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.

Transient Hypogonadism Is Associated With Heart Rate-Corrected QT Prolongation and Torsades de Pointes Risk During Active Systemic Inflammation in Men.

Background Systemic inflammation and male hypogonadism are 2 increasingly recognized "nonconventional" risk factors for long-QT syndrome and torsades de pointes (TdP). Specifically, inflammatory cytokines prolong, while testosterone shortens the heart rate-corrected QT interval (QTc) via direct electrophysiological effects on cardiomyocytes. Moreover, several studies demonstrated important interplays between inflammation and reduced gonad function in men. We hypothesized that, during inflammatory activation in men, testosterone levels decrease and that this enhances TdP risk by contributing to the overall prolonging effect of inflammation on QTc. Methods and Results We investigated (1) the levels of sex hormones and their relationship with inflammatory markers and QTc in male patients with different types of inflammatory diseases, during active phase and recovery; and (2) the association between inflammatory markers and sex hormones in a cohort of male patients who developed extreme QTc prolongation and TdP, consecutively collected over 10 years. In men with active inflammatory diseases, testosterone levels were significantly reduced, but promptly normalized in association with the decrease in C-reactive protein and interleukin-6 levels. Reduction of testosterone levels, which also inversely correlated with 17-ß estradiol over time, significantly contributed to inflammation-induced QTc prolongation. In men with TdP, both active systemic inflammation and hypogonadism were frequently present, with significant correlations between C-reactive protein, testosterone, and 17-ß estradiol levels; in these patients, increased C-reactive protein and reduced testosterone were associated with a worse short-term outcome of the arrhythmia. Conclusions During systemic inflammatory activation, interleukin-6 elevation is associated with reduced testosterone levels in males, possibly deriving from an enhanced androgen-to-estrogen conversion. While transient, inflammatory hypotestosteronemia is significantly associated with an increased long-QT syndrome/TdP risk in men.

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.

Androgen Deprivation Therapy for Prostatic Cancer in Patients With Torsades de Pointes.

BACKGROUND: Men normally have shorter heart rate-corrected QT interval (QTc) than women, at least in part due to accelerating effects of testosterone on ventricular repolarization. Accumulating data suggest that androgen-deprivation therapy (ADT) used for the treatment of prostatic cancer, may increase Torsades de Pointes (TdP) risk by prolonging QTc. However, the evidence for such an association is currently limited to few case reports, in most cases deriving from the analysis of uncontrolled sources such as pharmacovigilance databases. OBJECTIVE: To better determine the clinical impact of ADT on TdP development, we examined the prevalence of this therapy in a consecutive cohort of 66 TdP patients, prospectively collected over a ~10 years period. METHODS AND RESULTS: We found and described four patients who were under ADT for prostatic cancer when TdP occurred, and in two cases degenerated to cardiac arrest. Notably, in this unselected population, ADTs unexpectedly represented the second most frequently administered QT-prolonging medication in males (4/24, 17%), after amiodarone. Moreover, in the ADT patients, a blood withdrawal was performed within 24 h from TdP/marked QTc prolongation occurrence and circulating concentration of androgens and gonadothropins were measured. As expected, all cases showed markedly reduced testosterone levels (total, free, and available). CONCLUSION: We provide evidence that a significant proportion of patients developing TdP were under treatment with ADT for prostatic cancer, thus confirming the clinical relevance of previous pharmacovigilance signals. An accurate assessment of the arrhythmic risk profile should be included in the standard of care of prostatic cancer patients before starting ADT.

Arrhythmic risk during acute infusion of infliximab: a prospective, single-blind, placebo-controlled, crossover study in patients with chronic arthritis.

OBJECTIVE: Reports suggest that infliximab (IFX) may be associated with life-threatening tachyarrhythmias and bradyarrhythmias. We evaluated the prevalence of cardiac rhythm disorders during acute infusion of IFX in a prospective, single-blind, placebo-controlled crossover study of patients with chronic arthritis. Effects of the drug on measures of arrhythmia risk such as QT interval and heart rate variability (HRV) were evaluated. METHODS: Seventy-five patients with spondyloarthritis (SpA; n=55) or rheumatoid arthritis (RA) underwent an ambulatory 12-channel electrocardiogram (ECG) recording to monitor cardiac arrhythmias, QT interval, and HRV during the infusion of IFX and saline (placebo). RESULTS: The occurrence of both tachyarrhythmias and bradyarrhythmias was not statistically different during IFX or placebo infusion. During IFX infusion, new-onset ventricular tachyarrhythmias had an 8% incidence (2.7% with placebo; OR 3.17, 95% CI 0.61-16.26) and were more severe. In these patients, mainly with RA, baseline-corrected QT interval and HRV values were significantly prolonged and depressed, respectively, in comparison with subjects without such arrhythmias. IFX acutely produced a significant shift toward a relative vagal prevalence without affecting QT interval measurements. CONCLUSION: New-onset cardiac arrhythmias, particularly ventricular tachyarrhythmias, developed during IFX infusion, but their incidence did not achieve statistical significance. We identified some specific risk factors possibly characteristic of the small subset of patients with a higher risk for ventricular arrhythmias. The acute effects of IFX on autonomic balance may substantiate the role of the complex interaction between autonomic nervous system and inflammation during chronic arthritis.

Enthesitis of proximal insertion of the deltoid in the course of seronegative spondyloarthritis. An atypical enthesitis that can mime impingement syndrome.

OBJECTIVE: To study the frequence of deltoideal proximal insertion enthesitis (DPIE) in patients affected with spondyloarthritis (SpA) and to evaluate its clinical, sonographic and radiological characteristics. METHODS: A retrospective study of clinical, sonographic and radiological examinations of the shoulders of 100 symptomatic consecutive outpatients with SpA, compared to 4 groups of control patients: 100 with Rheumatoid Arthritis, 100 with Osteoarthritis, 100 with Painful Shoulder, and 50 with shoulders undamaged by local pathological processes. RESULTS: The frequence of DPIE in the course of SpA was 9%. DPIE appears most frequently in Psoriatic Arthritis (PsA) (17%, 7/41). DPIE does not appear to be related to the sex or the age of the patient. The clinical signs and symptoms are similar to those of an impingement syndrome. Sonography reveals thickening and hypoechogenicity of the enthesis, associated or not to the subchondral osseous rearrangement and enthesophytosis. Radiology only reveals the enthesophytosis in the later stages. CONCLUSIONS: DPIE can determine shoulder pain in the course of SpA, and in particular in PsA. The clinical manifestations of DPIE are very similar to those of an impingement syndrome; sonography can differentiate the two conditions.