Development and validation of machine learning algorithms to predict posthypertensive origin in left ventricular hypertrophy

BACKGROUND

Left ventricular hypertrophy is often associated with hypertension, which is not necessarily the cause of hypertrophy. Non-hypertension-related aetiologies often have a strong impact on patient management, and therefore require a thorough and careful workup. When considering all left ventricular hypertrophies, even the mild ones, the number of patients who need a workup increases drastically. This raises the need for a tool to evaluate the pretest probability of the origin of left ventricular hypertrophy.

AIM

To predict the hypertensive origin of left ventricular hypertrophy using machine learning on first-line clinical, laboratory and echocardiographic variables.

METHODS

We used a retrospective single-centre population of 591 patients with left ventricular hypertrophy, starting at 12mm maximal left ventricular wall thickness. After splitting data in a training and testing set, we trained three different algorithms: decision tree; random forest; and support vector machine. Model performances were validated on the testing set.

RESULTS

All models exhibited good areas under receiver operating characteristic curves: 0.82 (95% confidence interval: 0.77-0.88) for the decision tree; 0.90 (95% confidence interval 0.85-0.94) for the random forest; and 0.90 (95% confidence interval: 0.85-0.94) for the support vector machine. After threshold selection, the last model had the best balance between its specificity of 0.96 (95% confidence interval: 0.91-0.99) and its sensitivity of 0.31 (95% confidence interval: 0.17-0.44). All algorithms relied on similar most influential predictor variables. Online calculators were developed and made publicly available.

CONCLUSIONS

Machine learning models were able to determine the hypertensive origin of left ventricular hypertrophy with good performances. Implementation in clinical practice could reduce the number of aetiological workups needed in patients presenting with left ventricular hypertrophy.

Human liver microbiota modeling strategy at the early onset of fibrosis

BACKGROUND

Gut microbiota is involved in the development of liver diseases such as fibrosis. We and others identified that selected sets of gut bacterial DNA and bacteria translocate to tissues, notably the liver, to establish a non-infectious tissue microbiota composed of microbial DNA and a low frequency live bacteria. However, the precise set of bacterial DNA, and thereby the corresponding taxa associated with the early stages of fibrosis need to be identified. Furthermore, to overcome the impact of different group size and patient origins we adapted innovative statistical approaches. Liver samples with low liver fibrosis scores (F0, F1, F2), to study the early stages of the disease, were collected from Romania(n = 36), Austria(n = 10), Italy(n = 19), and Spain(n = 17). The 16S rRNA gene was sequenced. We considered the frequency, sparsity, unbalanced sample size between cohorts to identify taxonomic profiles and statistical differences.

RESULTS

Multivariate analyses, including adapted spectral clustering with L1-penalty fair-discriminant strategies, and predicted metagenomics were used to identify that 50% of liver taxa associated with the early stage fibrosis were Enterobacteriaceae, Pseudomonadaceae, Xanthobacteriaceae and Burkholderiaceae. The Flavobacteriaceae and Xanthobacteriaceae discriminated between F0 and F1. Predicted metagenomics analysis identified that the preQ0 biosynthesis and the potential pathways involving glucoryranose and glycogen degradation were negatively associated with liver fibrosis F1-F2 vs F0.

CONCLUSIONS

Without demonstrating causality, our results suggest first a role of bacterial translocation to the liver in the progression of fibrosis, notably at the earliest stages. Second, our statistical approach can identify microbial signatures and overcome issues regarding sample size differences, the impact of environment, and sets of analyses.

TRIAL REGISTRATION

TirguMECCH ROLIVER Prospective Cohort for the Identification of Liver Microbiota, registration 4065/2014. Registered 01 01 2014.

Genetic biomarkers of life-threatening pheochromocytoma-induced cardiomyopathy

The release of excessive amounts of catecholamine by pheochromocytoma-paragangliomas (PPGL) can lead to life-threatening catecholamine-induced cardiomyopathy (CIC). Single-nucleotide polymorphisms of the beta1 and alpha-2c adrenergic receptors alter myocyte receptor function and enhanced norepinephrine release. We tested the hypothesis that such genetic variations may impact the risk of developing CIC in the context of PPGL. Thirty-one patients with PPGL, including nine with a history of CIC, were analyzed for alpha-2-adrenergic receptors: ADRA2C, beta-1 and beta-2 adrenergic receptors: ADRB1 and ADRB2 genotyping. CIC was defined either by a history of heart failure or cardiogenic shock associated with dilated or Takotsubo cardiomyopathy. Subjects were genotyped for ADRA2C (rs61767072 for del322_325), ADRB1 (rs1801252 for Ser49Gly and rs1801253 for Arg389Gly) and ADRB2 (rs1042713 for Arg16Gly and rs1042714 for Gln27Glu). Single-locus analysis revealed that variant in ADRA2C (alpha 2CDel322-325) was more common among patients with CIC than among controls (allele frequency, 0.44 vs 0.05; P< 0.001). The lack of alpha 2CDel322-325 polymorphism has a negative predictive value of 95% for the onset of CIC. In a replication cohort including 26 patients with PPGL whom eight have developed a CIC, the association between Alpha 2CDel322-325 and CIC was confirmed (allele frequency, 0.33 vs 0.; P= 0.0001). In conclusion, Alpha 2CDel322-325 through the identification of patients at low risk of developing CIC can help physicians to better determine the most appropriate therapeutic approach, notably in patients at high risk of surgical complications.

The effect of camelina oil on vascular function in essential hypertensive patients with metabolic syndrome: a randomized, placebo-controlled, double-blind study

BACKGROUND

The effects of a dietary supplementation with the vegetable ω-3 α-linolenic acid (ALA) on cardiovascular homeostasis are unclear. In this context, it would be interesting to assess the effects of camelina oil.

OBJECTIVE

This study aimed to assess the cardiovascular and metabolic effects of camelina oil in hypertensive patients with metabolic syndrome.

METHODS

In a double-blind, placebo-controlled randomized study, treated essential hypertensive patients with metabolic syndrome received, during 6 mo, either cyclodextrin-complexed camelina oil containing ≈ 1.5 g ALA/d (n = 40) or an isocaloric placebo (n = 41), consisting of the same quantity of cyclodextrins and wheat starch. Anthropometric data, plasma lipids, glycemia, insulinemia, creatininemia, TBARs, high-sensitivity C-reactive protein, and n-3, n-6, and n-9 fatty acids in erythrocyte membranes were measured. Peripheral and central blood pressures, arterial stiffness, carotid intima-media thickness, and brachial artery endothelium-dependent flow-mediated dilatation (FMD) and endothelium-independent dilatation were assessed.

RESULTS

Compared with placebo, camelina oil increased ALA (mean ± SD: 0 ± 0.04 compared with 0.08 ± 0.06%, P <0.001), its elongation product EPA (0 ± 0.5 compared with 0.16 ± 0.65%, P <0.05), and the n-9 gondoic acid (GA; 0 ± 0.04 compared with 0.08 ± 0.04%, P <0.001). No between-group difference was observed for cardiovascular parameters. However, changes in FMD were associated with the magnitude of changes in EPA (r = 0.26, P = 0.03). Compared with placebo, camelina oil increased fasting glycemia (-0.2 ± 0.6 compared with 0.3 ± 0.5 mmol/L, P <0.001) and HOMA-IR index (-0.8 ± 2.5 compared with 0.5 ± 0.9, P <0.01), without affecting plasma lipids, or inflammatory and oxidative stress markers. Changes in HOMA-IR index were correlated with the magnitude of changes in GA (r = 0.32, P <0.01). Nutritional intake remained similar between groups.

CONCLUSION

ALA supplementation with camelina oil did not improve vascular function but adversely affected glucose metabolism in hypertensive patients with metabolic syndrome. Whether this adverse effect on insulin sensitivity is related to GA enrichment, remains to be elucidated.

Ambulatory blood pressure and drug treatment for orthostatic hypotension as predictors of mortality in patients with Multiple System Atrophy

OBJECTIVES

Multiple system atrophy (MSA) is a rare fatal neurodegenerative disease characterized by parkinsonism, cerebellar ataxia and autonomic failure. This study aimed at investigating possible associations between mortality, 24H blood pressure (BP) level and variability, and drug treatments for orthostatic hypotension (OH) in MSA patients.

METHODS

One hundred and twenty-nine patients followed at the French Reference Center for MSA who underwent routine 24H ambulatory BP monitoring, were included. Unified MSA Rating Scale (UMSARS) scores, drug treatments and the occurrence and cause of death were recorded.

RESULTS

Seventy patients died during follow-up (2.9±1.8 years), mainly from terminal illness, pulmonary or sudden death. Multivariate Cox regression analysis, after adjustment for gender, disease duration and severity (UMSARS I+II score), showed that increased daytime systolic BP variability, OH severity and OH drug treatment were independently correlated with mortality. OH treatment was associated with the risk of cardiac causes and/or sudden death (p=0.01). In a fully adjusted model, male gender [(female vs male) Hazard ratio (HR): 0.56 95% CI [0.34-0.94] p=0.03], UMSARS I+II score [HR: 1.04 95% CI [1.02-1.06] p<0.01], systolic BP daytime variability [HR: 3.66 95% CI (1.46-9.17 p<0.01] and OH treatment [HR: 2.13 95 % CI [1.15- 3.94]; p=0.02] predicted mortality.

CONCLUSION

Increased daytime BP variability and OH treatment were predictive of mortality in patients with MSA, independently from disease severity. Further studies are required to assess if these associations are explained by more severe autonomic dysfunction or if OH treatment exposes "per se" to a specific risk in this population.

Visit-to-Visit Blood Pressure Variability and Incident Frailty in Older Adults

This study aimed to determine whether visit-to-visit blood pressure (BP) variability (BPV) is associated with incident frailty. We included 1 394 nonfrail community-dwelling participants aged ≥70 years from the Multidomain Alzheimer Preventive Trial (MAPT) who underwent repeated clinical examinations, including BP and frailty, over a 5-year follow-up period. Systolic BPV (SBPV), diastolic BPV (DBPV), mean arterial pressure variability (MAPV), and pulse pressure variability (PPV) were evaluated using standard deviation (SD), coefficient of variation (CV), average real variability, successive variation, variation independent of mean, and residual SD. Incident frailty was assessed using the Fried phenotype. Cox proportional hazards models were used for the analyses. Higher SBPV was significantly associated with greater risk of frailty (1-SD increase of CV: hazard ratio [HR] = 1.18, 95% confidence interval [CI]: 1.02-1.36) after adjustment for demographics, systolic BP, antihypertensive drugs, body mass index, diabetes, ischemic heart disease, congestive heart failure, stroke, atrial fibrillation, MAPT randomization group, and frailty status. Similar results were observed with all indicators of variability. Higher PPV was associated with a greater risk of developing frailty over time (1-SD increase of CV: HR = 1.17, 95% CI: 1.01-1.35). DBPV and MAPV were not significantly associated with incident frailty. Higher SBPV and PPV were associated with greater risk of incident frailty. Our findings support the concept of BP physiological dysregulation underlying the frail state and suggest that BP instability could be an early marker of frailty.

Interactions between hypertension and inflammatory tone and the effect on blood pressure and outcomes in patients with COVID-19

Arterial hypertension represented one of the most common comorbidities in patients with COVID‐19. However, the impact of hypertension on outcome in COVID‐19 patients is not clear. Close connections between inflammation and blood pressure (BP) have been described, and inflammation plays a key role in the outcome for patients with COVID‐19. Whether hypertension impairs the relationship between inflammation, BP, and outcomes in this context is not known. The aim of this study was to examine the effects of the interactions between inflammation and hypertension status on BP and clinical outcome in patients hospitalized with COVID‐19. We designed a retrospective study in 129 patients hospitalized with COVID‐19 at Toulouse University Hospital. The hospital outcome was admission to the intensive care unit or death. The inflammatory markers were blood C‐reactive protein level (CRP), neutrophil to lymphocyte, and platelet to lymphocyte ratios. We identified strong correlations between CRP (P < .01) and the other inflammatory markers recorded on admission (P < .001) with mean BP within 3 days after admission in normotensive patients, whereas these correlations were absent in patients with hypertension. Also, we observed after multivariate adjustment (P < .05) that CRP level predicted a worse prognosis in hypertensive patients (relative risk 2.52; 95% confidence intervals [1.03‐ 6.17]; P = .04), whereas CRP was not predictive of outcome in patients without hypertension. In conclusion, the study revealed that in COVID‐19 patients, hypertension impairs the relationship between inflammation and BP and interacts with inflammation to affect prognosis. These findings provide insights that could explain the relationship between hypertension and outcomes in COVID‐19 patients.

Severe hypertensive flare-up after intravitreal injection of ranibizumab for retinal venous branch occlusion

Vascular endothelial growth factor (VEGF) proteins are involved in the regulation of angiogenesis. Systemic adverse effects of some anti-VEGF include hypertension, proteinuria and cardiovascular complications which could involve lower systemic VEGF levels. However, the question regarding intravitreal administration of anti-VEGF remains controversial given that the patients receiving these drugs are often elderly and present cardiac risk factors such as arterial hypertension or atrial fibrillation. We report a case of hypertensive flare-up following intravitreal injection of ranibizumab for retinal vein occlusion. The outcome was favourable after adapted antihypertensive treatment. This case report adds to the growing body of evidence suggesting that intravitreal administration of anti-VEGF, regardless of agents, may result in hypertensive episodes in some predisposed patients. Listing this adverse effect should help to minimize risks by heightening clinician and patient awareness and to improve blood pressure monitoring following the intravitreal administration of anti-VEGF agents.

Spécificités du traitement médicamenteux antihypertenseur chez la femme

The impact of antihypertensive drugs on blood pressure does not differ according to the sex. There are women-specific conditions or medical conditions encountered more frequently among womens that guide the selection of therapy such as a desire to become pregnant, a pregnancy, a polycystic ovarian syndrome, breast cancer, osteoporosis or migraine.

Blood Microbiota Modification After Myocardial Infarction Depends Upon Low-Density Lipoprotein Cholesterol Levels

Background

The role of bacteria on the onset of cardiovascular disease has been suggested. Reciprocally, increased intestinal bacterial translocation and bloodstream infection are common comorbidities associated with heart failure and myocardial infarction (MI). In this context, the aim of this study was to analyze the blood microbiome in patients shortly after acute myocardial infarction.

Methods and Results

We carried out a case control study comparing 103 patients at high cardiovascular risk but free of coronary disease and 99 patients who had an MI. The blood microbiome was analyzed both quantitatively by 16S quantitative polymerase chain reaction and qualitatively by 16S targeted metagenomic sequencing specifically optimized for blood samples. A significant increase in blood bacterial 16S rDNA concentration was observed in patients admitted for MI. This increase in blood bacterial DNA concentration was independent of post‐MI left ventricular function and was more marked in patients with low‐density lipoprotein cholesterol ≥1 g/L. In addition, differences in the proportion of numerous bacterial taxa in blood were significantly modified with the onset of MI, thus defining a blood microbiota signature of MI. Among the bacterial taxa whose proportions are decreased in patients with MI, at least 6 are known to include species able to metabolize cholesterol.

Conclusions

These results could provide the basis for the identification of blood microbiome‐based biomarkers for the stratification of MI patients. Furthermore, these findings should provide insight into the mechanism underlying the negative correlation reported between low‐density lipoprotein cholesterol concentration and the prognosis at the acute onset of MI and mortality.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02405468.

Microbiota-Host Crosstalk: A Bridge Between Cardiovascular Risk Factors, Diet, and Cardiovascular Disease

Cardiovascular disease is the leading cause of death and is also a major cause of disability worldwide. Indeed, even in well-treated patients for hypertension or dyslipidemia, there is still a high cardiovascular risk called residual risk. It is of utmost importance to identify the pathway leading from risk factors to cardiovascular disease to further improve stroke and myocardial infarction prevention. In this review, we presented some of experimental and epidemiological evidences suggesting that microbiota-host crosstalk is involved in this pathway and bridges the gap between cardiovascular risk factors, diet, and cardiovascular residual risk. We considered the 3 participants in this dialogue: the gut microbiota, the intestinal barrier, and bacterial translocation. We analyzed their relations with cardiovascular risk factors and cardiovascular diseases. Also, we presented some of therapeutic strategies aiming to control microbiota to further prevent cardiovascular disease and the take home messages that can be drawn for clinical practice.

[Host-microbiota crosstalk and cardiovascular diseases]

When analyzing the microbiota-host crosstalk, we have to consider three participants in this dialogue: the gut microbiota, the intestinal barrier and bacterial translocation. Experimental data demonstrate that host microbiota crosstalk plays a causal on the regulation of blood pressure, glucose metabolism and the development of atherosclerosis. Host microbiota crosstalk is associated in humans with main cardiovascular risk factors notably hypertension and type 2 diabetes. Host microbiota crosstalk is associated in humans with the onset of cardiovascular diseases. The Mediterranean diet has proven as proven to be an effective strategy in improving cardiovascular prognosis and in changing gut microbiota.

Changes in blood microbiota profiles associated with liver fibrosis in obese patients: A pilot analysis

The early detection of liver fibrosis among patients with nonalcoholic fatty liver disease (NAFLD) is an important clinical need. In view of the suggested role played by bacterial translocation in liver disease and obesity, we sought to investigate the relationship between blood microbiota and liver fibrosis (LF) in European cohorts of patients with severe obesity. We carried out a cross-sectional study of obese patients, well characterized with respect to the severity of the NAFLD, in the cohort FLORINASH. This cohort has been divided into a discovery cohort comprising 50 Spanish patients and then in a validation cohort of 71 Italian patients. Blood bacterial DNA was analyzed both quantitatively by 16S ribosomal DNA (rDNA) quantitative polymerase chain reaction and qualitatively by 16S rDNA targeted metagenomic sequencing and functional metagenome prediction. Spanish plasma bile acid contents were analyzed by liquid chromatography/mass spectrometry. The 16S rDNA concentration was significantly higher in patients of the discovery cohort with LF. By 16S sequencing, we found specific differences in the proportion of several bacterial taxa in both blood and feces that correlate with the presence of LF, thus defining a specific signature of the liver disease. Several secondary/primary bile acid ratios were also decreased with LF in the discovery cohort. We confirmed, in the validation cohort, the correlation between blood 16S rDNA concentration and LF, whereas we did not confirm the specific bacterial taxa signature, despite a similar trend in patients with more-severe fibrosis.

CONCLUSION

Changes in blood microbiota are associated with LF in obese patients. Blood microbiota analysis provides potential biomarkers for the detection of LF in this population. (Hepatology 2016;64:2015-2027).

[Management of arterial hypertension before 20weeks gestation in pregnant women]

In the first 6 months of pregnancy, the primary goal of antihypertensive treatment is to prevent the complications of severe hypertension. Initiation of antihypertensive drug treatment is recommended in pregnant women with severe hypertension (blood pressure>160/110mmHg). Initiation of antihypertensive drug treatment should also be considered in pregnant women at high cardiovascular risk (diabetes, chronic kidney disease, personal history of cardiovascular disease) with moderate hypertension (blood pressure between 140-159/90-109mmHg). A systolic blood pressure goal<160 and a diastolic blood pressure goal between 85 and 100mmHg is recommended in pregnancy. Labetalol, nifedipine, nicardipine and alphamethyldopa should be considered preferential antihypertensive drugs in pregnancy. Salt restriction, physical exercise and weight loss have not demonstrated any effect in the prevention of preeclampsia and serious maternal complications of hypertension.

Causes of secondary hypertension in the young population: A monocentric study

OBJECTIVE

To study the prevalence of different causes of hypertension in young adults referred to a hypertension center in the south west of France.

METHODS

We conducted a retrospective overview of patients younger than 40years old hospitalized consecutively in the Hypertension department of Toulouse University Hospital between 2012 and 2014. Clinical data about gender, age, anthropomorphic parameters and blood pressure measurement by 24h Ambulatory Blood Pressure Monitoring (ABPM) were recorded. Biological data concerned dosages of kalemia, renin and aldosterone in the supine or after 15min of seating. Recorded radiological examinations were renal artery ultrasound and abdominal CT scan.

RESULTS

One hundred and forty-eight detailed medical records were analyzed, 69 women and 79 men. Among the 69 women, the causes of secondary hypertension were primary aldosteronism (n=7), fibromuscular dysplasia (n=5) and renal disease (n=4). Oral contraceptives were involved in 13 women. In addition, essential hypertension concerned 40 women (58%). Among the 79 men, the causes of secondary hypertension were primary aldosteronism (n=10), fibromuscular dysplasia (n=3), left main renal artery entrapment by a diaphragmatic crura (n=2), renal disease (n=1), pheochromocytoma (n=3) and coarctation of the aorta (n=2). In addition, essential hypertension concerned 58 men (73%).

CONCLUSIONS

In our population, the prevalence of secondary hypertension is close to 33% (42% of females and 27% of males), with the following main causes: primary aldosteronism for 11.5%; fibromuscular dysplasia for 5.4%. Oral contraceptives were involved in the hypertension of 19% of the females.

[Medication reconciliation at hospital discharge focusing on patient with hypertension: Analysis of the output prescription]

PURPOSE

To describe pharmacists' interventions made at patients hospital discharge from Department of Hypertension.

METHODS

This is a single-center and prospective study over an 8-week period. At hospital discharge, the pharmacist compared pre-admission and inpatient medications with discharge orders and written instructions. Pharmacists' interventions were then classified in 4 categories. All variances and discrepancies were discussed with the prescribing physician when possible.

RESULTS

Over the 8-week period, 154 cases were analyzed. Pharmacists' interventions at discharge underwent 48 times on 21% of the patients (n=33) but none was clinically relevant. Among these 48 cases, 40% (n=19) were rated as "inappropriate administration", 27% (n=13) were classified as "incomplete prescription", 19% (n=9) were "variances" and 4% (n=2) were due to "omission prescription". In 10% of the cases (n=5), discrepancies appeared without any possible further analysis as no discussion with the prescriber occurred.

CONCLUSION

One fifth of all patients analyzed was the subject of a pharmacists' intervention. The complementary action of the pharmacist improves the consistency of the prescriptions and strengthens patient safety.

Triggering the adaptive immune system with commensal gut bacteria protects against insulin resistance and dysglycemia

OBJECTIVE

To demonstrate that glycemia and insulin resistance are controlled by a mechanism involving the adaptive immune system and gut microbiota crosstalk.

METHODS

We triggered the immune system with microbial extracts specifically from the intestinal ileum contents of HFD-diabetic mice by the process of immunization. 35 days later, immunized mice were fed a HFD for up to two months in order to challenge the development of metabolic features. The immune responses were quantified. Eventually, adoptive transfer of immune cells from the microbiota-immunized mice to naïve mice was performed to demonstrate the causality of the microbiota-stimulated adaptive immune system on the development of metabolic disease. The gut microbiota of the immunized HFD-fed mice was characterized in order to demonstrate whether the manipulation of the microbiota to immune system interaction reverses the causal deleterious effect of gut microbiota dysbiosis on metabolic disease.

RESULTS

Subcutaneous injection (immunization procedure) of ileum microbial extracts prevented hyperglycemia and insulin resistance in a dose-dependent manner in response to a HFD. The immunization enhanced the proliferation of CD4 and CD8 T cells in lymphoid organs, also increased cytokine production and antibody secretion. As a mechanism explaining the metabolic improvement, the immunization procedure reversed gut microbiota dysbiosis. Finally, adoptive transfer of immune cells from immunized mice improved metabolic features in response to HFD.

CONCLUSIONS

Glycemia and insulin sensitivity can be regulated by triggering the adaptive immunity to microbiota interaction. This reduces the gut microbiota dysbiosis induced by a fat-enriched diet.

Comprehensive description of blood microbiome from healthy donors assessed by 16S targeted metagenomic sequencing

BACKGROUND

Recent studies have revealed that the blood of healthy humans is not as sterile as previously supposed. The objective of this study was to provide a comprehensive description of the microbiome present in different fractions of the blood of healthy individuals.

STUDY DESIGN AND METHODS

The study was conducted in 30 healthy blood donors to the French national blood collection center (Établissement Français du Sang). We have set up a 16S rDNA quantitative polymerase chain reaction assay as well as a 16S targeted metagenomics sequencing pipeline specifically designed to analyze the blood microbiome, which we have used on whole blood as well as on different blood fractions (buffy coat [BC], red blood cells [RBCs], and plasma).

RESULTS

Most of the blood bacterial DNA is located in the BC (93.74%), and RBCs contain more bacterial DNA (6.23%) than the plasma (0.03%). The distribution of 16S DNA is different for each fraction and spreads over a relatively broad range among donors. At the phylum level, blood fractions contain bacterial DNA mostly from the Proteobacteria phylum (more than 80%) but also from Actinobacteria, Firmicutes, and Bacteroidetes. At deeper taxonomic levels, there are striking differences between the bacterial profiles of the different blood fractions.

CONCLUSION

We demonstrate that a diversified microbiome exists in healthy blood. This microbiome has most likely an important physiologic role and could be implicated in certain transfusion-transmitted bacterial infections. In this regard, the amount of 16S bacterial DNA or the microbiome profile could be monitored to improve the safety of the blood supply.

The Characterization of Novel Tissue Microbiota Using an Optimized 16S Metagenomic Sequencing Pipeline

Background

Substantial progress in high-throughput metagenomic sequencing methodologies has enabled the characterisation of bacteria from various origins (for example gut and skin). However, the recently-discovered bacterial microbiota present within animal internal tissues has remained unexplored due to technical difficulties associated with these challenging samples.

Results

We have optimized a specific 16S rDNA-targeted metagenomics sequencing (16S metabarcoding) pipeline based on the Illumina MiSeq technology for the analysis of bacterial DNA in human and animal tissues. This was successfully achieved in various mouse tissues despite the high abundance of eukaryotic DNA and PCR inhibitors in these samples. We extensively tested this pipeline on mock communities, negative controls, positive controls and tissues and demonstrated the presence of novel tissue specific bacterial DNA profiles in a variety of organs (including brain, muscle, adipose tissue, liver and heart).

Conclusion

The high throughput and excellent reproducibility of the method ensured exhaustive and precise coverage of the 16S rDNA bacterial variants present in mouse tissues. This optimized 16S metagenomic sequencing pipeline will allow the scientific community to catalogue the bacterial DNA profiles of different tissues and will provide a database to analyse host/bacterial interactions in relation to homeostasis and disease.

Defective NOD2 peptidoglycan sensing promotes diet-induced inflammation, dysbiosis, and insulin resistance

Pattern recognition receptors link metabolite and bacteria-derived inflammation to insulin resistance during obesity. We demonstrate that NOD2 detection of bacterial cell wall peptidoglycan (PGN) regulates metabolic inflammation and insulin sensitivity. An obesity-promoting high-fat diet (HFD) increased NOD2 in hepatocytes and adipocytes, and NOD2(-/-) mice have increased adipose tissue and liver inflammation and exacerbated insulin resistance during a HFD. This effect is independent of altered adiposity or NOD2 in hematopoietic-derived immune cells. Instead, increased metabolic inflammation and insulin resistance in NOD2(-/-) mice is associated with increased commensal bacterial translocation from the gut into adipose tissue and liver. An intact PGN-NOD2 sensing system regulated gut mucosal bacterial colonization and a metabolic tissue dysbiosis that is a potential trigger for increased metabolic inflammation and insulin resistance. Gut dysbiosis in HFD-fed NOD2(-/-) mice is an independent and transmissible factor that contributes to metabolic inflammation and insulin resistance when transferred to WT, germ-free mice. These findings warrant scrutiny of bacterial component detection, dysbiosis, and protective immune responses in the links between inflammatory gut and metabolic diseases, including diabetes.

The Gut Microbiota Regulates Intestinal CD4 T Cells Expressing RORγt and Controls Metabolic Disease

A high-fat diet (HFD) induces metabolic disease and low-grade metabolic inflammation in response to changes in the intestinal microbiota through as-yet-unknown mechanisms. Here, we show that a HFD-derived ileum microbiota is responsible for a decrease in Th17 cells of the lamina propria in axenic colonized mice. The HFD also changed the expression profiles of intestinal antigen-presenting cells and their ability to generate Th17 cells in vitro. Consistent with these data, the metabolic phenotype was mimicked in RORγt-deficient mice, which lack IL17 and IL22 function, and in the adoptive transfer experiment of T cells from RORγt-deficient mice into Rag1-deficient mice. We conclude that the microbiota of the ileum regulates Th17 cell homeostasis in the small intestine and determines the outcome of metabolic disease.

[Place of clinical pharmacist in the management of drugs in patients with hypertension]

PURPOSE

To synthesize pharmacists' interventions made in the department of internal medicine and hypertension of university hospital of Toulouse and assess the impact on medication orders.

METHODS

This is a single-center, prospective study using pharmacists' interventions recorded between September 2013 and March 2014 on the Act-IP(©) website of the French Society of Clinical Pharmacy. The clinical pharmacist is present everyday in the unit to establish the medication reconciliation of new patients (the process of comparing a patient's medication orders to all of the medications that the patient has been taking), and analysis of medication orders. When a risk of iatrogenic drug is identified, a therapeutic change is proposed to the prescriber.

RESULTS

A total of 2491 medication orders were analyzed for 7 months, leading to 39 pharmacists' interventions (1.6 pharmacists' interventions per 100 medication orders). The most commonly identified drug-related problems were improper administration (33%, n=13), not prescribed drug (21%, n=8), non-conformity to guidelines (18%, n=7), supratherapeutic dose (15%, n=6), and 13% (n=5) targeted prescribed treatment not administered, underdosing, incorrect administration or drug interaction. The most relevant molecules were atorvastatin (10%), bromazepam (8%) and levothyroxine (8%) and only 2 interventions targeted antihypertensive drugs. The rate of physicians' acceptance was 92%.

CONCLUSION

Pharmacists' interventions mainly concern the co-prescriptions of antihypertensive drugs and very few antihypertensive drugs. The clinical pharmacist contributes to preventing iatrogenic in patients with hypertension with a very good acceptance by the clinician.

Effect of postural changes on aldosterone to plasma renin ratio in patients with suspected secondary hypertension

AIMS

To study the influence of postural changes on aldosterone to renin ratio (ARR) in patients with suspected secondary hypertension and to evaluate the sensitivity and specificity of the recommended seated ARR compared to supine and upright ARR for primary aldosteronism screening.

METHODS

Fifty-three hypertensive patients were prospectively hospitalized for secondary hypertension exploration (age: 51 ± 12, 66% males). After withdrawal of drugs interfering with renin angiotensin system, plasma aldosterone and direct renin concentration were measured in the morning, at bed after an overnight supine position, then out of bed after 1 hour of upright position and finally 2 hours later after 15 minutes of seating. Minimal renin value was set at 5 μUI/mL.

RESULTS

Referring to ARR cut-off of 23 pg/μUI, the sensitivity of seated ARR was 57.1% and specificity was 92.3%. The negative and positive predictive values were 95.1% and 45.2% respectively. Compared to these results, a cut-off of 19 improved sensitivity to 85.7% with a specificity of 89.7%. Negative and positive predictive values were 98.3% and 41.1% respectively. Seated ARR mean value was lower than supine and upright ARR mean values, due to an overall increase in renin at seating compared to the supine position by factor 1.9 while aldosterone just slightly increased by factor 1.2. Seated ARR correlated to supine and upright ARR: correlation coefficients (r) 0.90 and 0.93 respectively (P<0.001).

CONCLUSIONS

Current recommended measurement of ARR in the seating position is fairly correlated to supine and upright ARR. A suggested cut-off value of 19 instead of 23 pg/μUI increased the discriminating power of this test.

Is it useful to repeat an adrenal venous sampling in patients with primary hyperaldosteronism?

Adrenal venous sampling (AVS) is a challenging technical procedure and few patients had AVS procedure twice.

AIM

To evaluate the reproducibility of the AVS, why AVS were repeated and the conclusions drawn from them.

PATIENTS AND METHODS

From 1997-2012, 12 patients underwent two AVS. A cortisol level in the adrenal vein greater than or equal to 1.1 to inferior vena cava defined a successful catheterization and a lateralization of secretion corresponded to an aldosterone-to-cortisol vein ratio greater than or equal to 2 between the one side to another.

RESULTS

The same side of lateralization of secretion was found in 75% of them. The second AVS were due to technical failure (n=4), unproven lateralization (n=2), a lateralization opposite to the main nodule and ipsilateral to hyperplasia (n=4) on first AVS. For two patients, as the CT was normal, AVS was required again. The second AVS was successful in all patients, including those with an initial technical failure but only patient with technical failure underwent surgery, as BP and kaliemia were controlled. Lateralization on the side of hyperplasia or opposite to the biggest nodule was confirmed in two of four cases.

CONCLUSION

When AVS is unsuccessful for technical reasons, it is worth doing it again but after being sure that surgery is still possibly indicated.

Metagenome and metabolism: the tissue microbiota hypothesis

Over the last decade, the research community has revealed the role of a new organ: the intestinal microbiota. It is considered as a symbiont that is part of our organism since, at birth, it educates the immune system and contributes to the development of the intestinal vasculature and most probably the nervous system. With the advent of new generation sequencing techniques, a catalogue of genes that belong to this microbiome has been established that lists more than 5 million non-redundant genes called the metagenome. Using germ free mice colonized with the microbiota from different origins, it has been formally demonstrated that the intestinal microbiota causes the onset of metabolic diseases. Further to the role of point mutations in our genome, the microbiota can explain the on-going worldwide pandemic of obesity and diabetes, its dissemination and family inheritance, as well as the diversity of the associated metabolic phenotypes. More recently, the discovery of bacterial DNA within host tissues, such as the liver, the adipose tissue and the blood, which establishes a tissue microbiota, introduces new opportunities to identify targets and predictive biomarkers based on the host to microbiota interaction, as well as to define new strategies for pharmacological, immunomodulatory vaccines and nutritional applications.

Retroperitoneoscopic adrenalectomy: comparison of retrograde and antegrade approach among a series of 279 cases

OBJECTIVE

To compare the results of retroperitoneal laparoscopic adrenalectomy using the antegrade and retrograde approach.

MATERIALS AND METHODS

We performed an analysis of a single-center series of 279 retroperitoneal laparoscopic adrenalectomies from 1996 to 2010. We compared 172 cases performed with an antegrade approach and 107 with a retrograde approach without dissection of the renal hilum and initial control of the adrenal vein in comparable populations.

RESULTS

The operative time was shorter in the group treated with the retrograde technique, 101±51 vs 140±40 minutes, respectively (Student's t test, P<.001). Blood loss was similar in both groups, 85±224 vs 80±126 mL, respectively (P=NS). Hemodynamic instability was defined as the maximal systolic blood pressure minus the minimal systolic blood pressure divided the maximal systolic blood pressure. It was lower in the group who underwent the retrograde technique (32.7 vs 37.6 mL; Student's t test, P=.005) with a lower perioperative consumption of ephedrine (2.2 vs 5.1 mg, P=.004) and atropine (0.09 vs 0.22 mg, P=.026). No difference was found between the 2 groups in the frequency of perioperative complications or postoperative mortality (1 death in each group of causes unrelated to the surgery).

CONCLUSION

Retroperitoneal laparoscopic adrenalectomy using a retrograde approach is a safe and reproducible technique. It makes it possible to perform adrenalectomy without dissection of the renal hilum, with a reduction in the operative time. The good hemodynamic stability observed with this technique makes it very attractive for the treatment of pheochromocytoma.

Pulse wave velocity, pulse pressure and number of carotid or femoral plaques improve prediction of cardiovascular death in a population at low risk

The assessment of cardiovascular risk is uniformly recommended as a decision-support for therapies aimed at preventing cardiovascular diseases. Our objective was to determine the prognostic significance of vascular markers in apparently healthy subjects. Analyses were based on the Third Toulouse MONICA Survey (1995-1997) carried out in participants aged 35-64, from the general population of South-western France. Causes of death were obtained 14 years after inclusion. There were 1132 participants (51% men). Over the 14-year follow-up period, 61 deaths were recorded, 20% due to a cardiovascular cause. Adding pulse wave velocity (PWV) to Framingham Risk Score (FRS) improved the accuracy of the risk prediction model. The C-statistic increased from 0.76 (95% confidence interval (CI): 0.64-0.89) (FRS alone) to 0.79 (95% CI: 0.64-0.95) (FRS+PWV). The Integrated Discrimination Improvement (IDI) reached 3.81% (P-value<0.001) and the net reclassification improvement (NRI) was equal to 32%. Risk prediction was also improved by integrating pulse pressure (PP) in the model (C-statistic=0.81 (95% CI: 0.66-0.96); IDI=4.99% (P-value<0.001); NRI=30%) or the number of carotid or femoral atherosclerotic plaques (C-statistic=0.78 (95% CI: 0.63-0.93); IDI=2.21% (P-value<0.001); NRI=21%). Vascular markers are independent determinants of cardiovascular mortality in apparently healthy subjects and improve risk prediction.

Blood microbiota dysbiosis is associated with the onset of cardiovascular events in a large general population: the D.E.S.I.R. study

Aim

We recently described a human blood microbiome and a connection between this microbiome and the onset of diabetes. The aim of the current study was to assess the association between blood microbiota and incident cardiovascular disease.

Methods and Results

D.E.S.I.R. is a longitudinal study with the primary aim of describing the natural history of the metabolic syndrome and its complications. Participants were evaluated at inclusion and at 3-, 6-, and 9-yearly follow-up visits. The 16S ribosomal DNA bacterial gene sequence, that is common to the vast majority of bacteria (Eubac) and a sequence that mostly represents Proteobacteria (Pbac), were measured in blood collected at baseline from 3936 participants. 73 incident cases of acute cardiovascular events, including 30 myocardial infarctions were recorded. Eubac was positively correlated with Pbac (r = 0.59; P<0.0001). In those destined to have cardiovascular complications, Eubac was lower (0.14±0.26 vs 0.12±0.29 ng/µl; P = 0.02) whereas a non significant increase in Pbac was observed. In multivariate Cox analysis, Eubac was inversely correlated with the onset of cardiovascular complications, (hazards ratio 0.50 95% CI 0.35–0.70) whereas Pbac (1.56, 95%CI 1.12–2.15) was directly correlated.

Conclusion

Pbac and Eubac were shown to be independent markers of the risk of cardiovascular disease. This finding is evidence for the new concept of the role played by blood microbiota dysbiosis on atherothrombotic disease. This concept may help to elucidate the relation between bacteria and cardiovascular disease.