A meta-analysis of antibiotic use for the secondary prevention of cardiovascular diseases

Research development on gut microbiota and vulnerable atherosclerotic plaque

The relationship between gut microbiota and its metabolites with cardiovascular disease (CVD) has been proven. In this review, we aim to conclude the potential mechanism of gut microbiota and its metabolites on inducing the formation of vulnerable atherosclerotic plaque, and to discuss the effect of intestinal metabolites, including trimethylamine-N-oxide (TMAO), lipopolysaccharide (LPS), phenylacetylglutamine (PAG), short-chain fatty acids (SCFAs) on plaque stability. Finally, we include the impact of gut microbiota and its metabolites on plaque stability, to propose a new therapeutic direction for coronary heart disease. Gut microbiota regulation intervenes the progress of arteriosclerosis, especially on coronary atherosclerosis, by avoiding or reducing the formation of vulnerable plaque, to lower the morbidity rate of myocardial infarction.

Targeting gut microbiota and immune crosstalk: potential mechanisms of natural products in the treatment of atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory reaction that primarily affects large and medium-sized arteries. It is a major cause of cardiovascular disease and peripheral arterial occlusive disease. The pathogenesis of AS involves specific structural and functional alterations in various populations of vascular cells at different stages of the disease. The immune response is involved throughout the entire developmental stage of AS, and targeting immune cells presents a promising avenue for its treatment. Over the past 2 decades, studies have shown that gut microbiota (GM) and its metabolites, such as trimethylamine-N-oxide, have a significant impact on the progression of AS. Interestingly, it has also been reported that there are complex mechanisms of action between GM and their metabolites, immune responses, and natural products that can have an impact on AS. GM and its metabolites regulate the functional expression of immune cells and have potential impacts on AS. Natural products have a wide range of health properties, and researchers are increasingly focusing on their role in AS. Now, there is compelling evidence that natural products provide an alternative approach to improving immune function in the AS microenvironment by modulating the GM. Natural product metabolites such as resveratrol, berberine, curcumin, and quercetin may improve the intestinal microenvironment by modulating the relative abundance of GM, which in turn influences the accumulation of GM metabolites. Natural products can delay the progression of AS by regulating the metabolism of GM, inhibiting the migration of monocytes and macrophages, promoting the polarization of the M2 phenotype of macrophages, down-regulating the level of inflammatory factors, regulating the balance of Treg/Th17, and inhibiting the formation of foam cells. Based on the above, we describe recent advances in the use of natural products that target GM and immune cells crosstalk to treat AS, which may bring some insights to guide the treatment of AS.

Association between age and infection in patients with acute ST-elevation myocardial infarction

Background

ST-elevation myocardial infarction (STEMI) in young patients has a unique risk profile. We aimed to detect bacteria in aspirate of infarct artery in young versus old patients.

Results

Aspirates of consecutive 140 patients who underwent a primary coronary intervention were taken for bacteriological, microscopical, and immunohistochemical (for bacterial pneumolysin) examinations. Their results were calculated in young (≤ 50 years) versus old (> 50 years) patients. Median age (interquartile range) was 45 (38–48) years in young (60 patients) and 59 (55–65) years in old (80 patients) patients, p < 0.0001. Both groups had similar baseline data except age, males, diabetes, hyperlipidemia, family history, lesion length, and ectatic vessel. Different bacteria were cultured in 11.3% of all patients involving 22.6% of young and 2.8% of old patients [hazard ratio 8.03 (95% CI 1.83–51.49), p = 0.002]. By multivariate analyses, age groups and leukocytic count were independent predictors of infection (bacteria and pneumolysin), p = 0.027 and p < 0.0001, respectively. Optimal cutoff value of leukocytic count was 12,250 cells/μl [ROC curve sensitivity 85.7%, specificity 86.4%, and AUC 0.97 (95% CI 0.95–1.0), p < 0.001]. Infection was an independent predictor of STEMI in young versus old patients, p < 0.001. Nevertheless, in-hospital events occurred insignificantly different and neither age groups nor infection was predictor of in-hospital events.

Conclusions

Young patients had significantly higher percentage of bacteria in their infarcted artery than old patients. High leukocytic count in patients below 50 predicts infection that causes acute myocardial infarction. Antibacterial trials directed toward this group are required for secondary prevention.

Gut Microbiota in Hypertension and Atherosclerosis: A Review

Gut microbiota and its metabolites such as short chain fatty acids (SCFA), lipopolysaccharides (LPS), and trimethylamine-N-oxide (TMAO) impact cardiovascular health. In this review, we discuss how gut microbiota and gut metabolites can affect hypertension and atherosclerosis. Hypertensive patients were shown to have lower alpha diversity, lower abundance of SCFA-producing microbiota, and higher abundance of gram-negative bacteria, which are a source of LPS. Animal studies point towards a direct role for SCFAs in blood pressure regulation and show that LPS has pro-inflammatory effects. Translocation of LPS into the systemic circulation is a consequence of increased gut permeability. Atherosclerosis, a multifactorial disease, is influenced by the gut microbiota through multiple pathways. Many studies have focused on the pro-atherogenic role of TMAO, however, it is not clear if this is a causal factor. In addition, gut microbiota play a key role in bile acid metabolism and some interventions targeting bile acid receptors tend to decrease atherosclerosis. Concluding, gut microbiota affect hypertension and atherosclerosis through many pathways, providing a wide range of potential therapeutic targets. Challenges ahead include translation of findings and mechanisms to humans and development of therapeutic interventions that target cardiovascular risk by modulation of gut microbes and metabolites.

Porphyromonas gingivalis triggers the shedding of inflammatory endothelial microvesicles that act as autocrine effectors of endothelial dysfunction

A link between periodontitis and atherothrombosis has been highlighted. The aim of this study was to determine the influence of Porphyromonas gingivalis on endothelial microvesicles (EMV_Pg) shedding and their contribution to endothelial inflammation. Endothelial cells (EC) were infected with P. gingivalis (MOI = 100) for 24 h. EMV_Pg were isolated and their concentration was evaluated by prothrombinase assay. EMV_Pg were significantly increased in comparison with EMV_Ctrl shedded by unstimulated cells. While EMV_Ctrl from untreated EC had no effect, whereas, the proportion of apoptotic EC was increased by 30 nM EMV_Pg and viability was decreased down to 25%, a value elicited by P. gingivalis alone. Moreover, high concentration of EMV_Pg (30 nM) induced a pro-inflammatory and pro-oxidative cell response including up-regulation of TNF-α, IL-6 and IL-8 as well as an altered expression of iNOS and eNOS at both mRNA and protein level. An increase of VCAM-1 and ICAM-1 mRNA expression (4.5 folds and 3 folds respectively (p < 0.05 vs untreated) was also observed after EMV_Pg (30 nM) stimulation whereas P. gingivalis infection was less effective, suggesting a specific triggering by EMV_Pg. Kinasome analysis demonstrated the specific effect induced by EMV_Pg on main pro-inflammatory pathways including JNK/AKT and STAT. EMV_Pg are effective pro-inflammatory effectors that may have detrimental effect on vascular homeostasis and should be considered as potential autocrine and paracrine effectors involved in the link between periodontitis and atherothrombosis.

The Role of Monocytes and Macrophages in Human Atherosclerosis, Plaque Neoangiogenesis, and Atherothrombosis

Atherosclerosis is one of the leading causes of death and disability worldwide. It is a complex disease characterized by lipid accumulation within the arterial wall, inflammation, local neoangiogenesis, and apoptosis. Innate immune effectors, in particular monocytes and macrophages, play a pivotal role in atherosclerosis initiation and progression. Although most of available evidence on the role of monocytes and macrophages in atherosclerosis is derived from animal studies, a growing body of evidence elucidating the role of these mononuclear cell subtypes in human atherosclerosis is currently accumulating. A novel pathogenic role of monocytes and macrophages in terms of atherosclerosis initiation and progression, in particular concerning the role of these cell subsets in neovascularization, has been discovered. The aim of the present article is to review currently available evidence on the role of monocytes and macrophages in human atherosclerosis and in relation to plaque characteristics, such as plaque neoangiogenesis, and patients' prognosis and their potential role as biomarkers.

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.

Long-Term Risk of Cardiovascular Death With Use of Clarithromycin and Roxithromycin: A Nationwide Cohort Study

Recent studies have raised concern that macrolide antibiotics may be associated with an increased long-term risk of cardiovascular death. We examined the 1-year risk associated with treatment with clarithromycin (n = 187,887) or roxithromycin (n = 698,899) compared with penicillin V (n = 3,473,081), matched 1:4 on propensity score, in a nationwide, registry-based cohort study in Danish outpatients, 1997-2011. Among clarithromycin courses, the rate ratio for cardiovascular death was 1.24 (95% confidence interval (CI): 0.96, 1.59). Among roxithromycin courses, the rate ratio was 0.99 (95% CI: 0.86, 1.16). In analyses by time after treatment start, the rate ratio associated with clarithromycin was 1.66 (95% CI: 0.98, 2.79) during days 0-7. This was attenuated in later time periods (days 8-89, rate ratio = 1.30, 95% CI: 0.88, 1.94; and days 90-364, rate ratio = 0.96, 95% CI: 0.63, 1.47). For roxithromycin, the rate ratios were 0.88 (95% CI: 0.59, 1.32) during days 0-7, 1.17 (95% CI: 0.92, 1.48) during days 8-89, and 0.88 (95% CI: 0.70, 1.10) during days 90-364. We found no increased risk of cardiovascular death in a general outpatient population. With clarithromycin, we observed a transient increased risk during days 0-7 after treatment start, which corresponds to the period of active treatment. This association was absent in later time periods, which is consistent with no long-term toxicity resulting in cardiovascular death.

An Unsettled Debate About the Potential Role of Infection in Pathogenesis of Atherosclerosis

Association of infection with atherosclerosis is by no means new. Several sero-epidemiological and pathologic studies as well as animal models have shown a link between infection and atherosclerosis. Exciting discoveries in recent times related to role of inter-individual genetic variation in modulating inflammatory response to infection have reignited the enthusiasm in proving a causal link between infection and atherosclerosis. The purpose of this article was to review and analyze the available evidence linking infection with atherosclerosis.

New and emerging biomarkers in cardiovascular disease

Cardiovascular disease (CVD) is the most common cause of death and disability worldwide. Therefore, great importance has been placed on the discovery of novel risk factors and metabolic pathways relevant in the prevention and management of CVD. Such research is ongoing and may continue to lead to better risk stratification of individuals and/or the development of new intervention targets and treatment options. This review highlights emerging biomarkers related to lipid metabolism, glycemia, inflammation, and cardiac damage, some of which show promising associations with CVD risk and provide further understanding of the underlying pathophysiology. However, their measurement methodology and assays will require validation and standardization, and it will take time to accumulate evidence of their role in CVD in various population settings in order to fully assess their clinical utility. Several of the novel biomarkers represent intriguing, potentially game-changing targets for therapy.

The role of T and B cells in human atherosclerosis and atherothrombosis

Far from being merely a passive cholesterol accumulation within the arterial wall, the development of atherosclerosis is currently known to imply both inflammation and immune effector mechanisms. Adaptive immunity has been implicated in the process of disease initiation and progression interwined with traditional cardiovascular risk factors. Although the body of knowledge regarding the correlation between atherosclerosis and immunity in humans is growing rapidly, a relevant proportion of it derives from studies carried out in animal models of cardiovascular disease (CVD). However, while the mouse is a well-suited model, the results obtained therein are not fully transferrable to the human setting due to intrinsic genomic and environmental differences. In the present review, we will discuss mainly human findings, obtained either by examination of post-mortem and surgical atherosclerotic material or through the analysis of the immunological profile of peripheral blood cells. In particular, we will discuss the findings supporting a pro-atherogenic role of T cell subsets, such as effector memory T cells or the potential protective function of regulatory T cells. Recent studies suggest that traditional T cell-driven B2 cell responses appear to be atherogenic, while innate B1 cells appear to exert a protective action through the secretion of naturally occurring antibodies. The insights into the immune pathogenesis of atherosclerosis can provide new targets in the quest for novel therapeutic targets to abate CVD morbidity and mortality.

Antibiotic-induced cardiac arrhythmias

This review aims to clarify the underlying risk of arrhythmia associated with the use of macrolides and fluoroquinolones antibiotics. Torsades de pointes (TdP) is a rare potential side effect of fluoroquinolones and macrolide antibiotics. However, the widespread use of these antibiotics compounds the problem. These antibiotics prolong the phase 3 of the action potential and cause early after depolarization and dispersion of repolarization that precipitate TdP. The potency of these drugs, as potassium channel blockers, is very low, and differences between them are minimal. Underlying impaired cardiac repolarization is a prerequisite for arrhythmia induction. Impaired cardiac repolarization can be congenital in the young or acquired in adults. The most important risk factors are a prolonged baseline QTc interval or a combination with class III antiarrhythmic drugs. Modifiable risk factors, including hypokalemia, hypomagnesemia, drug interactions, and bradycardia, should be corrected. In the absence of a major risk factor, the incidence of TdP is very low. The use of these drugs in the appropriate settings of infection should not be altered because of the rare risk of TdP, except among cases with high-risk factors.

Endobiogeny: a global approach to systems biology (part 1 of 2)

Endobiogeny is a global systems approach to human biology that may offer an advancement in clinical medicine based in scientific principles of rigor and experimentation and the humanistic principles of individualization of care and alleviation of suffering with minimization of harm. Endobiogeny is neither a movement away from modern science nor an uncritical embracing of pre-rational methods of inquiry but a synthesis of quantitative and qualitative relationships reflected in a systems-approach to life and based on new mathematical paradigms of pattern recognition.