Paracrine signalling by cardiac calcitonin controls atrial fibrogenesis and arrhythmia.

Atrial fibrillation, the most common cardiac arrhythmia, is an important contributor to mortality and morbidity, and particularly to the risk of stroke in humans1. Atrial-tissue fibrosis is a central pathophysiological feature of atrial fibrillation that also hampers its treatment; the underlying molecular mechanisms are poorly understood and warrant investigation given the inadequacy of present therapies2. Here we show that calcitonin, a hormone product of the thyroid gland involved in bone metabolism3, is also produced by atrial cardiomyocytes in substantial quantities and acts as a paracrine signal that affects neighbouring collagen-producing fibroblasts to control their proliferation and secretion of extracellular matrix proteins. Global disruption of calcitonin receptor signalling in mice causes atrial fibrosis and increases susceptibility to atrial fibrillation. In mice in which liver kinase B1 is knocked down specifically in the atria, atrial-specific knockdown of calcitonin promotes atrial fibrosis and increases and prolongs spontaneous episodes of atrial fibrillation, whereas atrial-specific overexpression of calcitonin prevents both atrial fibrosis and fibrillation. Human patients with persistent atrial fibrillation show sixfold lower levels of myocardial calcitonin compared to control individuals with normal heart rhythm, with loss of calcitonin receptors in the fibroblast membrane. Although transcriptome analysis of human atrial fibroblasts reveals little change after exposure to calcitonin, proteomic analysis shows extensive alterations in extracellular matrix proteins and pathways related to fibrogenesis, infection and immune responses, and transcriptional regulation. Strategies to restore disrupted myocardial calcitonin signalling thus may offer therapeutic avenues for patients with atrial fibrillation.

Repurposing Colchicine for Heart Disease.

Colchicine is one of the most ancient medications still prescribed. It is extracted from the Colchicum autumnale plant and is routinely used because of its broad anti-inflammatory properties to treat gout and familial Mediterranean fever. Colchicine has shown efficacy in various clinical settings in which inflammation is a key component, and it has become first-line therapy for acute and recurrent pericarditis. Two landmark clinical trials have recently shown that colchicine significantly improves cardiovascular outcomes on background statin and antiplatelet therapy in patients with coronary artery disease, supporting its role for the prevention of atherothrombotic events. Favorable results have also emerged in atrial fibrillation. We herein briefly review the most recent data related to the multiple cardiovascular conditions for which colchicine has been successfully repurposed.

New-onset atrial fibrillation and chronic coronary syndrome in the CLARIFY registry.

BACKGROUND AND AIMS: Data on new-onset atrial fibrillation (NOAF) in patients with chronic coronary syndromes (CCS) are scarce. This study aims to describe the incidence, predictors, and impact on cardiovascular (CV) outcomes of NOAF in CCS patients. METHODS: Data from the international (45 countries) CLARIFY registry (prospeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease) were used. Among 29 001 CCS outpatients without previously reported AF at baseline, patients with at least one episode of AF/flutter diagnosed during 5-year follow-up were compared with patients in sinus rhythm throughout the study. RESULTS: The incidence rate of NOAF was 1.12 [95% confidence interval (CI) 1.06-1.18] per 100 patient-years (cumulative incidence at 5 years: 5.0%). Independent predictors of NOAF were increasing age, increasing body mass index, low estimated glomerular filtration rate, Caucasian ethnicity, alcohol intake, and low left ventricular ejection fraction, while high triglycerides were associated with lower incidence. New-onset atrial fibrillation was associated with a substantial increase in the risk of adverse outcomes, with adjusted hazard ratios of 2.01 (95% CI 1.61-2.52) for the composite of CV death, non-fatal myocardial infarction, or non-fatal stroke, 2.61 (95% CI 2.04-3.34) for CV death, 1.64 (95% CI 1.07-2.50) for non-fatal myocardial infarction, 2.27 (95% CI 1.85-2.78) for all-cause death, 8.44 (95% CI 7.05-10.10) for hospitalization for heart failure, and 4.46 (95% CI 2.85-6.99) for major bleeding. CONCLUSIONS: Among CCS patients, NOAF is common and is strongly associated with worse outcomes. Whether more intensive preventive measures and more systematic screening for AF would improve prognosis in this population deserves further investigation.

Chronic coronary syndromes without standard modifiable cardiovascular risk factors and outcomes: the CLARIFY registry.

BACKGROUND AND AIMS: It has been reported that patients without standard modifiable cardiovascular (CV) risk factors (SMuRFs-diabetes, dyslipidaemia, hypertension, and smoking) presenting with first myocardial infarction (MI), especially women, have a higher in-hospital mortality than patients with risk factors, and possibly a lower long-term risk provided they survive the post-infarct period. This study aims to explore the long-term outcomes of SMuRF-less patients with stable coronary artery disease (CAD). METHODS: CLARIFY is an observational cohort of 32 703 outpatients with stable CAD enrolled between 2009 and 2010 in 45 countries. The baseline characteristics and clinical outcomes of patients with and without SMuRFs were compared. The primary outcome was a composite of 5-year CV death or non-fatal MI. Secondary outcomes were 5-year all-cause mortality and major adverse cardiovascular events (MACE-CV death, non-fatal MI, or non-fatal stroke). RESULTS: Among 22 132 patients with complete risk factor and outcome information, 977 (4.4%) were SMuRF-less. Age, sex, and time since CAD diagnosis were similar across groups. SMuRF-less patients had a lower 5-year rate of CV death or non-fatal MI (5.43% [95% CI 4.08-7.19] vs. 7.68% [95% CI 7.30-8.08], P = 0.012), all-cause mortality, and MACE. Similar results were found after adjustments. Clinical event rates increased steadily with the number of SMuRFs. The benefit of SMuRF-less status was particularly pronounced in women. CONCLUSIONS: SMuRF-less patients with stable CAD have a substantial but significantly lower 5-year rate of CV death or non-fatal MI than patients with risk factors. The risk of CV outcomes increases steadily with the number of risk factors.

Prediction of incident atrial fibrillation using deep learning, clinical models and polygenic scores.

BACKGROUND AND AIMS: Deep learning applied to electrocardiograms (ECG-AI) is an emerging approach for predicting atrial fibrillation or flutter (AF). This study introduces an ECG-AI model developed and tested at a tertiary cardiac centre, comparing its performance with clinical and AF polygenic scores (PGS). METHODS: ECG in sinus rhythm from the Montreal Heart Institute were analysed, excluding those from patients with preexisting AF. The primary outcome was incident AF at 5 years. An ECG-AI model was developed by splitting patients into non-overlapping datasets: 70% for training, 10% for validation, and 20% for testing. Performance of ECG-AI, clinical models and PGS was assessed in the test dataset. The ECG-AI model was externally validated in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) hospital dataset. RESULTS: A total of 669,782 ECGs from 145,323 patients were included. Mean age was 61±15 years, and 58% were male. The primary outcome was observed in 15% of patients and the ECG-AI model showed an area under the receiver operating characteristic curve (AUC) of 0.78. In time-to-event analysis including the first ECG, ECG-AI inference of high risk identified 26% of the population with a 4.3-fold increased risk of incident AF (95% confidence interval 4.02-4.57). In a subgroup analysis of 2,301 patients, ECG-AI outperformed CHARGE-AF (AUC=0.62) and PGS (AUC=0.59). Adding PGS and CHARGE-AF to ECG-AI improved goodness-of-fit (likelihood ratio test p<0.001), with minimal changes to the AUC (0.76-0.77). In the external validation cohort (mean age 59±18 years, 47% male, median follow-up 1.1 year) ECG-AI model performance= remained consistent (AUC=0.77). CONCLUSIONS: ECG-AI provides an accurate tool to predict new-onset AF in a tertiary cardiac centre, surpassing clinical and polygenic scores.

Study of effect modifiers of genetically predicted CETP reduction.

Genetic variants in drug targets can be used to predict the long-term, on-target effect of drugs. Here, we extend this principle to assess how sex and body mass index may modify the effect of genetically predicted lower CETP levels on biomarkers and cardiovascular outcomes. We found sex and body mass index (BMI) to be modifiers of the association between genetically predicted lower CETP and lipid biomarkers in UK Biobank participants. Female sex and lower BMI were associated with higher high-density lipoprotein cholesterol and lower low-density lipoprotein cholesterol for the same genetically predicted reduction in CETP concentration. We found that sex also modulated the effect of genetically lower CETP on cholesterol efflux capacity in samples from the Montreal Heart Institute Biobank. However, these modifying effects did not extend to sex differences in cardiovascular outcomes in our data. Our results provide insight into the clinical effects of CETP inhibitors in the presence of effect modification based on genetic data. The approach can support precision medicine applications and help assess the external validity of clinical trials.

Autoimmune Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) is by far the most common cardiac arrhythmia. In about 3% of individuals, AF develops as a primary disorder without any identifiable trigger (idiopathic or historically termed lone AF). In line with the emerging field of autoantibody-related cardiac arrhythmias, the objective of this study was to explore whether autoantibodies targeting cardiac ion channels can underlie unexplained AF. METHODS: Peptide microarray was used to screen patient samples for autoantibodies. We compared patients with unexplained AF (n=37 pre-existent AF; n=14 incident AF on follow-up) to age- and sex-matched controls (n=37). Electrophysiological properties of the identified autoantibody were then tested in vitro with the patch clamp technique and in vivo with an experimental mouse model of immunization. RESULTS: A common autoantibody response against Kir3.4 protein was detected in patients with AF and even before the development of clinically apparent AF. Kir3.4 protein forms a heterotetramer that underlies the cardiac acetylcholine-activated inwardly rectifying K+ current, IKACh. Functional studies on human induced pluripotent stem cell-derived atrial cardiomyocytes showed that anti-Kir3.4 IgG purified from patients with AF shortened action potentials and enhanced the constitutive form of IKACh, both key mediators of AF. To establish a causal relationship, we developed a mouse model of Kir3.4 autoimmunity. Electrophysiological study in Kir3.4-immunized mice showed that Kir3.4 autoantibodies significantly reduced atrial effective refractory period and predisposed animals to a 2.8-fold increased susceptibility to AF. CONCLUSIONS: To our knowledge, this is the first report of an autoimmune pathogenesis of AF with direct evidence of Kir3.4 autoantibody-mediated AF.

Childhood Maltreatment and Leukocyte Telomere Length: Cardiac Vagal Activity Influences the Relation in Older Adults.

OBJECTIVE: Childhood maltreatment is associated with shorter leukocyte telomere length (LTL). However, the influence of cardiac vagal control on this relation is unknown. We examined whether cardiac vagal control at rest and in response to stress moderates or cross-sectionally mediates the relationship between childhood maltreatment and LTL. METHODS: Participants were 1179 men and women (aged 65 [7.2] years) suffering from coronary artery disease or non-cardiovascular chronic disease. They completed a childhood maltreatment questionnaire and underwent a stress protocol while electrocardiogram was monitored. High-frequency heart rate variability (HF-HRV) measures were obtained at rest, during stress, and after stress in absolute and normalized units (nu). LTL was measured using quantitative polymerase chain reaction. Mediation and moderation analyses were performed. RESULT: HF-HRV and HF-HRV in normalized units (HFnu) measures did not mediate the childhood maltreatment-LTL relation. However, baseline HFnu ( p = .027) and HFnu reactivity ( p = .051) moderated the relation. Specifically, maltreatment was associated with significantly lower LTL among those with baseline HFnu at ( b = -0.059, p = .003) or below the mean ( b = -0.103, p < .001), but not among those with higher baseline HFnu. It was also associated with significantly lower LTL among participants who showed either blunted ( b = -0.058, p = .004) or increased HFnu ( b = -0.099, p = .001) responses to stress but not in those with large decreases in HFnu. CONCLUSIONS: Childhood maltreatment was associated with lower LTL in those who showed a distinct cardiac vagal profile at baseline and in response to stress. The mechanisms and implications remain to be determined.

Mitochondrial functions and fatty acid profiles in fish heart: an insight into physiological limitations linked to thermal tolerance and age.

Heart failure is among the first major consequences of heat stress in aquatic ectotherms. Mitochondria produce most of the ATP used by the heart and represent almost half of the volume in cardiac cells. It has therefore been hypothesized that mitochondrial dysfunction may be a major cause of heart failure associated with heat stress. The present study aims to investigate if CTmax is linked to the thermal sensitivity of cardiac mitochondria in the three-spined stickleback (Gasterosteus aculeatus), and if it is influenced by heart fatty acid composition and age. To do so, we measured the CTmax of 30 fish. The cardiac mitochondrial oxygen consumption was measured by high resolution respirometry at three temperatures and heart lipid profiles were obtained by gas chromatography (GC) coupled with a flame ionization detector (FID). Fish age was estimated via otolith readings. Fatty acid profiles showed no correlation with CTmax, but EPA levels were higher in older individuals. Mitochondrial respiration was measured in 35 fish using high-resolution respirometry. It was strongly affected by temperature and showed a drastic drop in OXPHOS respiration fed by complex I and complex I+complex II, while uncoupled respiration plateaued at CTmax temperature. Our results suggest that complex I is an important modulator of the impact of temperature on mitochondrial respiration at high temperatures but is not the main limiting factor in physiological conditions (maximal OXPHOS). Mitochondrial respiration was also affected by fish age, showing a general decrease in older individuals.

Combination of computed tomography angiography with coronary artery calcium score for improved diagnosis of coronary artery disease: a collaborative meta-analysis of stable chest pain patients referred for invasive coronary angiography.

OBJECTIVES: Coronary computed tomography angiography (CCTA) has higher diagnostic accuracy than coronary artery calcium (CAC) score for detecting obstructive coronary artery disease (CAD) in patients with stable chest pain, while the added diagnostic value of combining CCTA with CAC is unknown. We investigated whether combining coronary CCTA with CAC score can improve the diagnosis of obstructive CAD compared with CCTA alone. METHODS: A total of 2315 patients (858 women, 37%) aged 61.1 ± 10.2 from 29 original studies were included to build two CAD prediction models based on either CCTA alone or CCTA combined with the CAC score. CAD was defined as at least 50% coronary diameter stenosis on invasive coronary angiography. Models were built by using generalized linear mixed-effects models with a random intercept set for the original study. The two CAD prediction models were compared by the likelihood ratio test, while their diagnostic performance was compared using the area under the receiver-operating-characteristic curve (AUC). Net benefit (benefit of true positive versus harm of false positive) was assessed by decision curve analysis. RESULTS: CAD prevalence was 43.5% (1007/2315). Combining CCTA with CAC improved CAD diagnosis compared with CCTA alone (AUC: 87% [95% CI: 86 to 89%] vs. 80% [95% CI: 78 to 82%]; p < 0.001), likelihood ratio test 236.3, df: 1, p < 0.001, showing a higher net benefit across almost all threshold probabilities. CONCLUSION: Adding the CAC score to CCTA findings in patients with stable chest pain improves the diagnostic performance in detecting CAD and the net benefit compared with CCTA alone. CLINICAL RELEVANCE STATEMENT: CAC scoring CT performed before coronary CTA and included in the diagnostic model can improve obstructive CAD diagnosis, especially when CCTA is non-diagnostic. KEY POINTS: • The combination of coronary artery calcium with coronary computed tomography angiography showed significantly higher AUC (87%, 95% confidence interval [CI]: 86 to 89%) for diagnosis of coronary artery disease compared to coronary computed tomography angiography alone (80%, 95% CI: 78 to 82%, p < 0.001). • Diagnostic improvement was mostly seen in patients with non-diagnostic C. • The improvement in diagnostic performance and the net benefit was consistent across age groups, chest pain types, and genders.

Inflammation in heart failure: pathophysiology and therapeutic strategies.

A role for inflammation in the development and progression of heart failure (HF) has been proposed for decades. Multiple studies have demonstrated the potential involvement of several groups of cytokines and chemokines in acute and chronic HF, though targeting these pathways in early therapeutic trials have produced mixed results. These studies served to highlight the complexity and nuances of how pro-inflammatory pathways contribute to the pathogenesis of HF. More recent investigations have highlighted how inflammation may play distinct roles based on HF syndrome phenotypes, findings that may guide the development of novel therapies. In this review, we propose a contemporary update on the role of inflammation mediated by the innate and adaptive immune systems with HF, highlighting differences that exist across the ejection fraction spectrum. This will specifically be looked at through the lens of established and novel biomarkers of inflammation. Subsequently, we review how improvements in inflammatory pathways may mediate clinical benefits of existing guideline-directed medical therapies for HF, as well as future therapies in the pipeline targeting HF and inflammation.

Atrial cardiomyocytes contribute to the inflammatory status associated with atrial fibrillation in right heart disease.

AIMS: Right heart disease (RHD), characterized by right ventricular (RV) and atrial (RA) hypertrophy, and cardiomyocytes' (CM) dysfunctions have been described to be associated with the incidence of atrial fibrillation (AF). Right heart disease and AF have in common, an inflammatory status, but the mechanisms relating RHD, inflammation, and AF remain unclear. We hypothesized that right heart disease generates electrophysiological and morphological remodelling affecting the CM, leading to atrial inflammation and increased AF susceptibility. METHODS AND RESULTS: Pulmonary artery banding (PAB) was surgically performed (except for sham) on male Wistar rats (225-275 g) to provoke an RHD. Twenty-one days (D21) post-surgery, all rats underwent echocardiography and electrophysiological studies (EPS). Optical mapping was performed in situ, on Langendorff-perfused hearts. The contractility of freshly isolated CM was evaluated and recorded during 1 Hz pacing in vitro. Histological analyses were performed on formalin-fixed RA to assess myocardial fibrosis, connexin-43 levels, and CM morphology. Right atrial levels of selected genes and proteins were obtained by qPCR and Western blot, respectively. Pulmonary artery banding induced severe RHD identified by RV and RA hypertrophy. Pulmonary artery banding rats were significantly more susceptible to AF than sham. Compared to sham RA CM from PAB rats were significantly elongated and hypercontractile. Right atrial CM from PAB animals showed significant augmentation of mRNA and protein levels of pro-inflammatory interleukin (IL)-6 and IL1ß. Sarcoplasmic-endoplasmic reticulum Ca2+-ATPase-2a (SERCA2a) and junctophilin-2 were decreased in RA CM from PAB compared to sham rats. CONCLUSIONS: Right heart disease-induced arrhythmogenicity may occur due to dysfunctional SERCA2a and inflammatory signalling generated from injured RA CM, which leads to an increased risk of AF.

ExPheWas: a platform for cis-Mendelian randomization and gene-based association scans.

Establishing the relationship between protein-coding genes and phenotypes has the potential to inform on the molecular etiology of diseases. Here, we describe ExPheWas (exphewas.ca), a gene-based phenome-wide association study browser and platform that enables the conduct of gene-based Mendelian randomization. The ExPheWas data repository includes sex-stratified and sex-combined gene-based association results from 26 616 genes with 1746 phenotypes measured in up to 413 133 individuals from the UK Biobank. Interactive visualizations are provided through a browser to facilitate data exploration supported by false discovery rate control, and it includes tools for enrichment analysis. The interactive Mendelian randomization module in ExPheWas allows the estimation of causal effects of a genetically predicted exposure on an outcome by using genetic variation in a single gene as the instrumental variable.

Distinct spatial contributions of amyloid pathology and cerebral small vessel disease to hippocampal morphology.

INTRODUCTION: Cerebral small vessel disease (SVD) and amyloid beta (Aß) pathology frequently co-exist. The impact of concurrent pathology on the pattern of hippocampal atrophy, a key substrate of memory impacted early and extensively in dementia, remains poorly understood. METHODS: In a unique cohort of mixed Alzheimer's disease and moderate-severe SVD, we examined whether total and regional neuroimaging measures of SVD, white matter hyperintensities (WMH), and Aß, as assessed by 18F-AV45 positron emission tomography, exert additive or synergistic effects on hippocampal volume and shape. RESULTS: Frontal WMH, occipital WMH, and Aß were independently associated with smaller hippocampal volume. Frontal WMH had a spatially distinct impact on hippocampal shape relative to Aß. In contrast, hippocampal shape alterations associated with occipital WMH spatially overlapped with Aß-vulnerable subregions. DISCUSSION: Hippocampal degeneration is differentially sensitive to SVD and Aß pathology. The pattern of hippocampal atrophy could serve as a disease-specific biomarker, and thus guide clinical diagnosis and individualized treatment strategies for mixed dementia.

Low-Density Neutrophils Contribute to Subclinical Inflammation in Patients with Type 2 Diabetes.

Type 2 diabetes (T2D) is characterized by low-grade inflammation. Low-density neutrophils (LDNs) represent normally less than 2% of total neutrophils but increase in multiple pathologies, releasing inflammatory cytokines and neutrophil extracellular traps (NETs). We assessed the count and role of high-density neutrophils (HDNs), LDNs, and NET-related activities in patients with T2D. HDNs and LDNs were purified by fluorescence-activated cell sorting (FACS) and counted by flow cytometry. Circulating inflammatory and NETs biomarkers were measured by ELISA (Enzyme Linked Immunosorbent Assay). NET formation was quantified by confocal microscopy. Neutrophil adhesion onto a human extracellular matrix (hECM) was assessed by optical microscopy. We recruited 22 healthy volunteers (HVs) and 18 patients with T2D. LDN counts in patients with diabetes were significantly higher (160%), along with circulating NETs biomarkers (citrullinated H3 histone (H3Cit), myeloperoxidase (MPO), and MPO-DNA (137%, 175%, and 69%, respectively) versus HV. Circulating interleukins (IL-6 and IL-8) and C-Reactive Protein (CRP) were significantly increased by 117%, 171%, and 79%, respectively, in patients compared to HVs. Isolated LDNs from patients expressed more H3Cit, MPO, and NETs, formed more NETs, and adhered more on hECM compared to LDNs from HVs. Patients with T2D present higher levels of circulating LDN- and NET-related biomarkers and associated pro-inflammatory activities.

Dalcetrapib and anacetrapib increase apolipoprotein E-containing HDL in rabbits and humans.

The large HDL particles generated by administration of cholesteryl ester transfer protein inhibitors (CETPi) remain poorly characterized, despite their potential importance in the routing of cholesterol to the liver for excretion, which is the last step of the reverse cholesterol transport. Thus, the effects of the CETPi dalcetrapib and anacetrapib on HDL particle composition were studied in rabbits and humans. The association of rabbit HDL to the LDL receptor (LDLr) in vitro was also evaluated. New Zealand White rabbits receiving atorvastatin were treated with dalcetrapib or anacetrapib. A subset of patients from the dal-PLAQUE-2 study treated with dalcetrapib or placebo were also studied. In rabbits, dalcetrapib and anacetrapib increased HDL-C by more than 58% (P < 0.01) and in turn raised large apo E-containing HDL by 66% (P < 0.001) and 59% (P < 0.01), respectively. Additionally, HDL from CETPi-treated rabbits competed with human LDL for binding to the LDLr on HepG2 cells more than control HDL (P < 0.01). In humans, dalcetrapib increased concentrations of large HDL particles (+69%, P < 0.001) and apo B-depleted plasma apo E (+24%, P < 0.001), leading to the formation of apo E-containing HDL (+47%, P < 0.001) devoid of apo A-I. Overall, in rabbits and humans, CETPi increased large apo E-containing HDL particle concentration, which can interact with hepatic LDLr. The catabolism of these particles may depend on an adequate level of LDLr to contribute to reverse cholesterol transport.

Colchicine in Cardiovascular Disease: In-Depth Review.

Inflammation plays a prominent role in the development of atherosclerosis and other cardiovascular diseases, and anti-inflammatory agents may improve cardiovascular outcomes. For years, colchicine has been used as a safe and well-tolerated agent in diseases such as gout and familial Mediterranean fever. The widely available therapeutic has several anti-inflammatory effects, however, that have proven effective in a broad spectrum of cardiovascular diseases as well. It is considered standard-of-care therapy for pericarditis, and several clinical trials have evaluated its role in postoperative and postablation atrial fibrillation, postpericardiotomy syndrome, coronary artery disease, percutaneous coronary interventions, and cerebrovascular disease. We aim to summarize colchicine's pharmacodynamics and the mechanism behind its anti-inflammatory effect, outline thus far accumulated evidence on treatment with colchicine in cardiovascular disease, and present ongoing randomized clinical trials. We also emphasize real-world clinical implications that should be considered on the basis of the merits and limitations of completed trials. Altogether, colchicine's simplicity, low cost, and effectiveness may provide an important addition to other standard cardiovascular therapies. Ongoing studies will address complementary questions pertaining to the use of low-dose colchicine for the treatment of cardiovascular disease.

Effects of Randomized Treatment With Icosapent Ethyl and a Mineral Oil Comparator on Interleukin-1ß, Interleukin-6, C-Reactive Protein, Oxidized Low-Density Lipoprotein Cholesterol, Homocysteine, Lipoprotein(a), and Lipoprotein-Associated Phospholipase A2: A REDUCE-IT Biomarker Substudy.

BACKGROUND: REDUCE-IT (Reduction of Cardiovascular Events With Icosapent Ethyl-Intervention Trial) reported a 25% relative risk reduction in major adverse cardiovascular events with use of icosapent ethyl compared with pharmaceutical grade mineral oil. The mechanisms underlying this benefit remain uncertain. We explored whether treatment allocation in REDUCE-IT might affect a series of biomarkers in pathways known to associate with atherosclerosis risk. METHODS: Serum levels of interleukin-1ß, interleukin-6, high-sensitivity C-reactive protein, oxidized low-density lipoprotein cholesterol, homocysteine, lipoprotein(a), and lipoprotein-associated phospholipase A2 (Lp-PLA2) were measured at baseline, at 12 months, at 24 months, and at the end-of-study visit among REDUCE-IT participants with triglyceride levels ≥135 mg/dL and <500 mg/dL who were randomly allocated to treatment with either 4 grams daily of icosapent ethyl or mineral oil used as a comparator. RESULTS: At baseline, median levels of each biomarker were similar in the 2 treatment groups. The levels of biomarkers associated with atherosclerosis increased over time among those allocated to mineral oil treatment; in this group at 12 months, the median percent increases from baseline were 1.5% for homocysteine, 2.2% for lipoprotein(a), 10.9% for oxidized low-density lipoprotein cholesterol, 16.2% for interleukin-6, 18.5% for lipoprotein-associated phospholipase A2, 21.9% for high-sensitivity C-reactive protein, and 28.9% for interleukin-1ß (all P values <0.001), with similar changes at 24 months. In the icosapent ethyl group, there were minimal changes in these biomarkers at 12 and 24 months. As such, at study conclusion, between-group treatment differences largely reflected increases in the mineral oil group with median percent differences of 2.4% for lipoprotein(a), 3.0% for homocysteine, 4.2% for oxidized low-density lipoprotein cholesterol, 19.8% for interleukin-6, 26.2% for Lp-PLA2, 38.5% for high-sensitivity C-reactive protein, and 48.7% for interleukin-1ß (all P values ≤0.007). These data are consistent with previous REDUCE-IT results in which the median percent change for low-density lipoprotein cholesterol at 12 months was -1.2% among those allocated to icosapent ethyl and 10.9% among those allocated to the mineral oil comparator. CONCLUSIONS: Among participants in REDUCE-IT, allocation to icosapent ethyl had minimal effects on a series of biomarkers associated with atherosclerotic disease, whereas levels increased among those allocated to mineral oil. The effect of these findings on interpretation of the overall risk reductions in clinical events observed within REDUCE-IT is uncertain. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01492361.

Lipoprotein(a) Reduction in Persons with Cardiovascular Disease.

BACKGROUND: Lipoprotein(a) levels are genetically determined and, when elevated, are a risk factor for cardiovascular disease and aortic stenosis. There are no approved pharmacologic therapies to lower lipoprotein(a) levels. METHODS: We conducted a randomized, double-blind, placebo-controlled, dose-ranging trial involving 286 patients with established cardiovascular disease and screening lipoprotein(a) levels of at least 60 mg per deciliter (150 nmol per liter). Patients received the hepatocyte-directed antisense oligonucleotide AKCEA-APO(a)-LRx, referred to here as APO(a)-LRx (20, 40, or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week), or saline placebo subcutaneously for 6 to 12 months. The lipoprotein(a) level was measured with an isoform-independent assay. The primary end point was the percent change in lipoprotein(a) level from baseline to month 6 of exposure (week 25 in the groups that received monthly doses and week 27 in the groups that received more frequent doses). RESULTS: The median baseline lipoprotein(a) levels in the six groups ranged from 204.5 to 246.6 nmol per liter. Administration of APO(a)-LRx resulted in dose-dependent decreases in lipoprotein(a) levels, with mean percent decreases of 35% at a dose of 20 mg every 4 weeks, 56% at 40 mg every 4 weeks, 58% at 20 mg every 2 weeks, 72% at 60 mg every 4 weeks, and 80% at 20 mg every week, as compared with 6% with placebo (P values for the comparison with placebo ranged from 0.003 to <0.001). There were no significant differences between any APO(a)-LRx dose and placebo with respect to platelet counts, liver and renal measures, or influenza-like symptoms. The most common adverse events were injection-site reactions. CONCLUSIONS: APO(a)-LRx reduced lipoprotein(a) levels in a dose-dependent manner in patients who had elevated lipoprotein(a) levels and established cardiovascular disease. (Funded by Akcea Therapeutics; ClinicalTrials.gov number, NCT03070782.).

Childhood maltreatment and leukocyte telomere length in men and women with chronic illness: an evaluation of moderating and mediating influences.

BACKGROUND: Childhood maltreatment can result in lifelong psychological and physical sequelae, including coronary artery disease (CAD). Mechanisms leading to increased risk of illness may involve emotional dysregulation and shortened leukocyte telomere length (LTL). METHODS: To evaluate whether (1) childhood maltreatment is associated with shorter LTL among older adults with CAD or other chronic illnesses; (2) sex and/or CAD status influence these results; and (3) symptoms of anxiety, depression, and stress moderate or mediate the association between childhood maltreatment and LTL, men and women (N = 1247; aged 65 ± 7.2 years) with and without CAD completed validated questionnaires on childhood maltreatment, symptoms of depression, anxiety, and perceived stress. LTL was measured using quantitative polymerase chain reaction. Analyses included bivariate correlations, hierarchical regressions, and moderation/mediation analyses, controlling for sociodemographic and lifestyle variables. RESULTS: Childhood maltreatment was associated with significantly shorter LTL (r = -0.059, p = 0.038, b = -0.016, p = 0.005). This relation was not moderated by depression, anxiety, nor perceived stress, though there was mitigated evidence for absence of a maltreatment-LTL relation in men with CAD. Stress perception (but not anxiety or depression) partially mediated the relation between childhood maltreatment and LTL [Indirect effect, b = -0.0041, s.e. = 0.002, 95% CI (-0.0085 to -0.0002)]. CONCLUSIONS: Childhood maltreatment was associated with accelerated biological aging independently of patient characteristics. Emotional dysregulation resulting in chronic stress may contribute to this process. Whether stress management or other interventions may help prevent or slow premature aging in those who have suffered maltreatment requires study.