Association between corrected QT interval and inflammatory cytokines in rheumatoid arthritis

Exploring causal correlations between inflammatory cytokines and knee osteoarthritis: a two-sample Mendelian randomization

Objectives

Knee osteoarthritis (KOA) and certain inflammatory cytokines (such as interleukin 1 [IL-1] and tumor necrosis factor alpha [TNF-a]) are related; however, the causal relationship remains unclear. Here, we aimed to assess the causal relationship between 41 inflammatory cytokines and KOA using Mendelian randomization (MR).

Methods

Two-sample bidirectional MR was performed using genetic variation data for 41 inflammatory cytokines that were obtained from European Genome-Wide Association Study (GWAS) data (n=8293). KOA-related genetic association data were also obtained from European GWAS data (n=40,3124). Inverse variance weighting (IVW), MR, heterogeneity, sensitivity, and multiple validation analyses were performed.

Results

Granulocyte colony-stimulating factor (G-CSF) or colony-stimulating factor 3 (CSF-3) levels were negatively associated with the risk of developing KOA (OR: 0.93, 95%CI:0.89-0.99, P=0.015). Additionally, macrophage inflammatory protein-1 alpha (MIP-1A/CCL3) was a consequence of KOA (OR: 0.72, 95%CI:0.54-0.97, P=0.032). No causal relationship was evident between other inflammatory cytokines and KOA development.

Conclusion

This study suggests that certain inflammatory cytokines may be associated with KOA etiology. G-CSF exerts an upstream influence on KOA development, whereas MIP-1A (CCL-3) acts as a downstream factor.

Elevated Interleukin-6 Levels Are Associated With an Increased Risk of QTc Interval Prolongation in a Large Cohort of US Veterans

BACKGROUND

Although accumulating data indicate that IL-6 (interleukin-6) can promote heart rate-corrected QT interval (QTc) prolongation via direct and indirect effects on cardiac electrophysiology, current evidence comes from basic investigations and small clinical studies only. Therefore, IL-6 is still largely ignored in the clinical management of long-QT syndrome and related arrhythmias. The aim of this study was to estimate the risk of QTc prolongation associated with elevated IL-6 levels in a large population of unselected subjects.

METHODS AND RESULTS

An observational study using the Veterans Affairs Informatics and Computing Infrastructure was performed. Participants were US veterans who had an ECG and were tested for IL-6. Descriptive statistics and univariate and multivariate regression analyses were performed to study the relationship between IL-6 and QTc prolongation risk. Study population comprised 1085 individuals, 306 showing normal (<5 pg/mL), 376 moderately high (5-25 pg/mL), and 403 high (>25 pg/mL) IL-6 levels. Subjects with elevated IL-6 showed a concentration-dependent increase in the prevalence of QTc prolongation, and those presenting with QTc prolongation exhibited higher circulating IL-6 levels. Stepwise multivariate regression analyses demonstrated that increased IL-6 level was significantly associated with a risk of QTc prolongation up to 2 times the odds of the reference category of QTc (e.g. QTc >470 ms men/480 ms women ms: odds ratio, 2.28 [95% CI, 1.12-4.50] for IL-6 >25 pg/mL) regardless of the underlying cause. Specifically, the mean QTc increase observed in the presence of elevated IL-6 was quantitatively comparable (IL-6 >25 pg/mL:+6.7 ms) to that of major recognized QT-prolonging risk factors, such as hypokalemia and history of myocardial infarction.

CONCLUSIONS

Our data provide evidence that a high circulating IL-6 level is a robust risk factor for QTc prolongation in a large cohort of US veterans, supporting a potentially important arrhythmogenic role for this cytokine in the general population.

Changes in the expression of drug-metabolising enzymes and drug transporters in mice with collagen antibody-induced arthritis

1. We investigated the changes in the expression of drug-metabolising enzymes and drug transporters in the liver, small intestine and kidney of mice with collagen antibody-induced arthritis (CAIA) to determine whether changes in these expressions affect pharmacokinetics of drugs in patients with rheumatoid arthritis.2. mRNA expression levels of cytochrome P450 (Cyp) 2b10, Cyp2c29 and Cyp3a11 were observed to be lower in the liver and small intestine of CAIA mice than in control mice. Compared with control mice, mRNA expression levels of multidrug resistance 1 b, peptide transporter 2 and organic anion transporter (Oat) 2 were high in the liver of CAIA mice. Changes in these expression levels were different among organs. However, elevated expression of Oat2 mRNA was not associated with an increase in protein expression and transport activity evaluated using [³H]cGMP as a substrate.3. These results suggest that arthritis can change the expression of pharmacokinetics-related genes, but the changes may not necessarily be linked to the pharmacokinetics in patients with rheumatoid arthritis. On the other hand, we found Oat2 mRNA expression level was positively correlated with plasma interleukin-6 level, indicating that transcriptional activation of Oat2 may occur in inflammatory state.

C-reactive Protein Elevation Is Associated With QTc Interval Prolongation in Patients Hospitalized With COVID-19

Background

The relationship between inflammation and corrected QT (QTc) interval prolongation is currently not well defined in patients with COVID-19.

Objective

This study aimed to assess the effect of marked interval changes in the inflammatory marker C-reactive protein (CRP) on QTc interval in patients hospitalized with COVID-19.

Methods

In this retrospective cohort study of hospitalized adult patients admitted with COVID-19 infection, we identified 85 patients who had markedly elevated CRP levels and serial measurements of an ECG and CRP during the same admission. We compared mean QTc interval duration, and other clinical and ECG characteristics between times when CRP values were high and low. We performed mixed-effects linear regression analysis to identify associations between CRP levels and QTc interval in univariable and adjusted models.

Results

Mean age was 58 ± 16 years, of which 39% were women, 41% were Black, and 25% were White. On average, the QTc interval calculated via the Bazett formula was 15 ms higher when the CRP values were “high” vs. “low” [447 ms (IQR 427–472 ms) and 432 ms (IQR 412–452 ms), respectively]. A 100 mg/L increase in CRP was associated with a 1.5 ms increase in QTc interval [β coefficient 0.15, 95% CI (0.06–0.24). In a fully adjusted model for sociodemographic, ECG, and clinical factors, the association remained significant (β coefficient 0.14, 95% CI 0.05–0.23).

Conclusion

An interval QTc interval prolongation is observed with a marked elevation in CRP levels in patients with COVID-19.

Mechanistic Insights Into Inflammation-Induced Arrhythmias: A Simulation Study

Cardiovascular diseases are the primary cause of death of humans, and among these, ventricular arrhythmias are the most common cause of death. There is plausible evidence implicating inflammation in the etiology of ventricular fibrillation (VF). In the case of systemic inflammation caused by an overactive immune response, the induced inflammatory cytokines directly affect the function of ion channels in cardiomyocytes, leading to a prolonged action potential duration (APD). However, the mechanistic links between inflammatory cytokine-induced molecular and cellular influences and inflammation-associated ventricular arrhythmias need to be elucidated. The present study aimed to determine the potential impact of systemic inflammation on ventricular electrophysiology by means of multiscale virtual heart models. The experimental data on the ionic current of three major cytokines [i.e., tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1β), and interleukin-6 (IL-6)] were incorporated into the cell model, and the effects of each cytokine and their combined effect on the cell action potential (AP) were evaluated. Moreover, the integral effect of these cytokines on the conduction of excitation waves was also investigated in a tissue model. The simulation results suggested that inflammatory cytokines significantly prolonged APD, enhanced the transmural and regional repolarization heterogeneities that predispose to arrhythmias, and reduced the adaptability of ventricular tissue to fast heart rates. In addition, simulated pseudo-ECGs showed a prolonged QT interval—a manifestation consistent with clinical observations. In summary, the present study provides new insights into ventricular arrhythmias associated with inflammation.

ECG characteristics of COVID ‐19 patient with arrhythmias: Referral hospitals data from Indonesia

Background

Arrhythmia is a significant clinical modifier in COVID‐19 patient outcomes. Currently, data on arrhythmia and ECG characteristics in COVID‐19 from lower middle‐income countries are limited.

Methods

COVID‐19 was confirmed by polymerase chain reaction testing of a nasopharyngeal sample. All clinical records were systematically evaluated to obtain demographic characteristics and medical comorbidities. The ECG was recorded on admission, in‐hospital, and at discharge.

Results

Total documented arrhythmia events account for 22% of patients, comprising 6% of new‐onset arrhythmia and 16% of existing arrhythmia. Atrial fibrillation is the most common arrhythmia. The ECG changes were a decrease in heart rate (91 ± 22 vs. 83 ± 20, p < .001) and an increase in the QT interval (354.7 ± 53.70 vs. 371.4 ± 59.48 msec, p < .001) from hospital admission to hospital discharge, respectively. The in‐hospital HR of 85 bpm or higher increases the risk of death (OR = 2.69, p = .019).

Conclusion

The incidence of arrhythmias in COVID‐19 patients at COVID‐19 referral hospitals in Indonesia is 22%. Atrial fibrillation is the most common arrhythmia in COVID‐19 patients. Prolongation of QRS duration from admission to discharge was related to the occurrence of new‐onset arrhythmia. The in‐hospital HR of 85 bpm or higher increased the risk of death.

The role of inflammation in the pathogenesis and treatment of arrhythmias

The pathogenesis of arrhythmias is complex and multifactorial. The role of inflammation in the pathogenesis of both atrial and ventricular arrhythmias (VA) has been explored. However, developing successful pharmacotherapy regimens based on those pathways has proven more of a challenge. This narrative review provides an overview of five common arrhythmias impacted by inflammation, including atrial fibrillation (AF), myocardial infarction, arrhythmogenic cardiomyopathy, cardiac sarcoidosis, and QT prolongation, and the potential role for anti-inflammatory therapy in their management. We identified arrhythmias and arrhythmogenic disease states with the most evidence linking pathogenesis to inflammation and conducted comprehensive searches of United States National Library of Medicine MEDLINE^® and PubMed databases. Although a variety of agents have been studied for the management of AF, primarily in an effort to reduce postoperative AF following cardiac surgery, no standard anti-inflammatory agents are used in clinical practice at this time. Although inflammation following myocardial infarction may contribute to the development of VA, there is no clear benefit with the use of anti-inflammatory agents at this time. Similarly, although inflammation is clearly linked to the development of arrhythmias in arrhythmogenic cardiomyopathy, data demonstrating a benefit with anti-inflammatory agents are limited. Cardiac sarcoidosis, an infiltrative disease eliciting an immune response, is primarily treated by immunosuppressive therapy and steroids, despite a lack of primary literature to support such regimens. In this case, anti-inflammatory agents are frequently used in clinical practice. The pathophysiology of arrhythmias is complex, and inflammation likely plays a role in both onset and duration, however, for most arrhythmias the role of pharmacotherapy targeting inflammation remains unclear.

Antiviral and anti-inflammatory drugs to combat COVID-19: Effects on cardiac ion channels and risk of ventricular arrhythmias

Introduction: Drugs with no indication for the treatment of cardiovascular diseases (e.g., drugs employed to treat COVID-19) can increase the risk of arrhythmias. Of interest, a six-fold increase in the number of arrhythmic events was reported in patients with severe COVID-19. In this study, we reviewed (i) the pro-arrhythmic action of drugs given to patients with COVID-19 infection, and (ii) the effects of inflammatory cytokines on cardiac ion channels and possible generation of arrhythmias.

Methods: We conducted a literature search on the drugs with purported or demonstrated efficacy against COVID-19 disease, emphasizing the mechanisms by which anti-COVID-19 drugs and inflammatory cytokines interfere with cardiac ion channels.

Results:Antibiotics (azithromycin), antimalarials (hydroxychloroquine, chloroquine), antivirals (ritonavir/lopinavir, atazanavir), and some of the tyrosine kinase inhibitors (vandetanib) could induce long QT and increase risk for ventricular arrhythmias. The pro-arrhythmic action results from drug-induced inhibition of Kv11.1 (hERG) channels interfering with the repolarizing potassium IKr currents, leading to long QT and increased risk of triggered arrhythmias. At higher concentrations, these drugs may interfere with IKs, IK1, and/or Ito potassium currents, and even inhibit sodium (INa) and calcium (ICa) currents, inducing additional cardiac toxicity. Ibrutinib, an inhibitor of Bruton’s TK, increased the incidence of atrial fibrillation and ventricular tachycardia associated with a short QT interval. Inflammatory cytokines IL-6 and TNF-α inhibit IKr and Ito repolarizing potassium currents. High levels of inflammatory cytokines could contribute to the arrhythmic events. For remdesivir, favipiravir, dexamethasone, tocilizumab, anakinra, baricitinib, and monoclonal antibodies (bamlanivimab, etesevimab, and casirivimab), no evidence supports significant effects on cardiac ion channels, changes in the QT interval, and increased risk for ventricular arrhythmias.

Conclusion: This study supports the concept of hERG channel promiscuity. Different drug classes given to COVID-19 patients might delay repolarization, and increase the risk of ventricular arrhythmias. The presence of comorbid pro-arrhythmic disease states, and elevated levels of pro-arrhythmic cytokines, could increase the risk of ventricular arrhythmias. Discontinuation of nonessential drugs and correction of electrolyte abnormalities could prevent severe ventricular arrhythmias. Altogether, the most effective therapies against COVID-19 (remdesivir, dexamethasone, monoclonal antibodies) lack pro-arrhythmic activity.

Myositis-Specific Autoantibodies and QTc Changes by ECG in Idiopathic Inflammatory Myopathies

OBJECTIVES

The aim of this study was to investigate cardiac involvement detected by electrocardiography (ECG) in patients with idiopathic inflammatory myopathies (IIM) and to evaluate possible associations between autoantibody profile and ECG changes in these patients.

METHODS

In a Scandinavian cross-sectional study, patients were included from two Danish centres and one Swedish centre. Resting 12-lead ECG was investigated in 261 patients with IIM compared with 102 patients with systemic sclerosis (SSc) and 48 healthy controls (HCs). ECG changes were correlated to clinical manifestations and myositis-specific (MSAs) and myositis-associated (MAAs) autoantibodies.

RESULTS

Patients with IIM had longer mean QTc duration and more frequently presented with prolonged QTc (≥ 450 ms; p= 0.038) compared with HCs. Longer QTc duration was recorded in SSc compared with IIM (433 ± 23 ms vs 426 ± 24 ms, p= 0.011), yet, no significant difference in the fraction with prolonged QTc (SSc: 22%, IIM: 16%; p= 0.19). In multivariable regression analyses, anti-Mi2 (p= 0.01, p= 0.035) and anti-Pl-7 (p= 0.045, p= 0.014) were associated with QTc duration and prolonged QTc in IIM. Elevated CRP was associated with prolonged QTc (p= 0.041).

CONCLUSION

Presence of QTc abnormalities was as common in patients with IIM as in patients with SSc, including prolonged QTc seen in almost one fifth of the patients. Anti-Mi2, anti-Pl-7, and elevated CRP may serve as biomarkers for cardiac disease in IIM, but needs to be confirmed in a larger prospective study.

Prevalence and risk factors of QTc prolongation in prostate cancer patients undergoing brachytherapy

QTc prolongation is linked to Torsade de Pointes, sudden cardiac death, and overall cardiovascular mortality. 754 prostate cancer patients undergoing brachytherapy were analyzed, prolonged QTc was defined as ≥450ms. A prolonged QTc was more frequent (10.1% vs 5.1%, p = 0.040) in patients with high-risk cancer than in low to intermediate risk patients. The absolute QTc-time was correlated with age (r = 0.125), neutrophil count (r = 0.130) and negatively correlated with the testosterone level (r=-0.205). Treating physicians should be aware of this and monitor the QTc during ADT to possibly decrease cardiac morbidity/mortality in these patients who are more likely to require ADT.

Abrogation of CC Chemokine Receptor 9 Ameliorates Ventricular Electrical Remodeling in Mice After Myocardial Infarction

Introduction: Myocardial infarction (MI) triggers structural and electrical remodeling. CC chemokine receptor 9 (CCR9) mediates chemotaxis of inflammatory cells in MI. In our previous study, CCR9 knockout has been found to improve structural remodeling after MI. Here, we further investigate the potential influence of CCR9 on electrical remodeling following MI in order to explore potential new measures to improve the prognosis of MI.

Methods and Results: Mice was used and divided into four groups: CCR9^+/+/Sham, CCR9^−/−/Sham, CCR9^+/+/MI, CCR9^−/−/MI. Animals were used at 1 week after MI surgery. Cardiomyocytes in the infracted border zone were acutely dissociated and the whole-cell patch clamp was used to record action potential duration (APD), L-type calcium current (I_Ca,L) and transient outward potassium current (I_to). Calcium transient and sarcoplasmic reticulum (SR) calcium content under stimulation of Caffeine were measured in isolated cardiomyocytes by confocal microscopy. Multielectrode array (MEA) was used to measure the conduction of the left ventricle. The western-blot was performed for the expression level of connexin 43. We observed prolonged APD₉₀, increased I_Ca,L and decreased I_to following MI, while CCR9 knockout attenuated these changes (APD₉₀: 50.57 ± 6.51 ms in CCR9^−/−/MI vs. 76.53 ± 5.98 ms in CCR9^+/+/MI, p < 0.05; I_Ca,L: −13.15 ± 0.86 pA/pF in CCR9^−/−/MI group vs. −17.05 ± 1.11 pA/pF in CCR9^+/+/MI, p < 0.05; I_to: 4.01 ± 0.17 pA/pF in CCR9^−/−/MI group vs. 2.71 ± 0.16 pA/pF in CCR9^+/+/MI, p < 0.05). The confocal microscopy results revealed CCR9 knockout reversed the calcium transient and calcium content reduction in sarcoplasmic reticulum following MI. MEA measurements showed improved conduction velocity in CCR9^−/−/MI mice (290.1 ± 34.47 cm/s in CCR9^−/−/MI group vs. 113.2 ± 14.4 cm/s in CCR9^+/+/MI group, p < 0.05). Western-blot results suggested connexin 43 expression was lowered after MI while CCR9 knockout improved its expression.

Conclusion: This study shows CCR9 knockout prevents the electrical remodeling by normalizing ion currents, the calcium homeostasis, and the gap junction to maintain APD and the conduction function. It suggests CCR9 is a promising therapeutic target for MI-induced arrhythmia, which warrants further investigation.

Assessment of proarrhythmic ventricular electrophysiological remodeling in patients with rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is related to cardiovascular disease and results in increased mortality rates. Ischemia, autonomic nervous system dysfunction, impaired cardiac ionic currents, and genetic predisposition may be the underlying mechanisms. Proarrhythmic ventricular electrophysiological remodeling detected on the basis of Tp‑e interval, Tp-e/QT, and Tp-e/QTc ratios plays a key role in the prognosis. Our aim was to assess proarrhythmic ventricular electrophysiological remodeling in patients with RA, a well-known chronic inflammatory disorder.

MATERIALS AND METHODS

A total of 163 patients with RA and 47 patients as a control group were included in this retrospective study. Proarrhythmic ventricular electrophysiological remodeling markers were evaluated in both groups along with baseline demographic and clinical variables. Patients using medication or with chronic disorders that can affect ventricular repolarization markers were excluded.

RESULTS

The patients with RA had prolonged Tp‑e interval (66 ms [44-80]; 80 ms [78-96], p < 0.001) and increased Tp-e/QT ratio (0.18 [0.12-0.22]; 0.22 [0.20-0.24], p < 0.001) and Tp-e/QTc ratio (0.16 [0.11-0.19]; 0.20 [0.17-0.22], p < 0.001) compared to the control group.

CONCLUSION

The Tp‑e interval and Tp-e/QT ratio, which may help to clarify the pathophysiological mechanisms of ventricular arrhythmias, were increased in patients with RA.

Brugada syndrome and arrhythmogenic cardiomyopathy: overlapping disorders of the connexome?

Arrhythmogenic cardiomyopathy (ACM) and Brugada syndrome (BrS) are inherited diseases characterized by an increased risk for arrhythmias and sudden cardiac death. Possible overlap between the two was suggested soon after the description of BrS. Since then, various studies focusing on different aspects have been published pointing to similar findings in the two diseases. More recent findings on the structure of the cardiac cell-cell junctions may unite the pathophysiology of both diseases and give further evidence to the theory that they may in part be variants of the same disease spectrum. In this review, we aim to summarize the studies indicating the pathophysiological, genetic, structural, and electrophysiological overlap between ACM and BrS.

QTc prolongation among hydroxychloroquine sulphate-treated COVID-19 patients: An observational study

BACKGROUND

The liberal administration of hydroxychloroquine-sulphate (HCQ) to COVID-19 patients has raised concern regarding the risk of QTc prolongation and cardiac arrhythmias, particularly when prescribed with azithromycin. We evaluated the incidence of QTc prolongation among moderately and severely ill COVID-19 patients treated with HCQ and of the existence of concomitant alternative causes.

METHODS

All COVID-19 patients treated with HCQ (between Mar 1 and Apr 14, 2020) in a tertiary medical centre were included. Clinical characteristics and relevant risk factors were collected from the electronic medical records. Individual patient QTc intervals were determined before and after treatment with HCQ. The primary outcome measure sought was a composite end point comprised of either an increase ≥60 milliseconds (ms) in the QTc interval compared with pre-treatment QTc, and/or a maximal QTc interval >500 ms RESULTS: Ninety patients were included. Median age was 65 years (IQR 55-75) and 57 (63%) were male. Thirty-nine patients (43%) were severely or critically ill. Hypertension and obesity were common (n = 23 each, 26%). QTc prolongation evolved in 14 patients (16%). Age >65 years, congestive heart failure, severity of disease, C-reactive protein level, hypokalaemia and furosemide treatment, were all associated with QTc prolongation. Adjusted analysis showed that QTc prolongation was five times more likely with hypokalaemia [OR 5, (95% CI, 1.3-20)], and three times more likely with furosemide treatment [OR 3 (95% CI, 1.01-13.7)].

CONCLUSION

In patients treated with HCQ, QTc prolongation was associated with the presence of traditional risk factors such as hypokalaemia and furosemide treatment.

Chloroquine and hydroxychloroquine for COVID-19: Perspectives on their failure in repurposing

WHAT IS KNOWN AND OBJECTIVE

Non-clinical studies suggest that chloroquine (CQ) and hydroxychloroquine (HCQ) have antiviral activities. Early clinical reports of successful HCQ-associated reduction in viral load from small studies in COVID-19 patients spurred a large number of national and international clinical trials to test their therapeutic potential. The objective of this review is to summarize the current evidence on the safety and efficacy of these two agents and to provide a perspective on why their repurposing has hitherto failed.

METHODS

Published studies and rapidly emerging data were reviewed to gather evidence on safety and efficacy of CQ and HCQ in patients with COVID-19 infection or as prophylaxis. The focus is on clinically relevant efficacy endpoints and their adverse effects on QT interval.

RESULTS AND DISCUSSION

At the doses used, the two agents, given alone or with azithromycin (AZM), are not effective in COVID-19 infection. The choice of (typically subtherapeutic) dosing regimens, influenced partly by "QT-phobia," varied widely and seems anecdotal without any pharmacologically reliable supporting clinical evidence. A substantial proportion of patients receiving CQ/HCQ/AZM regimen developed QTc interval prolongation, many with absolute QTc interval exceeding the potential proarrhythmic threshold, but very few developed proarrhythmia.

WHAT IS NEW AND CONCLUSION

The strategy to repurpose CQ/HCQ to combat COVID-19 infection is overshadowed by concerns about their QT liability, resulting in choice of potentially subtherapeutic doses. Although the risk of QT-related proarrhythmia is real, it is low and manageable by careful monitoring. Recent discontinuation of HCQ from at least four large studies effectively marks the end of efforts at repurposing of CQ or HCQ for COVID-19 infection. This episode leaves behind important questions on dose selection and risk/benefit balance in repurposing drugs generally.

QT interval parameters, anti-Ro antibody status, and disease activity in systemic lupus erythematosus

BACKGROUND

The QT interval a marker of ventricular depolarization and repolarization is reported to be prolonged in some proportion of patients with systemic lupus erythematosus (SLE). We studied electrocardiographic (ECG) abnormalities, in particular QT interval and its relationship with anti-Ro antibodies, disease activity, and serum interleukin 1β (IL-1β), interleukin 6 (IL-6) in SLE.

METHODS

A 12-lead resting ECG was performed on 140 adult SLE patients fulflling SLICC/ACR classification criteria. All patients received hydroxychloroquine and prednisolone. Corrected QT (QTc) °440 milliseconds (ms) was defined as prolonged QTc. QT dispersion (QTd) °60 ms was defined as increased QTd.

RESULTS

Eighty-four patients had some form of ECG abnormality. Prolongation of QTc and QTd was present in 24 (17.1%) and 50 (35.7%) respectively. Anti-Ro/SSA antibodies were present in 63 (45%). Prolongation of QTc in anti-Ro positive versus anti-Ro negative was 17.5% and 17% respectively, p=0.98. Prolongation of QTd in anti-Ro-positive versus anti-Ro-negative was 32% and 39% respectively, p=0.37. Prolonged QTc was observed in 15% patients with SLEDAI ˛4 compared to 17.5% patients with SLEDAI °5, p=0.78. The median serum concentrations of IL-1β and IL-6 were similar in the groups with and without prolonged QTc, with and without prolonged QTd. On binary logistic regression analyses neither clinical nor laboratory factors were predictors of prolonged QTc. However, having valvular regurgitation and hypercholesterolemia was associated with significantly reduced odds of having prolonged QTd, adjusted OR 0.33 (CI 0.14-0.83), p=0.018 and 0.19 (CI 0.05-0.80), p=0.023 respectively. Those with high LDL cholesterol and hypertriglyceridemia had a significantly higher odds of having a normal QTd with adjusted OR of 4.34 (1.31-14.46) p=0.017and 5.59 (1.62-19.38) p=0.007respectively.

CONCLUSION

Though 17% and 35% SLE patients have QTc and QTd prolongation, association with anti-Ro antibodies or disease activity was absent. A large proportion has other asymptomatic ECG abnormalities that may reflect subclinical cardiac involvement.

The Role of Cardiac Macrophage and Cytokines on Ventricular Arrhythmias

In the heart, cardiac macrophages have widespread biological functions, including roles in antigen presentation, phagocytosis, and immunoregulation, through the formation of diverse cytokines and growth factors; thus, these cells play an active role in tissue repair after heart injury. Recent clinical studies have indicated that macrophages or elevated inflammatory cytokines secreted by macrophages are closely related to ventricular arrhythmias (VAs). This review describes the role of macrophages and macrophage-secreted inflammatory cytokines in ventricular arrhythmogenesis.

Proarrhythmic electrophysiological and structural remodeling in rheumatoid arthritis

Chronic inflammatory disorders, including rheumatoid arthritis (RA), are associated with a twofold increase in the incidence of sudden cardiac death (SCD) compared with the healthy population. Although this is partly explained by an increased prevalence of coronary artery disease, growing evidence suggests that ischemia alone cannot completely account for the increased risk. The present review explores the mechanisms of cardiac electrophysiological remodeling in response to chronic inflammation in RA. In particular, it focuses on the roles of nonischemic structural remodeling, altered cardiac ionic currents, and autonomic nervous system dysfunction in ventricular arrhythmogenesis and SCD. It also explores whether common genetic elements predispose to both RA and SCD. Finally, it evaluates the potential dual effects of disease-modifying therapy in both diminishing and promoting the risk of ventricular arrhythmias and SCD.

Anti-Inflammatory and Antiarrhythmic Effects of Beta Blocker in a Rat Model of Rheumatoid Arthritis

Background

Patients with rheumatoid arthritis are at twice the risk of ventricular arrhythmia and sudden cardiac death as the general population. We hypothesize that β‐blocker treatment of rheumatoid arthritis is antiarrhythmic by producing synergistic anticatecholaminergic and anti‐inflammatory effects.

Methods and Results

Collagen‐induced arthritis (CIA) was induced in Lewis rats by immunization with type II collagen in Freund's incomplete adjuvant. The treatment with propranolol (4 mg/kg) started on the first day of immunization. We evaluated the ventricular vulnerability to ventricular arrhythmia using in vivo programmed stimulation and performed ex vivo optical mapping to measure the electrical remodeling of the heart. The ventricular tissue was further processed for immunohistochemical staining and protein array analysis. The assessment of ventricular vulnerability showed that the number and duration of the induced ventricular arrhythmia episodes were increased in CIA rats, which were improved with propranolol treatment. The sympathovagal index and the plasma level of catecholamines significantly increased in CIA rats, whereas the use of propranolol attenuated sympathetic hyperactivity. In the optical mapping study, electrical remodeling, characterized by prolonged action potential duration, slow conduction velocity, and steepened action‐potential duration restitution, were noted in CIA rats and reversed in the propranolol‐treatment group. The propranolol treatment was associated with decreases in paw thickness, fewer inflammatory cell infiltrations in the heart, reduced levels of cardiac inflammatory cytokines, and less cardiac fibrosis as compared with the CIA group.

Conclusions

CIA increased ventricular arrhythmia vulnerability through sympathetic hyperinnervation and proarrhythmic ventricular electrophysiological remodeling. Treatment with propranolol in CIA rats was both anti‐inflammatory and antiarrhythmic.

Association between Corrected QT Interval and C-Reactive Protein in Patients with Inflammatory Bowel Diseases

Background and objectives: Electrocardiograph abnormalities (i.e., QT interval prolongation) have been described in inflammatory bowel diseases (IBD). We aimed to measure the QT interval in a cohort of patients with IBD and to analyze its relationship with clinical and inflammatory activity. Materials and Methods: We performed a cross-sectional study that included 38 IBD outpatients and 38 “age- and sex-matched” healthy controls. Nine patients had active IBD, and 29 were in clinical remission. Among the latter, 10 patients had sustained (lasting >1 year) and 19 had short-term remission (≤1 year). Corrected QT (QTc) interval was measured on standard 12-lead electrocardiograph. A systematic review of the literature on studies investigating the QT interval in patients with IBD was also performed. Results: QTc interval values were similar between IBD patients and healthy controls (417.58 ± 22.05 ms vs. 409.13 ± 19.61 ms, respectively; p: 0.479). Patients with active IBD had significantly higher QTc values (435.11 ± 27.31 ms) than both controls (409.13 ± 19.61 ms) and patients in remission (412.14 ± 17.33 ms) (p: 0.031). Post hoc analysis showed that the difference in QTc values between active IBD and remission was attributable to the group of patients with sustained remission (p < 0.05). Lastly, a significant correlation between QTc interval and C-reactive protein (CRP) values was observed (Spearman test: r = 0.563; p: 0.0005). Conclusions: Our study demonstrates an association between QTc duration and both clinical and inflammatory activity in patients with IBD. The higher the CRP value, the longer is the QTc duration. For practical purposes, all patients with active IBD should undergo a standard ECG. Prescription of drugs able to modify the QT interval should be avoided in patients with active IBD. The systematic review of the literature indicated that this is the first published study demonstrating an association between the QTc duration and CRP values in patients with IBD.

Cardiac Arrest Risk During Acute Infections: Systemic Inflammation Directly Prolongs QTc Interval via Cytokine-Mediated Effects on Potassium Channel Expression

BACKGROUND

During acute infections, the risk of malignant ventricular arrhythmias is increased, partly because of a higher propensity to develop QTc prolongation. Although it is generally believed that QTc changes almost exclusively result from concomitant treatment with QT-prolonging antimicrobials, direct effects of inflammatory cytokines on ventricular repolarization are increasingly recognized. We hypothesized that systemic inflammation per se can significantly prolong QTc during acute infections, via cytokine-mediated changes in K⁺ channel expression.

METHODS

We evaluated (1) the frequency of QTc prolongation and its association with inflammatory markers, in patients with different types of acute infections, during active disease and remission; (2) the prevalence of acute infections in a cohort of consecutive patients with Torsades de Pointes; (3) the relationship between K⁺ channel mRNA levels in ventricles and peripheral blood mononuclear cells and their changes in patients with acute infection over time.

RESULTS

In patients with acute infections, regardless of concomitant QT-prolonging antimicrobial treatments, QTc was significantly prolonged but rapidly normalized in parallel to CRP (C-reactive protein) and cytokine level reduction. Consistently in the Torsades de Pointes cohort, concomitant acute infections were highly prevalent (30%), despite only a minority (25%) of these cases were treated with QT-prolonging antimicrobials. KCNJ2 K⁺ channel expression in peripheral blood mononuclear cell, which strongly correlated to that in ventricles, inversely associated to CRP and IL (interleukin)-1 changes in acute infection patients.

CONCLUSIONS

During acute infections, systemic inflammation rapidly induces cytokine-mediated ventricular electrical remodeling and significant QTc prolongation, regardless concomitant antimicrobial therapy. Although transient, these changes may significantly increase the risk of life-threatening ventricular arrhythmia in these patients. It is timely and warranted to transpose these findings to the current coronavirus disease 2019 (COVID-19) pandemic, in which both increased amounts of circulating cytokines and cardiac arrhythmias are demonstrated along with a frequent concomitant treatment with several QT-prolonging drugs. Graphic Abstract: A graphic abstract is available for this article.

Cardiolipotoxicity, Inflammation, and Arrhythmias: Role for Interleukin-6 Molecular Mechanisms

Fatty acid infiltration of the myocardium, acquired in metabolic disorders (obesity, type-2 diabetes, insulin resistance, and hyperglycemia) is critically associated with the development of lipotoxic cardiomyopathy. According to a recent Presidential Advisory from the American Heart Association published in 2017, the current average dietary intake of saturated free-fatty acid (SFFA) in the US is 11–12%, which is significantly above the recommended <10%. Increased levels of circulating SFFAs (or lipotoxicity) may represent an unappreciated link that underlies increased vulnerability to cardiac dysfunction. Thus, an important objective is to identify novel targets that will inform pharmacological and genetic interventions for cardiomyopathies acquired through excessive consumption of diets rich in SFFAs. However, the molecular mechanisms involved are poorly understood. The increasing epidemic of metabolic disorders strongly implies an undeniable and critical need to further investigate SFFA mechanisms. A rapidly emerging and promising target for modulation by lipotoxicity is cytokine secretion and activation of pro-inflammatory signaling pathways. This objective can be advanced through fundamental mechanisms of cardiac electrical remodeling. In this review, we discuss cardiac ion channel modulation by SFFAs. We further highlight the contribution of downstream signaling pathways involving toll-like receptors and pathological increases in pro-inflammatory cytokines. Our expectation is that if we understand pathological remodeling of major cardiac ion channels from a perspective of lipotoxicity and inflammation, we may be able to develop safer and more effective therapies that will be beneficial to patients.

Interleukin-6 inhibition of hERG underlies risk for acquired long QT in cardiac and systemic inflammation

Increased proinflammatory interleukin-6 (IL-6) levels are associated with acquired long QT-syndrome (LQTS) in patients with systemic inflammation, leading to higher risks for life-threatening polymorphic ventricular tachycardia such as Torsades de Pointes. However, the functional and molecular mechanisms of this association are not known. In most cases of acquired LQTS, the target ion channel is the human ether-á-go-go-related gene (hERG) encoding the rapid component of the delayed rectifier K current, I_Kr, which plays a critical role in cardiac repolarization. Here, we tested the hypothesis that IL-6 may cause QT prolongation by suppressing I_Kr. Electrophysiological and biochemical assays were used to assess the impact of IL-6 on the functional expression of I_Kr in HEK293 cells and adult guinea-pig ventricular myocytes (AGPVM). In HEK293 cells, IL-6 alone or in combination with the soluble IL-6 receptor (IL-6R), produced a significant depression of I_Kr peak and tail current densities. Block of IL-6R or Janus kinase (JAK) reversed the inhibitory effects of IL-6 on I_Kr. In AGPVM, IL-6 prolonged action potential duration (APD) which was further prolonged in the presence of IL-6R. Similar to heterologous cells, IL-6 reduced endogenous guinea pig ERG channel mRNA and protein expression. The data are first to demonstrate that IL-6 inhibition of I_Kr and the resulting prolongation of APD is mediated via IL-6R and JAK pathway activation and forms the basis for the observed clinical QT interval prolongation. These novel findings may guide the development of targeted anti-arrhythmic therapeutic interventions in patients with LQTS and inflammatory disorders.

Heart Rate–corrected QT Interval Duration in Rheumatoid Arthritis and Its Reduction with Treatment with the Interleukin 6 Inhibitor Tocilizumab

Objective.

Individuals with rheumatoid arthritis (RA) are at a heightened risk of sudden cardiac death, an outcome increased in those with prolongation of the corrected electrocardiographic QT interval (QTc). We compared QTc between patients with RA and demographically matched controls and studied the change in QTc after treatment with the interleukin 6 inhibitor tocilizumab (TCZ).

Methods.

Standard 12-lead electrocardiograms were obtained and QTc was measured in patients with RA at baseline and after 24 weeks of TCZ treatment, then compared with non-RA controls who were frequency-matched on age and sex. Indicators of the baseline QTc and predictors of change in QTc were studied using multivariable linear regression.

Results.

A total of 94 RA and 42 non-RA controls were studied. The average baseline QTc was 10 ms longer in the RA group vs controls (422 vs 412 ms, respectively; p < 0.001) and decreased to an average of 406 ms with treatment (p < 0.001). Baseline QTc was significantly and independently higher among those with anticyclic citrullinated peptide antibodies seropositivity, higher swollen joint counts, and higher levels of C-reactive protein (CRP) and matrix metalloproteinase 3. Each log unit decrease in CRP with treatment was associated with an average reduction in QTc of 2.9 ms (p = 0.002) after adjusting for age and baseline QTc. Clinical response measures were not associated with the change in QTc.

Conclusion.

The marked normalization of QTc observed with TCZ treatment, and its close parallel with CRP reduction, support the premise that systemic inflammation contributes to cardiac repolarization abnormalities in RA that may be amenable to treatment.

Sirukumab for the treatment of rheumatoid arthritis: update on sirukumab, 2018

INTRODUCTION

Interleukin-6 (IL-6) is well-known for its pro-inflammatory properties, has been proven to target a wide range of cells in the joint, and has been implicated in extra-articular and articular manifestations in rheumatoid arthritis (RA). Tocilizumab (TCZ) is now widely used in patients with active RA and a number of additional agents that target the IL-6 pathways are under development, including sirukumab (SRK). Areas covered: SRK is an IgG1κ human anti-IL-6 monoclonal antibody which binds to IL-6 and prevents IL-6-mediated downstream effects. Initial trial results in phase-III studies in patients with RA seemed promising, showing improved results in patients with moderate-to-severe RA. Data derive from the phase-II study and the various SIRROUND studies (phase III). Expert commentary: The available data show that SRK50 mg every 4 weeks or 100 mg every 2 weeks will be effective in treating the RA population, with clinical improvements as early as week 2 and sustained over time. The adverse-event profile seems to be similar to TCZ, except for an increased mortality post open-label studies due to infections and cardiovascular events, our knowledge of which will be deepened with post-marketing surveillance and registry data.

Impact of cardiac rehabilitation on ventricular repolarization indexes in patients with rheumatid arthritis

OBJECTIVE

Abnormalities in ventricular repolarization (VR) parameters have been associated with sudden cardiac death (SCD) in patients with rheumatoid arthritis (RA). The benefits of cardiac rehabilitation (CR) in patients with RA are well recognized. We aimed to assess its impact on VR indexes in patients with RA.

METHODS

This study included 45 patients with RA (36 female, age 58 ± 5.5 years) and 50 age- and sex-matched otherwise healthy controls. Baseline electrocardiogram (ECG) recordings were used to compare VR parameters such as maximum and minimum QT intervals, and corrected, and dispersion (QTmax, QTmin, cQTmax, cQTmin, QTd, cQTd, respectively), JT and cJT intervals, Tp-e and cTp-e intervals, and Tp-e/QT and Tp-e/cQT ratios in patients with RA and healthy individuals. The effects of 6-week CR in patients with RA were also evaluated by comparing pre- and post-CR ECGs, exercise tolerance test (MET and VO2max) and RA characteristics (C-reactive protein (CRP), Disease Activity Score 28 (DAS28) and Health Assessment Questionnaire(HAQ)).

RESULTS

In comparison with the healthy individuals, the patients with RA had significantly higher cQTmax and QTmin intervals, QTd, cQTd, Tp-e and cTp-e intervals, and Tp-e/QT and Tp-e/cQT ratios. At the end of CR, all VR indexes (p < 005), except QTd, were significantly decreased as did the results for CRP, DAS28, and HAQ (all p < 0.05), and MET and VO2max (p < 0.05 for both) were significantly increased in patients with RA.

CONCLUSIONS

CR may provide an improvement in the majority of VR indexes which are related with ventricular arrhythmia and SCD in patients with RA. Changes in ETT parameters and RA characteristics may contribute to improvement of several VR indexes such as cQTd, cJT and Tp-e intervals at the end of CR.

Use of Interleukin-1 Blockers in Pericardial and Cardiovascular Diseases

PURPOSE OF REVIEW

This review aims to summarize the role of the interleukin-1 (IL-1) blocking agents in cardiovascular diseases, briefly describing the pathogenetic rationale and the most relevant clinical studies.

RECENT FINDINGS

IL-1 is a pivotal cytokine of the innate immune system. Anti-IL-1 agents are currently used for the treatment of several autoimmune and autoinflammatory conditions. Recently, the role of IL-1 has also emerged in cardiovascular diseases. Indeed, two recent randomized controlled trials have shown that the IL-1 receptor antagonist anakinra is effective for the treatment of idiopathic recurrent pericarditis and the IL-1β blocking agent canakinumab is effective in reducing myocardial infarction in people at risk. Interestingly, interfering with IL-1 has proved to be also effective in other cardiovascular manifestations, such as myocarditis, arrhythmias, and heart failure. Blocking the IL-1 pathway is a possible new therapeutic strategy, potentially leading to innovative therapies in many acute and chronic cardiovascular diseases.

Systemic inflammation and arrhythmic risk: lessons from rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic immuno-mediated disease primarily affecting the joints, characterized by persistent high-grade systemic inflammation. Cardiovascular morbidity and mortality are significantly increased in RA, with >50% of premature deaths attributable to cardiovascular disease. In particular, RA patients were twice as likely to experience sudden cardiac death compared with non-RA subjects, pointing to an increased propensity to develop malignant ventricular arrhythmias. Indeed, ventricular repolarization (QT interval) abnormalities and cardiovascular autonomic nervous system dysfunction, representing two well-recognized risk factors for life-threatening ventricular arrhythmias in the general population, are commonly observed in RA. Moreover, large population-based studies seem to indicate that also the prevalence of atrial fibrillation is significantly higher in RA subjects than in the general population, thus suggesting that these patients are characterized by an abnormal diffuse myocardial electrical instability. Although the underlying mechanisms accounting for the pro-arrhythmogenic substrate in RA are probably intricate, the leading role seems to be played by chronic systemic inflammatory activation, able to promote arrhythmias both indirectly, by accelerating the development of ischaemic heart disease and congestive heart failure, and directly, by affecting cardiac electrophysiology. In this integrated mechanistic view, lowering the inflammatory burden through an increasingly tight control of disease activity may represent the most effective intervention to reduce arrhythmic risk in these patients. Intriguingly, these considerations could be more generally applicable to all the diseases characterized by chronic systemic inflammation, and could help elucidate the link between low-grade chronic inflammation and arrhythmic risk in the general population.

A Review of Interleukin-1 in Heart Disease: Where Do We Stand Today?

Cardiovascular diseases are the leading cause of death worldwide. Research in the last two decades has emphasized the inflammatory process as a key component in the pathogenesis of many of them. The Interleukin-1 family is a pivotal element of inflammation and has been well studied as a therapeutic target in various inflammatory states. Recent trials have explored the effect of Interleukin-1 blockade in cardiovascular diseases and initial evidence of the relevance of such treatment in this field of medicine accumulate. This review will describe the role of Interleukin-1 in heart diseases and the potential therapeutic effect of its blockade in such diseases.

Sudden cardiac death in patients with rheumatoid arthritis

An increased cardiovascular morbidity and mortality, including the risk of sudden cardiac death (SCD), has been shown in patients with rheumatoid arthritis (RA). Abnormalities in autonomic markers such as heart rate variability and ventricular repolarization parameters, such as QTc interval and QT dispersion, have been associated with sudden death in patients with RA. The interplay between these parameters and inflammation that is known to exist with RA is of growing interest. In this article, we review the prevalence and predictors of SCD in patients with RA and describe the potential underlying mechanisms, which may contribute to this. We also review the impact of biologic agents on arrhythmic risk as well as cardiovascular morbidity and mortality.

Cardiac Ion Channel Regulation in Obesity and the Metabolic Syndrome: Relevance to Long QT Syndrome and Atrial Fibrillation

Obesity and its associated metabolic dysregulation leading to metabolic syndrome is an epidemic that poses a significant public health problem. More than one-third of the world population is overweight or obese leading to enhanced risk of cardiovascular disease (CVD) incidence and mortality. Obesity predisposes to atrial fibrillation, ventricular, and supraventricular arrhythmias; conditions that are underlain by dysfunction in electrical activity of the heart. To date, current therapeutic options for cardiomyopathy of obesity are limited, suggesting that there is considerable room for development of therapeutic interventions with novel mechanisms of action that will help normalize rhythm in obese patients. Emerging candidates for modulation by obesity are cardiac ion channels and Ca handling proteins. However, the underlying molecular mechanisms of the impact of obesity on these channels/Ca handling proteins remain incompletely understood. Obesity is marked by accumulation of adipose tissue associated with a variety of adverse adaptations including dyslipidemia (or abnormal levels of serum free fatty acids), increased secretion of pro-inflammatory cytokines, fibrosis, hyperglycemia, and insulin resistance, that will cause electrical remodeling and thus predispose to arrhythmias. Further, adipose tissue is also associated with the accumulation of subcutaneous and visceral fat, which are marked by distinct signaling mechanisms. Thus, there may also be functional differences in the outcome of regional distribution of fat deposits on ion channel/Ca handling proteins expression. Evaluating alterations in their functional expression in obesity will lead to progress in the knowledge about the mechanisms responsible for obesity-related arrhythmias. These advances are likely to reveal new targets for pharmacological modulation. The objective of this article is to review cardiac ion channel/Ca handling proteins remodeling that predispose to arrhythmias. Understanding how obesity and related mechanisms lead to cardiac electrical remodeling is likely to have a significant medical and economic impact.

Cardiac Fibrosis and Arrhythmogenesis

Myocardial injury, mechanical stress, neurohormonal activation, inflammation, and/or aging all lead to cardiac remodeling, which is responsible for cardiac dysfunction and arrhythmogenesis. Of the key histological components of cardiac remodeling, fibrosis either in the form of interstitial, patchy, or dense scars, constitutes a key histological substrate of arrhythmias. Here we discuss current research findings focusing on the role of fibrosis, in arrhythmogenesis. Numerous studies have convincingly shown that patchy or interstitial fibrosis interferes with myocardial electrophysiology by slowing down action potential propagation, initiating reentry, promoting after-depolarizations, and increasing ectopic automaticity. Meanwhile, there has been increasing appreciation of direct involvement of myofibroblasts, the activated form of fibroblasts, in arrhythmogenesis. Myofibroblasts undergo phenotypic changes with expression of gap-junctions and ion channels thereby forming direct electrical coupling with cardiomyocytes, which potentially results in profound disturbances of electrophysiology. There is strong evidence that systemic and regional inflammatory processes contribute to fibrogenesis (i.e., structural remodeling) and dysfunction of ion channels and Ca2+ homeostasis (i.e., electrical remodeling). Recognizing the pivotal role of fibrosis in the arrhythmogenesis has promoted clinical research on characterizing fibrosis by means of cardiac imaging or fibrosis biomarkers for clinical stratification of patients at higher risk of lethal arrhythmia, as well as preclinical research on the development of antifibrotic therapies. At the end of this review, we discuss remaining key questions in this area and propose new research approaches. © 2017 American Physiological Society. Compr Physiol 7:1009-1049, 2017.

ECG non-specific ST-T and QTc abnormalities in patients with systemic lupus erythematosus compared with rheumatoid arthritis

Objectives

Cardiovascular disease (CVD) is a leading cause of death in systemic lupus erythematosus (SLE) and in rheumatoid arthritis (RA). Although only explored in one study, ECG non-specific ST-T abnormalities, in addition to corrected QT-interval (QTc) prolongation, were recently reported in an SLE inception cohort. Importantly, these ECG abnormalities are known predictors of CVD mortality in the general population, yet their prevalence in patients with established SLE has not been evaluated.

Methods

We cross-sectionally investigated the presence of non-specific ST-T and QTc abnormalities in 50 patients with SLE, predominantly Hispanic and black, without CVD or SLE-related cardiac involvement and compared them with 139 patients with RA without CVD. Demographics, disease-specific characteristics and CVD risk factors were ascertained and adjusted for.

Results

Patients with SLE (mean age 36±13 years, 92% women, 6 years median disease duration, 96% Hispanics and blacks) had a 3.3-fold higher adjusted prevalence of non-specific ST-T abnormalities (56% vs 17%; p <0.0001) compared with RA, despite the older age and higher percentage of men in the RA group. The QTc was 26 ms longer in SLE compared with RA (p=0.002) in the setting of a higher percentage of women, blacks, Hispanics and higher C reactive protein levels in the SLE group.

Conclusions

This study demonstrates a high prevalence of ECG abnormalities in predominantly Hispanic and black patients with SLE. Longitudinal evaluation of the progression to potentially life-threatening arrhythmias and/or cardiovascular events is warranted.

Spotlight on sirukumab for the treatment of rheumatoid arthritis: the evidence to date

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease primarily affecting synovial joints and is characterized by persistent high-grade systemic inflammation. Proinflammatory cytokines, particularly interleukin-6 (IL-6), are of crucial importance in the pathogenesis of the disease, driving both joint inflammation and extra-articular comorbidities. Tocilizumab, a humanized IL-6 receptor-inhibiting monoclonal antibody, has been the first, and, to date, the only, IL-6 inhibitor approved for the treatment of RA. Many studies have demonstrated the potency and effectiveness of tocilizumab in controlling disease activity and radiological progression of RA. These successful results have encouraged the development of novel IL-6 inhibitors, among which a promising agent is sirukumab (SRK), a human anti-IL-6 monoclonal antibody currently under evaluation in Phase II/III studies in patients with RA, systemic lupus erythematosus, giant-cell arteritis, and major depressive disorder. The evidence to date indicates SRK as an effective and well-tolerated new therapeutic tool for patients with active RA, with some preliminary data suggesting a specific beneficial impact on relevant systemic complications associated with the disease, such as depression and cardiovascular disease. Conversely, although pathophysiological considerations make plausible the hypothesis that IL-6 blockade with SRK may also be beneficial in the treatment of many diseases other than RA (either autoimmune or not), available clinical data in patients with systemic lupus erythematosus do not seem to support this view, also giving rise to potentially relevant concerns about drug safety. If large Phase III clinical trials currently in progress in patients with RA confirm the efficacy and tolerability of SRK, then in the long term, this drug could, in the near future, occupy a place in the treatment of the disease, potentially also opening the doors to a more extended use of SRK in a wide range of disorders in which IL-6 plays a key pathogenic role.

Marked QTc Prolongation and Torsades de pointes in Patients with Chronic Inflammatory Arthritis

Mounting evidence indicates that in chronic inflammatory arthritis (CIA), QTc prolongation is frequent and correlates with systemic inflammatory activation. Notably, basic studies demonstrated that inflammatory cytokines induce profound changes in potassium and calcium channels resulting in a prolonging effect on cardiomyocyte action potential duration, thus on the QT interval on the electrocardiogram. Moreover, it has been demonstrated that in rheumatoid arthritis (RA) patients, the risk of sudden cardiac death is significantly increased when compared to non-RA subjects. Conversely, to date no data are available about torsades de pointes (TdP) prevalence in CIA, and the few cases reported considered CIA only an incidental concomitant disease, not contributing factor to TdP development. We report three patients with active CIA developing marked QTc prolongation, in two cases complicated with TdP degenerating to cardiac arrest. In these patients, a blood sample was obtained within 24 h from TdP/marked QTc prolongation occurrence, and levels of IL-6, TNFα, and IL-1 were evaluated. In all three cases, IL-6 was markedly elevated, ~10 to 100 times more than reference values. Moreover, one patient also showed high circulating levels of TNFα and IL-1. In conclusion, active CIA may represent a currently overlooked QT-prolonging risk factor, potentially contributing in the presence of other “classical” risk factors to TdP occurrence. In particular, a relevant role may be played by elevated circulating IL-6 levels via direct electrophysiological effects on the heart. This fact should be carefully kept in mind, particularly when recognizable risk factors are already present and/or the addition of QT-prolonging drugs is required.

Prolonged Tpeak-Tend interval in anti-Ro52 antibody-positive connective tissue diseases

Patients with connective tissue diseases (CTDs) may have prolonged corrected QT interval which indicates increased risk for ventricular arrhythmias. However, a more sensitive measure of ventricular repolarization, T-peak-to-end (Tpe) interval, has not been studied in CTDs. We aimed to investigate the relationship between ventricular repolarization abnormalities and anti-Ro52-positivity in subjects with connective tissue diseases (CTDs). We enrolled patients with anti-Ro52-positive CTDs, ANA-positive CTDs, and healthy subjects in this cross-sectional study. We excluded conditions potentially affecting the QT interval. We compared the ECG measures between the groups and performed analyses to define factors associated with ventricular repolarization measures. 15 ANA and anti-Ro52-positive, 39 ANA-positive and anti-Ro52-negative, and 22 healthy subjects were enrolled. None of the subjects had rhythm or conduction disturbances. Corrected QT intervals were similar between the groups. Tpe (84, 77.3, and 69.4 msn, respectively) and QT-dispersion (40, 27.2, and 20.1 msn, respectively) were higher in anti-Ro52-positive subjects compared with the ANA-positive and healthy subjects. Anti-Ro52 titers were correlated with Tpe and QT-dispersion (r = 0.52 and p < 0.001 for each). ANA and anti-Ro52-positivity were independently associated with higher Tpe (OR = 7.7, p = 0.001 and OR = 6.9, p = 0.001, respectively), corrected Tpe (OR = 11.3, p = 0.001 and OR = 8.4, p = 0.003, respectively), QT dispersion (OR = 7, p = 0.008 and OR = 13, p < 0.001, respectively), and QTc dispersion (OR = 9.1, p = 0.001 and OR = 14.1, p < 0.001, respectively). This study provides evidence that ANA positivity, especially when concomitant anti-Ro52-positivity is present, significantly deteriorates ventricular repolarization. The aforementioned ventricular repolarization abnormalities may render these subjects susceptible to serious rhythm or conduction disorders in the setting of predisposing conditions.

Relationship between QT Interval Length and Arterial Stiffness in Systemic Lupus Erythematosus (SLE): A Cross-Sectional Case-Control Study

INTRODUCTION AND OBJECTIVES

The QT interval on the electrocardiogram has been shown to be longer in patients with systemic lupus erythematosus (SLE) compared to that of the general population. The clinical significance of this finding is unknown. The aim of this study was to assess the relationship between QT interval and subclinical atherosclerosis, measured by carotid-femoral pulse-wave velocity.

MATERIAL AND METHODS

93 patients with SLE and 109 healthy women with similar basal characteristics were studied. All patients underwent a 12- lead electrocardiogram, and corrected QT interval (QTc) was measured using the Bazett's formula. The presence of atherosclerosis was evaluated by carotid-femoral pulse-wave velocity.

RESULTS

Clinical basal characteristics were similar in both groups. QTc interval was 415 ± 21.4 milliseconds in all patients, and 407 ± 19.1 milliseconds in the control group (p = 0.007). There was a positive correlation between QTc interval and carotid-femoral pulse-wave velocity (r = 0.235; p = 0.02) in patients with SLE. This association was independent of hypertension and age in a multivariate analysis.

CONCLUSION

QTc interval measured by electrocardiogram is prolonged in SLE patients; it is related to subclinical atherosclerosis, measured by carotid-femoral pulse-wave velocity. This measure may help stratify risk in routine clinical practice and select the patients that might benefit from a more aggressive therapy in the prevention of cardiovascular events.

Long QT Syndrome: An Emerging Role for Inflammation and Immunity

The long QT syndrome (LQTS), classified as congenital or acquired, is a multi-factorial disorder of myocardial repolarization predisposing to life-threatening ventricular arrhythmias, particularly torsades de pointes. In the latest years, inflammation and immunity have been increasingly recognized as novel factors crucially involved in modulating ventricular repolarization. In the present paper, we critically review the available information on this topic, also analyzing putative mechanisms and potential interplays with the other etiologic factors, either acquired or inherited. Accumulating data indicate inflammatory activation as a potential cause of acquired LQTS. The putative underlying mechanisms are complex but essentially cytokine-mediated, including both direct actions on cardiomyocyte ion channels expression and function, and indirect effects resulting from an increased central nervous system sympathetic drive on the heart. Autoimmunity represents another recently arising cause of acquired LQTS. Indeed, increasing evidence demonstrates that autoantibodies may affect myocardial electric properties by directly cross-reacting with the cardiomyocyte and interfering with specific ion currents as a result of molecular mimicry mechanisms. Intriguingly, recent data suggest that inflammation and immunity may be also involved in modulating the clinical expression of congenital forms of LQTS, possibly triggering or enhancing electrical instability in patients who already are genetically predisposed to arrhythmias. In this view, targeting immuno-inflammatory pathways may in the future represent an attractive therapeutic approach in a number of LQTS patients, thus opening new exciting avenues in antiarrhythmic therapy.