Daniele Pastori

Immediate Antioxidant and Antiplatelet Effect of Atorvastatin via Inhibition of Nox2

Background— Statins exert an antithrombotic effect in patients at risk of or with acute thrombosis, but no study has investigated whether this effect is immediate and whether there is an underline mechanism. Methods and Results— Patients with hypercholesterolemia were randomly allocated to a Mediterranean diet with low cholesterol intake (<300 mg/d; n=15) or atorvastatin (40 mg/d; n=15). Oxidative stress, as assessed by serum Nox2 and urinary isoprostanes, and platelet activation, as assessed by platelet recruitment, platelet isoprostanes, and thromboxane A2, platelet Nox2, Rac1, p47phox, protein kinase C, vasodilator-stimulated phosphoprotein, nitric oxide, and phospholipase A2, were determined at baseline and after 2, 24, and 72 hours and 7 days of follow-up. An in vitro study was also performed to see whether atorvastatin affects platelet oxidative stress and activation. The atorvastatin-assigned group showed a significant and progressive reduction of urinary isoprostanes and serum Nox2, along with inhibition of platelet recruitment, platelet isoprostanes, Nox2, Rac1, p47phox, and protein kinase C, starting 2 hours after administration. Platelet phospholipase A2 and thromboxane A2 significantly decreased and vasodilator-stimulated phosphoprotein and nitric oxide increased after 24 hours. Low-density lipoprotein cholesterol decreased significantly after 72 hours and further declined after 7 days. No changes were observed in the Mediterranean diet group. In vitro experiments demonstrated that atorvastatin dose-dependently inhibited platelet Nox2 and phospholipase A2 activation, along with inhibition of platelet recruitment, platelet isoprostanes, and thromboxane A2, and increased vasodilator-stimulated phosphoprotein and nitric oxide. Conclusions— The study provides the first evidence that atorvastatin acutely and simultaneously decreases oxidative stress and platelet activation by directly inhibiting platelet Nox2 and ultimately platelet isoprostanes and thromboxane A2. These findings provide a rationale for the use of statins to prevent or modulate coronary thrombosis. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01322711.

Oxidative stress: New insights on the association of non-alcoholic fatty liver disease and atherosclerosis.

Non-alcoholic fatty liver disease (NAFLD) represents the most common and emerging chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and more severe liver complications such as cirrhosis, hepatocellular carcinoma and liver mortality. NAFLD is strongly associated with obesity, insulin resistance, hypertension, and dyslipidaemia, and is now regarded as the liver manifestation of the metabolic syndrome. The increased mortality of patients with NAFLD is primarily a result of cardiovascular disease and, to a lesser extent, to liver related diseases. Increased oxidative stress has been reported in both patients with NAFLD and patient with cardiovascular risk factors. Thus, oxidative stress represents a shared pathophysiological disorder between the two conditions. Several therapeutic strategies targeting oxidative stress reduction in patients with NAFLD have been proposed, with conflicting results. In particular, vitamin E supplementation has been suggested for the treatment of non-diabetic, non-cirrhotic adults with active NASH, although this recommendation is based only on the results of a single randomized controlled trial. Other antioxidant treatments suggested are resveratrol, silybin, L-carnitine and pentoxiphylline. No trial so far, has evaluated the cardiovascular effects of antioxidant treatment in patients with NAFLD. New, large-scale studies including as end-point also the assessment of the atherosclerosis markers are needed.

The efficacy and safety of statins for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is an emerging liver disease in Western countries and the most frequent cause of incidental elevation of serum liver enzymes. Dyslipidaemia is frequently observed in patients with non-alcoholic fatty liver disease, and treatment of dyslipidaemia plays a critical role in the overall management of these patients. Moreover, coronary artery disease remains the most common cause of death. Statins are effective lipid-lowering agents, associated with a lowering the risk of cardiovascular events in several interventional randomized clinical trials. However, statins are often underused in patients with non-alcoholic fatty liver disease and many physicians are concerned about the prescription of statins to patients with unexplained persistent elevation of liver enzymes or active liver disease. Based on currently available data, statin therapy, at low-to-moderate doses, seems to be safe and has low liver toxicity. Treatment of dyslipidaemia in patients with non-alcoholic fatty liver disease is recommended and may also improve liver function tests. In these patients, the risks of not taking statins could outweigh the risks of taking the drug. Conversely, the usefulness of statins for the treatment of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis is still a matter of debate and randomized clinical trials of adequate size and duration are required.

Atrial Fibrillation and Myocardial Infarction: A Systematic Review and Appraisal of Pathophysiologic Mechanisms

Background A growing body of evidence suggests that atrial fibrillation (AF) is associated with myocardial infarction (MI). However, incidence and management of MI in AF is still undefined. Methods and Results We searched MEDLINE via PubMed and Cochrane database between 1965 and 2015. All observational clinical studies and interventional trials reporting 1‐year incidence of MI in AF were included. We also discussed pathophysiological mechanisms, predictors, and therapeutic approaches to reduce the risk of MI in AF. Twenty‐one observational studies and 10 clinical trials were included. The annual rate of MI in observational studies including AF patients ranged from 0.4% to 2.5%. Higher rates of MI were reported in AF patients with stable coronary artery disease (11.5%/year), vascular disease (4.47%/year), heart failure (2.9%/year), and in those undergoing coronary artery interventions (6.3%/year). However, lower annual rates have been described in AF patients from Eastern countries (0.2–0.3%/year), and in those enrolled in clinical trials (from 0.4 to 1.3%/year). Conclusions AF patients had a significant residual risk of MI despite anticoagulant treatment. Coexistence of atherosclerotic risk factors and platelet activation account for the increased risk of MI in AF. Identification of high‐risk AF patients is a needed first step to develop cost‐effective approaches for prevention. A new score, the 2MACE score, has been recently developed to stratify MI risk in AF, and may help not only in allocating resources to high‐risk groups, but also in design of studies examining novel therapies for prevention of MI in AF.

Incidence of Myocardial Infarction and Vascular Death in Elderly Patients With Atrial Fibrillation Taking Anticoagulants: Relation to Atherosclerotic Risk Factors

BACKGROUND Recent findings suggest that patients with atrial fibrillation (AF), in addition being at thromboembolic risk, are at risk of myocardial infarction (MI). Our aim was to investigate predictors of MI and cardiovascular death in a cohort of patients with AF who were taking anticoagulants. METHODS We prospectively followed up 1,019 patients with AF for a median of 33.7 months (3,223 person-years). All patients were treated with oral vitamin K antagonists. Primary outcome was a composite end point of cardiovascular events (CVEs) including fatal/nonfatal MI, cardiac revascularization, and cardiovascular death. RESULTS The mean age of the patients was 73.2 years, and 43.8% were women. At follow-up, 111 CVEs (3.43%/y) had occurred: 47 fatal-nonfatal MI/revascularization and 64 cardiovascular deaths. In addition, 31 stroke/transient ischemic attacks (0.96%/y) were recorded. Patients experiencing CVEs were older (P < .001) and had a higher prevalence of metabolic syndrome (MetS) (P = .005), heart failure (P = .001), and prior cardiac (P < .001) and cerebrovascular events (P < .001). On a Cox proportional hazard analysis, age (hazard ratio [HR], 1.083; 95% CI, 1.053-1.113; P < .001), smoking (HR, 2.158; 95% CI, 1.193-3.901; P = .011), history of cerebrovascular (HR, 1.704; 95% CI, 1.119-2.597; P = .013) and cardiac (HR, 1.658; 95% CI, 1.105-2.489; P = .015) events, MetS (HR, 1.663; 95% CI, 1.107-2.499; P = .014), heart failure (HR, 1.584; 95% CI, 1.021-2.456; P = .040), and male sex (HR, 1.499; 95% CI, 1.010-2.223; P = .044) predicted CVEs. CONCLUSIONS Patients with AF still experience a high rate of CVEs despite receiving anticoagulant treatment. MetS is a common clinical feature in patients with AF, which increases the risk of CVEs. A holistic approach is needed to reduce the cardiovascular risk in patients with AF. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01882114; URL: www.clinicaltrials.gov.

Inadequate anticoagulation by Vitamin K Antagonists is associated with Major Adverse Cardiovascular Events in patients with atrial fibrillation

BACKGROUND Time in therapeutic range (TTR) reflects the quality of anticoagulation and is inversely correlated with ischemic stroke in atrial fibrillation (AF) patients. Few data on the relationship between TTR and myocardial infarction (MI) are available. We investigated the association between TTR and Major Adverse Cardiovascular Events (MACE) in a cohort of anticoagulated AF patients. METHODS We calculated TTR for 627 AF patients on vitamin K antagonists, who were followed for a median of 30.8 months (1755 patients/year). The primary outcome was a combined endpoint of MACE including fatal/nonfatal MI and cardiovascular death. RESULTS Mean age was 73.3 (±8.2) years, and 40.2% were women. During follow-up, we recorded 67 events: 19 stroke/TIA (1.1%/year) and 48 MACE (2.9%/year): 24 MI and 24 cardiovascular deaths. The cohort was categorized according to tertiles of TTR values: TTR 13-58%, 59-74%, and 75-100%. There was a significant increased rate of MACE across tertiles of TTR (Log-Rank test: p<0.001). On Cox proportion hazard analysis, the 2nd vs. 1st tertile of TTR (p=0.002, hazard ratio [HR] 0.347, confidence interval [CI] 95% 0.177-0.680), 3rd vs. 1st tertile of TTR (p<0.001, HR 0.164, CI 95% 0.067-0.402), age (p<0.001, HR 1.094, CI 95% 1.042-1.148), history of stroke/TIA (p=0.015, HR 2.294, CI 95% 1.172-4.490) and smoking (p=0.003, HR 3.450, CI 95% 1.532-7.769) predicted MACE. CONCLUSION TTR was an independent predictor of MACE in our cohort of AF patients. Our findings suggest that a good anticoagulation control is necessary to reduce not only the risk of stroke but also that of MACE.

Modern approach to the clinical management of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is the most common and emerging form of chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to steatohepatitis, which may progress to cirrhosis, liver cancer, and liver mortality. Common metabolic diseases, which are well established cardiovascular risk factors, have been associated to NAFLD and cardiovascular disease is the single most important cause of morbidity and mortality in this patient population. The pathogenesis of NAFLD appears multifactorial and many mechanisms have been proposed as possible causes of fatty liver infiltration. Management of fatty liver has become a major challenge to healthcare systems as the consequence of the increasing rates of obesity worldwide. First-line management focuses on lifestyle modifications. Moderate weight reduction either by dietary restriction or by increased habitual physical activity is safe and highly recommended. Several therapeutic interventions have been proposed. These include insulin sensitizer agents, lipid lowering drugs, antioxidants such as vitamin E and supplementation of vitamin D3. However, therapeutic strategies have been largely empirical so far, and experimental trials have mostly been carried out in uncontrolled settings with small sample sizes. Metabolic conditions such as diabetes mellitus, obesity, hypertension and hyperlipidemia, should be strongly considered and a multidisciplinary approach should be personalized for individual patients. Treatment of co-morbidities should be regarded as of paramount importance in the management of these patients. The purpose of this review is to examine different approaches for the clinical management of non-alcoholic fatty liver disease.

Serum NOX2 and urinary isoprostanes predict vascular events in patients with atrial fibrillation

There are limited prospective data evaluating the role of urinary F2-IsoP and NOX2 as predictive markers in atrial fibrillation (AF). The aim of this study was to analyse the role of urinary prostaglandin PGF2alpha (8-iso-PGF2α) and NOX2, markers of systemic oxidative stress, in predicting cardiovascular (CV) events and mortality in anticoagulated non-valvular AF patients. This was a prospective study including 1,002 anticoagulated AF patients, followed for a median time of 25.7 months (interquartile range: 14.8-50.9). All major CV events, CV deaths and all-cause deaths were considered as primary outcomes of the study. CV events included fatal/nonfatal ischaemic stroke, fatal/nonfatal myocardial infarction (MI), cardiac revascularisation and transient ischaemic attack (TIA). Oxidative stress biomarkers, such as urinary 8-iso-PGF2α and serum sNOX2-dp, a marker of NOX2 activation, were measured. A CV event occurred in 125 patients (12.5 %); 78 CV deaths and 31 non-CV deaths were registered. 8-iso-PGF2α and sNOX2-dp were correlated (Rs=0.765 p< 0.001). A significant increased cumulative incidence of CV events and CV deaths was observed across tertiles for 8-iso-PGF2α and sNOX2-dp. An increased rate of all-cause death was observed across tertiles of urinary 8-iso-PGF2α. In Cox or Fine and Gray models, 8-iso-PGF2α predicted CV events and CV and non-CV deaths. The addition of tertiles of 8-iso-PGF2α to CHA2DS2-VASc score improved ROC curves for each outcome and NRI for CV events (0.24 [0.06-0.53] p=0.0067). The study shows that in AF patients 8-iso-PGF2α and NOX2 levels are predictive of CV events and total mortality. F2-IsoP may complement conventional risk factors in prediction of CV events.

Reduced Lysosomal Acid Lipase Activity in Adult Patients With Non-alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) is characterized by intra-hepatic fat accumulation and mechanisms involved in its pathogenesis are not fully explained. Lysosomal Acid Lipase (LAL) is a key enzyme in lipid metabolism. We investigated its activity in patients with fatty liver. LAL activity (nmol/spot/h) was measured in 100 adult healthy subjects (HS) and in 240 NAFLD patients. A sub-analysis on 35 patients with biopsy-proven non-alcoholic steatohepatitis (NASH) was performed. Median LAL activity was 1.15 (0.95–1.72) in HS. It was significantly reduced in NAFLD [0.78 (0.61–1.01), p < 0.001 vs. HS]. A further reduction was observed in the subgroup of NASH [0.67 (0.51–0.77), p < 0.001 vs. HS]. Patients with LAL activity below median had higher values of serum total cholesterol (p < 0.05) and LDL-c (p < 0.05), and increased serum liver enzymes (ALT, p < 0.001; AST, p < 0.01; GGT, p < 0.01). At multivariable logistic regression analysis, factors associated with LAL activity below median were ALT (OR: 1.018, 95% CI 1.004–1.032, p = 0.011) and metabolic syndrome (OR: 2.551, 95% CI 1.241–5.245, p = 0.011), whilst statin use predicted a better LAL function (OR: 0.464, 95% CI 0.248–0.866, p = 0.016). Our findings suggest a strong association between impaired LAL activity and NAFLD. A better knowledge of the role of LAL may provide new insights in NAFLD pathogenesis.

Anoxia-reoxygenation enhances platelet thromboxane A2 production via reactive oxygen species-generated NOX2: effect in patients undergoing elective percutaneous coronary intervention.

Objective—Platelets undergoing anoxia-reoxygenation (AR) simultaneously increase reactive oxygen species (ROS) and thromboxane (Tx) B2. Our aim was to assess whether there is an interplay between activation of NOX2, the catalytic subunit of NADPH oxidase, and platelet TxB2 in vitro and in vivo. Methods and Results—Platelets that underwent AR had enhanced ROS. This was associated with NOX2 activation and was inhibited by incubation with NOX2-blocking peptide. AR was associated with TxB2 and isoprostane production, which were inhibited by NOX2-blocking peptide, vitamin C, and the inhibitor of phospholipase A2. Platelet incubation with 100 &mgr;mol/L aspirin fully prevented AR-induced TxA2 but did not affect isoprostane production. We included 56 aspirin-treated patients undergoing elective percutaneous coronary intervention (PCI) who were randomly allocated to receive either placebo or intravenous infusion of 1 g of vitamin C. Blood TxB2, isoprostanes, and soluble NOX2-derived peptide, a marker of systemic NADPH oxidase activation, significantly increased at 60 and 120 minutes after PCI in placebo-treated but not in vitamin C-treated patients. Conclusion—AR is associated with overproduction of platelet TxB2 and isoprostanes, which is dependent on NOX2-dependent ROS generation. Low doses of aspirin are unable to prevent TxB2 formation in patients who undergo PCI.