Colchicine use is associated with decreased prevalence of myocardial infarction in patients with gout

Colchicine Improves Survival, Left Ventricular Remodeling, and Chronic Cardiac Function After Acute Myocardial Infarction

BACKGROUND

Several studies have reported that colchicine attenuated the infarct size and inflammation in acute myocardial infarction (MI). However, the sustained benefit of colchicine administration on survival and cardiac function after MI is unknown. It was hypothesized that the short-term treatment with colchicine could improve survival and cardiac function during the recovery phase of MI.Methods and Results:MI was induced in mice by permanent ligation of the left anterior descending coronary artery. Mice were then orally administered colchicine 0.1 mg/kg/day or vehicle from 1 h to day 7 after MI. Colchicine significantly improved survival rate (colchicine, n=48: 89.6% vs. vehicle, n=51: 70.6%, P<0.01), left ventricular end-diastolic diameter (5.0±0.2 vs. 5.6±0.2 mm, P<0.05) and ejection fraction (41.5±2.1 vs. 23.8±3.1%, P<0.001), as assessed by echocardiogram compared with vehicle at 4 weeks after MI. Heart failure development as pulmonary edema assessed by wet/dry lung weight ratio (5.0±0.1 vs. 5.5±0.2, P<0.01) and B-type natriuretic peptide expression in the heart was attenuated in the colchicine group at 4 weeks after MI. Histological and gene expression analysis revealed colchicine significantly inhibited the infiltration of neutrophils and macrophages, and attenuated the mRNA expression of pro-inflammatory cytokines and NLRP3 inflammasome components in the infarcted myocardium at 24 h after MI.

CONCLUSIONS

Short-term treatment with colchicine successfully attenuated pro-inflammatory cytokines and NLRP3 inflammasome, and improved cardiac function, heart failure, and survival after MI.

Allopurinol use and the risk of acute cardiovascular events in patients with gout and diabetes

Background

Few studies, if any, have examined cardiovascular outcomes in patients with diabetes and gout. Both diabetes and gout are risk factors for cardiovascular disease. The objective of this study was to examine the effect of allopurinol on the risk of incident acute cardiovascular events in patients with gout and diabetes.

Methods

We used the 2007–2010 Multi-Payer Claims Database (MPCD) that linked health plan data from national commercial and governmental insurances, representing beneficiaries with United Healthcare, Medicare, or Medicaid coverage. In patients with gout and diabetes, we assessed the current allopurinol use, defined as a new filled prescription for allopurinol, as the main predictor of interest. Our outcome of interest was the occurrence of the first Incident hospitalized myocardial infarction (MI) or stroke (composite acute cardiovascular event), after which observations were censored. We employed multivariable-adjusted Cox proportional hazards models that simultaneously adjusted for patient demographics, cardiovascular risk factors and other medical comorbidities. We calculated hazard ratios [HR] (95% confidence intervals [CI]) for incident composite (MI or stroke) acute cardiovascular events. We performed sensitivity analyses that additionally adjusted for the presence of immune diseases and colchicine use, as potential confounders.

Results

There were 2,053,185 person days (5621.3 person years) of current allopurinol use and 1,671,583 person days (4576.5 person years) of prior allopurinol use. There were 158 incident MIs or strokes in current and 151 in prior allopurinol users, respectively. Compared to previous allopurinol users, current allopurinol users had significantly lower adjusted hazard of incident acute cardiovascular events (incident stroke or MI), with an HR of 0.67 (95% CI, 0.53, 0.84). Sensitivity analyses, additionally adjusted for immune diseases or colchicine use, confirmed this association.

Conclusions

Current allopurinol use protected against the occurrence of acute cardiovascular events in patients with gout and diabetes. The underlying mechanisms for this potential cardio-protective effect of allopurinol need further exploration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0513-6) contains supplementary material, which is available to authorized users.

What's Old is New Again - A Review of the Current Evidence of Colchicine in Cardiovascular Medicine

Colchicine is a well-established drug approved by the Food and Drug Administration (FDA) for the prevention and treatment of gout. It possesses unique anti-inflammatory properties. Interests in the usage of colchicine in cardiovascular medicine have been rekindled recently with several large trials been carried out to investigate its efficacy in treatment of various cardiac conditions including pericarditis, postpericardiotomy syndrome, atrial fibrillation and coronary artery disease. In this review, the basic pharmacological properties of colchicine will be discussed, and the evidences of its benefits for different applications in cardiovascular medicine will be reviewed.

Inflammation and beyond: new directions and emerging drugs for treating atherosclerosis

INTRODUCTION

Cardiovascular (CV) atherosclerotic disease remains the leading cause of morbidity and mortality worldwide, despite the advances in contemporary therapies. Inflammation is an important process in atherosclerosis, leading to plaque rupture and acute coronary syndrome. Although statin therapy has substantially reduced CV events in primary and secondary prevention, many treated patients will have recurrent adverse CV events despite the standard of care. Thus, drug development aiming to target inflammatory pathways seems a promising avenue for novel therapies in atherosclerosis. Areas covered: Statins have been extensively studied and are the most effective lipid-lowering drugs available for CV prevention. Novel anti-inflammatory drugs are being tested in Phase II and III trials, targeting pathways like interleukin-1, leukotrienes, TNF-α, P-selectin, CCL2-CCR2 and MAP Kinase. Expert opinion: Novel anti-inflammatory therapies seem promising additions to address the residual CV risk present despite the current standard of care, but large clinical trials have not yet shown beneficial effects on clinical events. PCSK9 inhibitors have been shown to substantially reduce LDL-C, however their long-term safety and effects on CV risk are currently being investigated. Pharmacogenomics holds great potential in future lipid trials, enabling the identification of patients who will respond with greater benefits and smaller risk to therapies and to decrease failure rates in drug development, as genotype-dependent effects of the CETP inhibitor dalcetrapib were shown in the dal-OUTCOMES and dal-PLAQUE-2 trials.

Predictors of Mortality in People with Recent-onset Gout: A Prospective Observational Study

OBJECTIVE

To determine mortality rates and predictors of death at baseline in people with a recent onset of gout.

METHODS

People with gout disease duration < 10 years were recruited from primary and secondary care settings. Comprehensive clinical assessment was completed at baseline. Participants were prospectively followed for at least 1 year. Information about death was systematically collected from primary and secondary health records. Standardized mortality ratios (SMR) were calculated and risk factors for mortality were analyzed using Cox proportional hazard regression models.

RESULTS

The mean (SD) followup duration was 5.1 (1.6) years (a total 1511 patient-yrs accrued). Of the 295 participants, 43 (14.6%) had died at the time of censorship (SMR 1.96, 95% CI 1.44-2.62). In the reduced Cox proportional hazards model, these factors were independently associated with an increased risk of death from all causes: older age (70-80 yrs: HR 9.96, 95% CI 3.30-30.03; 80-91 yrs: HR 9.39, 95% CI 2.68-32.89), Māori or Pacific ethnicity (HR 2.48, 95% CI 1.17-5.29), loop diuretic use (HR 3.99, 95% CI 2.15-7.40), serum creatinine (per 10 µmol/l change; HR 1.04, 95% CI 1.00-1.07), and the presence of subcutaneous tophi (HR 2.85, 95% CI 1.49-5.44). The presence of subcutaneous tophi was the only baseline variable independently associated with both cardiovascular (CV) cause of death (HR 3.13, 95% CI 1.38-7.10) and non-CV cause of death (HR 3.48, 95% CI 1.25-9.63).

CONCLUSION

People with gout disease duration < 10 years have an increased risk of death. The presence of subcutaneous tophi at baseline is an independent predictor of mortality, from both CV and non-CV causes.

Colchicine in cardiovascular disease: an ancient drug with modern tricks

From the dark history of being a poison and purgative, colchicine has risen to become one of the few irrefutable positives in the history of pharmacology in the management of myriad inflammatory conditions. Colchicine exerts its action through binding to tubulin, which in turn affects several cellular processes and pathways modulating the inflammatory response. Despite narrow therapeutic-toxicity window and the most common complaint of gastrointestinal upset, its list of medicinal use is expanding in recent years as we continue to unravel the mystery of this ancient remedy. In this review, we summarise the history of colchicine use, discuss its pharmacokinetics and mechanism of actions, and examine the most up-to-date evidence of colchicine in the treatment of various cardiac conditions with a focus on cardiovascular disease.

Inflammatory cytokines in atherosclerosis: current therapeutic approaches

The notion of atherosclerosis as a chronic inflammatory disease has intensified research on the role of cytokines and the way these molecules act and interact to initiate and sustain inflammation in the microenvironment of an atherosclerotic plaque. Cytokines are expressed by all types of cells involved in the pathogenesis of atherosclerosis, act on a variety of targets exerting multiple effects, and are largely responsible for the crosstalk among endothelial, smooth muscle cells, leucocytes, and other vascular residing cells. It is now understood that widely used drugs such as statins, aspirin, methotrexate, and colchicine act in an immunomodulatory way that may beneficially affect atherogenesis and/or cardiovascular disease progression. Moreover, advancement in pharmaceutical design has enabled the production of highly specific antibodies against key molecules involved in the perpetuation of the inflammatory cascade, raising hope for advances in the treatment of atherosclerosis. This review describes the actions and effects of these agents, their potential clinical significance, and future prospects.

Effect of Colchicine on Platelet-Platelet and Platelet-Leukocyte Interactions: a Pilot Study in Healthy Subjects

The cardioprotective mechanisms of colchicine in patients with stable ischemic heart disease remain uncertain. We tested varying concentrations of colchicine on platelet activity in vitro and a clinically relevant 1.8-mg oral loading dose administered over 1 h in 10 healthy subjects. Data are shown as median [interquartile range]. Colchicine addition in vitro decreased light transmission platelet aggregation only at supratherapeutic concentrations but decreased monocyte- (MPA) and neutrophil-platelet aggregation (NPA) at therapeutic concentrations. Administration of 1.8 mg colchicine to healthy subjects had no significant effect on light transmission platelet aggregation but decreased the extent of MPA (28 % [22-57] to 22 % [19-31], p = 0.05) and NPA (19 % [16-59] to 15 % [11-30], p = 0.01), platelet surface expression of PAC-1 (370 mean fluorescence intensity (MFI) [328-555] to 333 MFI [232-407], p = 0.02) and P-selectin (351 MFI [269-492] to 279 [226-364], p = 0.03), and platelet adhesion to collagen (10.2 % [2.5-32.6] to 2.0 % [0.2-9.5], p = 0.09) 2 h post-administration. Thus, in clinically relevant concentrations, colchicine decreases expression of surface markers of platelet activity and inhibits leukocyte-platelet aggregation but does not inhibit homotypic platelet aggregation.

Chronic heart failure: Ca(2+), catabolism, and catastrophic cell death

Robust successes have been achieved in recent years in conquering the acutely lethal manifestations of heart disease. Many patients who previously would have died now survive to enjoy happy and productive lives. Nevertheless, the devastating impact of heart disease continues unabated, as the spectrum of disease has evolved with new manifestations. In light of this ever-evolving challenge, insights that culminate in novel therapeutic targets are urgently needed. Here, we review fundamental mechanisms of heart failure, both with reduced (HFrEF) and preserved (HFpEF) ejection fraction. We discuss pathways that regulate cardiomyocyte remodeling and turnover, focusing on Ca(2+) signaling, autophagy, and apoptosis. In particular, we highlight recent insights pointing to novel connections among these events. We also explore mechanisms whereby potential therapeutic approaches targeting these processes may improve morbidity and mortality in the devastating syndrome of heart failure.

Treatment Options for Acute Gout

Careful consideration of comorbidities and contraindications are important when determining the appropriate treatment of patients with gout.

Hyperuricaemia with deposition: latest evidence and therapeutic approach

This article reviews recent evidence on urate deposition and the opportunity for a therapeutic approach. We reviewed Pubmed 2013-2015 literature using the search terms 'deposition' with 'hyperuricaemia', 'gout', 'ultrasonography', 'DECT' (dual-energy computed tomography), 'radiography', 'CT'(computed tomography), 'MRI' (magnetic resonance imaging), or 'cardiovascular', in addition to a digital bibliographic library compiled by the authors with 2072 papers on hyperuricaemia and gout. Relevant papers on the topic were selected. Recent evidence, mostly based on imaging studies, showed a continuum from hyperuricaemia to deposition and clinical manifestations. Chronic inflammation and structural damage may be present even in asymptomatic patients with crystal-proved deposition. The impact of early intervention in patients with asymptomatic deposition either on vascular outcomes or further structural joint damage has not been demonstrated yet. In conclusion, a worldwide definition of gout is still lacking, stages from hyperuricaemia to clinical gout not being definitively defined. Although there is increasing interest on the impact of early deposits on joint damage and cardiovascular outcomes, robust evidence is still lacking to fully support interventions.

Hyperuricemia, gout, and cardiovascular disease: an update

Across the globe, both gout and hyperuricemia have become increasingly common over the last few decades. The burden of gouty disease is made heavier by its association with several comorbid conditions, including hypertension, cardiovascular disease, and chronic kidney disease. Accruing evidence from prospective studies suggests that gout is an independent risk factor for developing cardiovascular disease and for higher cardiovascular mortality. While asymptomatic hyperuricemia does not seem to be an independent risk factor for cardiovascular disease, increasing data implicates hyperuricemia as a risk factor for developing incidental hypertension. Important questions that remain unanswered include whether addressing asymptomatic hyperuricemia forestalls the onset of hypertension, and whether treating gout with urate-lowering agents improves cardiovascular outcomes. This article reviews the most recent data regarding the relationship between hyperuricemia, gout, hypertension, and cardiovascular disease, as well as emerging evidence as to whether treatment of hyperuricemia and gout improves cardiovascular outcomes.

Effects of colchicine on risk of cardiovascular events and mortality among patients with gout: a cohort study using electronic medical records linked with Medicare claims

BACKGROUND

Colchicine may have beneficial effects on cardiovascular (CV) disease, but there are sparse data on its CV effect among patients with gout. We examined the potential association between colchicine and CV risk and all-cause mortality in gout.

METHODS

The analyses used data from an electronic medical record (EMR) database linked with Medicare claims (2006-2011). To be eligible for the study cohort, subjects must have had a diagnosis of gout in the EMR and Medicare claims. New users of colchicine were identified and followed up from the first colchicine dispensing date. Non-users had no evidence of colchicine prescriptions during the study period and were matched to users on the start of follow-up, age and gender. Both groups were followed for the primary outcome, a composite of myocardial infarction, stroke or transient ischaemic attack. We calculated HRs in Cox regression, adjusting for potential confounders.

RESULTS

We matched 501 users with an equal number of non-users with a median follow-up of 16.5 months. During follow-up, 28 primary CV events were observed among users and 82 among non-users. Incidence rates per 1000 person-years were 35.6 for users and 81.8 for non-users. After full adjustment, colchicine use was associated with a 49% lower risk (HR 0.51, 95% CI 0.30 to 0.88) in the primary CV outcome as well as a 73% reduction in all-cause mortality (HR 0.55, 95% CI 0.35 to 0.85, p=0.007).

CONCLUSIONS

Colchicine use was associated with a reduced risk of a CV event among patients with gout.

Investigational new drugs for the treatment of acute coronary syndrome

INTRODUCTION

Ischemic heart disease is the most common cause of death worldwide. Despite improvements in interventional and pharmacological therapy for acute coronary syndrome (ACS), the risk of recurrent myocardial ischemia and mortality early after ACS remains high. Our improved understanding of the increasing role of inflammation in the pathogenesis of ACS and its relationship to atherosclerotic plaque rupture and thrombosis has led to the development of more potent anti-thrombotic and novel anti-inflammatory therapies for the treatment of ACS.

AREAS COVERED

In this review, the authors explore: the developing pharmacotherapy in the field of cardiology for ACS; antiplatelet agents (both further development of classical modalities together with pioneering agents); evolving use of anticoagulation in its treatment, and exploration in the use of novel anti-inflammatories and biological agents.

EXPERT OPINION

Data from trials involving the use of immunological and cellular-based treatments show promising results and herald further possible reduction in infarct burden in ACS alongside the possibility of recovery in cardiac function following infarction.

Impact of anti-inflammatory therapies, xanthine oxidase inhibitors and other urate-lowering therapies on cardiovascular diseases in gout

PURPOSE OF REVIEW

The purpose of this study is to give an overview of recently published articles covering the impact of anti-inflammatory therapies, xanthine oxidase inhibitors and other urate-lowering therapies on cardiovascular diseases in gout.

RECENT FINDINGS

In patients with gout, long-term xanthine oxidase inhibition might reduce some cardiovascular comorbidities because of the dual effect of lowering serum uric acid levels and reducing free-radical production during uric acid formation. Among the anti-inflammatory therapies, colchicine has been shown to reduce some major cardiovascular events.

SUMMARY

Epidemiological and experimental studies have shown that hyperuricaemia and gout are independent risk factors for cardiovascular diseases. The mechanisms that link high serum uric acid levels and gout with cardiovascular diseases are multifactorial, implicating low-grade systemic inflammation and xanthine oxidase activity as well as the deleterious effect of hyperuricaemia itself.

Colchicine as an anti-inflammatory and cardioprotective agent

INTRODUCTION

Colchicine has been successfully used for the treatment of neutrophilic disorders such as familial Mediterranean fever (FMF), Behçet disease (BD) and gout. There is a growing interest in its cardiovascular effects.

AREAS COVERED

A MEDLINE/PubMed search for English articles published from January 1972 to June 2015 was completed using the following terms: therapy, pharmacokinetics, efficiency, side effects, toxicity, heart, colchicine, inflammation, FMF, amyloidosis, BD, gout, cardiovascular disorders, pericarditis, arrhythmias, inflammation, neutrophils, platelets.

EXPERT OPINION

By targeting neutrophils, endothelial cells and platelets, inhibiting mitosis, vascular hyperplasia and fibrosis, colchicine improves outcomes of pericarditis, myocardial ischemia and coronary interventions. Studies in neutrophilic rheumatic diseases and cardiovascular disorders demonstrated that oral colchicine at doses of 0.5 - 2.5 mg/daily is useful for treating pericarditis, myocardial ischemia and coronary occlusion. In rheumatic and cardiovascular disorders, therapeutic doses of the drug reduce C-reactive protein to levels below 2 mg/L, prevent myocardial damage and preserve normal values of atrial and ventricular impulse generation. One of the drug's frequent side effects is diarrhea, which is treated by diet modification or temporary discontinuation of the therapy. Certain drugs (macrolides, statins), comorbidities and certain genetic factors increase risk of colchicine toxicity.

Colchicine: old and new

Although colchicine has been a focus of research, debate, and controversy for thousands of years, the US Food and Drug Administration just approved it in 2009. Over the past decade, advances in the knowledge of colchicine pharmacology, drug safety, and mechanisms of action have led to changes in colchicine dosing and to potential new uses for this very old drug. In this review, we discuss the pharmacologic properties of colchicine and summarize what is currently known about its mechanisms of action. We then discuss and update the use of colchicine in a variety of illnesses, including rheumatic and, most recently, cardiovascular diseases.

Association Between Colchicine and Risk of Diabetes Among the Veterans Affairs Population With Gout

PURPOSE

This study aimed to determine the association between colchicine use and the incidence of diabetes in a cohort of patients with gout.

METHODS

This is a retrospective study of 27,876 adults with gout identified via the Veterans Integrated Services Network 16 data warehouse. Patients had up to 11 years of follow-up (January 1999 through December 2010). The final study sample consisted of 1046 pairs of 1:1 propensity score-matched patients from the colchicine treated and control cohorts. Time to first diabetes development since the first gout diagnosis was modeled.

RESULTS

After the propensity score matching, the 12-month baseline variables (eg, age, sex, race, index year, body mass index, serum uric acid, antigout drug use, and health care use) were comparable between the matched cohorts (P > 0.05 for all). Among the 1046 matched pairs, 234 patients who had taken colchicine and 224 patients who had never taken colchicine developed diabetes; the incidence rates were 38.95 and 39.02 per 1000 patient-years, respectively. In Poisson and Cox proportional hazards regression, the risk of incident diabetes was reduced with increased duration of colchicine use, but the difference was not statistically significant (P > 0.05). In a time-varying Cox proportional hazards model, the hazard ratio for incident diabetes among patients who had taken colchicine was 0.877 (95% CI, 0.662-1.163; P = 0.362) compared with those who had not taken colchicine.

CONCLUSION

This study suggests a possible duration- or dose-related association between colchicine use and reduced risk of diabetes in adults with gout even though the risk reduction was not significant. Further studies are needed to confirm findings from this study.

Effects of Xie-Zhuo-Chu-Bi-Fang on miR-34a and URAT1 and their relationship in hyperuricemic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Xie-Zhuo-Chu-Bi-Fang (XZCBF) is an empirical formula that was developed based on the principles of traditional Chinese medicine, for the therapeutic purpose of treating hyperuricemia. XZCBF has been clinically utilized in the Department of Traditional Chinese Medicine at General Hospital of Guangzhou Military Command of PLA for many years and has exhibited favorable efficacy. The aim of the study is to evaluate the effects of XZCBF on the expression of uric acid transporter 1 (URAT1) and miR-34a in hyperuricemic mice and to determine, the correlation between the two expression levels.

MATERIALS AND METHODS

A hyperuricemic animal model was created by administering adenine and allantoxanic acid potassium salt to mice. The blood uric acid levels were measured in these model mice after treatment with XZCBF for 15 days. The potential targets of miR-34a were screened. The expression levels of miR-34a and URAT1 in the renal tissues collected from the model mice were determined by quantitative real-time polymerase chain reaction (qRT-PCR) analysis, and their correlation was further established by immunohistochemistry and in situ hybridization.

RESULTS

The uric acid levels in the model mice were significantly higher than those in the blank controls (P<0.05). These levels were significantly lower in the three groups receiving different doses of XZCBF (P<0.05), which was, in agreement with the downregulation of URAT1 and the upregulation of miR-34a in each group. The mRNA expression level of URAT1 was positively correlated with the concentration of uric acid but, negatively correlated with the expression level of miR-34a.

CONCLUSIONS

The ability of XZCBF to facilitate the excretion of uric acid and to lower its level in the model group was mediated by the upregulation of miR-34a and the inhibition of URAT1 mRNA expression, which suggests that XZCBF could be an option for the treatment of hyperuricemia in mice.

Anti-inflammatory therapies for atherosclerosis

The view of atherosclerosis as an inflammatory disease has emerged from observations of immune activation and inflammatory signalling in human atherosclerotic lesions, from the definition of inflammatory biomarkers as independent risk factors for cardiovascular events, and from evidence of low-density lipoprotein-induced immune activation. Studies in animal models of hyperlipidaemia have also supported the beneficial effects of countering inflammation to delay atherosclerosis progression. Specific inflammatory pathways with relevance to human diseases have been identified, and inhibitors of these pathways are either already in use for the treatment of other diseases, or are under development and evaluation. These include 'classic' drugs (such as allopurinol, colchicine, and methotrexate), biologic therapies (for example tumour necrosis factor inhibitors and IL-1 neutralization), as well as targeting of lipid mediators (such as phospholipase inhibitors and antileukotrienes) or intracellular pathways (inhibition of NADPH oxidase, p38 mitogen-activated protein kinase, or phosphodiesterase). The evidence supporting the use of anti-inflammatory therapies for atherosclerosis is mainly based on either observational or small interventional studies evaluating surrogate markers of disease activity. Nevertheless, these data are crucial to understand the role of inflammation in atherosclerosis, and to design randomized controlled studies to evaluate the effect of specific anti-inflammatory strategies on cardiovascular outcomes.

Safety profile of anti-gout agents: an update

PURPOSE OF REVIEW

Recent interest in gout has led to development of new drugs for acute gout and long-term urate-lowering, as well as interest in improving the use of older drugs. The patients' comorbidities and concomitant medications may contribute to the risk of adverse drug reactions with anti-gout therapies. This review will highlight recent data on the safety of drugs used in gout.

RECENT FINDINGS

Colchicine has a narrow therapeutic index, and low doses are effective with less gastrointestinal toxicity. There are significant interactions between colchicine and CYP3A4 and P-glycoprotein inhibitors, and the colchicine dose must be reduced. Allopurinol and febuxostat have similar adverse effect profiles. Recent data have highlighted the risk association of HLA-B5801 in some ethnic groups and of allopurinol starting dose in allopurinol hypersensitivity syndrome. Further long-term cardiovascular safety data in patients with cardiovascular disease or cardiovascular risk factors receiving febuxostat and allopurinol are pending. Infusion reactions are common in patients receiving pegloticase, particularly in patients with pre-infusion serum urate above 0.36mmol/l (6 mg/dl).

SUMMARY

In general, treatments for gout are well tolerated, although clinicians must keep in mind the potential for drug interactions and the contribution of comorbidities to the potential for adverse effects with gout therapies.

Colchicine for secondary prevention of cardiovascular disease

Preliminary evidence demonstrating that adding 0.5 mg of colchicine per day to statin and antiplatelet therapy reduced the risk of acute coronary events in patients with stable coronary artery disease has raised the hope that it may prove effective for the long-term secondary prevention of cardiovascular disease. The ability of colchicine to suppress blood levels of inflammatory mediators and prevent cholesterol-crystal-induced neutrophil-mediated inflammation implicated in the progression and instability of atherosclerosis adds plausibility to this clinical observation. Early intestinal intolerance in some patients is well recognized, but clinical experience gained over more than half a century with the continuous use of colchicine for the prevention of neutrophil-mediated inflammation in patients with familial Mediterranean fever and gout indicates that low-dose long-term therapy is safe. Nonetheless, before colchicine can be recommended for the secondary prevention of cardiovascular disease, further studies are required to confirm its safety and efficacy in a broad range of patients with coronary disease, and to determine whether doses of colchicine less than 0.5 mg/day might be effective and even better tolerated. Trials exploring the role of colchicine in the treatment of patients with acute coronary syndromes would also be of special interest but may require the use of doses higher than those used for long-term secondary prevention.

Mechanism of action of colchicine in the treatment of gout

PURPOSE

The aims of this article were to systematically review the literature about the mechanism of action of colchicine in the multimodal pathology of acute inflammation associated with gout and to consider the clinical utility of colchicine in other chronic inflammatory diseases.

METHODS

The English-language literature on PubMed was searched for articles published between 1990 and October 2013, with a cross-reference to citations across all years. Relevant articles pertaining to the mechanism of action of colchicine and the clinical applications of colchicine in gout and other inflammatory conditions were identified and reviewed.

FINDINGS

The molecular pathology of acute inflammation associated with gouty arthritis involves several concurrent pathways triggered by a variety of interactions between monosodium urate crystals and the surface of cells. Colchicine modulates multiple pro- and antiinflammatory pathways associated with gouty arthritis. Colchicine prevents microtubule assembly and thereby disrupts inflammasome activation, microtubule-based inflammatory cell chemotaxis, generation of leukotrienes and cytokines, and phagocytosis. Many of these cellular processes can be found in other diseases involving chronic inflammation. The multimodal mechanism of action of colchicine suggests potential efficacy of colchicine in other comorbid conditions associated with gout, such as osteoarthritis and cardiovascular disease.

IMPLICATIONS

Colchicine has multiple mechanisms of action that affect inflammatory processes and result in its utility for treating and preventing acute gout flare. Other chronic inflammatory diseases that invoke these molecular pathways may represent new therapeutic applications for colchicine.

Improving cardiovascular and renal outcomes in gout: what should we target?

Epidemiological and experimental studies have shown that hyperuricaemia and gout are intricately linked with hypertension, metabolic syndrome, chronic kidney disease and cardiovascular disease. A number of studies suggest that hyperuricaemia and gout are independent risk factors for the development of these conditions and that these conditions account, in part, for the increased mortality rate of patients with gout. In this Review, we first discuss the links between hyperuricaemia, gout and these comorbidities, and present the mechanisms by which uric acid production and gout might favour the development of cardiovascular and renal diseases. We then emphasize the potential benefit of urate-lowering therapies on cardiovascular and renal outcomes in patients with hyperuricaemia. The mechanisms that link elevated serum uric acid levels and gout with these comorbidities seem to be multifactorial, implicating low-grade systemic inflammation and xanthine oxidase (XO) activity, as well as the deleterious effects of hyperuricaemia itself. Patients with asymptomatic hyperuricaemia should be treated by nonpharmacological means to lower their SUA levels. In patients with gout, long-term pharmacological inhibition of XO is a treatment strategy that might also reduce cardiovascular and renal comorbidities, because of its dual effect of lowering SUA levels as well as reducing free-radical production during uric acid formation.

Microtubule-mediated defects in junctophilin-2 trafficking contribute to myocyte transverse-tubule remodeling and Ca2+ handling dysfunction in heart failure

BACKGROUND

Cardiac dysfunction in failing hearts of human patients and animal models is associated with both microtubule densification and transverse-tubule (T-tubule) remodeling. Our objective was to investigate whether microtubule densification contributes to T-tubule remodeling and excitation-contraction coupling dysfunction in heart disease.

METHODS AND RESULTS

In a mouse model of pressure overload-induced cardiomyopathy by transaortic banding, colchicine, a microtubule depolymerizer, significantly ameliorated T-tubule remodeling and cardiac dysfunction. In cultured cardiomyocytes, microtubule depolymerization with nocodazole or colchicine profoundly attenuated T-tubule impairment, whereas microtubule polymerization/stabilization with taxol accelerated T-tubule remodeling. In situ immunofluorescence of heart tissue sections demonstrated significant disorganization of junctophilin-2 (JP2), a protein that bridges the T-tubule and sarcoplasmic reticulum membranes, in transaortic banded hearts as well as in human failing hearts, whereas colchicine injection significantly preserved the distribution of JP2 in transaortic banded hearts. In isolated mouse cardiomyocytes, prolonged culture or treatment with taxol resulted in pronounced redistribution of JP2 from T-tubules to the peripheral plasma membrane, without changing total JP2 expression. Nocodazole treatment antagonized JP2 redistribution. Moreover, overexpression of a dominant-negative mutant of kinesin 1, a microtubule motor protein responsible for anterograde trafficking of proteins, protected against JP2 redistribution and T-tubule remodeling in culture. Finally, nocodazole treatment improved Ca(2+) handling in cultured myocytes by increasing the amplitude of Ca(2+) transients and reducing the frequency of Ca(2+) sparks.

CONCLUSION

Our data identify a mechanistic link between microtubule densification and T-tubule remodeling and reveal microtubule-mediated JP2 redistribution as a novel mechanism for T-tubule disruption, loss of excitation-contraction coupling, and heart failure.

Impact of allopurinol on risk of myocardial infarction

BACKGROUND

Gout therapy includes xanthine oxidase inhibitors (XOI) and colchicine, which have both been associated with decreased cardiovascular risk. However, their effects on major cardiac events, such as myocardial infarction (MI), need to be investigated further.

OBJECTIVES

To investigate whether XOIs and colchicine are associated with decreased risk of MI.

METHODS

This case-control study compared patients with first-ever MI and matched controls. Cases were recruited from the Pharmacoepidemiological General Research on MI registry. Controls were selected from a referent population (n=8444) from general practice settings.

RESULTS

The study sample consisted of 2277 MI patients and 4849 matched controls. Use of allopurinol was reported by 3.1% of cases and 3.8 of controls, and 1.1% of cases and controls used colchicine. The adjusted OR (95% CI) for MI with allopurinol use was 0.80 (0.59 to 1.09). When using less stringent matching criteria that allowed for inclusion of 2593 cases and 5185 controls, the adjusted OR was 0.73 (0.54 to 0.99). Similar results were found on analysis by sex and hypertension status. Colchicine used was not associated with a decreased risk of MI (aOR=1.17 (0.70 to 1.93)).

CONCLUSIONS

Allopurinol may be associated with a reduced risk of MI. No decreased risk of MI was found in colchicine users. Besides its urate-lowering property, allopurinol might have a cardioprotective effect.

Fenbendazole improves pathological and functional recovery following traumatic spinal cord injury

During a study of spinal cord injury (SCI), mice in our colony were treated with the anthelmintic fenbendazole to treat pinworms detected in other mice not involved in the study. As this was not part of the original experimental design, we subsequently compared pathological and functional outcomes of SCI in female C57BL/6 mice who received fenbendazole (150 ppm, 8 mg/kg body weight/day) for 4 weeks prior to moderate contusive SCI (50 kdyn force) as compared to mice on the same diet without added fenbendazole. The fenbendazole-treated mice exhibited improved locomotor function, determined using the Basso mouse scale, as well as improved tissue sparing following contusive SCI. Fenbendazole may exert protective effects through multiple possible mechanisms, one of which is inhibition of the proliferation of B lymphocytes, thereby reducing antibody responses. Autoantibodies produced following SCI contribute to the axon damage and locomotor deficits. Fenbendazole pretreatment reduced the injury-induced CD45R-positive B cell signal intensity and IgG immunoreactivity at the lesion epicenter 6 weeks after contusive SCI in mice, consistent with a possible effect on the immune response to the injury. Fenbendazole and related benzimadole antihelmintics are FDA approved, exhibit minimal toxicity, and represent a novel group of potential therapeutics targeting secondary mechanisms following SCI.

Targeting Cholesterol Crystal-Induced Inflammation for the Secondary Prevention of Cardiovascular Disease

Cholesterol crystals are present in nascent and advanced atherosclerotic plaque. Under some conditions, they may enlarge and cause direct plaque trauma or trigger an inflammatory cascade that promotes the growth and instability of atherosclerotic plaque. Therapies that reduce the risk of cholesterol crystal formation or prevent the associated inflammatory response have the potential to improve the clinical outcome of patients with cardiovascular disease. Statins have pleiotropic effects that can reduce the size of the free cholesterol pool contained within atherosclerotic plaques and prevent the formation of cholesterol crystals. Colchicine prevents crystal-induced inflammation by virtue of its ability to inhibit macrophage and neutrophil function. Both statins and colchicine have been demonstrated to reduce the risk of cardiovascular events in patients with stable coronary disease. The efficacy of statins and colchicine for cardiovascular prevention supports the hypothesis that crystal-induced inflammation plays an integral role in the progression and instability of coronary disease. Inhibition of cholesterol crystal-induced inflammation offers a promising new target for the secondary prevention of cardiovascular disease.

New therapies for gout

Gout prevalence is increasing, yet management remains suboptimal. Fortunately, new insights into gout biology are permitting the development of novel, potentially more effective strategies for both gouty inflammation and urate lowering. Colchicine, a drug long used for gout, has been recently approved (for the first time ever) by the FDA, based on a new, safer dosing regimen. The recently appreciated centrality of IL-1β in acute gouty inflammation has prompted studies of agents blocking the IL-1β receptor or soluble IL-1β signaling (canakinumab, rilonacept, anakinra). Novel approaches to urate lowering have led to mechanism-based therapies such as urate synthesis inhibitors (febuxostat is already FDA approved and BCX4208 is in development), URAT-1 inhibitors promoting renal uric acid excretion (lesinurad), and recombinant uricase to directly catabolize urate (pegloticase). These new treatments do not obviate the need for lifestyle and dietary management, another area in which significant scientific and clinical progress has recently been made.

Evaluation and treatment of gout as a chronic disease

Gout is a disease caused by deposition of monosodium urate crystals in tissues. One of the limitations for successful treatment of gout is to consider it as an intermittent disease rather than a chronic inflammatory disease which, if improperly treated, leads to chronic clinical manifestations. In addition, gout is linked to increased cardiovascular morbidity and mortality.Urate-lowering therapy comprises both nonpharmacologic and pharmacologic interventions, but most patients will need urate-lowering drugs to achieve target therapeutic serum urate levels. Reaching target serum urate levels is associated with improvement in clinical outcomes, including a reduction of acute inflammation episodes, resolution of tophi, and improvement in health-related quality of life perception.A number of urate-lowering drugs are available but a number of patients fail to achieve or maintain therapeutic serum urate levels and go on to develop refractory chronic gout. For such patients, efforts have been made to develop new treatments (e.g., febuxostat or pegloticase).This review intends to increase the awareness of gout as a chronic deposition disease, and show that efforts should be made to properly control serum urate levels in order to achieve complete disappearance of urate crystal deposition.