Matrix metalloproteinase-9 might affect adaptive immunity in non-ST segment elevation acute coronary syndromes by increasing CD31 cleavage on CD4+ T-cells.

Aims: In patients with acute coronary syndrome (ACS), the higher activity of effector T-cells suggests that mechanisms involving adaptive immunity dysregulation might play a role in coronary instability. The shedding of the functional CD31 domain 1-5 leads to uncontrolled lymphocyte activation. In experimental models, matrix metalloproteinase-9 (MMP-9) has been implicated in endothelial CD31 cleavage. Interestingly, higher serum levels of MMP-9 have been observed in ACS. We aim to investigate the mechanisms underlying CD31 dysregulation in ACS. Methods and results: To assess CD31 cleavage on CD4+ T-cells, we analysed by flow cytometry CD4+ T-cells of 30 ACS, 25 stable angina (SA) patients, and 28 controls (CTRL) using two different CD31 antibodies that specifically recognize domain 1-5 or the non-functional membrane-proximal domain 6. The ratio between the domains was significantly lower in ACS than in SA and CTRL (P = 0.002 ACS vs. SA; P = 0.002 ACS vs. CTRL). After stimulation with anti-CD3/CD28, the 1-5/6 domain ratio was significantly lower in ACS than in SA (P = 0.005). ELISA of supernatants obtained from T-cell receptor-stimulated CD4+ T-cells showed higher production of MMP-9 in ACS than in SA (P < 0.001). CD31 domain 1-5 expression in activated CD4+ T-cells from ACS patients increased after treatment with a specific MMP-9 inhibitor (P = 0.042). Conclusion: Our study suggest that enhanced MMP-9 release plays a key role in determining the cleavage and shedding of the functional CD31 domain 1-5 in CD4+ T-cells of ACS patients. This mechanism might represent an important therapeutic target to modulate T-cell dysregulation in ACS.

Prevalence and Predictors of Multiple Coronary Plaque Ruptures: In Vivo 3-Vessel Optical Coherence Tomography Imaging Study.

OBJECTIVE: Plaque rupture may be the local expression of a widespread coronary instability. This study aimed to investigate: (1) the prevalence and characteristics of nonculprit plaque rupture; (2) the pancoronary atherosclerotic phenotype in patients with and without nonculprit plaque rupture; and (3) the prevalence and predictors of multiple plaque ruptures. APPROACH AND RESULTS: Six hundred and seventy-five nonculprit plaques from 261 patients (34 acute myocardial infarction, 73 unstable angina pectoris, and 154 stable angina pectoris) were analyzed by 3-vessel optical coherence tomography. Nonculprit plaque ruptures were identified in 51 patients (20%). Patients with nonculprit plaque ruptures had higher prevalence of thin-cap fibroatheroma (51% versus 13%; P<0.001) in the 3 major epicardial coronary vessels. Multiple plaque ruptures were observed in 20% of patients (38% acute myocardial infarction versus 10% unstable angina pectoris versus 19% stable angina pectoris; P=0.042). Thin-cap fibroatheroma, intimal vasculature, and macrophages were independent morphological predictors of multiple plaque ruptures, whereas acute myocardial infarction and chronic kidney disease were independent clinical predictors. Patients with nonculprit plaque ruptures showed higher 1-year rates of nontarget lesion revascularization (11.8% versus 4.4%; P=0.039). CONCLUSIONS: Nonculprit plaque ruptures were observed in 20% of patients with coronary artery disease and were associated with pancoronary vulnerability and higher 1-year revascularization rate.

Where Does Inflammation Fit?

PURPOSE OF REVIEW: This review focuses on the complex relationship between inflammation and the onset of acute coronary syndrome and heart failure. RECENT FINDINGS: In the last few years, two important lines of research brought new and essential information to light in the pathogenesis of acute coronary syndrome: a) the understanding of the immune mediate mechanisms of inflammation in Ischemic Heart Disease (IHD) and b) evidence that the inflammatory mechanisms associated with atherosclerosis and its complications can be modulated by anti-inflammatory molecules. A large amount of data also suggests that inflammation is a major component in the development and exacerbation of heart failure (HF), in a symbiotic relationship. In particular, recent evidence underlies peculiar aspects of the phenomenon: oxidative stress and autophagy; DAMPS and TLR-4 signaling activation; different macrophages lineage and the contribution of NLRP-3 inflammasome; adaptive immune system. A possible explanation that could unify the pathogenic mechanism of these different conditions is the rising evidence that increased bowel permeability may allow translation of gut microbioma product into the circulation. These findings clearly establish the role of inflammation as the great trigger for two of the major cardiovascular causes of death and morbidity. Further studies are needed, to better clarify the issue and to define more targeted approaches to reduce pathological inflammation while preserving the physiological one.

Pancoronary plaque vulnerability in patients with acute coronary syndrome and ruptured culprit plaque: a 3-vessel optical coherence tomography study.

BACKGROUND: Recent studies described different clinical and underlying plaque characteristics between patients with and without plaque rupture presenting with acute coronary syndrome (ACS). In light of the systemic nature of atherosclerosis, we hypothesized that nonculprit plaques might also express different morphological features in these 2 groups of patients. METHODS: Thirty-eight patients with ACS who underwent 3-vessel optical coherence tomography imaging were identified from the Massachusetts General Hospital Optical Coherence Tomography Registry. Based on culprit plaque morphology, the study population was divided into 2 groups: patients with plaque rupture at the culprit lesion (group 1) and patients with nonruptured plaque at the culprit lesion (group 2). Prevalence and features of nonculprit plaques were compared between the 2 groups. RESULTS: A total of 118 nonculprit plaques were analyzed. Patients in group 1 (n = 17) had nonculprit plaques with higher prevalence of thin-cap fibroatheroma (52.9% vs 19.0%, P = .029) and disruption (35.3% vs 4.8%, P = .016) compared with patients in group 2 (n = 21). Nonculprit plaques in group 1 showed wider maximum lipid arc (198.9° ± 41.7° vs 170.2° ± 41.9°, P = .003), greater lipid length (7.8 ± 4.4 mm vs 5.1 ± 2.4 mm, P = .003), higher lipid index (1196.9 ± 700.5 vs 747.7 ± 377.3, P = .001), and thinner fibrous cap (107.0 ± 56.5 µm vs 137.3 ± 69.8 µm, P = .035) compared with those in group 2. CONCLUSIONS: The present study showed distinctive features of nonculprit plaques between patients with ACS caused by plaque rupture and patients with ACS caused by nonruptured plaques. Patients with plaque rupture had increased pancoronary vulnerability in nonculprit plaques, suggesting that a more aggressive treatment paradigm aiming at the stabilization of vulnerable plaques may offer additional benefit to these patients.

Altered CD31 expression and activity in helper T cells of acute coronary syndrome patients.

In acute coronary syndrome (ACS), T cell abnormalities are associated to a worse outcome. Loss of inhibitory activity of CD31, an Ig-like adhesion molecule, on peripheral leukocytes has been found to enhance atherosclerosis in experimental models. In this study, we examined the expression of CD31 on T cells, and its role on TCR signaling in 35 patients with non-ST elevation ACS, in 35 patients with stable angina (SA), and in 35 controls. Furthermore, 10 ACS and 10 SA patients were re-analyzed at 1-year follow-up. Flow-cytometry analysis showed that in ACS patients, CD31 expression was reduced on total CD4(+) and CD4(+)CD28(null) (P < 0.001, ACS vs. SA), on naïve (P < 0.001, ACS vs. SA) and on central-memory and effector-memory CD4(+) T cells (P < 0.05, ACS vs. SA and controls). The immunomodulatory effect of CD31 on TCR signaling of CD4(+) and CD4(+)CD28(null) T cells, was lower in ACS than SA patients (P < 0.05, for both comparisons). At 1-year follow-up, CD31 expression and function increased in ACS becoming similar to that found in SA. CD31 recruitment in the immunological synapse was lower in ACS than controls (P = 0.012). Moreover, CD31 modulated MAPK signaling and reduced the expression of T bet and Rorγ-t, necessary for Th1 and Th17 differentiation. Finally, we studied TCR signaling in CD31(+) naïve and primed T cell subsets observing a different pattern of protein phosphorylation. A CD31-mediated regulatory pathway is enhanced in SA and temporarily downregulated in ACS. As CD31 modulates both T cell activation, by increasing the threshold for TCR stimulation, and T cell differentiation, it might represent a novel molecular target to treat T cell abnormalities in ACS.

Polymorphonuclear neutrophils and instability of the atherosclerotic plaque: a causative role?

OBJECTIVE: The aim of this review is to examine the role of polymorphonuclear neutrophils (PMNs) in the evolution of atherosclerosis. INTRODUCTION: While the role of PMNs in the evolution of atherosclerosic process has failed until recently to attract much attention, a body of research carried out over the last decade has disclosed the unexpectedly complex behavior of these cells, unraveling an unexpected key role for PMNs in the onset and progression of atheroma. METHODS: A PubMed database search was performed for studies providing evidences on the role of PMNs in the development and progression of atherosclerotic lesion. RESULTS AND CONCLUSIONS: Activated PMNs were shown to produce and release reactive oxygen species, inflammatory leukotrienes and proteolytic lysosomal enzymes, directly inducing vascular damage. Activated PMNs also secrete myeloperoxidase, involved in lipoprotein oxidation. PMNs have a finite lifespan and typically die through apoptosis, which thus represents a counter-regulatory mechanism limiting the toxic potential of these short-lived, terminally differentiated cells. Dysregulation of this process probably contributes to the pathogenesis and progression of several inflammatory diseases. Moreover, high circulating levels of PMN-platelet aggregates have been reported in patients with clinical atherosclerosis, and recent studies suggest that these aggregates may play a role in vascular response to injury. It has been suggested that this heterotypic interaction between platelets and leukocytes might represent a link between hemostasis/thrombosis and the inflammatory response.

A case of unusual acute coronary syndrome.

Pheochromocytoma is a rare tumor that usually develops ahead of the neuroectodermal chromaffin cells of the adrenal medulla, but it may arise anywhere within plexus of sympathetic adrenergic nerves. Headache, palpitations, tremor, excessive sweating, abdominal pain, and hypertensive paroxysm are the common clinical presentations of the tumor, but it has also been reported several cardiac symptoms.

Risk stratification of ischaemic patients with implantable cardioverter defibrillators by C-reactive protein and a multi-markers strategy: results of the CAMI-GUIDE study.

AIMS: Patients at risk of sudden cardiac death (SCD) after myocardial infarction (MI) can be offered therapy with implantable cardioverter defibrillators (ICDs). Whether plasma biomarkers can help risk stratify for SCD and ventricular arrhythmias (VT/VF) is unclear. METHODS AND RESULTS: The primary objective of the CAMI-GUIDE study is to assess the predictive role of C-reactive protein for SCD or VT/VF in ischaemic patients with the ejection fraction <30% and ICDs. Secondary endpoints included all-cause mortality, hospitalizations, and death from heart failure. Additional analyses incorporated cystatin-C and NT-ProBNP in multi-marker approach for the prediction of adverse outcomes. A total of 300 patients were enrolled. All-cause mortality at 2 years was 22.6%, mortality from heart failure was 8.3%. Primary endpoint occurred in 17.3%. At a competing risk multivariable analysis adjusted for baseline variables, no significant difference in primary endpoint was found between patients with C-reactive protein ≤3 vs. >3 mg/L [heart rate (HR) 0.91 (0.50-1.64) P = 0.76], while C-reactive protein >3 mg/L was strongly associated with mortality due to heart failure [HR: 3.17 (1.54-6.54) P = 0.002]. NT-proBNP above median was significantly associated with the primary endpoint [adjusted HR: 1.46 (1.020-2.129) P = 0.042]. A risk function, including the three biomarkers, NYHA class and resting HR, allowed stratification of patient mortality risk from 5 to 50%. CONCLUSION: C-reactive protein >3 mg/L is not associated with SCD or fast VT/VF, however, is a strong predictor of HF mortality. Biomarkers combined with clinical markers allow an excellent risk stratification of mortality at 2 years.

Reversible atrial gap junction remodeling during hypoxia/reoxygenation and ischemia: a possible arrhythmogenic substrate for atrial fibrillation.

Alteration of cardiomyocyte gap-junctions and component connexins (Cx) has been suggested to contribute to the development of atrial fibrillation (AF), including postoperative AF. We tested different possible stimuli, such as hypoxia and ischemia, influencing Cx43 and Cx40 expression and distribution in cultured atrial cells (HL-1) and reversibility of these processes after reoxygenation. Western-blot analysis and immunostaining using anti-Cx43, anti-Cx40 and anti-zonula occludens polyclonal antibodies were performed. HL-1 cells exposed to hypoxia for 24 and 48 h showed a reduction of Cx43 protein levels by 75% and 90% respectively (p < 0.001). During reoxygenation following 24 h of hypoxia, Cx43 levels increased to reach the basal level within 48 h, while they remained at low level during reoxygenation following 48 h of hypoxia. Furthermore, atrial cardiomyocytes subjected to simulated ischemia (SI) were incubated in normoxic and hypoxic conditions for 3, 6, 9, 12 h. Atrial cardiomyocytes subjected to SI in addition to normoxia showed a progressive reduction of Cx43 levels beginning from 3 h. During SI and hypoxia, atrial Cx43 levels showed an initial decrease after 3 h with a subsequent rescue beginning from 6 h of exposure (p = 0.001). Hypoxia and ischemia per se downregulate Cx43 protein expression in atrial cardiomyocytes, but protein downregulation is reversible, depending on hypoxia duration and the association of the two triggers. These alterations characterize several conditions and might contribute to the generation of an arrhythmogenic substrate leading to AF onset and/or maintenance.

Prognostic utility of quantifying evolutionary ST-segment depression on early follow-up electrocardiogram in patients with non-ST-segment elevation acute coronary syndromes.

AIMS: Although ST-segment depression (STD) on the admission electrocardiogram (ECG) confers adverse prognosis in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS), the implications of STD on follow-up ECG remain uncertain. We determined the prognostic significance of STD on follow-up ECG performed within 12-24 h of admission and whether its quantitative evaluation can further refine risk stratification. METHODS AND RESULTS: The admission and follow-up ECGs of 3877 patients in the SYNERGY trial were analysed for the presence (>or=1 mm) and extent (maximum magnitude on any single lead) of STD. Of the 1110 patients presenting with STD on admission, 534 (48.1%) with persistent STD at follow-up had higher mortality at 30 days (7.1 vs. 3.6%, P = 0.01) and 6 months (10.7 vs. 5.2%, P = 0.001) than those with normalized STD. Among 2767 patients without STD on admission, 174 (6.3%) developed new STD on follow-up ECG and experienced increased mortality compared with those without such interval change (30 days: 4.0 vs. 1.7%, P = 0.035; 6 months: 8.0 vs. 3.3%, P = 0.001). After adjustment for established clinical prognosticators and the extent of STD on admission, every 1 mm increment of STD on the follow-up ECG independently predicted a graded increase in 30-day mortality [hazards ratio (HR) = 1.60, 95% confidence interval (CI) = 1.29-1.98, P < 0.0001], and death/myocardial infarction at 30 days (HR = 1.19, 95% CI = 1.03-1.36, P = 0.017) and 6 months (HR = 1.17, 95% CI = 1.03-1.32, P = 0.016). CONCLUSION: The magnitude of STD on a routine 12-24 h follow-up ECG provides incremental prognostic information beyond established clinical prognosticators and the extent of STD on admission. Incorporating a follow-up ECG and its quantitative evaluation for STD may further refine risk stratification of patients with NSTE-ACS.

Recommendations for the use of cardiac troponin measurement in acute cardiac care.

The release of cardiomyocyte components, i.e. biomarkers, into the bloodstream in higher than usual quantities indicates an ongoing pathological process. Thus, detection of elevated concentrations of cardiac biomarkers in blood is a sign of cardiac injury which could be due to supply-demand imbalance, toxic effects, or haemodynamic stress. It is up to the clinician to determine the most probable aetiology, the proper therapeutic measures, and the subsequent risk implied by the process. For this reason, the measurement of biomarkers always must be applied in relation to the clinical context and never in isolation. There are a large number of cardiac biomarkers, but they can be subdivided into four broad categories, those related to necrosis, inflammation, haemodynamic stress, and/or thrombosis. Their usefulness is dependent on the accuracy and reproducibility of the measurements, the discriminatory limits separating pathology from physiology, and their sensitivity and specificity for specific organ damage and/or disease processes. In recent years, cardiac biomarkers have become important adjuncts to the delivery of acute cardiac care. Therefore, the Working Group on Acute Cardiac Care of the European Society of Cardiology established a committee to deal with ongoing and newly developing issues related to cardiac biomarkers. The intention of the group is to outline the principles for the application of various biomarkers by clinicians in the setting of acute cardiac care in a series of expert consensus documents. The first of these will focus on cardiac troponin, a pivotal marker of cardiac injury/necrosis.

COX-1 sensitivity and thromboxane A2 production in type 1 and type 2 diabetic patients under chronic aspirin treatment.

AIMS: Although aspirin treatment is useful in reducing ischaemic events in diabetic patients, recent studies suggest that it is less effective when compared with non-diabetics (ND). We sought to evaluate COX-1 sensitivity and thromboxane A(2) (TxA(2)) production in type 1 (T1DM) and type 2 diabetic (T2DM) patients under chronic aspirin treatment, and also evaluate the association between thromboxane A(2) (TxA(2)) production and markers of inflammation and metabolic control, such as high-sensitivity C-reactive protein, fasting blood glucose, and haemoglobin A1c (HbA1c). METHODS AND RESULTS: Agonist-induced platelet aggregation (PA) and TxB(2), a stable metabolite of TxA(2), production, serum TxB(2), and platelet COX-1 and COX-2 expression were studied in T2DM patients, T1DM patients, and high-risk ND subjects, all receiving a low dose of aspirin. TxB(2) formation was studied in platelets treated in vitro with aspirin alone or with a COX-2 inhibitor (NS-398). PA, collagen-induced TxB(2) production, and serum TxB(2) were higher in T1DM and T2DM patients than in ND subjects. TxB(2) production was reduced in diabetic patients by in vitro treatment with aspirin. COX-2 was expressed in all diabetic patients but only in 46% of ND patients. In diabetic patients significant correlations were observed between TxB(2) production and both fasting plasma glucose and HbA1c. CONCLUSION: COX-1 sensitivity and TxB(2) production is similarly reduced in both T1DM and T2DM patients under chronic aspirin treatment. The association between TxB(2) production and either fasting plasma glucose and HbA1c levels suggests that in diabetic patients hyperglycaemia is a determinant of the reduced platelet sensitivity to aspirin.

Delayed neutrophil apoptosis in patients with unstable angina: relation to C-reactive protein and recurrence of instability.

AIMS: To investigate spontaneous polymorphonuclear neutrophils (PMNs) apoptosis in unstable angina (UA) and its association with recurrence of instability. METHODS AND RESULTS: We compared PMNs apoptotic rate at 4 and 24 h in patients with UA, stable angina (SA), and controls (H) with two different protocols by flow cytometry. We measured apoptotic rate of isolated PMNs (Protocol 1) in 30 UA patients, 13 SA patients, and 34 H; and apoptosis of PMNs in whole blood culture (Protocol 2) in further 10 UA patients, 7 SA patients, and 6 H. Serum high-sensitivity C-reactive protein was also measured. Polymorphonuclear neutrophils of UA patients showed a decreased apoptotic rate compared with SA patients and H at 4 h in Protocol 1 (both P < 0.01), and at 24 h in Protocol 2 (P < 0.05 and <0.01, respectively). In overall population, a negative correlation was found between apoptotic rate at 4 h and high-sensitivity C-reactive protein levels (P < 0.01). Six among 40 patients with UA had early recurrence of symptoms and their apoptotic rate was significantly reduced compared with UA patients without recurrence of symptoms (P = 0.024). CONCLUSIONS: Our study demonstrates delayed PMN apoptosis in UA. This alteration might be involved in the persistence of inflammatory activation and affects recurrence of instability.

Anakinra, a recombinant human interleukin-1 receptor antagonist, inhibits apoptosis in experimental acute myocardial infarction.

BACKGROUND: Experimental interleukin-1 receptor antagonist gene overexpression has shown that interleukin-1 receptor antagonist is cardioprotective during global cardiac ischemia. The aim of the present study was to test the impact of an exogenous recombinant human interleukin-1 receptor antagonist (anakinra) in experimental acute myocardial infarction. METHODS AND RESULTS: Two animal studies were conducted: one of immediate anakinra administration during ischemia in the mouse and one of delayed anakinra administration 24 hours after ischemia in the rat. Seventy-eight Institute of Cancer Research mice and 20 Wistar rats underwent surgical coronary artery ligation (or sham operation) and were treated with either anakinra 1 mg/kg or NaCl 0.9% (saline). Treatment was administered during surgery and then daily for 6 doses in the mice and starting on day 2 daily for 5 doses in the rats. Twenty-eight mice underwent infarct size assessment 24 hours after surgery, 6 saline-treated mice and 22 mice treated with increasing doses of anakinra (1 mg/kg [n=6], 10 mg/kg [n=6], and 100 mg/kg [n=10]); 6 mice were euthanized at 7 days for protein expression analysis. The remaining animals underwent transthoracic echocardiography before surgery and 7 days later just before death. Cardiomyocyte apoptosis was measured in the peri-infarct regions. The antiapoptotic effect of anakinra was tested in a primary rat cardiomyocyte culture during simulated ischemia and in vitro on caspase-1 and -9 activities. At 7 days, 15 of the 16 mice (94%) treated with anakinra were alive versus 11 of the 20 mice (55%) treated with saline (P=0.013). No differences in infarct size at 24 hours compared with saline were observed with the 1- and 10-mg/kg doses, whereas a 13% reduction in infarct size was found with the 100-mg/kg dose (P=0.015). Treatment with anakinra was associated with a significant reduction in cardiomyocyte apoptosis in both the immediate and delayed treatment groups (3.1+/-0.2% versus 0.5+/-0.3% [P<0.001] and 4.2+/-0.4% versus 1.1+/-0.2% [P<0.001], respectively). Compared with saline-treated animals, anakinra-treated mice and rats showed signs of more favorable ventricular remodeling. In vitro, anakinra significantly prevented apoptosis induced by simulated ischemia and inhibited caspase-1 and -9 activities. CONCLUSIONS: Administration of anakinra within 24 hours of acute myocardial infarction significantly ameliorates the remodeling process by inhibiting cardiomyocyte apoptosis in 2 different experimental animal models of AMI. This may open the door for using anakinra to prevent postischemic cardiac remodeling and heart failure.

Different apparent prognostic value of hsCRP in type 2 diabetic and nondiabetic patients with acute coronary syndromes.

BACKGROUND: C-reactive protein (CRP) is an established prognostic marker in acute coronary syndromes (ACS); however, no study has specifically addressed its prognostic role in type 2 diabetes with ACS. We evaluated the prognostic role of CRP separately in diabetic and nondiabetic patients with ACS. METHODS: We enrolled 251 patients with unstable angina and measured serum concentrations of high sensitivity (hs)CRP. Ninety-seven patients underwent coronary angiography with evaluation of atherosclerotic disease severity and extent by Bogaty score. Assessed endpoint was the combined occurrence of myocardial infarction (MI) and death at 1 year. RESULTS: No significant differences were found in hs-CRP between patients with and without diabetes. By Cox regression, hsCRP was not associated with 1-year follow-up events in diabetic patients but was strongly associated with events in nondiabetic patients (P = 0.0012). Coronary angiography exhibited a higher extent index in patients with diabetes than in those without (P = 0.04). hsCRP concentrations were not associated with angiographic atherosclerotic burden. By Cox analysis, hsCRP and extent score were associated with events in patients who underwent coronary angiography (P < 0.001 and P = 0.034, respectively). In nondiabetic patients, hsCRP was the only predictor of events at 1-year follow-up (P < 0.001), whereas in diabetic patients, hsCRP was not associated with events and a weak association was observed for extent score (P = 0.06). CONCLUSIONS: Our study suggests that different pathophysiological mechanisms may be responsible for MI and death in unstable angina patients with or without diabetes and that severity of coronary artery disease plays a major role in diabetes (and inflammation in the absence of diabetes).

Plasma levels of thromboxane A2 on admission are associated with no-reflow after primary percutaneous coronary intervention.

AIMS: Thromboxane A2 (TXA2) is a key mediator of platelet activation and aggregation, and an important mediator of platelet-induced coronary artery constriction. We sought to investigate whether baseline plasma levels of TXA2 are associated with coronary no-reflow after primary percutaneous coronary intervention (PPCI). METHODS AND RESULTS: A total of 47 consecutive patients (age, 62.5 +/- 12.7; male sex, 76.6%) admitted to our hospital for a first ST-segment elevation myocardial infarction and undergoing PPCI within 12 h of onset of symptoms were enrolled. Admission TXA2 plasma levels were measured by enzyme-linked immunosorbent assay (ELISA). Angiographic no-reflow was defined as a final TIMI flow of

High-sensitivity cardiac troponin assays and acute coronary syndrome: a matter of sex?

: Advances in technology have led to an improvement in the ability to detect and quantify acute cardiomyocyte injury with the measurement of high-sensitivity cardiac troponin as compared with conventional assays. The upper reference limit for the high-sensitivity cardiac troponin assays is defined as the 99th percentile cutoff value in a healthy reference population. Since sex-related threshold levels of high-sensitivity cardiac troponin assays have been proposed, this review will focus on the diagnostic and prognostic implications of adopting sex-specific threshold troponin values in patients with a suspected acute coronary syndrome.