictors of reverse LV remodeling. This is the first powered single-centre study to demonstrate that RDW and platelet count are independent predictors of long-term all-cause mortality and/or heart transplant in CRT patients. Further studies, on the role of these parameters in enhancing patient selection for CRT implantation should be conducted to confirm our findings.

Does stress hyperglycemia affect mortality? Acute myocardial infarction - case control study

Introduction

We aimed to investigate the effect of stress (acute) hyperglycemia in patients with acute coronary syndrome who had not been previously diagnosed with diabetes mellitus (DM) on the prognosis of the disease in terms of mortality.

Material and methods

Patients who were admitted to the Adana Numune Training and Research Hospital Emergency Service Clinic between August 2010 and August 2013 and whose plasma blood glucose level was over 140 mg/dl at the time of admission but were not previously diagnosed with DM, who were over the age of 18 and considered to have acute myocardial infarction were included.

Results

A total of 259 patients whose data were fully attainable were included in the study. 80.3% (n = 208) of the patients were male and 19.7% (n = 41) were female. Non-ST elevation myocardial infarction was found in 71.6%, ST elevation myocardial infarction was found in 28.4% of the patients with stress hyperglycemia. It was determined that 10.1% of patients with stress-related hyperglycemia and 1.3% of patients without stress-related hyperglycemia had died.

Conclusions

The plasma blood glucose level at presentation of patients diagnosed with acute myocardial infarction at the emergency room is associated with early in-hospital mortality.

Neutrophils in Post-myocardial Infarction Inflammation: Damage vs. Resolution?

Inflammation not only plays a crucial role in acute ischemic cardiac injury, but also contributes to post-infarction repair and remodeling. Traditionally, neutrophils have been merely considered as detrimental in the setting of an acute myocardial infarction. However, recently published studies demonstrated that neutrophils might also play an important role in cardiac repair by regulating reparative processes. An emerging concept is that different neutrophil subsets exist, which might exhibit separate functional properties. In support of the existence of distinct neutrophil subsets in the ischemic heart, transcriptional changes in cardiac neutrophils have been reported within the first few days after myocardial infarction. In addition, there is an increasing awareness of sex-specific differences in many physiological and pathophysiological responses, including cardiovascular parameters and inflammation. Of particular interest in this context are recent experimental data dissecting sex-specific differences in neutrophil signaling after myocardial infarction. Unraveling the distinct and possibly stage-dependent properties of neutrophils in cardiac repair may provide new therapeutic strategies in order to improve the clinical outcome for myocardial infarction patients. This review will briefly discuss recent advances in our understanding of the neutrophil functional repertoire and emerging insights of sex-specific differences in post-myocardial infarction inflammatory responses.

New Paradigms in Cell Therapy: Repeated Dosing, Intravenous Delivery, Immunomodulatory Actions, and New Cell Types

Perhaps the most important advance in the field of cell therapy for heart disease has been the recognition that all stem/progenitor cells (both adult and embryonic) fail to engraft in the heart to a significant extent and thus work via paracrine mechanisms. This fundamental advance has led to 4 new paradigms that are discussed in this review and that may importantly shape, or even revolutionize, the future of the field: (1) repeated cell therapy, (2) intravenous cell therapy, (3) immunomodulatory actions of cell therapy, and (4) new cell types. Because virtually all of our current knowledge of cell therapy is predicated on the effects of a single cell dose, the idea that the full therapeutic effects of a cell product require repeated doses is disruptive and has far-reaching implications. For example, inadequate dosing (single-dose protocols) may be responsible, at least in part, for the borderline or disappointing results obtained to date in clinical trials; furthermore, future studies (both preclinical and clinical) may need to incorporate repeated cell administrations. Another disruptive idea, supported by emerging preclinical and clinical evidence, is that intravenously injected cells can produce beneficial effects on the heart, presumably via release of paracrine factors in extracardiac organs or endocrine factors into the systemic circulation. Intravenous administration would obviate the need for direct delivery of cells to the heart, making cell therapy simpler, cheaper, safer, more scalable, and more broadly available, even on an outpatient basis. Although the mechanism of action of cell therapy remains elusive, there is compelling in vitro evidence that transplanted cells modulate the function of various immune cell types via release of paracrine factors, such as extracellular vesicles, although in vivo evidence is still limited. Investigation of the new paradigms reviewed herein should be a top priority because it may profoundly transform cell therapy and finally make it a reality.

Neutrophils orchestrate post-myocardial infarction healing by polarizing macrophages towards a reparative phenotype

Aims

Acute myocardial infarction (MI) is the leading cause of mortality worldwide. Anti-inflammatory strategies to reduce neutrophil-driven acute post-MI injury have been shown to limit acute cardiac tissue damage. On the other hand, whether neutrophils are required for resolving post-MI inflammation and repair is unknown.

Methods and Results

We show that neutrophil-depleted mice subjected to MI had worsened cardiac function, increased fibrosis, and progressively developed heart failure. Flow cytometry of blood, lymphoid organs and digested hearts revealed reduced numbers of Ly6Chigh monocytes in infarcts of neutrophil-depleted mice, whereas the number of macrophages increased, which was paralleled by reduced splenic Ly6Chigh monocyte mobilization but enhanced proliferation of cardiac macrophages. Macrophage subtype analysis revealed reduced cardiac expression of M1 markers, whereas M2 markers were increased in neutrophil-depleted mice. Surprisingly, we found reduced expression of phagocytosis receptor myeloid-epithelial-reproductive tyrosine kinase, a marker of reparative M2c macrophages which mediate clearance of apoptotic cells. In agreement with this finding, neutrophil-depleted mice had increased numbers of TUNEL-positive cells within infarcts. We identified neutrophil gelatinase-associated lipocalin (NGAL) in the neutrophil secretome as a key inducer of macrophages with high capacity to engulf apoptotic cells. The cardiac macrophage phenotype in neutrophil-depleted mice was restored by administration of neutrophil secretome or NGAL.

Conclusion

Neutrophils are crucially involved in cardiac repair after MI by polarizing macrophages towards a reparative phenotype. Therapeutic strategies to reduce acute neutrophil-driven inflammation after MI should be carefully balanced as they might interfere with the healing response and cardiac remodelling.

Prognostic value of neutrophil to lymphocyte ratio in heart failure patients

BACKGROUND

Neutrophil to lymphocyte ratio (NLR) has been indicated to be an independent predictor for all-cause mortality or adverse events in a variety of diseases. However, no consistent conclusions regarding it's relevance to patients with heart failure have been made. This meta-analysis was conducted to assess the significance of NLR in patients with heart failure.

METHODS

Pubmed and Embase databases were searched for eligible studies that reported the association between NLR and heart failure through September 2017. The overall hazard ratio (HR) and corresponding 95% confidence interval (CI) were used to assess the associations.

RESULTS

Ten studies met the eligibility criteria and a total of 5979 heart failure patients were included in the meta-analysis. The overall hazard ratio (HR) for all-cause mortality was 1.28 (95% CI 1.14-1.43) and the HR of renal dysfunction was 1.23 (95% CI 1.07-1.41) comparing the highest with the lowest category of NLR. However, the total pooled adjusted HR for in-hospital mortality (HR = 1.18, 95% CI 0.88-1.59) and rehospitalization (HR = 2.19, 95% CI 0.94-5.09) were not statistically significant. A subgroup analysis showed that sample size with moderate heterogeneity may be the origin of heterogeneity in all-cause mortality. Sensitivity analysis proved the stability of results of our meta-analysis.

CONCLUSIONS

The meta-analysis demonstrates that NLR is a predictor of all-cause mortality in patients with heart failure. Because the quality of the included studies varies, further well-designed studies are needed to confirm this association.

Association of Preoperative Cell Counts With Outcomes After Operation for Congenital Heart Disease

BACKGROUND

We examined the association of preoperative cell count abnormalities, which have been shown to be associated with outcomes in adult cardiac patients, with morbidity and mortality after operation for congenital heart disease (CHD) in children.

METHODS

We performed a retrospective cohort study on 4,865 children undergoing cardiac operation from 2004 to 2014. Our exposures of interest were presence of preoperative lymphopenia (lymphocyte count ≤ 3,000 cells/μL), thrombocytopenia (platelet count < 150 × 10³/μL), and neutrophilia (neutrophil count ≥ 7,000 cells/μL). Our outcomes of interest were mortality status, postoperative length of stay (LOS), and occurrence of postoperative complications. We performed logistic and linear regressions to determine the associations of preoperative cell counts with mortality, LOS, and complications, adjusting for age, sex, race or ethnicity, presence of a genetic syndrome, and Society of Thoracic Surgeons and European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality category.

RESULTS

Overall mortality was 2.8%, median LOS was 6 days, and 7.6% of patients had postoperative complications. Lymphopenia was associated with increased odds of postoperative mortality (odds ratio 1.67, 95% confidence interval: 1.15 to 2.43, p = 0.007). Lymphopenia, thrombocytopenia, and neutrophilia were all associated with longer postoperative LOS. Lymphopenia and thrombocytopenia were associated with increased occurrence of postoperative sepsis, and neutrophilia was associated with need for postoperative mechanical circulatory support.

CONCLUSIONS

In children undergoing CHD operation, preoperative lymphopenia is associated with increased in-hospital mortality postoperatively. Preoperative lymphopenia, neutrophilia, and thrombocytopenia are associated with longer postoperative LOS and with development of postoperative complications. Preoperative cell counts may serve as important prognostic markers in preoperative planning for patients with CHD.

Systemic inflammation in dogs with advanced-stage heart failure

BACKGROUND

Although human studies have shown that inflammation plays a role in the development of congestive heart failure, scarce information exists on white blood cell count (WBC) and differential cell counts in various stages of heart failure in man and dogs. A few studies demonstrated increased concentrations of C-reactive protein (CRP), a major acute-phase protein, in cardiac diseases in dogs. Our research aimed to investigate whether CRP concentration, WBC and neutrophil count (NEUT), as markers of systemic inflammation, are elevated in canine cardiovascular patients. We also aimed to find out whether there is an association between CRP concentration and WBC and NEUT, as well as associations between these inflammatory markers and selected echocardiographic parameters. Sixty-two client-owned canine cardiac patients and 12 healthy dogs were included in the study. The patients were classified into International Small Animal Cardiac Health Council classes (ISACHC I-III). The serum CRP concentration was determined using a canine CRP test kit. WBC and NEUT were determined using an automated hematology analyzer.

RESULTS

Significantly higher serum CRP concentration, WBC and NEUT were found in the decompensated stage of heart failure (ISACHC III) compared with healthy dogs and with patients in ISACHC group II and ISACHC group I. Serum CRP concentration significantly positively correlated with WBC (r = 0.65, P < 0.001) and NEUT (r = 0.58, P = 0.002) in the ISACHC III group, while no significant correlations were found in the ISACHC I and II groups. A significant negative correlation between serum CRP concentration and the left ventricular ejection fraction (r = - 0.49, P = 0.046) and a significant positive correlation between CRP and the E wave velocity of the mitral valve inflow (r = 0.52, P = 0.046) were found in the ISACHC III group.

CONCLUSIONS

The CRP concentration, WBC and NEUT were significantly increased in advanced-stage heart failure patients in comparison with compensated patients and healthy dogs, which indicate the presence of systemic inflammation. However, normal CRP concentration and normal WBC and NEUT can also be present in heart failure.

Immune responsive resolvin D1 programs myocardial infarction-induced cardiorenal syndrome in heart failure

Resolvins are innate, immune responsive, bioactive mediators generated after myocardial infarction (MI) to resolve inflammation. The MI-induced bidirectional interaction between progressive left ventricle (LV) remodeling and kidney dysfunction is known to advance cardiorenal syndrome (CRS). Whether resolvins limit MI-induced cardiorenal inflammation is unclear. Thus, to define the role of exogenous resolvin D (RvD)-1 in post-MI CRS, we subjected 8- to 12-wk-old male C57BL/6 mice to coronary artery ligation. RvD1 was injected 3 h after MI. MI mice with no treatment served as MI controls (d 1 and 5). Mice with no surgery served as naive controls. In the injected mice, RvD1 promoted neutrophil (CD11b⁺/Ly6G⁺) egress from the infarcted LV, compared with the MI control group at d 5, indicative of neutrophil clearance and thereby resolved inflammation. Further, RvD1-injected mice showed higher reparative macrophages (F4/80⁺/Ly6C^low/CD206⁺) in the infarcted LV than did MI control mice at d 5 after MI. RvD1 suppressed the miRNA storm at d 1 and limited the MI-induced edematous milieu in a remote area of the LV compared with the MI control at d 5 after MI. Also, RvD1 preserved the nephrin expression that was diffuse in the glomerular membrane at d 5 and 28 in MI controls, indicating renal injury. RvD1 attenuated MI-induced renal inflammation, decreasing neutrophil gelatinase-associated lipocalin and proinflammatory cytokines and chemokines in the kidney compared with the MI control. In summary, RvD1 clears MI-induced inflammation by increasing resolving leukocytes and facilitates renoprotective mechanisms to limit CRS in acute and chronic heart failure.-Halade, G. V., Kain, V., Serhan, C. N. Immune responsive resolvin D1 programs myocardial infarction-induced cardiorenal syndrome in heart failure.

Subclinical Inflammation in Heart Failure: A Neutrophil Perspective

Although it is widely recognized that inflammation plays a critical role in the development and pathology of heart failure (HF), very little is known about the involvement of one of the most abundant immune cells in the blood, a primary immune response cell: the neutrophil. This review summarizes the current literature on the role of subclinical inflammation, with a focus on the neutrophil in the pathophysiology of the HF syndrome. Some emerging therapeutic strategies are also discussed.

Usefulness of the delta neutrophil index to predict 30-day mortality in patients with ST segment elevation myocardial infarction

This study aimed to evaluate the association between the delta neutrophil index (DNI), which reflects immature granulocytes, and the severity of ST-elevation myocardial infarction (STEMI), as well as to determine the significance of the DNI as a prognostic marker for early mortality and other clinical outcomes in patients with STEMI who underwent reperfusion. This retrospective, observational cohort study was conducted using patients prospectively integrated in a critical pathway program for STEMI. We included 842 patients diagnosed with STEMI who underwent primary percutaneous coronary intervention (pPCI). Higher DNI values at time-I (within 2 h of pPCI; hazard ratio [HR], 1.075; 95% confidence interval [CI]: 1.046–1.108; p < 0.001) and time-24 (24 h after admission; HR, 1.066; 95% CI: 1.045–1.086; p < 0.001) were significant independent risk factors for 30-day mortality. Specifically, DNI values >2.5% at time-I (HR, 13.643; 95% CI: 8.13–22.897; p < 0.001) and > 2.9% at time-24 (HR, 12.752; 95% CI: 7.308–22.252; p < 0.001) associated with increased risks of 30-day mortality. In conclusion, an increased DNI value, which reflects the proportion of circulating immature granulocytes in the blood, was found to be an independent predictor of 30-day mortality and poor clinical outcomes in patients with acute STEMI post-pPCI.

Heart functional and structural compendium of cardiosplenic and cardiorenal networks in acute and chronic heart failure pathology

Heart failure (HF) secondary to myocardial infarction (MI) is linked to kidney complications that comprise cellular, structural, functional, and survival indicators. However, HF research is focused on left ventricular (LV) pathology. Here, we determined comprehensive functional analysis of the LV using echocardiography in transition from acute heart failure (AHF) to progressive chronic heart failure (CHF) pathology and developed a histological compendium of the cardiosplenic and cardiorenal networks in pathological remodeling. In surgically induced MI using permanent coronary ligation, the LV dysfunction is pronounced, with myocardium necrosis, wall thinning, and 20-30% LV rupture events that indicated AHF and CHF pathological remodeling in C57BL/6 male mice (2-4 mo old, n = 50). Temporal LV function analysis indicated that fractional shortening and strain are reduced from day 1 to day 5 in AHF and sustained to advance to CHF from day 28 to day 56 compared with naïve control mice ( n = 6). During the transition of AHF ( day 1 to day 5) to advanced CHF ( day 28 to day 56), histological and cellular changes in the spleen were definite, with bimodal inflammatory responses in kidney inflammatory biomarkers. Likewise, there was a unidirectional, progressive, and irreversible deposition of compact collagen in the LV along with dynamic changes in the cardiosplenic and cardiorenal networks post-MI. The renal histology and injury markers suggested that cardiac injury triggers irreversible dysregulation that actively alters the cardiosplenic and cardiorenal networks. In summary, the novel strategies or pathways that modulate comprehensive cardiosplenic and cardiorenal networks in AHF and CHF would be effective approaches to study either cardiac repair or cardiac pathology. NEW & NOTEWORTHY The present compendium shows irreversible ventricular dysfunction as assessed by temporal echocardiography while histological and structural measurements of the spleen and kidney added a novel direction to study cardiosplenic and cardiorenal networks in heart failure pathology. Therefore, the consideration of systems biology and integrative approach is essential to develop novel treatments.

Efferocytosis and Outside-In Signaling by Cardiac Phagocytes. Links to Repair, Cellular Programming, and Intercellular Crosstalk in Heart

Phagocytic sensing and engulfment of dying cells and extracellular bodies initiate an intracellular signaling cascade within the phagocyte that can polarize cellular function and promote communication with neighboring non-phagocytes. Accumulating evidence links phagocytic signaling in the heart to cardiac development, adult myocardial homeostasis, and the resolution of cardiac inflammation of infectious, ischemic, and aging-associated etiology. Phagocytic clearance in the heart may be carried out by professional phagocytes, such as macrophages, and non-professional cells, including myofibrolasts and potentially epithelial cells. During cardiac development, phagocytosis initiates growth cues for early cardiac morphogenesis. In diseases of aging, including myocardial infarction, heightened levels of cell death require efficient phagocytic debridement to salvage further loss of terminally differentiated adult cardiomyocytes. Additional risk factors, including insulin resistance and other systemic risk factors, contribute to inefficient phagocytosis, altered phagocytic signaling, and delayed cardiac inflammation resolution. Under such conditions, inflammatory presentation of myocardial antigen may lead to autoimmunity and even possible rejection of transplanted heart allografts. Increased understanding of these basic mechanisms offers therapeutic opportunities.

The infarcted myocardium solicits GM-CSF for the detrimental oversupply of inflammatory leukocytes

Myocardial infarction elicits massive recruitment of monocytes and neutrophils to the myocardium, but the mechanisms that control these processes are not fully understood. Here, Anzai et al. show that GM-CSF is a powerful orchestrator contributing to monocyte and neutrophil production, recruitment, and function.

Myocardial infarction (MI) elicits massive inflammatory leukocyte recruitment to the heart. Here, we hypothesized that excessive leukocyte invasion leads to heart failure and death during acute myocardial ischemia. We found that shortly and transiently after onset of ischemia, human and mouse cardiac fibroblasts produce granulocyte/macrophage colony-stimulating factor (GM-CSF) that acts locally and distally to generate and recruit inflammatory and proteolytic cells. In the heart, fibroblast-derived GM-CSF alerts its neighboring myeloid cells to attract neutrophils and monocytes. The growth factor also reaches the bone marrow, where it stimulates a distinct myeloid-biased progenitor subset. Consequently, hearts of mice deficient in either GM-CSF or its receptor recruit fewer leukocytes and function relatively well, whereas mice producing GM-CSF can succumb from left ventricular rupture, a complication mitigated by anti–GM-CSF therapy. These results identify GM-CSF as both a key contributor to the pathogenesis of MI and a potential therapeutic target, bolstering the idea that GM-CSF is a major orchestrator of the leukocyte supply chain during inflammation.

The time-of-day of myocardial infarction onset affects healing through oscillations in cardiac neutrophil recruitment

Myocardial infarction (MI) is the leading cause of death in Western countries. Epidemiological studies show acute MI to be more prevalent in the morning and to be associated with a poorer outcome in terms of mortality and recovery. The mechanisms behind this association are not fully understood. Here, we report that circadian oscillations of neutrophil recruitment to the heart determine infarct size, healing, and cardiac function after MI. Preferential cardiac neutrophil recruitment during the active phase (Zeitgeber time, ZT13) was paralleled by enhanced myeloid progenitor production, increased circulating numbers of CXCR2^hi neutrophils as well as upregulated cardiac adhesion molecule and chemokine expression. MI at ZT13 resulted in significantly higher cardiac neutrophil infiltration compared to ZT5, which was inhibited by CXCR2 antagonism or neutrophil‐specific CXCR2 knockout. Limiting exaggerated neutrophilic inflammation at this time point significantly reduced the infarct size and improved cardiac function.

Evaluation of Innate Immunity Biomarkers on Admission and at Discharge From an Acute Heart Failure Episode

BACKGROUND

The involvement of the immune system in heart failure (HF) has been demonstrated. Evidence shows that innate immunity can have a role in the remodeling process and progression of HF. With previous studies showing the prognostic value of some innate immunity markers and their relevance in this condition, we aim to evaluate how these markers vary on hospitalization due to an acute episode of HF and at discharge.

METHODS

About 154 patients admitted with acute HF were prospectively recruited. Patients were evaluated on admission and at discharge from the hospital. Patients with infection were separately analyzed. Innate immunity, inflammatory, and cardiac biomarkers were measured and were compared between groups and between admission and discharge and with reference values of biological variation.

RESULTS

Median patients' age was 78 years, and half of the patients were men. The median duration of hospitalization was 6 days. C3 and C4 protein levels significantly increased (P < 0.001) between admission and discharge, as well as eosinophils (P < 0.001) and BNP levels decreased (P < 0.001). Variation in all these variables was independent of infection and biological variation.

CONCLUSION

Our results show that innate immunity markers such as C3 and C4 increase after treatment for acute HF, supporting the hypothesis that they can be involved in the resolution of the acute episode.

Two parameters reflect lipid-driven inflammatory state in acute coronary syndrome: atherogenic index of plasma, neutrophil-lymphocyte ratio

BACKGROUND

Atherosclerosis is a systemic, lipid-driven immune-inflammatory disease.

METHODS

We retrospectively reviewed institutional electronic medical records to seek chest pain patients who were suspicious of acute coronary syndrome (ACS) between January 2011 and December 2013. All the patients were identified by undergoing coronary angiography. On admission white blood cell and its subtypes were measured as part of the automated complete blood count and fasting venous blood samples were obtained and analyzed for lipids profiles used automated analysis.

RESULTS

A total of 376 consecutive patients with ACS were investigated. In the same period, 378 patients admitted with chest pain suspicious of ACS were also included in this study for control. Blood glucose, serum creatinine, white blood cell, neutrophil and monocyte were insignificantly higher in the ACS group. ACS group had higher total cholesterol and lower high density lipid-cholesterol. However, triglyceride and low density lipid-cholesterol were similar between ACS and control groups. Atherogenic index of plasma (AIP) was significantly higher in ACS group compared to control group (p = 0.029). Similarly, ACS group had higher neutrophil-lymphocyte ratio (NLR) than those in control group. In the subgroups, the NLR were significantly higher in the STEMI group (p < 0.001). However, AIP were similar between the three subgroups (p = 0.748).

CONCLUSIONS

Our data firstly investigated the lipid-driven inflammatory state in acute coronary syndrome through two easily feasible parameters. There suggest that there are higher AIP and NLR in the ACS patients. Moreover, ACS subgroups are all lipid-driven states, but inflammation levels are different in the entity ACS subgroups.

Neutrophil count improves the GRACE risk score prediction of clinical outcomes in patients with ST-elevation myocardial infarction

OBJECTIVE

Both the Global Registry of Acute Coronary Events (GRACE) risk score and neutrophil count could predict clinical outcomes in patients with acute coronary syndromes. However, the ability of them to identify high risk patients leaves room for improvement. The purpose of the present study was to evaluate whether the combination of them could have a better performance in predicting clinical outcomes in patients with ST-elevation myocardial infarction (STEMI).

METHODS

A total of 1287 consecutive STEMI patients were recruited at two centers in China. Neutrophil count was measured and the GRACE risk score was calculated.

RESULTS

During a median period of 37 months (IQR, 29-47), 135 (10.9%) patients had major adverse cardiovascular events (MACE), including 116 all-cause death. Neutrophil count and the GRACE risk score were higher in patients with MACE. Both neutrophil count and the GRACE score were significant and independent predictors for MACE [HR: 1.260 (1.203-1.319), P < 0.001; HR: 1.007 (1.002-1.011), P < 0.001; respectively). Combination of them increased the area under the ROC (0.698 vs. 0.796, P < 0.001). The addition of neutrophil count to GRACE model enhanced net reclassification improvement (0.637, P = 0.020) and integrated discrimination improvement (0.180, P < 0.001), suggesting effective discrimination and reclassification.

CONCLUSION

Both neutrophil count and the GRACE risk score are independent predictors for MACE in patients with STEMI. A combination of them could derive a more accurate prediction for clinical outcomes in these patients.

Prognostic Value of the Percentage of Neutrophils on Admission in Patients with ST-elevated Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND AND AIMS

An elevated neutrophil count or neutrophil/lymphocyte ratio on admission has been reported to be an independent predictor of adverse cardiac events in patients with acute coronary syndrome (ACS). The relationship between the percentage of neutrophils (N%) at the time of admission and the long-term outcomes in patients with ST-segment elevated myocardial infarction (STEMI) who have undergone primary percutaneous coronary intervention (PCI) remains unclear. The aim of this study was to investigate the usefulness of the admission N% in predicting long-term mortality in patients with STEMI who were undergoing primary PCI.

METHODS

We evaluated 701 consecutive patients admitted to nine medical institutions in northwest China within 24 h after symptom onset from January 1, 2009-December 31, 2011. Using a receiver-operating characteristic analysis, N% ≥82.1% was the best predictor of long-term mortality. Patients were divided into two groups according to this criterion. Mean follow-up time was 39.03 months.

RESULTS

The long-term all-cause mortality rate was significantly higher in patients with a high N% level (7.17 vs. 3.11%, p = 0.015) as was the rate of cardiac mortality (6.48 vs. 2.59%, p = 0.013). In a multivariate logistic analysis, a high N% level was an independent predictor of long-term all-cause mortality (odds ratio 2.59, 95% confidence interval 1.21-5.53, p = 0.002) and long-term cardiac mortality (odds ratio 2.79, 95% confidence interval 1.24-6.28, p = 0.013).

CONCLUSIONS

A high N% level on admission is an independent predictor of long-term mortality in STEMI patients undergoing primary PCI.

Inflammatory markers in ST-elevation acute myocardial infarction

After acute myocardial infarction, ventricular remodeling is characterized by changes at the molecular, structural, geometrical and functional level that determine progression to heart failure. Inflammation plays a key role in wound healing and scar formation, affecting ventricular remodeling. Several, rather different, components of the inflammatory response were studied as biomarkers in ST-elevation acute myocardial infarction. Widely available and inexpensive tests, such as leukocyte count at admission, as well as more sophisticated immunoassays provide powerful predictors of adverse outcome in patients with ST-elevation acute myocardial infarction. We review the value of inflammatory markers in ST-elevation acute myocardial infarction and their association with ventricular remodeling, heart failure and sudden death. In conclusion, the use of these biomarkers may identify subjects at greater risk of adverse events and perhaps provide an insight into the mechanisms of disease progression.

Elevated levels of RDW is associated with non-valvular atrial fibrillation

Red cell distribution width (RDW) and neutrophil/lymphocyte ratio (NLR) have been found to be associated with cardiovascular diseases. Only a few trials have investigated the correlation of these parameters with postoperative atrial fibrillation (AF). However, the correlation of these parameters in non-valvular AF is still unclear. We retrospectively analyzed consecutive AF patients from medical records and included 117 non-valvular AF patients (103 paroxysmal and 14 chronic AF). All subjects underwent physical examination and echocardiographic imaging. Complete blood counts (CBCs) were analyzed for hemoglobin, RDW, neutrophil and lymphocyte counts as well as mean corpuscular volume. Results of CBC tests within the previous year were also included and the averages were used. The demographic and echocardiographic properties of non-valvular AF group were comparable to the control group except for left atrial volumes which were increased in AF (median 33.1, IQR 26.3-41.1 cm(3) vs. median 26.4, IQR 24.2-28.9 cm(3); p = 0.01). RDW levels were significantly higher in the AF group (median 13.4 %, IQR 12.9-14.1 %) compared to the control (median 12.6 %, IQR 12.0-13.1 %; p = 0.01). NLR was not statistically different in the AF group and the controls (2.04 ± 0.94 vs. 1.93 ± 0.64, respectively; p = 0.32). Hs-CRP levels were higher in the AF group compared to the controls (median 0.84, IQR 0.30-1.43 mg/L vs. median 0.29, IQR 0.18-0.50 mg/L, respectively; p = 0.01). Multivariate logistic regression analysis revealed RDW (OR 4.18, 95 % CI 2.15-8.15; p = 0.01), hs-CRP (OR 3.76, 95 % CI 1.43-9.89; p = 0.01) and left atrial volume (OR 1.31, 95 % CI 1.06-1.21; p = 0.01) as the independent markers of non-valvular AF. Multivariate linear regression analysis revealed that hemoglobin levels (standardized β coefficient = -0.252; p = 0.01) and the presence of AF (standardized β coefficient = 0.336; p = 0.01) were the independent correlates of RDW levels. Elevated RDW levels, not NLR, may be an independent risk marker for non-valvular AF.

Association between peak neutrophil count, clopidogrel loading dose, and left ventricular systolic function in patients with primary percutaneous coronary intervention

Inflammation plays an important role in plaque development and left ventricular remodeling during acute myocardial infarction (AMI). Clopidogrel may exhibit some anti-inflammatory properties and high loading dose of clopidogrel results in improved clinical outcomes in patients with AMI. 357 patients who received successful primary percutaneous coronary intervention from January 2008 to March 2011 in Peking University Third Hospital were included in this study. Different loading dose of clopidogrel (300 mg, 450 mg, or 600 mg) was given at the discretion of the clinician. Neutrophils reached their peak values on the first day after AMI. Higher levels of peak neutrophil and lower left ventricular ejection fraction (LVEF) were found in patients of low clopidogrel loading dose group (300 mg or 450 mg). After adjusting for the related confounders, a logistic regression model showed that low clopidogrel loading dose remained an independent predictor of low LVEF (LVEF ≤ 50%) [OR: 1.97, 95% CI: 1.03–3.79, P = 0.04]. Low clopidogrel loading dose was associated with higher peak neutrophil count and poor left ventricular systolic function, suggesting an important role of clopidogrel loading dose in the improvement of left ventricular function and high loading dose may exhibit better anti-inflammatory properties.

The immunological axis in heart failure: importance of the leukocyte differential

The important role of the immune system and inflammation in the pathophysiology of heart failure (HF) is becoming increasingly appreciated. We have reviewed the prognostic significance of under-recognized aspects of the leukocyte differential in HF, including lymphocytes, monocytes, eosinophils and mast cells. Studies to date evaluating lymphocyte counts in both chronic and hospitalized HF patients have consistently shown worse prognosis associated with low lymphocyte counts, despite widely heterogeneous study designs. Limited data suggest elevations in monocyte-derived cytokines and serum monocyte count may be predictive of poor outcomes in HF. Further data are required to better define the relationship between eosinophils, mast cells and HF. Leukocyte differentials are widely available, simple, inexpensive and appear to have independent prognostic significance, beyond traditional risk factors. Enhanced sympathetic activation and increased circulating cytokine levels (particularly tumor necrosis factor) have been implicated in the variability of leukocyte subpopulations. To date, immune-modulators targeting these mediators have been largely unsuccessful in improving cardiovascular outcomes in HF. Given the potential role of the immunological axis in HF, there may be an unmet need for novel therapeutic agents that can safely and effectively ameliorate these leukocyte derangements and perhaps improve the unacceptably high event rate in this population. Variations in leukocyte differentials may identify a high-risk subset of patients that may benefit from tailored immune therapies.

Gene expression profiles associated with acute myocardial infarction and risk of cardiovascular death

Background

Genetic risk scores have been developed for coronary artery disease and atherosclerosis, but are not predictive of adverse cardiovascular events. We asked whether peripheral blood expression profiles may be predictive of acute myocardial infarction (AMI) and/or cardiovascular death.

Methods

Peripheral blood samples from 338 subjects aged 62 ± 11 years with coronary artery disease (CAD) were analyzed in two phases (discovery N = 175, and replication N = 163), and followed for a mean 2.4 years for cardiovascular death. Gene expression was measured on Illumina HT-12 microarrays with two different normalization procedures to control technical and biological covariates. Whole genome genotyping was used to support comparative genome-wide association studies of gene expression. Analysis of variance was combined with receiver operating curve and survival analysis to define a transcriptional signature of cardiovascular death.

Results

In both phases, there was significant differential expression between healthy and AMI groups with overall down-regulation of genes involved in T-lymphocyte signaling and up-regulation of inflammatory genes. Expression quantitative trait loci analysis provided evidence for altered local genetic regulation of transcript abundance in AMI samples. On follow-up there were 31 cardiovascular deaths. A principal component (PC1) score capturing covariance of 238 genes that were differentially expressed between deceased and survivors in the discovery phase significantly predicted risk of cardiovascular death in the replication and combined samples (hazard ratio = 8.5, P < 0.0001) and improved the C-statistic (area under the curve 0.82 to 0.91, P = 0.03) after adjustment for traditional covariates.

Conclusions

A specific blood gene expression profile is associated with a significant risk of death in Caucasian subjects with CAD. This comprises a subset of transcripts that are also altered in expression during acute myocardial infarction.

Superiority of total white blood cell count over other leukocyte differentials for predicting long-term outcomes in patients with non-ST elevation acute coronary syndrome

CONTEXT

Leukocytes have been found to be the predictor of outcome following acute coronary syndrome (ACS).

OBJECTIVE

We sought to determine the relationship between leukocyte differentials and developing major adverse cardiac events (MACE) in patients with non-ST elevation ACS (NSTE-ACS).

MATERIALS AND METHODS

A total of 490 consecutive patients were enrolled, and MACE incidence was evaluated at long-term follow-up period.

RESULTS

Total white blood cell (WBC) was higher in subjects occurring MACE. Moreover, elevated total WBC, ≥7.5 × 10(3)/µL, independently predicted MACE.

DISCUSSION AND CONCLUSION

Elevated admission total WBC can predict long-term MACE in NSTE-ACS patients better than other differentials.

Phagocyte-myocyte interactions and consequences during hypoxic wound healing

Myocardial infarction (MI), secondary to atherosclerotic plaque rupture and occlusive thrombi, triggers acute margination of inflammatory neutrophils and monocyte phagocyte subsets to the damaged heart, the latter of which may give rise briefly to differentiated macrophage-like or dendritic-like cells. Within the injured myocardium, a primary function of these phagocytic cells is to remove damaged extracellular matrix, necrotic and apoptotic cardiac cells, as well as immune cells that turn over. Recognition of dying cellular targets by phagocytes triggers intracellular signaling, particularly in macrophages, wherein cytokines and lipid mediators are generated to promote inflammation resolution, fibrotic scarring, angiogenesis, and compensatory organ remodeling. These actions cooperate in an effort to preserve myocardial contractility and prevent heart failure. Immune cell function is modulated by local tissue factors that include secreted protease activity, oxidative stress during clinical reperfusion, and hypoxia. Importantly, experimental evidence suggests that monocyte function and phagocytosis efficiency is compromised in the setting of MI risk factors, including hyperlipidemia and ageing, however underlying mechanisms remain unclear. Herein we review seminal phagocyte and cardiac molecular factors that lead to, and culminate in, the recognition and removal of dying injured myocardium, the effects of hypoxia, and their relationship to cardiac infarct size and heart healing.

New Approaches to Treating Cardiac Cachexia in the Older Patient

Congestive heart failure (CHF) is a leading cause of morbidity and mortality in the elderly, accounting for more hospitalizations than any other condition. Advanced stages of congestive heart failure can be associated with serious complications such as cardiac cachexia (defined here as unintentional weight loss of more than 6% in 6 months). Cardiac cachexia and the associated progressive weight loss are sometimes overlooked by older patients, their families and care providers. A delay in the diagnosis can result in further loss of vital organ tissue, progressive weakness, fall-related injuries and even long-term care institutionalization and/or death. During the past several years, researchers have begun to broaden their understanding of this common, morbid and often fatal condition, and these findings will help to characterize the features that assist in its diagnosis, minimize its exacerbation, delay the progressive decline, and educate clinicians about the potential management options.

White Blood Cell Subtypes and Neutrophil-Lymphocyte Ratio in Prediction of Coronary Thrombus Formation in Non-ST-Segment Elevated Acute Coronary Syndrome

Leukocytes are reported as crucial not only for plaque activation but also in thrombus formation in acute coronary syndromes (ACSs). Among the markers of inflammation, in coronary artery disease neutrophil-lymphocyte ratio (NLR) has been reported to have the greatest predictive power of poor outcomes. Our aim was to evaluate the association of NLR with coronary thrombus in patients with non-ST-segment elevated ACSs (NST-ACSs). A total of 251 patients were hospitalized with a diagnosis of NST-ACS including non-ST-segment elevated myocardial infarction and unstable angina pectoris. Coronary angiographies were performed. In 167 patients, coronary thrombus was detected. Between the patient groups with and without coronary thrombus, neutrophil count, platelet count, and NLR are significantly increased, and lymphocyte count is significantly decreased in the group with coronary thrombus as compared to patient group without coronary thrombus. Leukocyte count and NLR may give an indication about the presence of coronary thrombus. In NST-ACS, blood parameters may give valuable information about the status of the coronary arteries.