Effects of two-month treatment with a mixture of natural activators of autophagy on oxidative stress and arterial stiffness in patients with essential hypertension: A pilot study

BACKGROUND AND AIMS

Trehalose, spermidine, nicotinamide, and polyphenols are natural substances that exert pro-autophagic and antioxidant properties. Their role in blood pressure (BP) regulation and preservation of vascular function in essential hypertension is unknown. The aim of this study was to evaluate the effect of a mixture of these agents on BP level, markers of oxidative stress, autophagy, endothelial function, and vascular stiffness in outpatients with grade 1 uncomplicated essential hypertension.

METHODS AND RESULTS

A single-centre, open-label, case-control, pilot study was conducted in adult outpatients (aged ≥18 years) receiving or not the mixture for two months along with the standard therapies. Both at baseline and at the end of the treatment the following clinical parameters were evaluated: brachial seated office BP level, central aortic pressure, pulse wave velocity, augmentation index (AI@75). Both at baseline and at the end of the treatment, a blood sample was drawn for the measurement of: H2O2, HBA%, levels of sNOX2-dp, Atg 5, P62, endothelin 1, and NO bioavailability. The mixture of nutraceuticals did not influence BP levels. Patients receiving the mixture showed a significant decrease of oxidative stress, stimulation of autophagy, increased NO bioavailability and no increase of the AI@75, in contrast to what observed in hypertensive patients not receiving the mixture.

CONCLUSIONS

The supplementation of the trehalose, spermidine, nicotinamide, and polyphenols mixture counteracted hypertension-related arterial stiffness through mechanisms likely dependent on oxidative stress downregulation and autophagy stimulation. These natural activators of autophagy may represent favourable adjuvants for prevention of the hypertensive cardiovascular damage.

Optical coherence tomography-derived lipid core burden index and clinical outcomes: results from the CLIMA registry

AIMS

The aim of this study was to assess the morphological characteristics and prognostic implications of the optical coherence tomography (OCT)-derived lipid core burden index (LCBI).

METHODS AND RESULTS

OCT-LCBI was assessed in 1003 patients with 1-year follow-up from the CLIMA multicentre registry using a validated software able to automatically obtain a maximum OCT-LCBI in 4 mm (maxOCT-LCBI4mm). Primary composite clinical endpoint included cardiac death, myocardial infarction, and target-vessel revascularization. A secondary analysis using clinical outcomes of CLIMA study was performed. Patients with a maxOCT-LCBI4mm ≥ 400 showed higher prevalence of fibrous cap thickness (FCT) <75 μm [odds ratio (OR) 1.43, 95% confidence interval (CI) 1.03-1.99; P = 0.034], lipid pool arc >180° (OR 3.93, 95%CI 2.97-5.21; P < 0.001), minimum lumen area <3.5 mm2 (OR 1.5, 95%CI 1.16-1.94; P = 0.002), macrophage infiltration (OR 2.38, 95%CI 1.81-3.13; P < 0.001), and intra-plaque intimal vasculature (OR 1.34, 95%CI 1.05-1.72; P = 0.021). A maxOCT-LCBI4mm ≥400 predicted the primary endpoint [adjusted hazard ratio (HR) 1.86, 95%CI 1.1-3.2; P = 0.019] as well as the CLIMA endpoint (HR 2.56, 95%CI 1.24-5.29; P = 0.011). Patients with high lipid content and thin FCT < 75 µm were at higher risk for adverse events (HR 4.88, 95%CI 2.44-9.72; P < 0.001).

CONCLUSIONS

A high maxOCT-LCBI4mm was related to poor outcome and vulnerable plaque features. This study represents a step further in the automated assessment of the coronary plaque risk profile.

[From regression to stabilization: new insights into the evolution of coronary atherosclerotic plaque]

Coronary artery atherosclerosis is a constantly evolving disease. Over the years, new drug therapies have been shown to reduce adverse cardiovascular events and improve the survival of patients with coronary artery disease. New intracoronary imaging modalities, including intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy, have been introduced to detect the anatomic changes which follow an effective lipid-lowering therapy in human coronary plaques. Particularly, the use of optical coherence tomography made it possible to evaluate plaque composition and showed how an intensive lipid-lowering therapy can stabilize atherosclerosis by improving vulnerable plaque features. Future non-invasive applications are required for large-scale use of these findings.

The Role of the Association Between Serum C-Reactive Protein Levels and Coronary Plaque Macrophage Accumulation in Predicting Clinical Events - Results from the CLIMA Registry

The present investigation aims to study the interaction between systemic and intra-plaque inflammation in predicting cardiac events. We investigated C-reactive protein (CRP) levels as well as plaque inflammation with optical coherence tomography (OCT)-detected macrophages in the CLIMA study. 689 patients had admission CRP serum values reported, and high CRP values were defined as ≥ 2 mg/dl. The main study endpoint was a composite of cardiac death, myocardial infarction, and/or target vessel revascularization at 1-year follow-up. At multivariate Cox regression analysis, a large (hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.2-4.3; p = 0.013) and superficial (HR 2.78, 95%CI 1.5-5.1; p = 0.001) macrophage arc was predicted of the main composite endpoint in patients with high CRP levels. Patients with large/superficial macrophage accumulation and low CRP levels were not at higher risk of adverse events. The presence of high CRP levels and large/superficial macrophage accumulation at OCT analysis identified patients at higher risk of clinical events.

The risk of acute coronary events in microvascular disease

The microvascular disease represents a widespread clinical entity in the general population, especially among women. The dysfunction of the microcirculation is often responsible for myocardial ischaemia and angina in the absence of significant stenosis of the epicardial district, while in other cases it can represent a contributing cause of angina even in the presence of coronary artery disease, cardiomyopathies or heart failure. The cardiovascular risk factors of people with microvascular disease are similar to those who develop epicardial atherosclerotic disease. However, the prognostic significance of microvascular disease remains a matter of debate. An element to be clarified, in fact, is whether subjects with dysfunction of the microcirculation and coronary tree without significant stenoses present an increased risk of myocardial infarction and sudden death. In recent years, several studies seem to confirm an association between microvascular disease and progression of coronary epicardial atherosclerosis. The prognosis of microvascular disease would therefore not be benign as was previously believed, but associated with an increased risk of cardiovascular events including revascularization, heart attack, and cardiac death.

Renal arteries denervation: from the treatment of resistant hypertension to the treatment of atrial fibrillation

Renal denervation (RDN) is a therapeutic strategy for patients with uncontrolled arterial hypertension characterized by considerable fluctuations during its progression. After initial strong enthusiasm, the procedure came to an abrupt halt following the publication of the Symplicity HTN-3 study results. The results of recently published studies highlight the reduction in blood pressure values after RDN and justify the inclusion in the Guidelines of new recommendations for the use of RDN in clinical practice, in selected patients. Additionally, RDN findings are summarized in view of other potential indications such as atrial fibrillation. Six prospective, randomized studies are presented that evaluated RDN as an adjunct therapy to pulmonary vein isolation for the treatment of atrial fibrillation. In five studies, patients had uncontrolled hypertension despite therapy with three antihypertensive drugs. The analysis of these studies showed that RDN reduced the recurrence of atrial fibrillation (AF) by 57% compared to patients with pulmonary vein isolation (PVI) only. Modulation of the autonomic nervous system by RDN has been shown not only to reduce blood pressure but also to have an antiarrhythmic effect in symptomatic AF patients when the strategy is combined with PVI, thus opening up new therapeutic scenarios.

Perclose Proglide™ for vascular closure

In the past 20 years, numerous percutaneous vascular closure devices have been tested and compared with manual compression and to surgical cut-down. The suture-mediated closure device Perclose ProGlide™ system (Abbott Vascular, CA, USA) emerged as a safe and effective alternative for many procedures requiring either small or large bore vascular accesses. In this review, we will discuss the characteristics of this vascular closure device and the main studies that proved its potential to reduce vascular complications, time to deambulation, time to discharge and patient discomfort.

Dissipative non-equilibrium Green function methodology to treat short range Coulomb interaction: current through a 1D nanostructure

A methodology describing Coulomb blockade in the non-equilibrium Green function formalism is presented. We carried out ballistic and dissipative simulations through a 1D quantum dot using an Einstein phonon model. Inelastic phonons with different energies have been considered. The methodology incorporates the short-range Coulomb interaction between two electrons through the use of a two-particle Green function. Unlike previous work, the quantum dot has spatial resolution i.e. it is not just parameterized by the energy level and coupling constants of the dot. Our method intends to describe the effect of electron localization while maintaining an open boundary or extended wave function. The formalism conserves the current through the nanostructure. A simple 1D model is used to explain the increase of mobility in semi-crystalline polymers as a function of the electron concentration. The mechanism suggested is based on the lifting of energy levels into the transmission window as a result of the local electron-electron repulsion inside a crystalline domain. The results are aligned with recent experimental findings. Finally, as a proof of concept, we present a simulation of a low temperature resonant structure showing the stability diagram in the Coulomb blockade regime.

Engineering the Photoresponse of InAs Nanowires

We report on individual-InAs nanowire optoelectronic devices which can be tailored to exhibit either negative or positive photoconductivity (NPC or PPC). The NPC photoresponse time and magnitude is found to be highly tunable by varying the nanowire diameter under controlled growth conditions. Using hysteresis characterization, we decouple the observed photoexcitation-induced hot electron trapping from conventional electric field-induced trapping to gain a fundamental insight into the interface trap states responsible for NPC. Furthermore, we demonstrate surface passivation without chemical etching which both enhances the field-effect mobility of the nanowires by approximately an order of magnitude and effectively eliminates the hot carrier trapping found to be responsible for NPC, thus restoring an "intrinsic" positive photoresponse. This opens pathways toward engineering semiconductor nanowires for novel optical-memory and photodetector applications.

High Conductivity in Molecularly p-Doped Diketopyrrolopyrrole-Based Polymer: The Impact of a High Dopant Strength and Good Structural Order

[3]-Radialene-based dopant CN6-CP studied herein, with its reduction potential of +0.8 versus Fc/Fc+ and the lowest unoccupied molecular orbital level of -5.87 eV, is the strongest molecular p-dopant reported in the open literature, so far. The efficient p-doping of the donor-acceptor dithienyl-diketopyrrolopyrrole-based copolymer having the highest unoccupied molecular orbital level of -5.49 eV is achieved. The doped films exhibit electrical conductivities up to 70 S cm(-1) .

Heart failure and iron deficiency anemia in Italy: results from CARMES-1 registry

Aims: To assess the prevalence of anemia and iron deficiency anemia in heart failure (HF) patients, to evaluate the effectiveness of current iron deficiency treatment strategies after discharge, and to analyze hospital readmissions and mortality rates in patients with and without anemia. Patients & methods: A patient registry-based, multicenter, retrospective, observational, cohort study of 418 hospitalized HF patients in Italy, monitored from 1 March 2010 to 30 March 2011. Results: Among patients with HF, 35.9% had anemia at admission; only 51.3% were treated with current iron deficiency treatment strategies during hospitalization and then only 29% of patients who were anemic at discharge were treated with iron at home. After a 4-week follow-up, only 11% of these patients reached the hemoglobin target value (study primary end point). However, current iron deficiency treatment strategies were not significantly associated with reduced risk of rehospitalization, but with a significantly reduced mortality rate after a 6-month follow-up (study secondary end points: 11.7 vs 51.7%; p < 0.0001). Conclusion: In HF patients, there is poor attention paid to anemia, its causes and treatment. Current iron deficiency treatment strategies are mismanaged and CARMES-1 demonstrated that they appear to be insufficient at improving patient outcome in terms of rehospitalization rate reduction, generating high costs, which could be avoided through an optimized treatment strategy. Therefore, more efficacious, efficient and cost–effective treatment strategies are required in Italy for HF patients with iron deficiency anemia to meet this unmet medical need.

Spectroscopic investigation of oxygen- and water-induced electron trapping and charge transport instabilities in n-type polymer semiconductors

We present an optical spectroscopy study on the role of oxygen and water in electron trapping and storage/bias-stress degradation of n-type polymer field-effect transistors based on one of the most widely studied electron transporting conjugated polymers, poly{[N,N9-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,59-(2,29-bisthiophene)} (P(NDI2OD-T2)). We combine results obtained from charge accumulation spectroscopy, which allow optical quantification of the concentration of mobile and trapped charges in the polymer film, with electrical characterization of P(NDI2OD-T2) organic field-effect transistors to study the mechanism for storage and bias-stress degradation upon exposure to dry air/oxygen and humid nitrogen/water environments, thus separating the effect of the two molecules and determining the nature of their interaction with the polymer. We find that the stability upon oxygen exposure is limited by an interaction between the neutral polymer and molecular oxygen leading to a reduction in electron mobility in the bulk of the semiconductor. We use density functional theory quantum chemical calculations to ascribe the drop in mobility to the formation of a shallow, localized, oxygen-induced trap level, 0.34 eV below the delocalized lowest unoccupied molecular orbital of P(NDI2OD-T2). In contrast, the stability of the polymer anion against water is limited by two competing reactions, one involving the electrochemical oxidation of the polymer anion by water without degradation of the polymer and the other involving a radical anion-catalyzed chemical reaction of the polymer with water, in which the electron can be recycled and lead to further degradation reactions, such that a significant portion of the film is degraded after prolonged bias stressing. Using Raman spectroscopy, we have been able to ascribe this to a chemical interaction of water with the naphthalene diimide unit of the polymer. The degradation mechanisms identified here should be considered to explain electron trapping in other rylene diimides and possibly in other classes of conjugated polymers as well.

High resolution optical spectroscopy of air-induced electrical instabilities in n-type polymer semiconductors

We use high-resolution charge-accumulation optical spectroscopy to measure charge accumulation in the channel of an n-type organic field-effect transistor. We monitor the degradation of device performance in air, correlate the onset voltage shift with the reduction of charge accumulated in the polymer semiconductor, and explain the results in view of the redox reaction between the polymer, water and oxygen in the accumulation layer.