Loss of developmentally derived Irf8+ macrophages promotes hyperinnervation and arrhythmia in the adult zebrafish heart.

Recent developments in cardiac macrophage biology have broadened our understanding of the critical functions of macrophages in the heart. As a result, there is further interest in understanding the independent contributions of distinct subsets of macrophage to cardiac development and function. Here, we demonstrate that genetic loss of interferon regulatory factor 8 (Irf8)-positive embryonic-derived macrophages significantly disrupts cardiac conduction, chamber function, and innervation in adult zebrafish. At 4 months post-fertilization (mpf), homozygous irf8st96/st96 mutants have significantly shortened atrial action potential duration and significant differential expression of genes involved in cardiac contraction. Functional in vivo assessments via electro- and echocardiograms at 12 mpf reveal that irf8 mutants are arrhythmogenic and exhibit diastolic dysfunction and ventricular stiffening. To identify the molecular drivers of the functional disturbances in irf8 null zebrafish, we perform single cell RNA sequencing and immunohistochemistry, which reveal increased leukocyte infiltration, epicardial activation, mesenchymal gene expression, and fibrosis. Irf8 null hearts are also hyperinnervated and have aberrant axonal patterning, a phenotype not previously assessed in the context of cardiac macrophage loss. Gene ontology analysis supports a novel role for activated epicardial-derived cells (EPDCs) in promoting neurogenesis and neuronal remodeling in vivo. Together, these data uncover significant cardiac abnormalities following embryonic macrophage loss and expand our knowledge of critical macrophage functions in heart physiology and governing homeostatic heart health.

On the rise: Development of a multi-tiered, indoor duckweed cultivation system.

Duckweed species (Lemnaceae) are suitable for remediation and valorization of agri-feed industry wastewaters and therefore can contribute to a more sustainable, circular economy where waste is a resource. Industrial applications will, however, require space efficient cultivation methods that are not affected by prevailing weather conditions. Here, the development and operation of a multi-tiered duckweed bioreactor is described. The developed prototype bioreactor depicted in this paper is composed of four cultivation layers (1 m2 each) with integrated LED lighting (generating up to 150 µmol m-2  s-1 ), a system of pumps and valves to manage the recirculatory flow (2.5 L min-1 ) of wastewater, and an automatic harvesting system. Using a nutrient poor medium, good growth of the duckweed species Lemna minor was achieved in the bioreactor, and this was matched by strong nutrient depletion from the medium, especially for phosphorus (45-mg total phosphorus [TP] removed per m-2  day-1 ). A fully automatic harvesting arm reliably captured similar amounts of duckweed biomass across multiple harvesting cycles, revealing a future scenario whereby labor and interventions by human operators are minimized. Further developments to advance the system towards fully automated operation will include, for example, the use of specific nutrient sensors to monitor and control medium composition. It is envisaged that multi-tiered, indoor bioreactors can be employed in the agri-feed industry where wastewaters are, in many cases, continuously generated throughout the year and need remediating immediately to avoid costly storage. Given the extensive use of automation technology in conventional wastewater treatment plants, multi-tiered duckweed bioreactors can be realistically integrated within the operating environment of such treatment plants. PRACTITIONER POINTS: Duckweed is suitable for remediation and valorization of agri-feed wastewater. Industrial duckweed applications require space efficient cultivation methods. Development and operation of a multi-tiered duckweed bioreactor is detailed. Flow dynamics and automatic harvesting in the bioreactor are optimized. It is concluded that a multi-tiered bioreactor can be used in industry.

Attitudes towards and engagement in self-directed learning among paramedics in New South Wales, Australia: a cross sectional study.

BACKGROUND: Australian paramedics must engage in continuing professional development (CPD), including self-directed learning (SDL). This study aimed to examine paramedics' attitudes towards training and learning activities and perceptions about what could increase engagement in self-directed CPD. METHODS: A cross-sectional survey was conducted with New South Wales Ambulance paramedics. The 48-item survey examined learning attitudes, attitudes towards SDL and socio-demographic and professional characteristics. RESULTS: Most of the 149 participants (19% consent rate) were male (74.5%) and worked full-time (96.5%). All participants agreed that paramedics should reflect on the quality of their practice (100%) and most were committed to undertaking learning to improve their skills and capability (95.2%). However, 26.3% of participants did not feel motivated to undertake learning and 58.9% did not feel supported. Paramedics reported neutral to modestly positive attitudes towards SDL. Most participants agreed they would be more likely to engage in SDL if they had access to training equipment at their station (91%) and dedicated time during work hours (90.4%). CONCLUSION: Paramedics are highly committed to undertaking CPD. Increased engagement may be supported by providing SDL materials at work locations and ensuring dedicated time for learning during work hours.

Long-term statin therapy is associated with severe coronary artery calcification.

BACKGROUND: Atherosclerosis and consequent risk of cardiovascular events or mortality can be accurately assessed by quantifying coronary artery calcium score (CACS) derived from computed tomography. HMG-CoA-reductase inhibitors (statins) are the primary pharmacotherapy used to reduce cardiovascular events, yet there is growing data that support statin use may increase coronary calcification. We set out to determine the likelihood of severe CACS in the context of chronic statin therapy. METHODS: We established a retrospective, case-control study of 1,181 U.S. veterans without coronary artery disease (CAD) from a single site, the Providence VA Medical Center. Duration of statin therapy for primary prevention was divided into 5-year categorical increments. The primary outcome was CACS derived from low-dose lung cancer screening computed tomography (LCSCT), stratified by CACs severity (none = 0; mild = 1-99; moderate = 100-399; and severe ≥400 AU). Statin duration of zero served as the referent control. Ordinal logistic regression analysis determined the association between duration of statin use and CACS categories. Proportional odds assumption was tested using likelihood ratio test. Atherosclerotic cardiovascular disease (ASCVD) risk score, body mass index, and CKD (glomerular filtration rate of <60 ml/min/1.73 m2) were included in the adjustment models. RESULTS: The mean age of the study population was 64.7±7.2 years, and 706 (60%) patients were prescribed a statin at baseline. Duration of statin therapy was associated with greater odds of having increased CACS (>0-5 years, OR: 1.71 [CI: 1.34-2.18], p<0.001; >5-10 years, OR: 2.80 [CI: 2.01-3.90], p<0.001; >10 years, OR: 5.30 [CI: 3.23-8.70], p<0.001), and the relationship between statin duration and CACS remained significant after multivariate adjustment (>0-5 years, OR: 1.49 [CI: 1.16-1.92], p = 0.002; >5-10 years, OR: 2.38 [CI: 1.7-3.35], p<0.001; >10 years, OR: 4.48 [CI: 2.7-7.43], p<0.001). CONCLUSIONS: Long-term use of statins is associated with increased likelihood of severe CACS in patients with significant smoking history. The use of CACS to interpret cardiovascular event risk may require adjustment in the context of chronic statin therapy.

Role of innovation in pharmaceutical regulation: A proposal for principles to evaluate EU General Pharmaceutical Legislation from the innovator perspective.

Because the EU General Pharmaceutical Legislation is under review, the EFPIA Innovation Board developed evaluation principles for the policy proposals and key considerations on how the regulatory framework can support innovation while ensuring only safe, efficacious and quality medicines are authorized. The evaluation principles are anchored on actions to promote: agile adoption of new methodologies with soft law tools; continued emphasis on regulatory science to inform policies; a cost/benefit assessment of the new regulation to ensure they have an overall positive impact; and mitigation of any negative externalities or unintended effects for any type of innovation or products. The evaluation principles are intended to guide the impact assessment of the pharmaceutical legislation in the EU but the principles can be applied globally.

NLRP3 inflammasome activation in cigarette smoke priming for Pseudomonas aeruginosa-induced acute lung injury.

It is increasingly recognized that cigarette smoke (CS) exposure increases the incidence and severity of acute respiratory distress syndrome (ARDS) in critical ill humans and animals. However, the mechanism(s) is not well understood. This study aims to investigate mechanism underlying the priming effect of CS on Pseudomonas aeruginosa-triggered acute lung injury, by using pre-clinic animal models and genetically modified mice. We demonstrated that CS impaired P. aeruginosa-induced mitophagy flux, promoted p62 accumulation, and exacerbated P. aeruginosa-triggered mitochondrial damage and NLRP3 inflammasome activation in alveolar macrophages; an effect associated with increased acute lung injury and mortality. Pharmacological inhibition of caspase-1, a component of inflammasome, attenuated CS primed P. aeruginosa-triggered acute lung injury and improved animal survival. Global or myeloid-specific knockout of IL-1ß, a downstream component of inflammasome activation, also attenuated CS primed P. aeruginosa-triggered acute lung injury. Our results suggest that NLRP3 inflammasome activation is an important mechanism for CS primed P. aeruginosa-triggered acute lung injury. (total words: 155).

Association Between Periodontal Disease and Cardiovascular Disease (from the NHANES).

As observational studies support the association between periodontal disease (PD) and cardiovascular diseases (CVDs), we examined this relationship using the National Health and Nutrition Examination Survey 2013 to 2014 data. This cross-sectional study involved 2,830 adult participants, aged ≥30 years who underwent a home interview, followed by a standardized assessment at a mobile examination center from 2013 to 2014. PD was defined using the new classification scheme issued by American Academy of Periodontology Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions in 2017, and CVD was defined as the composite of coronary artery disease and stroke. The gathered data were subjected to weighted statistical analysis to examine the relation between CVD prevalence and PD. The sample (mean age 51.5 ± 13.6 years) comprised 50.1% men and 69.5% White participants. Stage I (mild/subclinical), II (moderate), and III to IV (severe) PD was noted in 16.7% (95% confidence interval [CI] 12.7 to 21.7), 57.4% (95% CI 53.9 to 60.9), and 25.9% (95% CI 21.4 to 30.8) of the participants, respectively. Patients with stage III and IV PD were more likely to have CVD than those with stage I (adjusted odds ratio 3.59, 95% CI 1.12 to 11.54, p = 0.03). Similarly, participants who reported fair/poor gum health were more likely to have CVD than those who reported excellent/very good gum health (adjusted odds ratio 2.17, 95% CI 0.98 to 4.79, p = 0.055). In conclusion, the data from the National Health and Nutrition Examination Survey 2013 to 2014 demonstrated that PD severity is associated with CVD risk. However, the information gathered by trained professionals during periodontal examinations is a more reliable predictor of PD-CVD associations compared with self-reported measures of oral health.

Macrophage IL-1ß promotes arteriogenesis by autocrine STAT3- and NF-κB-mediated transcription of pro-angiogenic VEGF-A.

Peripheral artery disease (PAD) leads to considerable morbidity, yet strategies for therapeutic angiogenesis fall short of being impactful. Inflammatory macrophage subsets play an important role in orchestrating post-developmental angiogenesis, but the underlying mechanisms are unclear. Here, we find that macrophage VEGF-A expression is dependent upon the potent inflammatory cytokine, IL-1ß. IL-1ß promotes pro-angiogenic VEGF-A165a isoform transcription via activation and promoter binding of STAT3 and NF-κB, as demonstrated by gene-deletion, gain-of-function, inhibition, and chromatin immunoprecipitation assays. Conversely, IL-1ß-deletion or inhibition of STAT3 or NF-κB increases anti-angiogenic VEGF-A165b isoform expression, indicating IL-1ß signaling may also direct splice variant selection. In an experimental PAD model of acute limb ischemia, macrophage IL-1ß expression is required for pro-angiogenic VEGF-A expression and for VEGF-A-induced blood flow recovery via angio- or arteriogenesis. Though further study is needed, macrophage IL-1ß-dependent transcription of VEGF-A via STAT3 and NF-κB may have potential to therapeutically promote angiogenesis in the setting of PAD.

Rac GTPase Signaling in Immune-Mediated Mechanisms of Atherosclerosis.

Coronary artery disease caused by atherosclerosis is a major cause of morbidity and mortality around the world. Data from preclinical and clinical studies support the belief that atherosclerosis is an inflammatory disease that is mediated by innate and adaptive immune signaling mechanisms. This review sought to highlight the role of Rac-mediated inflammatory signaling in the mechanisms driving atherosclerotic calcification. In addition, current clinical treatment strategies that are related to targeting hypercholesterolemia as a critical risk factor for atherosclerotic vascular disease are addressed in relation to the effects on Rac immune signaling and the implications for the future of targeting immune responses in the treatment of calcific atherosclerosis.

Coronary Artery Calcification and Plaque Characteristics in People Living With HIV: A Systematic Review and Meta-Analysis.

Background Studies have reported that people living with HIV have higher burden of subclinical cardiovascular disease, but the data are not adequately synthesized. We performed meta-analyses of studies of coronary artery calcium and coronary plaque in people living with HIV. Methods and Results We performed systematic search in electronic databases, and data were abstracted in standardized forms. Study-specific estimates were pooled using meta-analysis. 43 reports representing 27 unique studies and involving 10 867 participants (6699 HIV positive, 4168 HIV negative, mean age 52 years, 86% men, 32% Black) were included. The HIV-positive participants were younger (mean age 49 versus 57 years) and had lower Framingham Risk Score (mean score 6 versus 18) compared with the HIV-negative participants. The pooled estimate of percentage with coronary artery calcium >0 was 45% (95% CI, 43%-47%) for HIV-positive participants, and 52% (50%-53%) for HIV-negative participants. This difference was no longer significant after adjusting for difference in Framingham Risk Score between the 2 groups. The odds ratio of coronary artery calcium progression for HIV-positive versus -negative participants was 1.64 (95% CI, 0.91-2.37). The pooled estimate for prevalence of noncalcified plaque was 49% (95% CI, 47%-52%) versus 20% (95% CI, 17%-23%) for HIV-positive versus HIV-negative participants, respectively. Odds ratio for noncalcified plaque for HIV-positive versus -negative participants was 1.23 (95% CI, 1.08-1.38). There was significant heterogeneity that was only partially explained by available study-level characteristics. Conclusions People living with HIV have higher prevalence of noncalcified coronary plaques and similar prevalence of coronary artery calcium, compared with HIV-negative individuals. Future studies on coronary artery calcium and plaque progression can further elucidate subclinical atherosclerosis in people living with HIV.

Effect of Missed Doses on the Therapeutic Effect of Methotrexate for Rheumatoid Arthritis: A Pharmacokinetic Modeling Study.

INTRODUCTION: Patients rarely, if ever, take their medications exactly as prescribed. The extent to which missed doses interfere with a drug's therapeutic effect remains unclear. METHODS: After weekly oral dosing of methotrexate (MTX) for rheumatoid arthritis, its polyglutamate derivatives (MTXglu) accumulate in red blood cells, where they are markers for the drug's therapeutic effectiveness. We used Medication Event Monitoring System data and pharmacokinetic modeling to analyze whether missing MTX doses causes the MTXglu level in red blood cells to fall below the range associated with the drug's clinical effect. RESULTS: For patients initiating oral MTX, the threshold for clinical effectiveness and the steady state level were reached in medians of 6 weeks and 22 weeks, respectively. For patients at steady state who discontinued MTX, the MTXglu level fell below the therapeutic threshold after a median of 3 weeks. After initiating MTX, single missed doses did not cause a loss of therapeutic effect in the median patient if they occurred after 10 weeks, while runs of ≥3 consecutive missed doses did cause the MTXglu level to fall below the therapeutic threshold. CONCLUSION: While there is considerable variation between patients, pharmacokinetic modeling indicates that instances of isolated single missed doses of MTX typically will not cause polyglutamated methotrexate levels in red blood cells to fall below the range associated with the therapeutic effect. Runs of ≥3 consecutive missed doses, however, are typically expected to result in a loss of the therapeutic effect.

Aortic Valve Calcification Is Associated with Future Cognitive Impairment.

BACKGROUND: While an association between atherosclerosis and dementia has been identified, few studies have assessed the longitudinal relationship between aortic valve calcification (AVC) and cognitive impairment (CI). OBJECTIVE: We sought to determine whether AVC derived from lung cancer screening CT (LCSCT) was associated with CI in a moderate-to-high atherosclerotic risk cohort. METHODS: This was a single site, retrospective analysis of 1401 U.S. veterans (65 years [IQI: 61, 68] years; 97%male) who underwent quantification of AVC from LCSCT indicated for smoking history. The primary outcome was new diagnosis of CI identified by objective testing (Mini-Mental Status Exam or Montreal Cognitive Assessment) or by ICD coding. Time-to-event analysis was carried out using AVC as a continuous variable. RESULTS: Over 5 years, 110 patients (8%) were diagnosed with CI. AVC was associated with new diagnosis of CI using 3 Models for adjustment: 1) age (HR: 1.104; CI: 1.023-1.191; p = 0.011); 2) Model 1 plus hypertension, hyperlipidemia, diabetes, CKD stage 3 or higher (glomerular filtration rate < 60 mL/min) and CAD (HR: 1.097; CI: 1.014-1.186; p = 0.020); and 3) Model 2 plus CVA (HR: 1.094; CI: 1.011-1.182; p = 0.024). Sensitivity analysis demonstrated that the association between AVC and new diagnosis of CI remained significant upon exclusion of severe AVC (HR: 1.100 [1.013-1.194]; p = 0.023). Subgroup analysis demonstrated that this association remained significant when including education in the multivariate analysis (HR: 1.127 [1.030-1.233]; p = 0.009). CONCLUSION: This is the first study demonstrating that among mostly male individuals who underwent LCSCT, quantified aortic valve calcification is associated with new diagnosis of CI.

α7 Nicotinic acetylcholine receptor mediates right ventricular fibrosis and diastolic dysfunction in pulmonary hypertension.

Right ventricular (RV) fibrosis is a key feature of maladaptive RV hypertrophy and dysfunction and is associated with poor outcomes in pulmonary hypertension (PH). However, mechanisms and therapeutic strategies to mitigate RV fibrosis remain unrealized. Previously, we identified that cardiac fibroblast α7 nicotinic acetylcholine receptor (α7 nAChR) drives smoking-induced RV fibrosis. Here, we sought to define the role of α7 nAChR in RV dysfunction and fibrosis in the settings of RV pressure overload as seen in PH. We show that RV tissue from PH patients has increased collagen content and ACh expression. Using an experimental rat model of PH, we demonstrate that RV fibrosis and dysfunction are associated with increases in ACh and α7 nAChR expression in the RV but not in the left ventricle (LV). In vitro studies show that α7 nAChR activation leads to an increase in adult ventricular fibroblast proliferation and collagen content mediated by a Ca2+/epidermal growth factor receptor (EGFR) signaling mechanism. Pharmacological antagonism of nAChR decreases RV collagen content and improves RV function in the PH model. Furthermore, mice lacking α7 nAChR exhibit improved RV diastolic function and have lower RV collagen content in response to persistently increased RV afterload, compared with WT controls. These finding indicate that enhanced α7 nAChR signaling is an important mechanism underlying RV fibrosis and dysfunction, and targeted inhibition of α7 nAChR is a potentially novel therapeutic strategy in the setting of increased RV afterload.

Association of plasma adiponectin with pulmonary hypertension, mortality and heart failure in African Americans: Jackson Heart Study.

BACKGROUND: Adiponectin is a polypeptide hormone related to obesity, and a known modulator of pulmonary vascular remodeling. Association between plasma adiponectin levels and pulmonary hypertension (PH) has not been studied in African Americans (AAs) who are disproportionately affected by obesity. The relationship between adiponectin and heart failure (HF) and mortality, outcomes associated with PH, is unclear. METHODS: We performed cross-sectional and longitudinal analysis to examine if there is an association between plasma adiponectin and PH and associated clinical outcomes, in participants of Jackson Heart Study (JHS). JHS is a prospective observational cohort study of heart disease in AAs from Jackson, Mississippi. RESULTS: Of the 3161 participants included in the study, mean age (SD) was 56.38 (12.61) years, 1028 were men (32.5%), and mean (SD) BMI was 31.42 (7.05) kg/m2. Median (IQR) adiponectin was 4516.82 (2799.32-7065.85) ng/mL. After adjusting for potential confounders including BMI, higher adiponectin levels were associated with increased odds of PH (adjusted odds ratio per log increment in adiponectin, (1.81; 95% CI, 1.41-2.32). High adiponectin levels were also associated with associated HF admissions (adjusted hazard ratio [HR] per log increment in adiponectin, 1.63, 95% CI, 1.24-2.14) and mortality (adjusted HR per log increment in adiponectin, 1.20; 95% CI 1.02-1.41). CONCLUSIONS: Elevated plasma adiponectin levels are associated with PH, HF admissions and mortality risk in AAs. High adiponectin levels may help identify an at-risk population that could be evaluated for targeted prevention and management strategies in future studies.

Association of poor housing conditions with COVID-19 incidence and mortality across US counties.

OBJECTIVE: Poor housing conditions have been linked with worse health outcomes and infectious disease spread. Since the relationship of poor housing conditions with incidence and mortality of COVID-19 is unknown, we investigated the association between poor housing condition and COVID-19 incidence and mortality in US counties. METHODS: We conducted cross-sectional analysis of county-level data from the US Centers for Disease Control, US Census Bureau and John Hopkins Coronavirus Resource Center for 3135 US counties. The exposure of interest was percentage of households with poor housing conditions (one or greater of: overcrowding, high housing cost, incomplete kitchen facilities, or incomplete plumbing facilities). Outcomes were incidence rate ratios (IRR) and mortality rate ratios (MRR) of COVID-19 across US counties through 4/21/2020. Multilevel generalized linear modeling (with total population of each county as a denominator) was utilized to estimate relative risk of incidence and mortality related to poor housing conditions with adjustment for population density and county characteristics including demographics, income, education, prevalence of medical comorbidities, access to healthcare insurance and emergency rooms, and state-level COVID-19 test density. We report incidence rate ratios (IRRs) and mortality ratios (MRRs) for a 5% increase in prevalence in households with poor housing conditions. RESULTS: Across 3135 US counties, the mean percentage of households with poor housing conditions was 14.2% (range 2.7% to 60.2%). On April 21st, the mean (SD) number of cases and deaths of COVID-19 were 255.68 (2877.03) cases and 13.90 (272.22) deaths per county, respectively. In the adjusted models standardized by county population, with each 5% increase in percent households with poor housing conditions, there was a 50% higher risk of COVID-19 incidence (IRR 1.50, 95% CI: 1.38-1.62) and a 42% higher risk of COVID-19 mortality (MRR 1.42, 95% CI: 1.25-1.61). Results remained similar using earlier timepoints (3/31/2020 and 4/10/2020). CONCLUSIONS AND RELEVANCE: Counties with a higher percentage of households with poor housing had higher incidence of, and mortality associated with, COVID-19. These findings suggest targeted health policies to support individuals living in poor housing conditions should be considered in further efforts to mitigate adverse outcomes associated with COVID-19.

Aortic valve calcification predicts all-cause mortality independent of coronary calcification and severe stenosis.

BACKGROUND AND AIMS: Calcific aortic valve disease is highly prevalent in patients with significant smoking history and is a marker of atherosclerosis. The aim of this study was to define the prognostic value of aortic valve calcification (AVC) derived from low dose, lung cancer screening computed tomography (LCSCT) for all-cause mortality in this higher risk population. METHODS: This is a single site, retrospective analysis of 1529 moderate-to-high atherosclerotic cardiovascular risk U.S. veterans (65 years [IQI: 61, 68] years; 96% male), who underwent clinically indicated LCSCT. CTs were scored for aortic valve calcification (AVC) and coronary artery calcification (CAC). The primary endpoint was all-cause mortality and secondary endpoints were nonfatal myocardial infarction (MI) and nonfatal cerebrovascular accident (CVA). RESULTS: Over 4-year follow-up, 227 patients (15%) died, 112 patients (7%) had nonfatal MI, and 52 patients (3%) had nonfatal CVA. AVC was predictive of all-cause mortality (HR per 100: 1.041 [1.030-1.052], p < 0.001), and this association remained significant after multivariate adjustment for traditional atherosclerotic risk factors, including CAC (1.021 [1.007-1.036], p = 0.003). After excluding patients with severe aortic stenosis (AS) or severe AVC (≥1274 AU in women and ≥2065 AU in men), in a subset of 765 patients who had echocardiograms, this association remained significant after multivariate analysis (HR per 100: 1.052 [1.010-1.095], p = 0.014). Despite controlling for CAC in the models, AVC was still associated with MI (HR per 100: 1.021 [1.004-1.039], p = 0.017) and with CVA (HR per 100: 1.027 [1.002-1.051], p = 0.032). CONCLUSIONS: Scoring AVC derived from LCSCT is predictive of mortality, nonfatal MI, and nonfatal CVA in patients at known risk for cardiovascular disease, independent of coronary calcification or severe aortic valve stenosis.

Statins Disrupt Macrophage Rac1 Regulation Leading to Increased Atherosclerotic Plaque Calcification.

OBJECTIVE: Calcification of atherosclerotic plaque is traditionally associated with increased cardiovascular event risk; however, recent studies have found increased calcium density to be associated with more stable disease. 3-hydroxy-3-methylglutaryl coenzymeA reductase inhibitors or statins reduce cardiovascular events. Invasive clinical studies have found that statins alter both the lipid and calcium composition of plaque but the molecular mechanisms of statin-mediated effects on plaque calcium composition remain unclear. We recently defined a macrophage Rac (Ras-related C3 botulinum toxin substrate)-IL-1ß (interleukin-1 beta) signaling axis to be a key mechanism in promoting atherosclerotic calcification and sought to define the impact of statin therapy on this pathway. Approach and Results: Here, we demonstrate that statin therapy is independently associated with elevated coronary calcification in a high-risk patient population and that statins disrupt the complex between Rac1 and its inhibitor RhoGDI (Rho GDP-dissociation inhibitor), leading to increased active (GTP bound) Rac1 in primary monocytes/macrophages. Rac1 activation is prevented by rescue with the isoprenyl precursor geranylgeranyl diphosphate. Statin-treated macrophages exhibit increased activation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), increased IL-1ß mRNA, and increased Rac1-dependent IL-1ß protein secretion in response to inflammasome stimulation. Using an animal model of calcific atherosclerosis, inclusion of statin in the atherogenic diet led to a myeloid Rac1-dependent increase in atherosclerotic calcification, which was associated with increased serum IL-1ß expression, increased plaque Rac1 activation, and increased plaque expression of the osteogenic markers, alkaline phosphatase and RUNX2 (Runt-related transcription factor 2). CONCLUSIONS: Statins are capable of increasing atherosclerotic calcification through disinhibition of a macrophage Rac1-IL-1ß signaling axis.