Risk of venous and arterial thromboembolism in patients with giant cell arteritis and/or polymyalgia rheumatica: A Veterans Health Administration population-based study in the United States

The platelet-mitochondria nexus in autoimmune and musculoskeletal diseases

Platelets are crucial for thrombosis and hemostasis. Importantly, they contain mitochondria that are responsible for energy generation and therefore vital for platelet survival and activation. Activated platelets can release mitochondria that may be free or encapsulated in platelet extracellular vesicles (EVs). Extruded mitochondria are a well-known source of mitochondrial DNA, and mitochondrial antigens that can be targeted by autoantibodies forming immune complexes (IC). Interaction of IC with the platelet cell surface FcγRIIA receptor results in platelet activation and release of platelet granule components. In this review, we summarize how platelets and mitochondria may contribute to the pathogenesis of different autoimmune and musculoskeletal diseases. Targeting key drivers of mitochondrial extrusion may ultimately lead to urgently needed targeted pharmacological interventions for treating inflammation and thrombotic diathesis, and halting organ damage in some of these rheumatological conditions.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Distinguishing laboratory characteristics in giant cell arteritis: a real-world retrospective cohort study

BACKGROUND

Untreated Giant Cell Arteritis (GCA) has the potential to cause serious complications such as vision loss. Appropriate initial assessment by General Practitioners, early treatment and specialist referral are therefore essential in reducing morbidity. However, lack of awareness around the range of presentations can lead to a delay in diagnosis.

OBJECTIVE

We aim to evaluate the discriminative diagnostic performance of laboratory characteristics associated with GCA in our population over a period of 18 months.

DISCUSSION

This is a real-world retrospective review of patients referred to ophthalmology services with concern for GCA. The pre-test probability of a patient referred with suspected GCA was 13.9% to have GCA, highlighting the need for specialist referrals to continue. White Cell Count (p = 0.01), Platelet Count (p = 0.02), Erythrocyte sedimentation rate (p = 0.004) and C-reactive protein (p = 0.002) were significantly different between GCA and non-GCA cases. Moreover, this study demonstrates that absolute neutrophil count (p = 0.02) can be a useful parameter in initial investigations for GCA.

Mitochondrial-mediated inflammation and platelet activation in giant cell arteritis

Markers of extracellular mitochondria are present in giant cell arteritis (GCA) patients. However, their role in promoting inflammation and platelet activation is no known. To investigate this, isolated mitochondria were opsonized with plasma from GCA patients or healthy individuals and incubated with peripheral blood mononuclear cells (PBMCs) or platelets and assessed for inflammatory cytokine production and platelet activation. Plasma from GCA patients promoted increased mitochondrial-mediated cytokine production by PBMCs as compared to healthy controls (p < 0.05). Mitochondria opsonized with plasma factors from patients with GCA induced higher platelet activation as compared to mitochondria opsonized with plasma factors from healthy individuals (p = 0.0015). Platelet levels of P-selectin were associated with disease activity in GCA (r = 0.34, p = 0.01). GCA patients have impaired ability to regulate the clearance of extracellular mitochondria, possibly contributing to excessive inflammation and platelet activation. Targeting key drivers of mitochondrial extrusion and/or their clearance could lead to new therapeutic interventions in GCA.

Neutrophil extracellular trap formation in anti-neutrophil cytoplasmic antibody-associated and large-vessel vasculitis

Levels of neutrophil extracellular traps (NETs) were measured in plasma of healthy controls (HC, n = 30) and patients with granulomatosis with polyangiitis (GPA, n = 123), microscopic polyangiitis (MPA, n = 61), Takayasu's arteritis (TAK, n = 58), and giant cell arteritis (GCA, n = 68), at times of remission or activity and correlated with levels of the platelet-derived thrombospondin-1 (TSP-1). Levels of NETs were elevated during active disease in patients with GPA (p < 0.0001), MPA (p = 0.0038), TAK (p < 0.0001), and GCA (p < 0.0001), and in remission for GPA, p < 0.0001, MPA, p = 0.005, TAK, p = 0.03, and GCA, p = 0.0009. All cohorts demonstrated impaired NET degradation. Patients with GPA (p = 0.0045) and MPA (p = 0.005) had anti-NET IgG antibodies. Patients with TAK had anti-histone antibodies (p < 0.01), correlating with presence of NETs. Levels of TSP-1 were increased in all patients with vasculitis, and associated with NET formation. NET formation is a common process in vasculitides. Targeting NET formation or degradation could be potential therapeutic approaches for vasculitides.

Cardiovascular risk in vasculitis

The present review summarizes the burden, risk factors, biomarkers of and therapeutic consideration for cardiovascular disease in systemic vasculitis. Ischemic heart disease (IHD) and stroke are intrinsic features of Kawasaki disease, Takayasu arteritis, Giant Cell Arteritis (GCA), and Behcet's disease. The risk of IHD and stroke is increased in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and cryoglobulinemic vasculitis. Behcet's disease could present with venous thromboembolism. The risk of venous thromboembolism is increased in AAV, polyarteritis nodosa, and GCA. The risk of cardiovascular events is greatest at or immediately after the diagnosis of AAV or GCA, therefore, controlling vasculitis disease activity is of utmost importance. Traditional as well as disease-related risk factors drive the heightened cardiovascular risk in vasculitis. Aspirin or statins reduce the risk of IHD or stroke in GCA or the risk of IHD in Kawasaki Disease. Venous thromboembolism in Behcet's disease should be treated with immunosuppressive therapy rather than with anticoagulation.

Venous Thromboembolism in the Inflammatory Rheumatic Diseases

Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a cardiovascular event whose risk is increased in most inflammatory rheumatic diseases (IRDs). Mechanisms that increase VTE risk include antiphospholipid antibodies (APLs), particularly anticardiolipin antibodies, anti-beta2glycoprotein I antibodies and lupus anticoagulant present together, and inflammation-mediated endothelial injury. Patients with IRDs should receive long-term anticoagulation drugs when the risk of VTE recurrence is high. In the light of recent warnings from regulatory agencies regarding heightened VTE risk with Janus kinase inhibitors, these drugs should be initiated only after a careful assessment of VTE risk in those with IRDs.

Predictive models for thromboembolic events in giant cell arteritis: A US veterans health administration population-based study

Giant cell arteritis (GCA) that affects older patients is an independent risk factor for thromboembolic events. The objective of this study was to identify predictive factors for thromboembolic events in patients with GCA and develop quantitative predictive tools (prognostic nomograms) for pulmonary embolism (PE) and deep venous thrombosis (DVT). A total of 13,029 patients with a GCA diagnosis were included in this retrospective study. We investigated potential predictors of PE and DVT using univariable and multivariable Cox regression models. Nomograms were then constructed based on the results of our Cox models. We also assessed the accuracy and predictive ability of our models by using calibration curves and cross-validation concordance index. Age, inpatient status at the time of initial diagnosis of GCA, number of admissions before diagnosis of GCA, and Charlson comorbidity index were each found to be independent predictive factors of thromboembolic events. Prognostic nomograms were then prepared based on these predictors with promising prognostic ability. The probability of developing thromboembolic events over an observation period of 5 years was estimated by with time-to-event analysis using the method of Kaplan and Meier, after stratifying patients based on predicted risk. The concordance index of the time-to-event analysis for both PE and DVT was &gt; 0.61, indicating a good predictive performance. The proposed nomograms, based on specific predictive factors, can accurately estimate the probability of developing PE or DVT among patients with GCA.

Concurrent baseline diagnosis of giant cell arteritis and polymyalgia rheumatica - A systematic review and meta-analysis

INTRODUCTION

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) can be concurrent diseases. We aimed to estimate the point-prevalence of concurrent GCA and PMR. Additionally, an incidence rate (IR) of GCA presenting after PMR diagnosis in patients was estimated.

METHODS

Two authors performed a systematic literature search, data extraction and risk of bias assessment independently. Studies assessing cohorts of patients presenting with both GCA and PMR were included. The outcomes were point-prevalence of concurrent GCA and PMR and IR for development of GCA after PMR diagnosis. A meta-analysis was performed to calculate a pooled prevalence of concurrent PMR and GCA.

RESULTS

We identified 29 studies investigating concurrent GCA and PMR. Only two studies applied imaging systematically to diagnose GCA and none to diagnose PMR. GCA presenting after PMR diagnosis was assessed in 12 studies but imaging was not applied systematically. The point-prevalence of concurrent GCA present at PMR diagnosis ranged from 6%-66%. The pooled estimate of the point-prevalence from the meta-analysis was 22%. The point-prevalence of PMR present at GCA diagnosis ranged from 16%-65%. The pooled estimate of the point-prevalence from the meta-analysis was 42%. The IR ranged between 2-78 cases of GCA presenting after PMR per 1000 person-years.

CONCLUSION

This review and meta-analysis support that concurrent GCA and PMR is frequently present at the time of diagnosis. Additionally, we present the current evidence of GCA presenting in patients after PMR diagnosis. These results emphasize the need for studies applying imaging modalities to diagnose GCA.

Patients' Baseline Characteristics, but Not Tocilizumab Exposure, Affect Severe Outcomes Onset in Giant Cell Arteritis: A Real-World Study

Objectives: Giant cell arteritis (GCA) is associated with severe outcomes such as infections and cardiovascular diseases. We describe here the impact of GCA patients’ characteristics and treatment exposure on the occurrence of severe outcomes. Methods: Data were collected retrospectively from real-world GCA patients with a minimum of six-months follow-up. We recorded severe outcomes and treatment exposure. In the survival analysis, we studied the predictive factors of severe outcomes occurrence, including treatment exposure (major glucocorticoids (GCs) exposure (>10 g of the cumulative dose) and tocilizumab (TCZ) exposure), as time-dependent covariates. Results: Among the 77 included patients, 26% were overweight (BMI ≥ 25 kg/m2). The mean cumulative dose of GCs was 7977 ± 4585 mg, 18 patients (23%) had a major GCs exposure, and 40 (52%) received TCZ. Over the 48-month mean follow-up period, 114 severe outcomes occurred in 77% of the patients: infections—29%, cardiovascular diseases—18%, hypertension—15%, fractural osteoporosis—8%, and deaths—6%. Baseline diabetes and overweight were predictive factors of severe outcomes onset (HR, 2.41 [1.05−5.55], p = 0.039; HR, 2.08 [1.14−3.81], p = 0.018, respectively) independently of age, sex, hypertension, and treatment exposure. Conclusion: Diabetic and overweight GCA patients constitute an at-risk group requiring tailored treatment, including vaccination. The effect of TCZ exposure on the reduction of severe outcomes was not proved here.