David Montaigne

Bio: David Montaigne is an academic researcher from university of lille. The author has contributed to research in topics: Medicine & Internal medicine. The author has an hindex of 25, co-authored 95 publications receiving 2250 citations. Previous affiliations of David Montaigne include Centre Hospitalier Regional et Universitaire de Lille & Lille University of Science and Technology.

Myocardial Contractile Dysfunction Is Associated With Impaired Mitochondrial Function and Dynamics in Type 2 Diabetic but Not in Obese Patients

Abstract: Background—Obesity and diabetes mellitus are independently associated with the development of heart failure In this study, we determined the respective effects of obesity, insulin resistance, and diabetes mellitus on the intrinsic contraction and mitochondrial function of the human myocardium before the onset of cardiomyopathy Methods and Results—Right atrial myocardium was obtained from 141 consecutive patients presenting no sign of cardiomyopathy We investigated ex vivo isometric contraction, mitochondrial respiration and calcium retention capacity, and respiratory chain complex activities and oxidative stress status Diabetes mellitus was associated with a pronounced impairment of intrinsic contraction, mitochondrial dysfunction, and increased myocardial oxidative stress, regardless of weight status In contrast, obesity was associated with less pronounced contractile dysfunction without any significant perturbation of mitochondrial function or oxidative stress status Tested as continuous variables

Endothelial glycocalyx damage during endotoxemia coincides with microcirculatory dysfunction and vascular oxidative stress.

Abstract: The glycocalyx constitutes the first line of the blood tissue interface and is thus involved in many physiological processes, deregulation of which may lead to microvascular dysfunction. Because administration of LPS is accompanied by severe microvascular dysfunction, the purpose of the study was to investigate microvascular glycocalyx function during endotoxemia. Bolus infusion of LPS (10 mg kg(-1)) to male Sprague-Dawley rats elicited the development of hyporeactivity to vasoactive agents and microvascular derangements, including decreased capillary density and significant increases in intermittent and stopped flow capillaries in the small intestine muscularis layer compared with controls. LPS elicited plasma hyluronan release and reduction in endothelial surface thickness, indicative of glycocalyx degradation. Because endothelial glycocalyx is extremely sensitive to free radicals, oxidative stress was evaluated by oxidation of dihydrorhodamine in microvascular beds and levels of heart malondialdehyde and plasma carbonyl proteins, which were all increased in LPS-treated rats. Activated protein C (240 microg kg(-1) h(-1)) enhanced systemic arterial pressure response to norepinephrine in LPS-treated rats. Activated protein C (240 microg kg(-1) h(-1)) prevented capillary perfusion deficit in the septic microvasculature that were associated with reduced oxidative stress and preservation of glycocalyx. Our findings support the conclusion that LPS induces major microcirculation dysfunction accompanied by microvascular oxidative stress and glycocalyx degradation that may be limited by activated protein C treatment.

PPAR control of metabolism and cardiovascular functions

Abstract: Peroxisome proliferator-activated receptor-α (PPARα), PPARδ and PPARγ are transcription factors that regulate gene expression following ligand activation. PPARα increases cellular fatty acid uptake, esterification and trafficking and regulates lipoprotein metabolism genes. PPARδ stimulates lipid and glucose utilization by increasing mitochondrial function and fatty acid desaturation pathways. By contrast, PPARγ promotes fatty acid uptake, triglyceride formation and storage in lipid droplets, thereby improving insulin sensitivity and glucose metabolism. PPARs also exert anti-atherogenic and anti-inflammatory effects on the vascular wall and immune cells. Clinically, PPARγ activation by glitazones and PPARα activation by fibrates improve insulin resistance and dyslipidaemia, respectively. PPARs are also physiological master switches in the heart, steering cardiac energy metabolism in cardiomyocytes, thereby affecting pathological heart failure and diabetic cardiomyopathy. Novel PPAR agonists in clinical development are providing new opportunities in the management of metabolic and cardiovascular diseases.

Outcomes of Patients With Asymptomatic Aortic Stenosis Followed Up in Heart Valve Clinics.

Abstract: Importance The natural history and the management of patients with asymptomatic aortic stenosis (AS) have not been fully examined in the current era. Objective To determine the clinical outcomes of patients with asymptomatic AS using data from the Heart Valve Clinic International Database. Design, Setting, and Participants This registry was assembled by merging data from prospectively gathered institutional databases from 10 heart valve clinics in Europe, Canada, and the United States. Asymptomatic patients with an aortic valve area of 1.5 cm2or less and preserved left ventricular ejection fraction (LVEF) greater than 50% at entry were considered for the present analysis. Data were collected from January 2001 to December 2014, and data were analyzed from January 2017 to July 2018. Main Outcomes and Measures Natural history, need for aortic valve replacement (AVR), and survival of asymptomatic patients with moderate or severe AS at entry followed up in a heart valve clinic. Indications for AVR were based on current guideline recommendations. Results Of the 1375 patients included in this analysis, 834 (60.7%) were male, and the mean (SD) age was 71 (13) years. A total of 861 patients (62.6%) had severe AS (aortic valve area less than 1.0 cm2). The mean (SD) overall survival during medical management (mean [SD] follow up, 27 [24] months) was 93% (1%), 86% (2%), and 75% (4%) at 2, 4, and 8 years, respectively. A total of 104 patients (7.6%) died under observation, including 57 patients (54.8%) from cardiovascular causes. The crude rate of sudden death was 0.65% over the duration of the study. A total of 542 patients (39.4%) underwent AVR, including 388 patients (71.6%) with severe AS at study entry and 154 (28.4%) with moderate AS at entry who progressed to severe AS. Those with severe AS at entry who underwent AVR did so at a mean (SD) of 14.4 (16.6) months and a median of 8.7 months. The mean (SD) 2-year and 4-year AVR-free survival rates for asymptomatic patients with severe AS at baseline were 54% (2%) and 32% (3%), respectively. In those undergoing AVR, the 30-day postprocedural mortality was 0.9%. In patients with severe AS at entry, peak aortic jet velocity (greater than 5 m/s) and LVEF (less than 60%) were associated with all-cause and cardiovascular mortality without AVR; these factors were also associated with postprocedural mortality in those patients with severe AS at baseline who underwent AVR (surgical AVR in 310 patients; transcatheter AVR in 78 patients). Conclusions and Relevance In patients with asymptomatic AS followed up in heart valve centers, the risk of sudden death is low, and rates of overall survival are similar to those reported from previous series. Patients with severe AS at baseline and peak aortic jet velocity of 5.0 m/s or greater or LVEF less than 60% have increased risks of all-cause and cardiovascular mortality even after AVR. The potential benefit of early intervention should be considered in these high-risk patients.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

Abstract: Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure flux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation, it is imperative to target by gene knockout or RNA interference more than one autophagy-related protein. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways implying that not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular assays, we hope to encourage technical innovation in the field.

Exercise-based cardiac rehabilitation for coronary heart disease

Abstract: Background Coronary heart disease (CHD) is the most common cause of death globally. However, with falling CHD mortality rates, an increasing number of people living with CHD may need support to manage their symptoms and prognosis. Exercise‐based cardiac rehabilitation (CR) aims to improve the health and outcomes of people with CHD. This is an update of a Cochrane Review previously published in 2016. Objectives To assess the clinical effectiveness and cost‐effectiveness of exercise‐based CR (exercise training alone or in combination with psychosocial or educational interventions) compared with 'no exercise' control, on mortality, morbidity and health‐related quality of life (HRQoL) in people with CHD. Search methods We updated searches from the previous Cochrane Review, by searching CENTRAL, MEDLINE, Embase, and two other databases in September 2020. We also searched two clinical trials registers in June 2021. Selection criteria We included randomised controlled trials (RCTs) of exercise‐based interventions with at least six months’ follow‐up, compared with 'no exercise' control. The study population comprised adult men and women who have had a myocardial infarction (MI), coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI), or have angina pectoris, or coronary artery disease. Data collection and analysis We screened all identified references, extracted data and assessed risk of bias according to Cochrane methods. We stratified meta‐analysis by duration of follow‐up: short‐term (6 to 12 months); medium‐term (> 12 to 36 months); and long‐term ( > 3 years), and used meta‐regression to explore potential treatment effect modifiers. We used GRADE for primary outcomes at 6 to 12 months (the most common follow‐up time point). Main results This review included 85 trials which randomised 23,430 people with CHD. This latest update identified 22 new trials (7795 participants). The population included predominantly post‐MI and post‐revascularisation patients, with a mean age ranging from 47 to 77 years. In the last decade, the median percentage of women with CHD has increased from 11% to 17%, but females still account for a similarly small percentage of participants recruited overall ( < 15%). Twenty‐one of the included trials were performed in low‐ and middle‐income countries (LMICs). Overall trial reporting was poor, although there was evidence of an improvement in quality over the last decade. The median longest follow‐up time was 12 months (range 6 months to 19 years). At short‐term follow‐up (6 to 12 months), exercise‐based CR likely results in a slight reduction in all‐cause mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.73 to 1.04; 25 trials; moderate certainty evidence), a large reduction in MI (RR 0.72, 95% CI 0.55 to 0.93; 22 trials; number needed to treat for an additional beneficial outcome (NNTB) 75, 95% CI 47 to 298; high certainty evidence), and a large reduction in all‐cause hospitalisation (RR 0.58, 95% CI 0.43 to 0.77; 14 trials; NNTB 12, 95% CI 9 to 21; moderate certainty evidence). Exercise‐based CR likely results in little to no difference in risk of cardiovascular mortality (RR 0.88, 95% CI 0.68 to 1.14; 15 trials; moderate certainty evidence), CABG (RR 0.99, 95% CI 0.78 to 1.27; 20 trials; high certainty evidence), and PCI (RR 0.86, 95% CI 0.63 to 1.19; 13 trials; moderate certainty evidence) up to 12 months' follow‐up. We are uncertain about the effects of exercise‐based CR on cardiovascular hospitalisation, with a wide confidence interval including considerable benefit as well as harm (RR 0.80, 95% CI 0.41 to 1.59; low certainty evidence). There was evidence of substantial heterogeneity across trials for cardiovascular hospitalisations (I2 = 53%), and of small study bias for all‐cause hospitalisation, but not for all other outcomes. At medium‐term follow‐up, although there may be little to no difference in all‐cause mortality (RR 0.90, 95% CI 0.80 to 1.02; 15 trials), MI (RR 1.07, 95% CI 0.91 to 1.27; 12 trials), PCI (RR 0.96, 95% CI 0.69 to 1.35; 6 trials), CABG (RR 0.97, 95% CI 0.77 to 1.23; 9 trials), and all‐cause hospitalisation (RR 0.92, 95% CI 0.82 to 1.03; 9 trials), a large reduction in cardiovascular mortality was found (RR 0.77, 95% CI 0.63 to 0.93; 5 trials). Evidence is uncertain for difference in risk of cardiovascular hospitalisation (RR 0.92, 95% CI 0.76 to 1.12; 3 trials). At long‐term follow‐up, although there may be little to no difference in all‐cause mortality (RR 0.91, 95% CI 0.75 to 1.10), exercise‐based CR may result in a large reduction in cardiovascular mortality (RR 0.58, 95% CI 0.43 to 0.78; 8 trials) and MI (RR 0.67, 95% CI 0.50 to 0.90; 10 trials). Evidence is uncertain for CABG (RR 0.66, 95% CI 0.34 to 1.27; 4 trials), and PCI (RR 0.76, 95% CI 0.48 to 1.20; 3 trials). Meta‐regression showed benefits in outcomes were independent of CHD case mix, type of CR, exercise dose, follow‐up length, publication year, CR setting, study location, sample size or risk of bias. There was evidence that exercise‐based CR may slightly increase HRQoL across several subscales (SF‐36 mental component, physical functioning, physical performance, general health, vitality, social functioning and mental health scores) up to 12 months' follow‐up; however, these may not be clinically important differences. The eight trial‐based economic evaluation studies showed exercise‐based CR to be a potentially cost‐effective use of resources in terms of gain in quality‐adjusted life years (QALYs). Authors' conclusions This updated Cochrane Review supports the conclusions of the previous version, that exercise‐based CR provides important benefits to people with CHD, including reduced risk of MI, a likely small reduction in all‐cause mortality, and a large reduction in all‐cause hospitalisation, along with associated healthcare costs, and improved HRQoL up to 12 months' follow‐up. Over longer‐term follow‐up, benefits may include reductions in cardiovascular mortality and MI. In the last decade, trials were more likely to include females, and be undertaken in LMICs, increasing the generalisability of findings. Well‐designed, adequately‐reported RCTs of CR in people with CHD more representative of usual clinical practice are still needed. Trials should explicitly report clinical outcomes, including mortality and hospital admissions, and include validated HRQoL outcome measures, especially over longer‐term follow‐up, and assess costs and cost‐effectiveness.