Statin use and the risk of cardiovascular implantable electronic device infection: A cohort study in a veteran population

Statins, Allies against Antibiotic Resistance?

Due to the ever-increasing rate of antibacterial resistance, the search for effective antibacterial agents has become imperative. Researchers have investigated the potential antimicrobial properties of various classes of nonantibiotic drugs. Statins are a group of antihyperlipidemic drugs with several cholesterol-independent effects, including antiinflammatory, immune-modulating, antioxidant, and antibacterial effects. In vitro and in vivo studies have demonstrated the antibacterial properties of statins against various grampositive and gram-negative bacteria. Simvastatin and atorvastatin are the most potent members of the family. Their antibacterial effect can be attributed to several direct and indirect mechanisms. Bacterial invasion, growth, and virulence are affected by statins. However, since in vitro minimum inhibitory concentrations (MICs) are significantly higher than serum concentrations at the lipid-lowering dosage, indirect mechanisms have been suggested to explain the positive clinical results, including reducing inflammation and improving immune response capacity. Further, statins have shown promising results when combined with antibiotics and other antibacterial agents, such as triazenes and silver nanoparticles. Despite this, the controversial aspects of statins have cast doubt on their efficacy as a possible solution for antibacterial resistance, and further research is required. Consequently, this review will examine in detail the current clinical and in vitro findings and controversies regarding statins' antibacterial properties and their relevance to antibacterial resistance.

Innovations in Evaluating Statin Benefit and Efficacy in Staphylococcus aureus Intracellular Infection Management

An emerging therapeutic approach in the treatment of infectious disease is to augment the host response through repurposing of well-tolerated, non-antibiotic, host-directed therapeutics. Earlier retrospective studies identify a positive association between statin use and a decreased risk of death due to sepsis or bacteremia. However, more recent randomized control trials fail to detect a therapeutic benefit in these complex infection settings. It is postulated that unrecognized biases in certain observational studies may have led to an overestimation of benefit and that statin use is instead a marker for health status, wealth, and demographic characteristics which may separately affect death due to infection. What remains unresolved is that in vitro and in vivo evidence reproducibly indicates that statin pharmacology limits infection and augments immunomodulatory responses, suggesting that therapeutic benefits may be attainable in certain infection settings, such as intracellular infection by S. aureus. Carefully considering the biological mechanisms capable of driving the relationship between statins and infections and constructing a methodology to avoid potential biases in observational studies would enable the examination of protective effects against infection and limit the risk of underestimating statin efficacy. Such an approach would rely on the examination of statin use in defined infection settings based on an underlying mode-of-action and pharmacology, where the inhibition of HMG-CoA-reductase at the rate-limiting step in cholesterol biosynthesis diminishes not only cholesterol levels but also isoprenoid intermediates central to host cell invasion by S. aureus. Therapeutic benefit in such settings, if existent, may be of clinical importance.

Pleiotropic Effects of Statins: New Therapeutic Approaches to Chronic, Recurrent Infection by Staphylococcus aureus

An emergent approach to bacterial infection is the use of host rather than bacterial-directed strategies. This approach has the potential to improve efficacy in especially challenging infection settings, including chronic, recurrent infection due to intracellular pathogens. For nearly two decades, the pleiotropic effects of statin drugs have been examined for therapeutic usefulness beyond the treatment of hypercholesterolemia. Interest originated after retrospective studies reported decreases in the risk of death due to bacteremia or sepsis for those on a statin regimen. Although subsequent clinical trials have yielded mixed results and earlier findings have been questioned for biased study design, in vitro and in vivo studies have provided clear evidence of protective mechanisms that include immunomodulatory effects and the inhibition of host cell invasion. Ultimately, the benefits of statins in an infection setting appear to require attention to the underlying host response and to the timing of the dosage. From this examination of statin efficacy, additional novel host-directed strategies may produce adjunctive therapeutic approaches for the treatment of infection where traditional antimicrobial therapy continues to yield poor outcomes. This review focuses on the opportunistic pathogen, Staphylococcus aureus, as a proof of principle in examining the promise and limitations of statins in recalcitrant infection.

Prior Statin Use and Risk of Mortality and Severe Disease From Coronavirus Disease 2019: A Systematic Review and Meta-analysis

BACKGROUND

Statins up-regulate angiotensin-converting enzyme 2, the receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while also exhibiting pleiotropic antiviral, antithrombotic, and anti-inflammatory properties. Uncertainties exist about their effect on the course of SARS-CoV-2 infection. We sought to systematically review the literature and perform a meta-analysis to examine the association between prior statin use and outcomes of patients with coronavirus disease 2019 (COVID-19).

METHODS

We searched Ovid Medline, Web of Science, Scopus, and the preprint server medRxiv from inception to December 2020. We assessed the quality of eligible studies with the Newcastle-Ottawa quality scale. We pooled adjusted relative risk (aRRs) of the association between prior statin use and outcomes of patients with COVID-19 using the DerSimonian-Laird random-effects model and assessed heterogeneity using the I 2 index.

RESULTS

Overall, 19 (16 cohorts and 3 case-control) studies were eligible, with a total of 395 513 patients. Sixteen of 19 studies had low or moderate risk of bias. Among 109 080 patients enrolled in 13 separate studies, prior statin use was associated with a lower risk of mortality (pooled aRR, 0.65 [95% confidence interval {CI}, .56-.77], I 2 = 84.1%) and a reduced risk of severe COVID-19 was also observed in 48 110 patients enrolled in 9 studies (pooled aRR, 0.73 [95% CI, .57-.94], I 2 = 82.8%), with no evidence of publication bias.

CONCLUSIONS

Cumulative evidence suggests that prior statin use is associated with lower risks of mortality or severe disease in patients with COVID-19. These data support the continued use of statins medications in patients with an indication for lipid-lowering therapy during the COVID-19 pandemic.

Loading Gentamicin and Zn2+ on TiO2 Nanotubes to Improve Anticoagulation, Endothelial Cell Growth, and Antibacterial Activities

Titanium and its alloys are widely used in blood-contacting implantable and interventional medical devices; however, their biocompatibility is still facing great challenges. In the present study, in order to improve the biocompatibility and antibacterial activities of titanium, TiO2 nanotubes were firstly in situ prepared on the titanium surface by anodization, followed by the introduction of polyacrylic acid (PAA) and gentamicin (GS) on the nanotube surface by layer-by-layer assembly, and finally, zinc ions were loaded on the surface to further improve the bioactivities. The nanotubes displayed excellent hydrophilicity and special nanotube-like structure, which can selectively promote the albumin adsorption, enhance the blood compatibility, and promote the growth of endothelial cells to some degree. After the introduction of PAA and GS, although the superhydrophilicity cannot be achieved, the results of platelet adhesion, cyclic guanosine monophosphate (cGMP) activity, hemolysis rate, and activated partial thromboplastin time (APTT) showed that the blood compatibility was improved, and the blood compatibility was further enhanced after zinc ion loading. On the other hand, the modified surface showed good cytocompatibility to endothelial cells. The introduction of PAA and zinc ions not only promoted the adhesion and proliferation of endothelial cells but also upregulated expression of vascular endothelial growth factor (VEGF) and nitric oxide (NO). The slow and continuous release of GS and Zn2+ over 14 days can significantly improve the antibacterial properties. Therefore, the present study provides an effective method for the surface modification of titanium-based blood-contacting materials to simultaneously endow with good blood compatibility, endothelial growth behaviors, and antibacterial properties.

Biological and Psychological Factors Determining Neuropsychiatric Outcomes in COVID-19

PURPOSE OF REVIEW

We present biological and psychological factors implicated in psychiatric manifestations of SARS-CoV-2, as well as its neuroinvasive capability and immune pathophysiology.

RECENT FINDINGS

Preexisting mental illness leads to worse clinical outcomes in COVID-19. The presence of the virus was reported in the cerebrospinal fluid (CSF) and brain tissue post-mortem. Most common psychiatric manifestations include delirium, mood disorders, anxiety disorders, and posttraumatic stress disorder. "Long-COVID" non-syndromal presentations include "brain-fogginess," autonomic instability, fatigue, and insomnia. SARS-CoV-2 infection can trigger prior vulnerabilities based on the priming of microglia and other cells, induced or perpetuated by aging and mental and physical illnesses. COVID-19 could further induce priming of neuroimmunological substrates leading to exacerbated immune response and autoimmunity targeting structures in the central nervous system (CNS), in response to minor immune activating environmental exposures, including stress, minor infections, allergens, pollutants, and traumatic brain injury.

Assembly of Metal-Phenolic/Catecholamine Networks for Synergistically Anti-Inflammatory, Antimicrobial, and Anticoagulant Coatings

The development of a facile and versatile strategy to endow surfaces with synergistically anti-inflammatory, antimicrobial, and anticoagulant functions is of particular significance for blood-contacting biomaterials and medical devices. In this work, we report a simple and environmentally friendly "one-pot" method inspired by byssal cuticle chemistry, namely, [Fe(dopa)₃] coordination chemistry for assembly of copper ions (Cu²⁺) and plant polyphenol (tannic acid)/catecholamine (dopamine or norepinephrine) to form metal-phenolic/catecholamine network-based coatings. This one-pot method enabled us to easily develop a multifunctional surface based on the combination of the characteristic functions of metal ions and plant polyphenol or catecholamine. The residual phenolic hydroxyl groups on the coatings imparted the modified surface with excellent antioxidant and anti-inflammatory functions. The robust chelation of copper ions to the metal-phenolic/catecholamine networks provided not only durable antibacterial property but also glutathione peroxidase like catalytic capability to continuously and controllably produce antithrombotic nitric oxide by catalyzing endogenous S-nitrothiol. The biological functions of such coatings could be well regulated by adjusting the ratios of the feed concentration of Cu²⁺ ions to plant polyphenol or catecholamine. We envision that our simple, multifunctional, and bioinspired coating strategy can hold great application promise for bioengineering blood-contacting devices.