Andrea Celestini

Hyperfibrinolysis in liver disease.

The incidence of hyperfibrinolysis in patients with cirrhosis is still debated. The reasons for this uncertainty probably lie in the lack of appropriate laboratory tests for its evaluation. There is a relative consensus, however, that hyperfibrinolysis can complicate the clinical course of liver cirrhosis, especially in cases of moderate to severe liver failure. Hyperfibrinolysis correlates positively with the severity of underlying liver disease, and low-grade systemic fibrinolysis is found in 30% to 46% of patients who have end-stage liver disease. Accelerated intravascular coagulation with secondary hyperfibrinolysis has been reported in patients who have liver failure. Hyperfibrinolysis may delay primary hemostasis, thereby aggravating variceal bleeding and facilitating recurrence.

Tumour necrosis factor α upregulates platelet CD40L in patients with heart failure

AIMS Patients with heart failure (HF) have elevated values of the pro-inflammatory protein CD40L but the underlying mechanism is unclear. This study was performed to evaluate the interplay between tumour necrosis factor alpha (TNFalpha) and CD40L in HF. METHODS AND RESULTS In patients with HF (n=86) and healthy subjects (HS, n=43), plasma levels of soluble CD40L (sCD40L), TNFalpha, soluble receptors of TNFalpha such as soluble TNF receptors I and II (sTNFR1 and sTNFR2), and 8OH-dG, a marker of oxidative stress, were determined. Also, an in vitro study was performed by determining platelet CD40L regulation upon platelet stimulation with TNFalpha. Compared with HS, HF patients had higher plasma values of sCD40L, TNFalpha, sTNFR1 and sTNFR2, and higher platelet expression of TNFR1 and TNFR2 with a progressive increase from NYHA I to NYHA IV classification. sCD40L significantly correlated with TNFalpha, sTNFR1, and sTNFR2; plasma levels of TNFalpha significantly correlated with sCD40L. Incubation of platelets from HF patients with a TNFalpha receptor inhibitor significantly decreased platelet CD40L expression. The in vitro study demonstrated that TNFalpha significantly increased CD40L expression, an effect weakly influenced by aspirin but significantly reduced by AACOCF3, an inhibitor of PLA(2), apocynin, an inhibitor of NADPH oxidase, or staurosporine, an inhibitor of PKC. CONCLUSION The study shows that in HF patients, platelet CD40L is upregulated by TNFalpha via a cyclooxygenase-1-independent, arachidonic acid-mediated oxidative stress mechanism.

Different behaviour of NOX2 activation in patients with paroxysmal/persistent or permanent atrial fibrillation

Background NOX2, the catalytic subunit of NADPH oxidase, is suggested to play a role in favouring the occurrence of atrial fibrillation (AF) after cardiac surgery via formation of reactive oxidant species. However, its role in spontaneous AF is still unclear. Objective To define the role of NOX2 and isoprostanes, a marker of oxidative stress, in the different settings of AF. Methods The study was performed on 174 patients with AF (82 with paroxysmal/persistent AF and 92 with permanent AF) and 90 controls matched for sex, age and atherosclerotic risk factors. Urinary isoprostanes and serum levels of soluble NOX2-derived peptide (sNOX2-dp) were measured in each patient. Results Urinary isoprostanes and sNOX2-dp concentrations were significantly higher in patients with paroxysmal/persistent AF than in those with permanent AF and controls. Compared with controls, patients with permanent AF showed a weak increase in sNOX2-dp and no difference in isoprostanes. Multivariable analyses demonstrated that baseline values of sNOX2-dp and urinary isoprostanes were independently associated with the type of AF (paroxysmal/persistent vs permanent; β=−224, p=0.007 and β=−231, p=0.005, respectively). A significant correlation between sNOX2-dp levels and urinary excretion of isoprostanes was also detected (R=0.707, p<0.001). Conclusions This study provides evidence that NOX2 is upregulated only in patients with paroxysmal/persistent AF and is responsible for overproduction of isoprostanes. This finding warrants further study to see if inhibition of NOX2 may reduce the risk of paroxysmal/persistent AF.

Patients with microvascular obstruction after primary percutaneous coronary intervention show a gp91phox (NOX2) mediated persistent oxidative stress after reperfusion.

Background: Persistent oxidative stress may play a key role in microvascular obstruction (MVO). We aimed at assessing the role of platelet gp91phox (NOX2), the catalytic subunit of NADPH oxidase in MVO. Methods: We enrolled 40 patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention within 12 h from symptoms onset, either with angiographic MVO (n=20) or good angiographic myocardial reperfusion (MR) (n=20). Angiographic MVO was defined as a final thrombolysis in myocardial infarction (TIMI) flow ≤2 or TIMI flow of 3 with myocardial blush grade <2. NOX2 and isoprostanes (8-iso-PGF2α) levels, as assessed by enzyme-linked immunoadsorbent assay (ELISA) or by an enzyme immunoassays, respectively, were measured on admission, at 24 h and pre-discharge. Results: NOX2 levels increased from baseline to pre-discharge in patients with angiographic MVO (20.25 (15–24.75) pg/ml vs 25.50 (17–29.25) pg/ml, p=0.02), but not in MR patients (p=0.45), with a significant interaction between baseline and pre-discharge levels among the two groups (p=0.04). The levels of 8-iso-PGF2α showed a trend to increase from baseline to pre-discharge in angiographic MVO patients (295 (183.50–389.25) pmol/l vs 322 (206–370) pmol/l, p=0.06), but not in patients with MR (p=0.56), with a trend for interaction between baseline and pre-discharge levels among the two groups (p=0.09). Conclusion: Patients with MVO, but not those with myocardial reperfusion, have a sustained increase of NOX2 and 8-iso-PGF2α. Therapies targeting NOX2 or high dosage antioxidants should be tested for MVO prevention and treatment.

Is NOX2 Upregulation Implicated in Myocardial Injury in Patients with Pneumonia

In the present study, we tested the hypothesis that oxidative stress could be implicated in myocardial damage during the acute phase of pneumonia. NOX2 activation, the catalytic subunit of NADPH oxidase, and high-sensitivity cardiac troponin T (hs-cTnT) elevation have been analyzed in two hundred forty-eight consecutive patients hospitalized for community-acquired pneumonia. Serum NOX2-derived peptide (sNOX2-dp), a marker of NOX2 activation, and 8-isoprostaglandin F2α (8-iso-PGF2α), a marker of oxidative stress, were measured upon admission; serum hs-cTnT and ECG were measured every 12 and 24 h, respectively. One hundred thirty-five patients (54%) showed elevated serum levels of hs-cTnT (>0.014 μg/L). A logistic regression analysis showed sNOX2-dp (p<0.001), Pneumonia Severity Index score (p<0.001), renal failure (p=0.024), and ejection fraction (p<0.001) as independent predictors of elevated serum levels of hs-cTnT. Serum sNOX2-dp was linearly correlated with hs-cTnT (Rs=0.538; p<0.001) and 8-iso-PGF2α (Rs=0.354; p<0.001). The study provides the first evidence of a significant association between serum cardiac Troponin T elevation and NOX2 upregulation in patients with pneumonia. This finding raises the hypothesis that NOX2-derived oxidative stress may be implicated in myocardial injury and that its inhibition could be a novel therapeutic strategy to limit it.

A case for assessment of oscillatory breathing during cardiopulmonary exercise test in risk stratification of elderly patients with chronic heart failure

UNLABELLED The prognostic value of exercise oscillatory breathing (EOB) during cardiopulmonary test (CPX) has been described in young chronic heart failure (HF) patients. We assessed the prognostic role of EOB vs other clinical and ventilatory parameters in elderly HF patients performing a maximal CPX. METHODS AND RESULTS We prospectively followed-up 370 HF outpatients ≥ 65 years after a symptom limited CPX. We tested the predictive value of clinical and ventilatory parameters for all-cause mortality and a composite of all-cause mortality and HF hospitalizations. Median age was 74 years, 51% had ischemic heart disease, 25% NYHA class III; ejection fraction was 41% [34-50]. Peak oxygen consumption (PVO(2)) was 11.9 [9.9-14] mL/kg/min, the slope of the regression line relating ventilation to CO(2) output, (VE/VCO(2) slope) was 33.9 [29.8-39.2]. EOB was found in 58% of patients. At follow-up, 84 patients died and overall 158, using a time-to-first event approach, met the composite end-point. Independent predictors of all-cause mortality were CPX EOB and the ratio of VE/VCO(2) slope to peak VO(2), hemoglobin, creatinine and body mass index. The area under the ROC curve (AUC) of the Cox multivariable model was 0.80 (95% CI 0.73 to 0.87). Independent predictors of the composite end-point were EOB, VE/VCO(2) slope, hemoglobin and HF admissions in the previous year (Model AUC 0.75) (95% CI 0.69 to 0.81). CONCLUSIONS Among elderly HF patients, EOB prevalence is higher than middle-aged cohorts. EOB and the ratio of VE/VCO(2) slope to peak VO(2) resulted the strongest ventilatory predictor of all-cause mortality, independent of ventricular function.

Additive prognostic value of cardiopulmonary exercise testing in elderly patients with heart failure.

To date, the role of CPET (cardiopulmonary exercise testing) for risk stratification in elderly patients with HF (heart failure) with depressed or preserved ventricular function has not been evaluated. In the present study, we analysed whether CPET is useful in predicting outcome in this population. A total of 220 NYHA (New York Heart Association) class I-III patients with HF > or =70 years of age [median age, 75 years; 23% had NYHA class III; and 59% had preserved ventricular systolic function (left ventricular ejection fraction > or =40%)] performed maximal CPET (peak expiratory exchange ratio >1.00). Median peak oxygen uptake was 11.9 ml.kg(-1) of body weight.min(-1), median VE/VCO(2) slope (slope of the minute ventilation/carbon dioxide production ratio) was 33.2 and 45% had an EVR (enhanced ventilatory response) to exercise (VE/VCO(2) slope > or =34). During 19 months of follow-up, 94 patients (43%) met the combined end point of death and hospital admission for worsening HF, arrhythmias or acute coronary syndromes. By Cox multivariable analysis, a creatinine clearance of <50 ml/min {HR (hazard ratio), 1.657 [95% CI (confidence interval), 1.055-2.602]} and EVR [HR, 1.965 (95% CI, 1.195-3.231)] were the best predictors of outcome, while ventricular function had no influence on prognosis. In conclusion, in elderly patients with HF, a steeper VE/VCO(2) slope provides additional information for risk stratification across the spectrum of ventricular function and identifies a high-risk population, commonly not considered in exercise testing guidelines.

Role of platelets in NOX2 activation mediated by TNFα in heart failure

Tumor necrosis factor (TNF) α may contribute to the deterioration of cardiovascular function in heart failure (HF) through various mechanisms, including the generation of reactive oxygen species (ROS). NADPH oxidase is the major source of ROS in the vascular system, but the interplay between TNFα and NADPH oxidase activation is elusive. As platelets possess NADPH oxidase enzyme, they represent an important tool to investigate the interplay between NADPH oxidase and TNFα in patients with HF. Serum gp91phox (NOX2), the catalytic core of NADPH oxidase, and serum TNFα were measured in 120 HF patients and in 60 healthy subjects. Compared with healthy subjects, HF patients had higher blood levels of NOX2 and TNFα with a progressive increase from NYHA I to NYHA IV classes. NOX2 levels in blood were independently associated with TNFα in HF patients. An in vitro study, performed on platelets from a subgroup of HF patients, shows that TNFα, at concentrations commonly found in HF patients’ peripheral circulation, activates platelet NOX2. Thus, TNFα increases ROS production and the extracellular levels of NOX2. These phenomena are inhibited by the NOX2-specific blocking peptide gp91ds-tat. The study provides evidence that circulating NOX2, as well as the activation of NOX2 on platelets, is increased in HF likely as a consequence of the underlying inflammatory process.

Impaired flow-mediated dilation in hospitalized patients with community-acquired pneumonia

BACKGROUND Community-acquired pneumonia (CAP) is complicated by cardiovascular events as myocardial infarction and stroke but the underlying mechanism is still unclear. We hypothesized that endothelial dysfunction may be implicated and that endotoxemia may have a role. METHODS Fifty patients with CAP and 50 controls were enrolled. At admission and at discharge, flow-mediated dilation (FMD), serum levels of endotoxins and oxidative stress, as assessed by serum levels of nitrite/nitrate (NOx) and isoprostanes, were studied. RESULTS At admission, a significant difference between patients with CAP and controls was observed for FMD (2.1±0.3 vs 4.0±0.3%, p<0.001), serum endotoxins (157.8±7.6 vs 33.1±4.8pg/ml), serum isoprostanes (341±14 vs 286±10 pM, p=0.009) and NOx (24.3±1.1 vs 29.7±2.2μM). Simple linear correlation analysis showed that serum endotoxins significantly correlated with Pneumonia Severity Index score (Rs=0.386, p=0.006). Compared to baseline, at discharge CAP patients showed a significant increase of FMD and NOx (from 2.1±0.3 to 4.6±0.4%, p<0.001 and from 24.3±1.1 to 31.1±1.5μM, p<0.001, respectively) and a significant decrease of serum endotoxins and isoprostanes (from 157.8±7.6 to 55.5±2.3pg/ml, p<0.001, and from 341±14 to 312±14 pM, p<0.001, respectively). Conversely, no changes for FMD, NOx, serum endotoxins and isoprostanes were observed in controls between baseline and discharge. Changes of FMD significantly correlated with changes of serum endotoxins (Rs=-0.315; p=0.001). CONCLUSIONS The study provides the first evidence that CAP is characterized by impaired FMD with a mechanism potentially involving endotoxin production and oxidative stress.

The Wellens’ Syndrome in the management of acute coronary syndromes

We read with great interest the letter by Corrao et al. [1], which reported a case of Wellens’ syndrome (WS); this clinical condition is characterized by the development of precordial negative T waves, after an episode of unstable angina, in patients with critical stenosis of the left descending anterior coronary artery (LAD). Although a PubMed search of WS allows one to retrieve about 150 citations, most of the articles are single case reports or reviews; therefore the real incidence and the real prognostic significance of this condition in the context of acute coronary syndromes (ACS) are not clearly understood. So far, the more extensive data regarding the epidemiological and clinical features of WS come from two observational studies conducted in the 1980s. In these studies, which respectively enrolled 145 and 1,260 subjects admitted for unstable angina, the prevalence of the ECG features of WS ranges from 14 to 18%. Moreover they demonstrate that WS presents a very high specificity in predicting a significant LAD lesion and, as a consequence, is related to a high risk in developing myocardial infarction (about 75% in pharmacologically treated patients) [2, 3]. The peculiar feature of WS is given by the fact that the ECG alterations usually appear in the pain-free period, several hours after the episode of angina, that typically lasts no more than 15–20 min; thus, WS is associated with an absent or only minimal release of troponin. The pathophysiological basis of this late onset is clearly given by Oreto et al. [4]. In fact, the reversal of the precordial T waves is an electrocardiographic sign, named ‘‘subepicardial ischemia’’. Unlike the electric vector of the ‘‘subepicardial lesion’’ (i.e. ST elevation) that ‘‘looks’’ to the ischemic zone, the vector of the ‘‘subepicardial ischemia’’ ‘‘escapes’’ from the culprit point, thus producing T wave inversion in the leads of the ischemic wall. As well as in the vector formation, these two electrocardiographic signs differ in the time of their onset; unlike ‘‘subepicardial lesion’’, indeed, ‘‘subepicardial ischemia’’ usually occurs only after hours or days, as it is considered a post-ischemic event, which appears when the acute phase of the ischemia is finished. Traditionally, ‘‘subepicardial ischemia’’ is considered one of the three ECG signs of the ‘‘ST elevation myocardial infarction’’ (STEMI) together with the above-mentioned ‘‘subepicardial lesion’’ and the ‘‘necrosis wave’’; however in particular conditions, ‘‘subepicardial ischemia’’ may occur without the other two signs, maintaining its late onset. The presence of ‘‘subepicardial ischemia’’, and the absence of the other two ECG signs of STEMI is the feature of the WS. In conclusion, WS is a ‘‘non ST elevation acute coronary syndrome’’ (NSTE-ACS), that shows not quite a ‘‘subendocardial lesion’’ (i.e. ST depression) but a ‘‘subepicardial ischemia’’; this particular ECG pattern is probably linked to the angiographic characteristic of the WS; in fact the ischemia induced by the critical stenosis of the LAD produces the ‘‘subepicardial ischemia’’, but, since there is no total occlusion and the ischemia lasts only a short time, it cannot produce the other two ECG signs of STEMI. As reported by some reviews, WS may be divided in two categories, depending on the morphology of the alteration of T wave: deep and symmetrical T waves in V2–V3 characterize type 1 WS, whereas biphasic T waves in most of the precordial leads define type 2 WS [5]. A. Celestini (&) Department of Cardiology, San Paolo Hospital, Civitavecchia, Rome, Italy e-mail: andrea.celestini@gmail.com