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Atrial fibrillation (AF) is a common cardiac arrhythmia with an estimated prevalence of 1% in the general population. It is associated with an increased risk of ischemic stroke, silent cerebral ischemia, and cognitive impairment. Due to the blood flow stasis and morphology, thrombus formation occurs mainly in the left atrial appendage (LAA), particularly in the setting of nonvalvular AF (NVAF). Previous studies have shown that >90% of emboli related to NVAF originate from the LAA, thus prevention of systemic cardioembolism is indicated. According to the current guidelines, anticoagulant therapy with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs), represents the standard of care in AF patients, in order to prevent ischemic stroke and peripheral embolization. Although these drugs are widely used and DOACs have shown, compared to VKAs, non-inferiority for stroke prevention with significantly fewer bleeding complications, some issues remain a matter of debate, including contraindications, side effects, and adherence. An increasing number of patients, indeed, because of high bleeding risk or after experiencing life-threatening bleedings, must take anticoagulants with extreme caution if not contraindicated. While surgical closure or exclusion of LAA has been historically used in patients with AF with contradictory results, in the recent years, a novel procedure has emerged to prevent the cardioembolic stroke in these patients: The percutaneous left atrial appendage occlusion (LAAO). Different devices have been developed in recent years, though not all of them are approved in Europe and some are still under clinical investigation. Currently available devices have shown a significant decrease in bleeding risk while maintaining efficacy in preventing thromboembolism. The procedure can be performed percutaneously through the femoral vein access, under general anesthesia. A transseptal puncture is required to access left atrium and is guided by transesophageal echocardiography (TEE). Evidence from the current literature indicates that percutaneous LAAO represents a safe alternative for those patients with contraindications for long-term oral anticoagulation. This review summarizes scientific evidences regarding LAAO for stroke prevention including clinical indications and an adequate patient selection.

Several studies have shown that T-cells might be involved in pathophysiology of acute coronary syndromes (ACS). Tissue factor (TF) plays a key role in ACS. Many evidences have indicated that some statins reduce TF expression in several cell types. However, literature about rosuvastatin and TF and about statins effects on T-cells is still scanty. Colchicine is an anti-inflammatory drug recently proven to have beneficial effects in ACS via unknown mechanisms. This study investigates the effects of colchicine and rosuvastatin on TF expression in oxLDL-activated T-cells. T-cells, isolated from buffy coats of healthy volunteers, were stimulated with oxLDL (50µg/dL). T-cells were pre-incubated with colchicine (10µM) or rosuvastatin (5µM) for 1h and then stimulated with oxLDL (50μg/mL). TF gene (RT-PCR), protein (western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. NF-κB/IκB axis was examined by western blot analysis and translocation assay. Colchicine and rosuvastatin significantly reduced TF gene, and protein expression and procoagulant activity in oxLDL stimulated T-cells. This effect was associated with a significant reduction in TF surface expression as well as its procoagulant activity. These phenomena appear modulated by drug effects on the transcription factor NF-kB. Rosuvastatin and colchicine prevent TF expression in oxLDL-stimulated T-cells by modulating the NF-κB/IκB axis. Thus, we speculate that this might be another mechanism by which these drugs exert benefic cardiovascular effects.

Among acute coronary syndrome (ACS) patients, 15% have concomitant cancer, especially in the first 6 months after their diagnosis, as well as in advanced metastatic stages. Lung, gastric, and pancreatic cancers are the most frequent malignancies associated with ACS. Chemotherapy and radiotherapy exert prothrombotic, vasospastic, and proinflammatory actions. The management of cancer patients with ACS is quite challenging: percutaneous revascularization is often underused, and antiplatelet and anticoagulant pharmacological therapy should be individually tailored to the thrombotic risk and to the bleeding complications. Sometimes oncological patients also show different degrees of thrombocytopenia, which further complicates the pharmacological strategies. The aim of this review is to summarize the current evidence regarding the treatment of ACS in cancer patients and to suggest the optimal management and therapy to reduce the risk of adverse coronary events after ACS in this high-risk population.

Grittani, Mario, Grazia Pellegrino, Stefano Conte, Andrea Morello, Alberto Autore, Giovanni Cimmino, Bruno Trimarco, Fabio Morgagni, and Plinio Cirillo. Effects of hypobaric hypoxia on endothelial function and adiponectin levels in airforce aviators. High Alt Med Biol 00:000-000, 2019. Background: Hypobaric hypoxia (HH) increases the risk of high altitude-related illnesses (HARI). The pathophysiological mechanism(s) involved are still partially unknown. Altered vascular reactivity as consequence of endothelial dysfunction during HH might play a role in this phenomenon. Adiponectin exerts protective effect on cardiovascular system since it modulates NO release, antagonizing endothelial dysfunction. Aims of this study, performed in a selected population of airforce aviators, were (1) to investigate whether exposure to acute HH might be associated with endothelial dysfunction and (2) to evaluate whether adiponectin might be involved in modulating this phenomenon. Methods: Twenty aviators were exposed to acute HH in a hypobaric chamber by simulating altitude of 8000 and then 6000 m for 2 hours. Vascular reactivity was evaluated by the EndoPAT test immediately before and after the HH; salivary and blood adiponectin levels were measured. Results: EndoPAT performed immediately after HH divided pilots in two groups: 12 pilots with preserved vascular reactivity and 8 pilots with reduction of vascular reactivity, indicating that HH exposure might cause endothelial dysfunction. Salivary and blood adiponectin levels increased post-HH in a time-dependent manner in all aviators, but the significant increase was observed only in those with preserved vascular reactivity suggesting that HH stimulated release of adiponectin that, in turn, by exerting a protective effect, might reduce endothelial dysfunction. Conclusions: Acute HH may cause endothelial dysfunction due, at least in part, to reduced release of adiponectin. This phenomenon might be involved in pathophysiology of HARI..

The key role of platelets in pathophysiology of Acute Coronary Syndromes (ACS) has been well recognized. Platelet activation and aggregation, together with tissue factor-pathway activation, lead to acute thrombus formation in the coronary vessels at sites of plaque rupture. Thus, antiplatelet therapy with drugs able to interfere with platelet activation/aggregation represents a cornerstone of ACS treatment in intensive care units and catheterisation labs. Several observational studies have described that residual high platelet reactivity, despite antiplatelet therapy, is associated with increased risk of nonfatal Myocardial Infarction (MI), definite/probable stent thrombosis and cardiovascular mortality. Thus, assessment of platelet function with reliable and reproducible platelet function tests might be crucial to identify patients at high risk of thrombosis or not responding to ongoing antiplatelet strategies. However, despite this promising background, some randomized clinical trials have failed to demonstrate improvement in outcomes when using platelet function tests for clinical decision-making. This review, after describing platelet biology and pathophysiology of ACS, briefly considers the drugs currently approved for use in patients with ACS or treated by the percutaneous coronary intervention (PCI). Finally, we provide an updated overview of the current methods to evaluate platelet reactivity in the clinical setting of ACS illustrating their potential advantages/limitations in current clinical practice.

It is generally accepted that the initial event in coagulation and intravascular thrombus formation is the exposure of the flowing blood to cell-surface protein, such as tissue factor (TF). Vascular injury and/or atherosclerotic plaque complication is responsible for this exposure, leading to clinical manifestations such as acute coronary syndromes. For many years, TF has been considered one of the major determinants of plaque-related thrombosis. However, the discoveries of different pools of TF that circulates in the blood as cell-associated TF, microparticles bound, and as soluble form have changed this dogma. Recent evidence suggests that an increased circulating TF activity may potentiate the initial thrombogenic stimulus related to vessel wall-associated TF, leading to the formation of larger and/or more stable thrombus and thus more severe clinical manifestations. Different pathological conditions, such as inflammatory status, enhance TF expression and activity. Conversely, TF upregulation may facilitate inflammation by formation of proinflammatory fibrin fragments and coagulation proteases generation, including FVIIa, FXa, and thrombin. Furthermore, the biology of TF has become more complex by the demonstration that, apart from its known effects on blood coagulation, it is involved in intracellular signaling, proliferation, angiogenesis, and tumor metastasis.

The role of low-density lipoproteins (LDLs) as a major risk factor for cardiovascular disease has been demonstrated by several epidemiological studies. The molecular basis for LDLs in atherosclerotic plaque formation and progression is not completely unraveled yet. Pharmacological modulation of plasma LDL-C concentrations and randomized clinical trials addressing the impact of lipid-lowering interventions on cardiovascular outcome have clearly shown that reducing plasma LDL-C concentrations results in a significant decrease in major cardiovascular events. For many years, statins have represented the most powerful pharmacological agents available to lower plasma LDL-C concentrations. In clinical trials, it has been shown that the greater the reduction in plasma LDL-C concentrations, the lower the rate of major cardiovascular events, especially in high-risk patients, because of multiple risk factors and recurrent events. However, in a substantial number of patients, the recommended LDL target is difficult to achieve because of different factors: genetic background (familial hypercholesterolemia), side effects (statin intolerance), or high baseline plasma LDL-C concentrations. In the last decade, our understanding of the molecular mechanisms involved in LDL metabolism has progressed significantly and the key role of proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged. This protein is an enzyme able to bind the LDL receptors (LDL-R) on hepatocytes, favoring their degradation. Blocking PCSK9 represents an intriguing new therapeutic approach to decrease plasma LDL-C concentrations, which in recent studies has been demonstrated to also result in a significant reduction in major cardiovascular events.

BACKGROUND: Antithrombotic management of patients with atrial fibrillation (AF) requiring percutaneous coronary intervention (PCI) is highly variable; limited evidence‐based guidelines exist to influence practice. HYPOTHESIS: Patient characteristics and availability of novel drugs may have contributed to practice variability. METHODS: We undertook an international multicenter retrospective registry of AF patients treated with PCI. The primary measures of interest were antiplatelet and OAC prescriptions at discharge. We compared temporal trends between Prior (2010–2012) and Recent (2013–2015) cohorts and investigated variables associated with OAC prescription. RESULTS: We identified 488 cases (140 Prior, 348 Recent). Median CHADS(2) and HAS‐BLED scores were 2 (IQR, 1–3) and 2 (IQR, 2–3). Clinical characteristics were similar between cohorts, with high (85%) prevalence of ACS. More patients in the Recent cohort, compared with Prior, received OAC (56.9% vs 44.3%; P = 0.01) and NOAC (27.3% vs 3.6%; P

In recent years, Pregnancy-associated Plasma Protein-A (PAPP-A), a metalloproteinase originally identified in the plasma of pregnant women and then found in both men and women, has been studied for its potential involvement in cardiovascular disease. Several studies have indicated that PAPP-A might be considered as a marker of Acute Coronary Syndromes (ACS) able to predict outcome of patients with this clinical presentation. We have recently demonstrated that PAPP-A is able to induce TF expression in endothelial cells in vitro, suggesting an active involvement of this metalloproteinase in thrombotic events. We found that transcoronary PAPP-A levels were significantly higher in ACS-NSTEMI patients as compared to patients with SCAD and that elevated PAPP-A concentrations were associated with higher rate of TF consumption. results of this study permit for the first time to speculate that this metalloproteinase, does not represent only an independent risk factor for adverse cardiovascular or a marker of disease to obtain and early diagnosis of ACS, but it rather might play an “active” role in the pathophysiology of ACS as an effector molecule able to induce thrombus formation in the coronary circulation.

Tissue factor pathway inhibitor (TFPI) is a serine-protease inhibitor, which modulates coagulation tissue factor-dependent (TF). It binds directly and inhibits the TF-FVII/FVIIa complex as well as FXa. Time to reperfusion of acute ischemic myocardium is essential for tissue salvage. However, reperfusion also results in a unique form of myocardial damage, such as contractile dysfunction, decreased coronary flow and altered vascular reactivity. Oxidants and reactive oxygen species (ROS) formation is increased in the post-ischemic heart and is responsible of post-ischemic injury. It has been reported that ROS promote a procoagulant state via TF expression while no data are available on the effect on TFPI. Endothelial cells were incubated with two different ROS generating systems, xanthine (X)/xanthine oxidase (XO) for 5 min, or H2O2 (500 μM) for 24 h. TFPI activity was measured in supernatants by chromogenic assay and TFPI-mRNA analyzed by RT-PCR 2 h after ROS exposure. Unstimulated cells and cells exposed to either X or XO served as controls. Western blot and ligand dot blot was performed to evaluate ROS effect on TFPI structure and binding to FXa. ROS generated by X/XO as well as H2O2 system resulted in decreased TFPI activity compared to unstimulated cells while X or XO alone had no effect. No differences in TFPI mRNA levels versus controls was observed. A significant degradation of TFPI was induced by ROS exposure, resulting in a decreased ability to bind FXa. ROS induce a procoagulant state in endothelial cells by altering TFPI structure, resulting in inhibition of TFPI binding to Factor Xa and loss of activity. This phenomenon might have important consequences during reperfusion of post-ischemic myocardium.

Background Matrix metalloproteases (MMPs) have been implicated in the pathogenesis of acute coronary syndromes (ACS). However, little is known about the mechanisms responsible for MMP expression in ACS. C-reactive protein (CRP) not only is an independent risk factor for cardiovascular events, but also may exert direct pro-atherosclerotic effects. Therefore, we aimed at determining whether CRP might induce MMP-9 in two different experimental conditions: 1) smooth muscle cells (SMCs) in vitro, and 2) patients with ACS. Methods and results Effects of increasing concentrations of CRP on MMP-9 expression were evaluated in vitro in human SMCs. TIMP-1 protein expression, the selective inhibitor of MMP-9, was also evaluated. CRP dose-dependently induced MMP-9 expression in SMCs by promoting MMP-mRNA transcription, as well as MMP-9 secretion. In contrast, no differences were found for TIMP-1 protein expression. In vivo, MMP-9 and CRP levels were measured in blood samples obtained from the aorta (Ao) and the coronary sinus (Cs) of patients with normal coronary arteries (controls, n=21), stable angina (n=24), and ACS (n=30). Both MMP-9 and CRP plasma levels were significantly increased across the coronary circulation only in patients with ACS. Interestingly, a significant correlation between MMP-9 and CRP plasma levels was found. Conclusions CRP induced MMP-9 expression and activity in human SMCs in culture; patients presenting with ACS have increased transcoronary plasma levels of MMP-9 and CRP with a significant correlation between these two markers. This may explain the heightened risk of coronary events in subjects with elevated levels of CRP.

Worldwide increase in life expectancy is a major contributor to the epidemic of chronic degenerative diseases. Aging, indeed, simultaneously affects multiple organ systems, and it has been hypothesized that systemic alterations in regulators of tissue physiology may regulate this process. Cardiac aging itself is a major risk factor for cardiovascular diseases and, because of the intimate relationship with the brain, may contribute to increase the risk of neurodegenerative disorders. Blood-borne factors may play a major role in this complex and still elusive process. A number of studies, mainly based on the revival of parabiosis, a surgical technique very popular during the 70s of the 20 th century to study the effect of a shared circulation in two animals, have indeed shown the potential that humoral factors can control the aging process in different tissues. In this article we review the role of circulating factors in cardiovascular aging. A better understanding of these mechanisms may provide new insights in the aging process and provide novel therapeutic opportunities for chronic age-related disorders.

Acute thrombus formation is the pathophysiological substrate underlying several clinical conditions, such as acute coronary syndrome (ACS) and stroke. Activation of coagulation cascade is a key step of the thrombotic process: vessel injury results in exposure of the glycoprotein tissue factor (TF) to the flowing blood. Once exposed, TF binds factor VII/VIIa (FVII/FVIIa) and in presence of calcium ions, it forms atertiary complex able to activate FX to FXa, FIX to FIXa, and FVIIa itself. The final step is thrombin formation at the site of vessel injury with subsequent platelet activation, fibrinogen to fibrin conversion and ultimately thrombus formation. Platelets are the key cells in primary hemostasis. For years they have been considered only as cell fragments participating to primary hemostasis and onto which coagulation factors are assembled in the process of thrombus formation. However, recent advances in platelets pathophysiology have shown that these cells are able to regulate their gene and protein expression, make de novo protein synthesis, and release different mediators with paracrine effects that may interfere with different cell function. Pharmacological modulation of both side of thrombosis, coagulation cascade and platelet activation, is of great clinical importance. Several clinical trials have clearly shown the efficacy of anticoagulation and/or anti platelet aggregation in different thrombotic disorders. This article aims at reviewing the recent advancements on the two faces of thrombosis focusing on the emerging role of platelets not only as clot-forming components, but highlighting their involvement in the inflammatory-immune system, as well as in modulation of different cell function.

Background Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (beta-TM) patients. The aim of the current study was to evaluate the atrial electromechanical delay (AEMD) in a large beta-TM population with normal cardiac function and its relationship to atrial fibrillation (AF) onset.Methods Eighty beta-TM patients ( 44 men, 36 women), with a mean age of 36.2 +/- 11.1 years, and 80 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of AF during a 5-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram ( ECG).Results Compared to the healthy control group, the beta-TM patients showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the beta-TM group into two subgroups (patients with or without AF), the inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD were significantly higher in the subgroup with AF compared to the subgroup without AF. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cut-off value of 40.1 ms for intra-left AEMD had a sensitivity of 76.2% and a specificity of 97.5% in identifying beta-TM patients with AF risk. A cut-off value of 44.8 ms for inter-AEMD had a sensitivity of 81.2% and a specificity of 98.7% in identifying this category of patients.Conclusions Our results showed that the echocardiographic atrial electromechanical delay indices (intra-left and inter-AEMD) and the PD were significantly increased in beta-TM subjects with normal cardiac function. PD and AEMD represent non-invasive, inexpensive, useful, and simple parameters to assess the AF risk in beta-TM patients.

In the last twenty years, our comprehension of the molecular mechanisms involved in formation, progression and complication of atherosclerotic plaque has advanced significantly and the main role of inflammation and immunity in this phenomenon is now largely accepted. Accumulating evidence highlight the crucial role of different inflammatory and immune cells, such as monocytes and T-lymphocytes, in the pathophysiology of atherosclerotic lesion, particularly in contributing to its complications, such as rupture or ulceration. According to the new terminology, "vulnerable plaque" identifies an inflamed atherosclerotic lesion that is particularly prone to rupture. Once disrupted, prothrombotic material is exposed to the flowing blood, thus activating coagulation cascade and platelet aggregation, ultimately leading to acute thrombus formation within the coronary vessel. To date this is the key event underlying the clinical manifestation of acute coronary syndromes (ACS). The degree of vessel occlusion (complete vs. incomplete) and the time of blood flow cessation will define the severity of clinical picture. This phenomenon seems to be the final effect of a complex interaction between different local and systemic factors, involving the degree of inflammation, type of cells infiltration and the rheological characteristics of blood flow at the site of plaque rupture, thrombogenic substrates within the atherosclerotic lesion and different soluble mediators, already present or acutely released in the circulating blood. This article will review currently available data on the pathophysiology of ACS, emphasizing the immunological and inflammatory aspects of vulnerable plaque. We may postulate that intraplaque antigens and local microenvironment will define the immune-inflammatory response and cells phenotype, thus determining the severity of clinical manifestations. In the last twenty years, our comprehension of the molecular mechanisms involved in the formation, progression and complication of atherosclerotic plaque has advanced significantly and the main role of inflammation and immunity in this phenomenon is now largely accepted. Accumulating evidence highlight the crucial role of different inflammatory and immune cells, such as monocytes and T-lymphocytes, in the pathophysiology of atherosclerotic lesion, particularly in contributing to its complications, such as rupture or ulceration. According to the new terminology, “vulnerable plaque” identifies an inflamed atherosclerotic lesion that is particularly prone to rupture. Once disrupted, prothrombotic material is exposed to the flowing blood, thus activating coagulation cascade and platelet aggregation, ultimately leading to acute thrombus formation within the coronary vessel. To date this is the key event underlying the clinical manifestations of acute coronary syndromes (ACS). The degree of vessel occlusion (complete vs. incomplete) and the time of blood flow cessation will define the severity of clinical picture. This phenomenon seems to be the final effect of a complex interaction between different local and systemic factors, involving the degree of inflammation, type of cells infiltration and the rheological characteristics of blood flow at the site of plaque rupture, thrombogenic substrates within the atherosclerotic lesion and different soluble mediators, already present or acutely released in the circulating blood. This article will review currently available data on the pathophysiology of ACS, emphasizing the immunological and inflammatory aspects of vulnerable plaque. We may postulate that intraplaque antigens and local microenvironment will define the immune-inflammatory response and cells phenotype, thus determining the severity of clinical manifestations.

Background. Inflammation plays an essential role in the development and complications of atherosclerotic plaques, including acute coronary syndromes (ACS). Indeed, previous reports have shown that within the coronary circulation of ACS patients, several soluble mediators are released. Moreover, it has been demonstrated that endothelial dysfunction might play an important role in atherosclerosis as well as ACS pathophysiology. However, the mechanisms by which these soluble mediators might affect endothelial functions are still largely unknown. We have evaluated whether soluble mediators contained in serum from coronary circulation of ACS patients might promote changes of gene profile in human coronary endothelial cells (HCAECs). Methods. HCAECs were stimulated in vitro for 12 hours with serum obtained from the coronary sinus (CS) and the aorta (Ao) of ACS patients; stable angina (SA) patients served as controls. Gene profiles of stimulated cells were evaluated by microarray gene expression profiling and Real-time PCR. Results. HCAECs stimulated with serum from CS of ACS patients showed a significant change (up-regulation and down-regulation) in gene expression profile as compared with cells stimulated with serum form CS of SA patients. Moreover, ad-hoc subanalysis indicated the upregulation of Th-17/IL-17 pathway-related genes. Conclusions. This study demonstrates that, in ACS patients,the chemical mediators released in the coronary circulation might be able to perturb coronary endothelial cells modifying their gene profile. These modified endothelial cells, through down-regulation of protective gene and, mainly, through up-regulation of gene able to modulate the Th-17/IL-17 pathway, might play a key role in progression of coronary atherosclerosis and in developing future acute events.

The incidence of ST-segment elevation myocardial infarction (STEMI) has significantly decreased. Conversely, the rate of non-STEMI (NSTEMI) has increased. Patients with NSTEMI have lower short-term mortality compared to patients with STEMI, whereas at long-term follow-up, the mortality becomes comparable. This might be due to the differences in baseline characteristics, including older age and a greater prevalence of comorbidities in the NSTEMI population. Although antithrombotic strategies used in patients with NSTEMI have been well studied in clinical trials and updated guidelines are available, patterns of use and outcomes in clinical practice are less well described. Thus, a panel of Italian cardiology experts assembled under the auspices of the "Campania NSTEMI Study Group" for comprehensive discussion and consensus development to provide practical recommendations, for both clinical and interventional cardiologists, regarding optimal management of antithrombotic therapy in patients with NSTEMI. This position article presents and discusses various clinical scenarios in patients with NSTEMI or unstable angina, including special subsets (eg, patients aged ≥85 years, patients with chronic renal disease or previous cerebrovascular events, and patients requiring triple therapy or long-term antithrombotic therapy), with the panel recommendations being provided for each scenario. The incidence of ST-segment elevation myocardial infarction (STEMI) has significantly decreased. Conversely, the rate of non-STEMI (NSTEMI) has increased. Patients with NSTEMI have lower short-term mortality compared to patients with STEMI, whereas at long-term follow-up, the mortality becomes comparable. This might be due to the differences in baseline characteristics, including older age and a greater prevalence of comorbidities in the NSTEMI population. Although antithrombotic strategies used in patients with NSTEMI have been well studied in clinical trials and updated guidelines are available, patterns of use and outcomes in clinical practice are less well described. Thus, a panel of Italian cardiology experts assembled under the auspices of the "Campania NSTEMI Study Group" for comprehensive discussion and consensus development to provide practical recommendations, for both clinical and interventional cardiologists, regarding optimal management of antithrombotic therapy in patients with NSTEMI. This position article presents and discusses various clinical scenarios in patients with NSTEMI or unstable angina, including special subsets (eg, patients aged ≥85 years, patients with chronic renal disease or previous cerebrovascular events, and patients requiring triple therapy or long-term antithrombotic therapy), with the panel recommendations being provided for each scenario.

Pregnancy-Associated Plasma Protein-A (PAPP-A) is a zinc-binding metalloproteinase protein produced by placental syncytio-trophoblasts and secreted into the maternal circulation where its concentration progressively increases until term. In recent years, PAPP-A has been studied for its potential involvement in cardiovascular (CV) disease. However, all those studies did not provide a clear view to identify the pathophysiological links between PAPP-A plasma levels and the occurrence of CV events. In this review, starting from a complete description of PAPP-A structure and biology, we present an updated overview of experimental as well as clinical evidence on the role of this metalloproteinase in CV disease. Finally, we discuss possible therapeutic approaches to antagonize its potential detrimental CV effects. Pregnancy-Associated Plasma Protein-A (PAPP-A) is a zinc-binding metalloproteinase protein produced by placental syncytio-trophoblasts and secreted into the maternal circulation where its concentration progressively increases until term. In recent years, PAPP-A has been studied for its potential involvement in cardiovascular (CV) disease. However, all those studies did not provide a clear view to identify the pathophysiological links between PAPP-A plasma levels and the occurrence of CV events. In this review, starting from a complete description of PAPP-A structure and biology, we present an updated overview of experimental as well as clinical evidence on the role of this metalloproteinase in CV disease. Finally, we discuss possible therapeutic approaches to antagonize its potential detrimental CV effects.

Objective: To verify the existence of association between plasma levels of pro- or anti-inflammatory mediators and atherosclerotic burden at coronary and carotid arteries in individuals aged of 80 or more years old. Methods: Healthy individuals aged between 80 and 102 years old (n = 178) underwent evaluation of plasma cytokines and acute phase proteins, intima-media thickness (IMT) and presence of plaques in carotid arteries by ultrasound and coronary artery calcification (CAC) by cardiac computed tomography. Results: There was no association between CAC and carotid plaques (p = 0.8), maximum (p = 0.06) or mean IMT (p = 0.2). No association was found between the presence of carotid plaques and CRP (p = 0.4), TNF-α (p = 0.8) or IL-10 (p = 0.2). Likewise, individuals in the first three quartiles for CRP, TNF-α or IL-10 had similar values of CAC, mean and maximum IMT. In contrast, individuals above the 75th percentile for CRP or for TNF-α had enhanced maximum IMT (p = 0.017 and p < 0.0001) and CAC (p = 0.026 and p = 0.01) and subjects with IL-10 levels above the 75th percentile had lower maximum IMT (p = 0.027) and CAC (p = 0.006) as compared with those below this percentile. There was no difference in mean IMT for individuals above or below the 75th percentile for CRP, TNF-α or IL-10. Conclusion: In very old individuals, CAC and maximum IMT were positively associated with systemic inflammatory activity only in those above the 75th percentile. The markers of atherosclerotic burden at coronary and carotid arteries were not related to each other and were distinctly associated with pro- and anti-inflammatory mediators, suggesting that atherosclerosis development is different in these vascular beds.

Background The structural secuelae of acute myocardial infarction (AMI) is mostly dictated by left ventricular (LV) remodelling, leading to heart failure. Monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play a critical role in LV remodelling. β-blockers are first line therapy for AMI and heart failure; however, the mechanisms responsible for their benefits remain poorly understood. Different β-blocker agents have been shown to exert beneficial activities both in AMI and heart failure, however, their role in early remodelling after ischemia/reperfusion is to be fully elucidated. We sought to compare the effect of 2 of the most prescribed β-blocker agents in early markers of LV remodelling after AMI. Methods A reperfused AMI was induced in Yorshire pigs, being randomized to early intravenous carvedilol, metoprolol or placebo. Twenty-four hours after reperfusion markers of early remodelling were addressed in the LV. Results The early administration of both β-blockers is able to significantly reduce macrophage infiltration as well as the expression and activity of MCP-1 and MMP-2 compared to placebo. The effects of carvedilol were much stronger than those of metoprolol. Conversely, carvedilol upregulated the expression TIMP-2 to a greater extent than metoprolol. Conclusions In an AMI model closely mimicking human pathophysiology, the early administration of carvedilol reduced the expression of markers associated with early LV remodelling to greater extent than metoprolol. These findings may explain the superior clinical benefits exerted by carvedilol in heart failure.

Aims The aim of this study was to investigate the effects of liver X receptors (LXRs)-β preferential activation by LXR-623 (WAY-252623), a novel LXRs agonist, on plaque progression/regression in a rabbit model of advanced atherosclerosis. Methods and results Advanced atherosclerosis was induced in New Zealand White Rabbits ( n = 41). At the end of atherosclerosis induction, animals underwent a baseline magnetic resonance imaging (MRI) and were randomized to receive LXR-623 (1.5, 5, or 15 mg/kg/day), simvastatin (5 mg/kg/day), or placebo. The combination of LXR-1.5/simvastatin was also tested. After a final MRI, animals were euthanized and their aortas processed for further analysis. Simvastatin significantly reduced lesion progression (−25%; P < 0.01) in comparison with the placebo group. A similar effect was observed in the LXR-1.5 and -5 groups. A significant regression (16.5%; P < 0.01) of existing atherosclerosis was observed in the LXR-1.5/simvastatin group. Histological and molecular analysis showed plaque stabilization in the animals treated with the LXR-1.5 and -5, and LXR-1.5/simvastatin. The effects of LXR-623 were observed in the presence of a non-significant effect on total-cholesterol, low-density lipoproteins-cholesterol, and triglyceride levels. Conclusion The results of the present study show that LXR-623 significantly reduces the progression of atherosclerosis and induces plaque regression in combination with simvastatin. These observations could drive future development of novel anti-atherosclerotic therapeutic approaches.

Acute thrombus formation on disrupted atherosclerotic plaques plays a key role during the onset of acute coronary syndromes. Lesion disruption facilitates the interaction between circulating blood and prothrombotic substances, such as tissue factor (TF) present within the atherosclerotic lesion. For a long period of time, vessel-wall TF has been considered the major determinant of thrombosis. However, this old dogma has been recently changed owing to the discovery of a different pool of TF that circulates in flowing blood (blood-borne TF). Several studies have shown that blood-borne TF circulates in different pools that are associated with selected blood cells, such as monocytes, granulocytes and platelets in cell-derived microparticles, and as a soluble protein generated by alternative splicing of its full-length mRNA. Recent studies have identified a hypercoagulable state associated with an increased circulating TF activity, leading to the concept of 'vulnerable blood'. Part of the blood-borne TF circulates in an 'inactive' form and it is required to be 'activated' to exert its thrombogenic potential. Certain pathological conditions, such as smoking, hyperlipidemia and diabetes, show a higher incidence of thrombotic complications. These conditions are also characterized by the presence of high levels of circulating TF activity. Recent evidence may also suggest that an increased circulating TF activity may potentiate the initial thrombogenic stimulus represented by vessel wall-associated TF, leading to the formation of larger and/or more stable thrombus, and thus more severe acute coronary syndromes. It has been reported that inflammation increases TF expression and activity by different cell types. On the other hand, TF upregulation may facilitate inflammation by enhancing intravascular fibrin deposition, formation of proinflammatory fragments of fibrin, and by generating coagulation proteases, including FVIIa, FXa and thrombin, that activate protease-activated receptors. Furthermore, the biology of TF is know known to be more complex than previously thought by the demonstration that this protein, apart from its known effects on blood coagulation, can also function as a signaling receptor.

Adaptive immune responses are involved in all stages of atherosclerotic plaque development, including plaque complication (i.e., rupture, ulceration, etc), which may lead to the clinical occurrence of Acute Coronary Syndromes (ACS) [1]. Unstable coronary plaques, in addition to macrophages, contain a 10-fold increase in T-lymphocytes, as compared to stable plaques [2]. T-cells produce and release cytokines, and, in turn, regulate macrophage activity [3]; thus, T-cell activation, through cytokine production, might play a pivotal role in the pathophysiology of plaque complication [4]. Several studies have focused on cytokine plasma levels in patients with ACS, demonstrating that many of these substances are elevated in the systemic blood of patients with ACS (for a review, see Ref. [5]), some of which may even correlate with an adverse prognosis [6]. However, most of these studies have measured cytokine levels in the peripheral blood, raising the issue that the local cytokine milieu is still largely unexplored. This is not a trivial issue, since the assessment of the local inflammatory milieu could contribute to a better understanding of different inflammatory and immune-mediated pathways determining different outcomes in patients affected by ACS [7]. Twenty-eight patients with a clinical diagnosis of ACS and 16 patients with Stable Angina (SA) undergoing coronary angiography were studied. After coronary angiography, a 6 F multipurpose catheter was positioned into the Coronary Sinus (CS); thereafter, blood samples (4.5 mL) were simultaneously obtained from the CS and the ascending aorta (Ao) and placed in pre-chilled Vacutainer tubes containing sodium citrate. Transcoronary cytokine levels (expressed as a Δ% of CS–Ao levels) were measured by LuminexTM technology [8]. We found that transcoronary serum levels of IL-1β, IL-2, IL-6, IL12p40/70, IL-15, and IFN-γ – all of which can be ascribed to a Th1related response – were all significantly increased with the exception of IL-2. (Fig. 1, panel A). On the contrary, transcoronary serum levels of IL-4, IL-5, IL-10, IL-13, (Th2-related response) did not change significantly in patients with ACS as compared to SA patients, with the exception of IL-10 transcoronary levels, which were significantly lower in the ACS group (Fig. 1, panel B). Finally, we have found a significant increase in the transcoronary blood levels of EGF, eotaxin, MCP-1, IP-10, RANTES, and TNF-α in the ACS patients, as compared to their SA counterparts (Fig. 2). Systemic inflammation has been associatedwith an altered pattern of cytokine profile in patients with ACS [5]. However, many large studies attempting to link specific cytokine/chemokine levels to ACS have been inconclusive [9], probably because the inflammatory responses accounting for the outcome of the lesion occur predominantly at the level of the complicated plaque, which may not be paralleled by similar changes in the peripheral blood. Therefore, consistent with this hypothesis, we have focused our attention on the local, i.e., intracoronary cytokine production profile in patients with ACS and compared it to patients with SA. In particular, we have observed that local cytokine release was characterized by an increase in the transcardiac levels of those substances which characterize a Th1-like type of immune response. In contrast, the local production of those cytokines which represent the “fingerprint” of the Th2-like response, did not change significantlywhen compared to that found in patients with SA. Interestingly, the transcoronary levels of IL-10, a cytokine able to down-regulate the inflammatory responses via multiple mechanisms, were even lower in ACS patients, as compared to those obtained in patients with SA. The observed increase in IP-10 and MCP-1 transcoronary blood levels also suggests that the recruitment of inflammatory cells is taking place locally, i.e., at the International Journal of Cardiology 176 (2014) 227–299

Objectives The aims of this study were to investigate the feasibility of contrast-enhanced ultrasound (CEU) imaging for in vivo visualization of intraplaque neovascularization and to correlate the in vivo observations with histological assessment of neovessel density and plaque composition in an experimental animal model of advanced atherosclerosis. Background Recent evidence has linked plaque angiogenesis with enhanced atherosclerotic plaque progression and vulnerability. Increased neovascularization has been detected in ruptured human lesions and is associated with clinical manifestations of plaque rupture. Methods Advanced aortic atherosclerosis was induced in New Zealand white rabbits (n = 21; high cholesterol–rich diet/double-balloon aortic denudation). Animals underwent standard and CEU imaging at the end of the atherosclerosis induction period. Six age-matched animals served as control subjects. Within 24 h, animals were euthanized and aortas processed for histopathological evaluation of plaque composition and neovascularization. Imaged plaques were classified as contrast enhanced (CE) positive or CE negative, according to their contrast enhancement on CEU imaging. The lesions were also classified as class III (predominantly echogenic) or class II (predominantly echolucent), according to their echogenicity on non-CEU images. Results No contrast enhancement was observed in control animals. In atherosclerotic animals, class III lesions showed an increased contrast enhancement compared with class II lesions and CE-positive lesions showed greater neovascularization than CE-negative plaques. Macrophage density, but not smooth muscle cell density, was significantly higher in CE-positive than CE-negative lesions. As expected, class III lesions showed increased macrophage density compared with class II plaques. Intraplaque neovessel density at histology was significantly higher in CE-positive than in CE-negative lesions. Class III plaques showed a significantly higher neovessel density compared with class II lesions. A strong correlation between intraplaque neovessels and contrast enhancement was found. Conclusions CEU imaging is a feasible noninvasive imaging modality to evaluate intraplaque neovascularization. A noninvasive imaging modality to assess lesion neovascularization could be of great importance to identify vascularized, “high-risk” lesions before rupture.

High plasma levels of low density lipoproteins (LDLs) represent one of the major risk factors for cardiovascular disease, as shown by many epidemiological studies. On the other hand, randomized trials designed to address the clinical impact of lipid lowering interventions, have clearly shown that reduction in LDL plasma levels lead to a significant decrease in major cardiovascular events. Based on these observations, pharmacological modulation of LDLs has been highly investigated. Statins, alone or in combination, represent the most powerful agents to date available to reach the LDLs levels suggested by the current guidelines. However, in some patients the recommended LDL reduction is difficult to be achieved because of genetic background (familial hypercholesterolemia), side effects (statin intolerance), or simply because of a non-sufficient response. In the last few years, our understanding of the basic mechanisms involved in the lipoprotein metabolism has progressed significantly. The crucial role of proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged. The main characterized function of PCSK9 relates to the binding to LDL-C receptors (LDLR) in hepatocytes. However, PCSK9 does not interfere with the binding between LDL and its own receptor, but with the ability of the latest to return to the surface of the hepatocyte and bind new LDL molecules. Based on these observations, blocking PCSK-9 may reduce the LDLR clearance, thus increasing the ability of LDLR to remove circulating LDLs. Pharmacological inhibition of this protein has been proposed as new therapeutic approach. The clinical evidence available to date seem to fully support this hypothesis.

Objective T-lymphocyte activation plays an important role in the pathophysiology of acute coronary syndromes (ACS). Plaques from ACS patients show a selective oligoclonal expansion of T-cells, indicating a specific, antigen-driven recruitment of T-lymphocytes within the unstable lesions. At present, however, it is not known whether T-cells may contribute directly to thrombosis by expressing functional tissue factor (TF). Accordingly, the aim of the present study was to investigate whether T-cells are able to express functional TF in their activated status. Methods In vitro , CD3 + -cells, isolated from buffy coats, were stimulated with anti-CD3/CD28 beads, IL-6, TNF-α, IL-17, INF-γ or PMA/ionomycin. Following stimulation, TF expression on cell-surface, at gene and protein levels, as well as its procoagulant activity in whole cells and microparticles was measured. In vivo , TF expression was evaluated in CD3 + -cells isolated from the aorta and the coronary sinus of ACS-NSTEMI and stable coronary artery disease (SCAD) patients. The presence of CD3 + -TF + cells was also evaluated by immunohistochemistry in thrombi aspirated from ACS-STEMI patients. Results PMA/ionomycin and IL-17 plus INF-γ stimulation resulted in a significant TF increase at gene and protein levels as well as at cell-surface expression. This was accompanied by a parallel increase in FXa generation, both in whole cells and in microparticles, indicating that the induced membrane-bound TF was active. Furthermore, transcardiac TF gradient was significantly higher in CD3 + -cells obtained from ACS-patients compared to SCAD-patients. Interestingly, thrombi from ACS-STEMI patients resulted enriched in CD3 + -cells, most of them expressing TF. Conclusions Our data demonstrate that activated T-lymphocytes in vitro express functional TF on their membranes, suggesting a direct pathophysiological role of these cells in the thrombotic process; this hypothesis is further supported by the observations in vivo that CD3 + -cells from coronary circulation of ACS-NSTEMI patients show increased TF levels and that coronary thrombi from ACS-STEMI patients are enriched in CD3 + -cells expressing TF.

Background— β-Blockers improve clinical outcome when administered early after acute myocardial infarction. However, whether β-blockers actually reduce the myocardial infarction size is still in dispute. Cardiac magnetic resonance imaging can accurately depict the left ventricular (LV) ischemic myocardium at risk (T2-weighted hyperintense region) early after myocardial infarction, as well as the extent of necrosis (delayed gadolinium enhancement). The aim of this study was to determine whether early administration of metoprolol could increase myocardial salvage, measured as the difference between the extent of myocardium at risk and myocardial necrosis. Methods and Results— Twelve Yorkshire pigs underwent a 90-minute left anterior descending coronary occlusion, followed by reperfusion. They were randomized to metoprolol (7.5 mg during myocardial infarction) or placebo. Global and regional LV function, extent of myocardium at risk, and myocardial necrosis were quantified by cardiac magnetic resonance imaging studies performed 4 and 22 days after reperfusion in 10 survivors. Despite similar extent of myocardium at risk in metoprolol- and placebo-treated pigs (30.9% of LV versus 30.6%; P =NS), metoprolol resulted in 5-fold-larger salvaged myocardium (32.4% versus 6.2% of myocardium at risk; P =0.015). The LV ejection fraction significantly improved in metoprolol-treated pigs between days 4 and 22 (37.2% versus 43.0%; P =0.037), whereas it remained unchanged in pigs treated with placebo (35.1% versus 35.0%; P =NS). The extent of myocardial salvage was related directly to LV ejection fraction improvement ( P =0.031) and regional LV wall motion recovery ( P =0.039) at day 22. Conclusions— Early metoprolol administration during acute coronary occlusion increases myocardial salvage. The extent of myocardial salvage, measured as the difference between myocardium at risk and myocardial necrosis, was associated with regional and global LV motion improvement.

Tissue factor pathway inhibitor (TFPI) is a multivalent, Kunitz-type plasma proteinase inhibitor that modulates tissue factor-dependent coagulation in vivo. TFPI possesses a peculiar two-step mechanism of action; it directly inhibits activated factor X and subsequently produces feedback inhibition of the factor VIIa/tissue factor catalytic complex in a factor Xa-dependent fashion. TFPI biochemistry and physiology have been extensively studied during the last decade. Its pathophysiologic role in thrombotic disorders has, however, only recently started to be unraveled. In particular, circulating plasma TFPI levels have been found to modulate the activity of the tissue factor-dependent coagulation cascade. In animal models, neutralization of circulating TFPI activity results in restoration of intravascular thrombus formation previously abolished by aspirin. In patients with acute myocardial infarction, TFPI plasma levels measured in blood samples obtained from the coronary sinus were significantly lower than those measured in blood obtained from the ascending aorta, indicating acute consumption of TFPI within the coronary circulation of patients with intracoronary thrombosis. Finally, recent data indicate that transfection of the arterial wall with the gene coding for TFPI is an effective therapeutic intervention to prevent intravascular thrombus fort-nation. Taken together, these observations underline the pathophysiologic importance of TFPI in regulating the procoagulant activity of tissue factor and open new potential therapeutic approaches for the treatment of thrombotic disorders.

It is generally accepted that the initial event in coagulation and intravascular thrombus formation is the exposure of cell-surface protein, such as tissue factor (TF). TF is exposed to the flowing blood as a consequence of vascular injury induced, for instance, by PTCA, or by spontaneous rupture of an atherosclerotic plaque. Expression of TF may also be induced in monocytes and endothelial cells in several conditions such as sepsis and cancer, causing a more generalized activation of clotting. In addition to its essential role in hemostasis, TF may be also implicated in several pathophysiological processes, such as intracellular signaling, cell proliferation, and inflammation. For all these reasons, TF has been the subject of intense research focus. Many experimental studies have demonstrated that inhibition of TF:factor VIIa procoagulant activity is a powerful inhibitor of in vivo thrombosis and that this approach usually results in a less-pronounced bleeding tendency compared with other "more classical" antithrombotic interventions. Alternative approaches may be represented by antibodies directed against TF, by transfection of the arterial wall with natural inhibitors of the TF:factor VIIa complex, such as the TF pathway inhibitor, or with catalytic RNA (ribozyme), which could inhibit the expression of the TF protein by the disruption of cellular TF mRNA. All these approaches seem particularly attractive because they may result in complete inhibition of local thrombosis without incurring potentially harmful systemic effects. Further studies are warranted to determine the efficacy and safety of such approaches in patients.

Acute ApoA-I Milano administration induces plaque regression and stabilisation in the long term

SummaryAdipocytes are cells able to produce and secrete several active substances (adipokines) with direct effects on vascular cells. Apelin, one of the most recently identified adipokines has been studied in cardiovascular system physiology in regard to vessel vasodilation and myocardial contraction, but it has not yet completely characterised for its pathophysiological role in cardiovascular disease and especially in acute coronary syndromes (ACS). Several studies have indicated that tissue factor (TF) plays a pivotal role in the pathophysiology of ACS by triggering the formation of intracoronary thrombi following endothelial injury. This study investigates the effects of apelin 12 and apelin 13 on TF in human umbilical endothelial cells (HUVECs) and monocytes. Cells were stimulated with increasing concentrations of apelin 12 or apelin 13 and then processed to evaluate TF-mRNA levels by real-time PCR as well as TF expression/activity by FACS analysis and pro-coagulant activity. Finally, a potential molecular pathway involved in modulating this phenomenon was investigated. We demonstrate that apelin 13 but not apelin 12 induces transcription of mRNA for TF. In addition, we show that this adipokine promotes surface expression of TF that is functionally active. Apelin 13 effects on TF appear modulated by the activation of the G-protein-transcription factor nuclear factor (NF)-ΚB axis since G-protein inhibitors suppressed NF-ΚB mediated TF expression. Data of the present study, although in vitro, indicate that apelin-13, induces a procoagulant phenotype in HUVECs and monocytes by promoting TF expression. These observations support the hypothesis that this adipokine might play a relevant role as an active partaker in athero-thrombotic disease.

Apolipoprotein A-I (ApoA-I)/high-density lipoprotein (HDL)-raising treatments are effective antiatherosclerotic strategies. We have compared the antiatherogenic effects of human ApoA-I (hApoA-I) overexpression by intraportal and intramuscular gene transfer in atherosclerotic ApoE-knockout mice. Atherosclerotic lesions were induced by atherogenic diet. After atherosclerosis induction, a group of animals was killed and served as atherosclerosis baseline-control group. The remaining animals were randomized into the following groups: (1) atherosclerosis-progression-control, (2) intraportal/vector administration, and (3) intramuscular/vector administration. Aortas and hearts were processed for atherosclerotic quantification by en face Sudan IV and Oil Red-O, respectively. Liver and muscle specimens were processed for protein/gene expression analysis. A sustained increase in hApoA-I/HDL plasma levels was observed in both transduced groups. hApoA-I overexpression abolished plaque progression versus progression-control group. hApoA-I overexpression significantly reduced lesion macrophage, feature indicative of plaque stabilization. Scavenger receptor class-B type I (SR-BI), but not ATP-binding cassette, sub-family A (ABCA), member 1 (ABCA-1), was significantly upregulated in treated groups versus progression-controls. The results of this study show a similar effect of hApoA-I/HDL overexpression on plaque progression/stabilization by 2 different routes of administration. Our results showing similar effects using either intramuscular administration and intraportal route of administration may have significant clinical implications, given the reduced medical risk to patient and cost of intramuscular injections.

During the last two decades, a new perspective on atherosclerosis has prevailed based on accumulating evidence on the role of inflammatory and immune-competent cells, such as monocytes and T-lymphocytes, in contributing to the development of this disease. It is now generally accepted that a specific T-cell response is crucial in determining not only the development and growth of the atherosclerotic lesion, but also its fate toward a stable or an unstable pattern of evolution (i.e., rupture or ulceration), eventually leading to the clinical occurrence of acute coronary syndromes (ACS). We found that transcoronary IL-17 levels tended to be higher in ACS patients as compared to patients with Stable Angina. We observed a bimodal distribution of IL-17 transcoronary gradients, with 10 out of 23 patients showing elevated IL-17 transcoronary gradients. The ACS patients with elevated transcoronary IL-17 levels, showed also a significant increase in the percentage of Th-17 lymphocytes when samples from the coronary sinus were compared to the ones obtained from the Aorta Finally, patients with a Δ% transcoronary IL-17 gradient > 10 showed troponin I (Tn I) levels at admission significantly higher as compared to the levels measured in the patient population with a Δ% transcoronary IL-17 gradient < 10. Intriguingly, a significant correlation between ∆% transcoronary IL-17 levels and Tn I levels at admission was found only in patients with ∆% transcoronary IL-17 levels > 10 while no correlation was found in the other ACS patients. Our findings highlight that expansion of Th-17 lymphocytes, with the consequent increase in transcoronary IL-17 gradient, might have an important pathophysiological role in a subset of patients with ACS. In addition, data about relationship existing between IL-17 and troponin levels, indicate that this subset of patients presents with a more severe disease and suggest that they may possibly have a poorer prognosis.

Aims To investigate whether selected matrix metalloproteinases (MMPs) are released in the coronary circulation of patients with acute coronary syndrome (ACS), whether this release is related to platelet activation, and whether it contributes to sustained platelet activation. Methods and results Blood from the aorta (Ao) and the coronary sinus (Cs) was obtained from 21 controls (non-cardiac chest pain), 24 stable angina (SA), and 30 ACS patients, before performing percutaneous transluminal coronary angioplasty. Selected MMPs, some platelet activation- and atheroma-related markers, and the platelet activation-potentiating activity of plasma were measured. Total MMP-2, active MMP-2, and MMP-9 were released in the coronary circulation of patients with ACS, but not of those with SA or controls. Similarly, transcoronary gradients of b-thromboglobulin (b-TG) and platelet factor 4, two platelet-specific proteins, and of soluble CD40L and secretory phospholipase A2 (sPLA2), markers of inflammation and platelet activation, were higher in ACS patients than in the other groups. In contrast, plasma monocyte chemoattractant protein-1, a platelet-unrelated marker of atherogenesis, was not increased in the Cs compared with Ao in any of the groups. Transcoronary gradients of both b-TG and sPLA2 correlated with those of total and active MMP-2 in ACS, but not in controls or SA. Plasma from the Cs of ACS patients potentiated platelet activation, an effect suppressed by the specific MMP-2-inhibitor, tissue inhibitor of MMP-2 (TIMP-2). Conclusion Matrix metalloproteinase-2 is released in the coronary circulation of ACS patients, derives in part from activated platelets, and may contribute to sustained intracoronary platelet activation.

Background C-reactive protein (CRP) plasma levels correlate with cardiovascular events. Although a direct role for CRP in atherothrombosis has been suggested, at the moment little is known about its involvement in the pathophysiology of acute coronary syndromes (ACS). Thus, the aim of this study was to determine whether CRP is produced in the culprit lesion and released within the coronary circulation of patients with ACS and whether it may affect coronary endothelial function. Methods Blood samples were simultaneously obtained from the aorta (Ao) and the coronary sinus (CS) of patients with normal coronary artery (n=16), stable angina (n=30), and ACS (n=29) for later measurement of plasma CRP levels. Endothelium-dependent and -independent coronary vasodilation were evaluated by means of a Doppler Flow Wire in response to the increasing intracoronary doses of acetylcholine and adenosine, respectively. Results CRP plasma levels were significantly higher across the coronary circulation only in ACS patients with the culprit lesion located in the left coronary artery, while no differences between CS and Ao CRP plasma levels were observed in all other groups. Transcardiac CRP levels were correlated with impairment in coronary endothelium-dependent vasodilation. In six additional patients (SA=3 and ACS=3), subjected to coronary atherectomy, real-time quantitative PCR revealed presence of CRP mRNA only in unstable plaques. Conclusions Thus, CRP is produced and released within the coronary circulation of patients with ACS; this is associated with impairment of endothelial function, suggesting a new pathophysiological link between CRP and ACS.

Background: Myocardial infarct size is a strong predictor of cardiovascular events. Intravenous metoprolol before coronary reperfusion has been shown to reduce infarct size; however, it is unknown whether oral metoprolol initiated early after reperfusion, as clinical guidelines recommend, is similarly cardioprotective. We compared the extent of myocardial salvage associated with intravenous pre-reperfusion-metoprolol administration in comparison with oral post-reperfusion-metoprolol or placebo. We also studied the effect on suspected markers of reperfusion injury. Methods: Thirty Yorkshire-pigs underwent a reperfused myocardial infarction, being randomized to pre-reperfusion-metoprolol, post-reperfusion-metoprolol or placebo. Cardiac magnetic resonance imaging was performed in eighteen pigs at day 3 for the quantification of salvaged myocardium. The amounts of at-risk and infarcted myocardium were quantified using T2-weighted and post-contrast delayed enhancement imaging, respectively. Twelve animals were sacrificed after 24 h for reperfusion injury analysis. Results: The pre-reperfusion-metoprolol group had significantly larger salvaged myocardium than the post-reperfusion-metoprolol or the placebo groups (31 +/- 4%, 13 +/- 6%, and 7 +/- 3% of myocardium at-risk respectively). Post-mortem analyses suggest lesser myocardial reperfusion injury in the pre-reperfusion-metoprolol in comparison with the other 2 groups (lower neutrophil infiltration, decreased myocardial apoptosis, and higher activation of the salvage-kinase phospho-Akt). Salvaged myocardium and reperfusion injury pair wise comparisons proved there were significant differences between the pre-reperfusion-metoprolol and the other 2 groups, but not among the latter two. Conclusions: The intravenous administration of metoprolol before coronary reperfusion results in larger myocardial salvage than its oral administration initiated early after reperfusion. If confirmed in the clinical setting, the timing and route of beta-blocker initiation could be revisited. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Atherosclerosis constitutes the single most important contributor to the increasing problem of cardiovascular disease. Endothelial dysfunction is considered the early pivotal event in atherogenesis and precedes development of clinically detectable atherosclerotic plaques. The term “vulnerable plaque” identifies an atherosclerotic plaque that is particularly susceptible to disruption, with exposure of tissue factor to the blood flow and subsequent activation of coagulation cascade resulting in lumen occlusion by overlying thrombi. Despite the central role of vulnerable plaques in the onset of cardiovascular events, there are still certain situations (e.g. eroded lesions) wherein hyperactive blood (vulnerable blood) takes the central role. The magnitude and severity of arterial thrombosis is a complex phenomenon and depends on several factors: arterial vessel wall substrates, local rheologic characteristics of blood flow, and systemic factors in the circulating blood. Biomarker of “vulnerable blood,” including blood markers reflecting hypercoagulability, is one tool to identify high-risk individuals for accurate diagnosis and stratification. The importance of the coagulation/fibrinolytic system is highlighted by several autopsic studies that show a high prevalence of old plaque disruptions without infarctions. The imbalance between coagulation and anticoagulation systems is likely to result in an acute event. The prolonged presence of residual thrombus over a disrupted or eroded plaque can induce smooth muscle migration and produce new intima, leading to plaque expansion. Therefore, an active fibrinolytic system may be able to prevent luminal thrombosis in some cases of plaque disruption. Its rapid decline is associated with an increasing plaque burden and vulnerability, and it is related to endothelial cell injury. Identification of vulnerable atherosclerotic plaque and improvement of endothelial function represent a primary approach in the management of cardiovascular patients.

Aims Aortic stenosis (AS) is associated with significant morbidity and mortality. Recombinant apolipoprotein A-I Milano (rApoA-IM) induces atherosclerotic plaque regression. The aims of this study were to determine the effects of rApoA-IM on experimental aortic valve degeneration and its mechanisms of action. Methods and results New Zealand White rabbits ( n = 20) were fed an atherogenic diet for 9 months and then randomized to either placebo or rApoA-IM. Echocardiography was used to assess the effect of the treatments on AS. Porcine aortic valve myofibroblasts (PAVMF) treated with oxidized low-density lipoprotein served to define the effects of rApoA-IM on the expression of monocyte chemoattractant protein-1 (MCP-1), nuclear factor (NF)-κB, and alkaline phosphatase (AP). Recombinant apolipoprotein A-I Milano increased aortic valve area (AVA) by 32% (0.25 ± 0.05 to 0.34 ± 0.07 cm2, P < 0.01); whereas AVA remained unchanged in the placebo group (0.24 ± 0.05 to 0.26 ± 0.04 cm2, P = 0.58). Histopathological examination of aortic valves in the rApoA-IM animals showed significantly less leaflet thickening, inflammation, and calcification vs. the placebo group. In vitro , rApoA-IM significantly inhibited MCP-1, AP, and NF-κB and decreased intracellular cholesterol content in PAVMF. Conclusion Recombinant apolipoprotein A-I Milano treatment reverses AS in this experimental rabbit model. The beneficial effects seem to be mediated by enhanced cholesterol removal and by reduced inflammation and calcification.

Atherosclerosis is a diffuse pathological process characterized by the deposition of lipid and other blood-borne material within the arterial wall of almost all vascular territories. Cholesterol accumulation plays a central role in atherogenesis. It is the result of an imbalance between cholesterol influx and efflux. The disease progresses silently with focal clinical manifestation due to plaque rupture with superimposed thrombus: atherothrombosis. It has been shown that the atherosclerotic plaque composition rather than the degree of arterial stenosis can be the determinant of rupture. This has led to the search for new imaging techniques that can provide information about plaque composition. Ultrasound measurements of carotid and aortic wall thickness are an accurate ‘noninvasive’ technique that permits correlation with clinical events. Magnetic resonance imaging can evaluate in detail the arterial anatomy of almost all vascular territories. Multidetector computed tomography recently emerged for measuring luminal stenosis, coronary calcium, and even the extent of non-calcified coronary plaque volume. Next future is the molecular imaging based on the knowledge of molecular mechanisms involved in the genesis and progression of atherosclerotic lesions and the contrast agent able to identify different molecules and/or cells in the target zone.

Assessment of changes in plaque volume is increasingly used as a surrogate-endpoint in clinical trials testing the efficacy of anti-atherosclerotic interventions. Multi-detector computed tomography (MDCT) can detect and quantify non-calcified atherosclerotic plaques, but its ability to monitor changes in plaque volume has not yet been tested. We sought to test the ability of MDCT to detect and quantify serial changes in atheroma burden in comparison with magnetic resonance imaging (MRI). Methods Rabbits ( n =12) with experimentally induced abdominal atherosclerosis were randomized to receive a plaque-regressing agent (recombinant apoA-I Milano , n =8) or placebo ( n =4). All animals underwent two 64-slice MDCT angiography and MRI studies (pre- and post-treatment). The primary endpoint was the change in plaque burden (defined as vessel wall volume in the 5cm distal to the left renal artery) between pre- and post-treatment MDCT in comparison with MRI. Results MDCT detected a significant decrease in plaque burden caused by recombinant apoA-I Milano (464 [423–535] to 405 [363–435]mm 3 , p =0.03) that was confirmed by MRI (324 [286–412] to 298 [282–399]mm 3 , p =0.03). No significant effect was noted in the placebo group either by MDCT or MRI. There were strong correlations between both modalities for the quantification of plaque burden ( r =0.750, p r =0.657, p =0.020). MDCT overestimated plaque burden compared to MRI. On MDCT, the mean interobserver variability for plaque burden was 2.5±0.4%. Conclusions In an animal model of atherosclerosis, MDCT accurately documented serial changes in aortic plaque burden, demonstrating good correlation and agreement with MRI-derived measurements and low interobserver variability.

Background— Recent studies indicate that T-cell activation may play an important role in the pathophysiology of acute coronary syndromes (ACS). However, although those studies detected T-cell expansion in peripheral blood cells, demonstration of specific T-cell expansion within the plaque of patients with ACS is lacking. The present study aims to address whether a specific, immune-driven T-lymphocyte recruitment occurs within the unstable plaque of patients with ACS. Methods and Results— We simultaneously examined the T-cell repertoire using CDR3 size analysis both in coronary plaques (obtained by directional atherectomy) and in peripheral blood of patients with either ACS (n=11) or chronic stable angina (n=10). Unstable plaques showed a 10-fold increase in T-cell content by quantitative PCR. Using spectratyping analysis, we found several specific T-cell clonotype expansions only in unstable plaque from each patient with ACS, indicating a specific, antigen-driven recruitment of T cells within unstable lesions. Conclusions— For the first time, T-cell repertoire was investigated directly into coronary plaques; using this approach, we demonstrate that coronary plaque instability in the setting of ACS is associated with immune-driven T-cell recruitment, specifically within the plaque.