Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential

HPC Framework for Performing in Silico Trials Using a 3D Virtual Human Cardiac Population as Means to Assess Drug-Induced Arrhythmic Risk

Following the 3 R's principles of animal research-replacement, reduction, and refinement-a high-performance computational framework was produced to generate a platform to perform human cardiac in-silico clinical trials as means to assess the pro-arrhythmic risk after the administrations of one or combination of two potentially arrhythmic drugs. The drugs assessed in this study were hydroxychloroquine and azithromycin. The framework employs electrophysiology simulations on high-resolution three-dimensional, biventricular human heart anatomies including phenotypic variabilities, so as to determine if differential QT-prolongation responds to drugs as observed clinically. These simulations also reproduce sex-specific ionic channel characteristics. The derived changes in the pseudo-electrocardiograms, calcium concentrations, as well as activation patterns within 3D geometries were evaluated for signs of induced arrhythmia. The virtual subjects could be evaluated at two different cycle lengths: at a normal heart rate and at a heart rate associated with stress as means to analyze the proarrhythmic risks after the administrations of hydroxychloroquine and azithromycin. Additionally, a series of experiments performed on reanimated swine hearts utilizing Visible Heart® methodologies in a four-chamber working heart model were performed to verify the arrhythmic behaviors observed in the in silico trials.The obtained results indicated similar pro-arrhythmic risk assessments within the virtual population as compared to published clinical trials (21% clinical risk vs 21.8% in silico trial risk). Evidence of transmurally heterogeneous action potential prolongations after providing a large dose of hydroxychloroquine was found as the observed mechanisms for elicited arrhythmias, both in the in vitro and the in silico models. The proposed workflow for in silico clinical drug cardiotoxicity trials allows for reproducing the complex behavior of cardiac electrophysiology in a varied population, in a matter of a few days as compared to the months or years it requires for most in vivo human clinical trials. Importantly, our results provided evidence of the common phenotype variants that produce distinct drug-induced arrhythmogenic outcomes.

Advances in the design, generation, and application of tissue-engineered myocardial equivalents

Due to the limited regenerative ability of cardiomyocytes, the disabling irreversible condition of myocardial failure can only be treated with conservative and temporary therapeutic approaches, not able to repair the damage directly, or with organ transplantation. Among the regenerative strategies, intramyocardial cell injection or intravascular cell infusion should attenuate damage to the myocardium and reduce the risk of heart failure. However, these cell delivery-based therapies suffer from significant drawbacks and have a low success rate. Indeed, cardiac tissue engineering efforts are directed to repair, replace, and regenerate native myocardial tissue function. In a regenerative strategy, biomaterials and biomimetic stimuli play a key role in promoting cell adhesion, proliferation, differentiation, and neo-tissue formation. Thus, appropriate biochemical and biophysical cues should be combined with scaffolds emulating extracellular matrix in order to support cell growth and prompt favorable cardiac microenvironment and tissue regeneration. In this review, we provide an overview of recent developments that occurred in the biomimetic design and fabrication of cardiac scaffolds and patches. Furthermore, we sift in vitro and in situ strategies in several preclinical and clinical applications. Finally, we evaluate the possible use of bioengineered cardiac tissue equivalents as in vitro models for disease studies and drug tests.

Targeting cAMP signaling compartments in iPSC-derived models of cardiovascular disease

Adenosine 3',5'-cyclic monophosphate (cAMP) acts as a second messenger that is involved in the regulation of a plethora of processes. The activation of cAMP signaling in defined compartments is critical for cells to respond to an extracellular stimulus in a specific manner. Rapid advances in the field of human induced pluripotent stem cells (iPSCs) reflect their great potential for cardiovascular disease modeling, drug screening, regenerative and precision medicine. This review discusses cAMP signaling in iPSC-derived cardiovascular disease models, and the prospects of using such systems to elucidate disease mechanisms, drug actions and to identify novel drug targets for the treatment of cardiovascular diseases with unmet medical need, such as hypertension and heart failure.

Dissimilar effects of stereoisomers and racemic hydroxychloroquine on Ca2+ oscillations in human induced pluripotent stem cell-derived cardiomyocytes

All currently employed pharmaceutical formulations of hydroxychloroquine (HCQ) sulfate are a racemate, consisting of equal parts mixture of two stereoisomers: R(-)HCQ and S(+)HCQ sulfates. The aims of the current study were first, to obtain and characterize pure HCQ enantiomers. The separation and purification of free base HCQ enantiomers from the racemate form were performed using semi-preparative chiral high-performance liquid chromatography. Second, we compared the pharmacological properties of both optical isomers and racemic mixture on the intracellular Ca2+ oscillations employing an in vitro model of human cardiomyocytes derived from induced pluripotent stem cells (iPSCs). The results of the pharmacological investigations indicate that the racemic and pure stereoisomer forms of HCQ sulfate exhibited a dose-dependent inhibition of spontaneous Ca2+ oscillations (as measured from their frequency and Ca2+ peak widths) in cardiomyocytes 5-45 min following exposure. In addition, the concentration-response relationships for all three compounds indicated that the rank order of potency (IC50 ) was R(-)HCQ >racemic HCQ >S(+)HCQ for the frequency of the Ca2+ oscillations and width of Ca2+ peaks for all time points examined. These studies indicate that both R(-) and S(+) stereoisomers exhibit differing pharmacological actions on hiPSC cardiomyocytes, with the former effecting a greater potency on cell Ca2+ handling.

Hydroxychloroquine Attenuates hERG Channel by Promoting the Membrane Channel Degradation: Computational Simulation and Experimental Evidence for QT-Interval Prolongation with Hydroxychloroquine Treatment

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has led to millions of confirmed cases and deaths worldwide and has no approved therapy. Currently, more than 700 drugs are tested in the COVID-19 clinical trials, and full evaluation of their cardiotoxicity risks is in high demand.

METHODS

We mainly focused on hydroxychloroquine (HCQ), one of the most concerned drugs for COVID-19 therapy, and investigated the effects and underlying mechanisms of HCQ on hERG channel via molecular docking simulations. We further applied the HEK293 cell line stably expressing hERG-wild-type channel (hERG-HEK) and HEK293 cells transiently expressing hERG-p.Y652A or hERG-p.F656A mutants to validate our predictions. Western blot analysis was used to determine the hERG channel, and the whole-cell patch clamp was utilized to record hERG current (IhERG).

RESULTS

HCQ reduced the mature hERG protein in a time- and concentration-dependent manner. Correspondingly, chronic and acute treatment of HCQ decreased the hERG current. Treatment with brefeldin A (BFA) and HCQ combination reduced hERG protein to a greater extent than BFA alone. Moreover, disruption of the typical hERG binding site (hERG-p.Y652A or hERG-p.F656A) rescued HCQ-mediated hERG protein and IhERG reduction.

CONCLUSION

HCQ can reduce the mature hERG channel expression and IhERG via enhancing channel degradation. The QT prolongation effect of HCQ is mediated by typical hERG binding sites involving residues Tyr652 and Phe656.

Hydroxychloroquine and azithromycin alter the contractility of living porcine heart slices

The cardiotoxicity risk of hydroxychloroquine (HCQ) and azithromycin (AZM) has been the subject of intensive research triggered by safety concerns in COVID-19 patients. HCQ and AZM have been associated with QT interval prolongation and drug-induced arrhythmias, however other cardiotoxicity mechanisms remain largely unexplored. Our group has pioneered the living heart slice preparation, an ex-vivo platform that maintains native cardiac tissue architecture and physiological electrical and contractile properties. Here, we evaluated the cardiotoxic effect of HCQ and AZM applied alone or in combination on cardiac contractility by measuring contractile force and contraction kinetics in heart slices prepared from porcine hearts. Our results show that clinically relevant concentrations of HCQ monotherapy (1-10 µM) reduced contractile force and contraction kinetics in porcine slices in a dose-dependent manner. However, AZM monotherapy decreased contractile force and contraction kinetics only at higher concentrations (30 µM). Combination of HCQ and AZM induced a dose-dependent effect similar to HCQ alone. Furthermore, pre-treating porcine heart slices with the L-type calcium channel agonist Bay K8644 prevented the effect of both drugs, while administration of Bay K8644 after drugs interventions largely reversed the effects, suggesting a mechanism involving inhibition of L-type calcium channels. These findings indicate that HCQ and AZM alter cardiac function beyond QT prolongation with significant contractile dysfunction in intact cardiac tissue. Our porcine heart slices provide a powerful platform to investigate mechanisms of drug cardiotoxicity.

Cardiovascular concentration-effect relationships of amodiaquine and its metabolite desethylamodiaquine: Clinical and preclinical studies

AIMS

Amodiaquine is a 4-aminoquinoline used extensively for the treatment and prevention of malaria. Orally administered amodiaquine is largely converted to the active metabolite desethylamodiaquine. Amodiaquine can cause bradycardia, hypotension, and electrocardiograph QT interval prolongation, but the relationship of these changes to drug concentrations is not well characterized.

METHODS

We conducted a secondary analysis of a pharmacokinetic study of the cardiac safety of amodiaquine (10 mg base/kg/day over 3 days) in 54 Kenyan adults (≥18 years) with uncomplicated malaria. Nonlinear mixed effects modelling was used to assess amodiaquine and desethylamodiaquine concentration-effect relationships for vital sign (pulse rate, blood pressure) and electrocardiograph interval (QT, QRS, PR) outcomes. We also measured the spontaneous beating heart rate after cumulative dosing of amodiaquine and desethylamodiaquine in isolated mouse atrial preparations.

RESULTS

Amodiaquine and desethylamodiaquine caused concentration-dependent mean decreases in pulse rate (1.9 beats/min per 100 nmol/L; 95% confidence interval: 1.5-2.4), supine systolic blood pressure (1.7 mmHg per 100 nmol/L; 1.2-2.1), erect systolic blood pressure (1.5 mmHg per 100 nmol/L; 1.0-2.0) and erect diastolic blood pressure (1.4 mmHg per 100 nmol/L; 1.0-1.7). The mean QT interval prolongation was 1.4 ms per 100 nmol/L irrespective of correction factor after adjustment for residual heart rate dependency. There was no significant effect of drug concentration on postural change in blood pressure or PR and QRS intervals. In mouse atria, the spontaneous beating rate was significantly reduced by amodiaquine (n = 6) and desethylamodiaquine (n = 8) at 3 μmol/L (amodiaquine: 10 ± 2%; desethylamodiaquine: 12 ± 3%) and 10 μmol/L (amodiaquine: 50 ± 7%; desethylamodiaquine: 46 ± 6%) concentrations with no significant difference in potency between the 2 compounds.

CONCLUSION

Amodiaquine and desethylamodiaquine have concentration-dependent effects on heart rate, blood pressure, and ventricular repolarization.

Hydroxychloroquine Mitigates Dilated Cardiomyopathy Phenotype in Transgenic D94A Mice

In this study, we aimed to investigate whether short-term and low-dose treatment with hydroxychloroquine (HCQ), an antimalarial drug, can modulate heart function in a preclinical model of dilated cardiomyopathy (DCM) expressing the D94A mutation in cardiac myosin regulatory light chain (RLC) compared with healthy non-transgenic (NTg) littermates. Increased interest in HCQ came with the COVID-19 pandemic, but the risk of cardiotoxic side effects of HCQ raised concerns, especially in patients with an underlying heart condition, e.g., cardiomyopathy. Effects of HCQ treatment vs. placebo (H₂O), administered in Tg-D94A vs. NTg mice over one month, were studied by echocardiography and muscle contractile mechanics. Global longitudinal strain analysis showed the HCQ-mediated improvement in heart performance in DCM mice. At the molecular level, HCQ promoted the switch from myosin's super-relaxed (SRX) to disordered relaxed (DRX) state in DCM-D94A hearts. This result indicated more myosin cross-bridges exiting a hypocontractile SRX-OFF state and assuming the DRX-ON state, thus potentially enhancing myosin motor function in DCM mice. This bottom-up investigation of the pharmacological use of HCQ at the level of myosin molecules, muscle fibers, and whole hearts provides novel insights into mechanisms by which HCQ therapy mitigates some abnormal phenotypes in DCM-D94A mice and causes no harm in healthy NTg hearts.

cAMP-PKA signaling modulates the automaticity of human iPSC-derived cardiomyocytes

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been used to screen and characterize drugs and to reveal mechanisms underlying cardiac diseases. However, before hiPSC-CMs can be used as a reliable experimental model, the physiological mechanisms underlying their normal function should be further explored. Accordingly, a major feature of hiPSC-CMs is automaticity, which is regulated by both Ca2+ and membrane clocks. To investigate the mechanisms coupling these clocks, we tested three hypotheses: (1) normal automaticity of spontaneously beating hiPSC-CMs is regulated by local Ca2+ releases (LCRs) and cAMP/PKA-dependent coupling of Ca2+ clock to M clock; (2) the LCR period indicates the level of crosstalk within the coupled-clock system; and (3) perturbing the activity of even one clock can lead to hiPSC-CM-altered automaticity due to diminished crosstalk within the coupled-clock system. By measuring the local and global Ca2+ transients, we found that the LCRs properties are correlated with the spontaneous beat interval. Changes in cAMP-dependent coupling of the Ca2+ and M clocks, caused by a pharmacological intervention that either activates the β-adrenergic or cholinergic receptor or upregulates/downregulates PKA signaling, affected LCR properties, which in turn altered hiPSC-CMs automaticity. Clocks' uncoupling by attenuating the pacemaker current If or the sarcoplasmic reticulum Ca2+ kinetics, decreased hiPSC-CMs beating rate, and prolonged the LCR period. Finally, LCR characteristics of spontaneously beating (at comparable rates) hiPSC-CMs and rabbit SAN are similar. In conclusion, hiPSC-CM automaticity is controlled by the coupled-clock system whose function is mediated by Ca2+-cAMP-PKA signaling.

Drug Treatment Effect Model Based on MODWT and Hawkes Self-Exciting Point Process

In precision medicine, especially in the pharmacodynamic area, the lack of an adequate long-term drug effect monitoring model leads to a quite low robustness to the instant drug treatment. Modelling the effect of drug based on the monitoring variables is essential to measure the drug benefit and its side effect preciously. In order to model the complex drug behavior in the context of time series, a sin function is selected to describe the basic trend of heart rate variable that is medically monitored. A Hawkes self-exciting point process model is chosen to describe the effect caused by multiple and sequential drug usage at different time points. The model considers the time lag between the drug given time and the drug effect during the whole drug emission period. A cumulative Gamma distribution is employed to describe the time lag effect. Simulation results demonstrate the established model effectively when describing the baseline trend and the drug effect with low noise levels, where the maximal overlap discrete wavelet transformation is utilized for the information decomposition in the frequency zone. The real data of the variables heart rate and drug liquemin from a medical database is analyzed. Instead of the original time series, scale variable s4 is selected according to the Granger cointegration test. The results show that the model accurately characterizes the cumulative drug effect with the Pearson correlation test value as 0.22, which is more significant for the value under 0.1. In the future, the model can be extended to more complicated scenarios through taking into account multiple monitoring variables and different kinds of drugs.

Review of Hydroxychloroquine Cardiotoxicity: Lessons From the COVID-19 Pandemic

Purpose of Review

The coronavirus disease 2019 (COVID-19) pandemic has popularized the usage of hydroxychloroquine and chloroquine (HCQ/CQ) as treatments for COVID-19. Previously used as anti-malarial and now commonly used in rheumatologic conditions, preliminary in vitro studies have demonstrated these medications also have anti-viral properties. Retinopathy and neuromyopathy are well recognized complications of using these treatments; however, cardiotoxicity is under-recognized. This review will discuss the implications and cardiotoxicity of HCQ/CQ, their mechanisms of action, and their utility in COVID-19.

Recent Findings

Early clinical trials demonstrated a modest benefit of HCQ in COVID-19, causing a push for the usage of it. However, further large multi-center randomized control centers, demonstrated no benefit, and even a trend towards worse outcomes. The predominant cardiac complication observed with HCQ in COVID-19 was cardiac arrhythmias and prolonging of the QT interval. However, with chronic usage of HCQ/CQ, the development of heart failure (HF) and cardiomyopathy (CM) can occur.

Summary

Although, most adverse cardiac events related to HCQ/CQ usage in COVID-19 were secondary to conduction disorders given the short duration of treatment, HCQ/CQ can cause CM and HF, with chronic usage. Given the insufficient evidence, HCQ/CQ usage in COVID-19 is not routinely recommended, especially with novel therapies now being developed and used. Additionally, usage of HCQ/CQ should prompt initial cardiac evaluation with ECG, and yearly monitoring, with consideration for advanced imaging if clinically warranted. The diagnosis of HCQ/CQ cardiomyopathy is important, as prompt cessation can allow for recovery when these changes are still reversible.

Robust, Automated Analysis of Electrophysiology in Induced Pluripotent Stem Cell-Derived Micro-Heart Muscle for Drug Toxicity

Drugs are often removed from clinical trials or market progression owing to their unforeseen effects on cardiac action potential and calcium handling. Induced pluripotent stem cell-derived cardiomyocytes and tissues fabricated from these cells are promising as screening tools for early identification of these potential cardiac liabilities. In this study, we describe an automated, open-source MATLAB-based analysis software for calculating cardiac action potentials and calcium transients from fluorescent reporters. We first identified the most robust manner in which to automatically identify the initiation point for action potentials and calcium transients in a user-independent manner, and used this approach to quantify the duration and morphology of these signals. We then demonstrate the software by assessing changes to action potentials and calcium transients in our micro-heart muscles after exposure to hydroxychloroquine, an antimalarial drug with known cardiac liability. Consistent with clinical observations, our system predicted mild action potential prolongation. However, we also observed marked calcium transient suppression, highlighting the advantage of testing multiple physiologic readouts in cardiomyocytes rather than relying on heterologous overexpression of single channels such as the human ether-a-go-go-related gene channel. This open-source software can serve as a useful, high-throughput tool for analyzing cardiomyocyte physiology from fluorescence imaging.

Hydroxychloroquine and Risk of Long QT Syndrome in Rheumatoid Arthritis: A Veterans Cohort Study With Nineteen-Year Follow-up

OBJECTIVE

Recent evidence suggests that hydroxychloroquine use is not associated with higher 1-year risk of long QT syndrome (LQTS) in patients with rheumatoid arthritis (RA). Less is known about its long-term risk, the examination of which was the objective of this study.

METHODS

We conducted a propensity score-matched active-comparator safety study of hydroxychloroquine in 8,852 veterans (mean age 64 ± 12 years, 14% women, 28% Black) with newly diagnosed RA. A total of 4,426 patients started on hydroxychloroquine and 4,426 started on another nonbiologic disease-modifying antirheumatic drug (DMARD) and were balanced on 87 baseline characteristics. The primary outcome was LQTS during 19-year follow-up through December 31, 2019.

RESULTS

Incident LQTS occurred in 4 (0.09%) and 5 (0.11%) patients in the hydroxychloroquine and other DMARD groups, respectively, during the first 2 years. Respective 5-year incidences were 17 (0.38%) and 6 (0.14%), representing 11 additional LQTS events in the hydroxychloroquine group (number needed to harm 403; [95% confidence interval (95% CI)], 217-1,740) and a 181% greater relative risk (95% CI 11%-613%; P = 0.030). Although overall 10-year risk remained significant (hazard ratio 2.17; 95% CI 1.13-4.18), only 5 extra LQTS occurred in hydroxychloroquine group over the next 5 years (years 6-10) and 1 over the next 9 years (years 11-19). There was no association with arrhythmia-related hospitalization or all-cause mortality.

CONCLUSIONS

Hydroxychloroquine use had no association with LQTS during the first 2 years after initiation of therapy. There was a higher risk thereafter that became significant after 5 years of therapy. However, the 5-year absolute risk was very low, and the absolute risk difference was even lower. Both risks attenuated during longer follow-up. These findings provide evidence for long-term safety of hydroxychloroquine in patients with RA.

Overview of Hydroxychloroquine and Remdesivir on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the ongoing pandemic named COVID-19 which causes a serious emergency on public health hazards of international concern. In the face of a critical medical emergency, repositioning of drugs is one of the most authentic options to design an adequate treatment for infected patients immediately. In this strategy, Remdesivir (Veklury), Hydroxychloroquine appears to be the drug of choice and garnered unprecedented attention as potential therapeutic agents against the pandemic realized worldwide due to SARS-CoV-2 infection. These are the breathtaking instances of possible repositioning of drugs, whose pharmacokinetics and optimal dosage are familiar. In this review, we provide an overview of these medications, their synthesis, and the possible mechanism of action against SARS-CoV-2.

ESC guidance for the diagnosis and management of cardiovascular disease during the COVID-19 pandemic: part 2-care pathways, treatment, and follow-up

AIMS

Since its emergence in early 2020, the novel severe acute respiratory syndrome coronavirus 2 causing coronavirus disease 2019 (COVID-19) has reached pandemic levels, and there have been repeated outbreaks across the globe. The aim of this two part series is to provide practical knowledge and guidance to aid clinicians in the diagnosis and management of cardiovascular (CV) disease in association with COVID-19.

METHODS AND RESULTS

A narrative literature review of the available evidence has been performed, and the resulting information has been organized into two parts. The first, which was reported previously, focused on the epidemiology, pathophysiology, and diagnosis of CV conditions that may be manifest in patients with COVID-19. This second part addresses the topics of: care pathways and triage systems and management and treatment pathways, both of the most commonly encountered CV conditions and of COVID-19; and information that may be considered useful to help patients with CV disease (CVD) to avoid exposure to COVID-19.

CONCLUSION

This comprehensive review is not a formal guideline but rather a document that provides a summary of current knowledge and guidance to practicing clinicians managing patients with CVD and COVID-19. The recommendations are mainly the result of observations and personal experience from healthcare providers. Therefore, the information provided here may be subject to change with increasing knowledge, evidence from prospective studies, and changes in the pandemic. Likewise, the guidance provided in the document should not interfere with recommendations provided by local and national healthcare authorities.

Transcriptional Effects of Candidate COVID-19 Treatments on Cardiac Myocytes

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) has emerged as a major cause of morbidity and mortality worldwide, placing unprecedented pressure on healthcare. Cardiomyopathy is described in patients with severe COVID-19 and increasing evidence suggests that cardiovascular involvement portends a high mortality. To facilitate fast development of antiviral interventions, drugs initially developed to treat other diseases are currently being repurposed as COVID-19 treatments. While it has been shown that SARS-CoV-2 invades cells through the angiotensin-converting enzyme 2 receptor (ACE2), the effect of drugs currently repurposed to treat COVID-19 on the heart requires further investigation.

Methods

Human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) were treated with five repurposed drugs (remdesivir, lopinavir/ritonavir, lopinavir/ritonavir/interferon beta (INF-β), hydroxychloroquine, and chloroquine) and compared with DMSO controls. Transcriptional profiling was performed to identify global changes in gene expression programs.

Results

RNA sequencing of hiPSC-CMs revealed significant changes in gene programs related to calcium handling and the endoplasmic reticulum stress response, most prominently for lopinavir/ritonavir and lopinavir/ritonavir/interferon-beta. The results of the differential gene expression analysis are available for interactive access at https://covid19drugs.jakobilab.org.

Conclusion

Transcriptional profiling in hiPSC-CMs treated with COVID-19 drugs identified unfavorable changes with lopinavir/ritonavir and lopinavir/ritonavir/INF-β in key cardiac gene programs that may negatively affect heart function.

Pharmacometric and Electrocardiographic Evaluation of Chloroquine and Azithromycin in Healthy Volunteers

Chloroquine and azithromycin were developed in combination for the preventive treatment of malaria in pregnancy, and more recently were proposed as coronavirus disease 2019 (COVID‐19) treatment options. Billions of doses of chloroquine have been administered worldwide over the past 70 years but concerns regarding cardiotoxicity, notably the risk of torsades de pointes (TdP), remain. This investigation aimed to characterize the pharmacokinetics and electrocardiographic effects of chloroquine and azithromycin observed in a large previously conducted healthy volunteer study. Healthy adult volunteers (n = 119) were randomized into 5 arms: placebo, chloroquine alone (600 mg base), or chloroquine with either 500 mg, 1,000 mg, or 1,500 mg of azithromycin all given daily for 3 days. Chloroquine and azithromycin levels, measured using liquid‐chromatography tandem mass spectrometry, and electrocardiograph intervals were recorded at frequent intervals. Time‐matched changes in the PR, QRS, and heart rate‐corrected JT, and QT intervals were calculated and the relationship with plasma concentrations was evaluated using linear and nonlinear mixed‐effects modeling. Chloroquine and azithromycin pharmacokinetics were described satisfactorily by two‐ and three‐compartment distribution models, respectively. No drug–drug interaction between chloroquine and azithromycin was observed. Chloroquine resulted in concentration‐dependent prolongation of the PR, QRS, JTc and QTc intervals with a minimal additional effect of azithromycin. QRS widening contributed ~ 28% of the observed QT prolongation. Chloroquine causes significant concentration‐dependent delays in both ventricular depolarization and repolarization. Co‐administration of azithromycin did not significantly increase these effects. The arrhythmogenic risk of TdP associated with chloroquine may have been substantially overestimated in studies which did not separate electrocardiograph QRS and JT prolongation.

Increase in Ca2+-Activated cAMP/PKA Signaling Prevents Hydroxychloroquine-Induced Bradycardia of the Cardiac Pacemaker

Bradycardia or tachycardia are known side effects of drugs that limit their clinical use. The heart pacemaker function which control the heart rate under normal conditions is determined by coupled clock system. Thus, interfering with specific clock mechanism will affect other clock mechanisms through changes in interconnected signaling and can lead to rhythm disturbance. However, upregulation of a different clock components can compensate for this change. We focus here on hydroxychloroquine (HCQ), which has been shown effective in treating COVID-19 patients, however its bradycardic side effect limits its clinical use. We aim to decipher the mechanisms underlying the effect of HCQ on pacemaker automaticity, to identify a potential drug that will eliminate the bradycardia. We used isolated rabbit sinoatrial node (SAN) cells, human-induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs) and mouse SAN cells residing in SAN tissue. Further, we employed SAN cell computational model to suggest mechanistic insights of the effect of HCQ on pacemaker function. HCQ increased mean spontaneous beat interval and variability in all three models in parallel to slower intracellular kinetics. The computational model suggested that HCQ affects the pacemaker (funny) current (If), L-type Ca2+ current (ICa,L), transient outward potassium (Ito) and due to changes in Ca2+ kinetics, the sodium-calcium exchanger current (INCX). Co-application of 3’-isobutylmethylxanthine (IBMX) and HCQ prevented the increase in beat interval and variability in all three experimental models. The HCQ-induced increase in rabbit and mice SAN cell and hiPSC-CM spontaneous beat interval, can be prevented by a phosphodiester inhibitor that restores automaticity due to slower intracellular Ca2+ kinetics.

Whole blood drug levels do not correlate with QTc intervals in hydroxychloroquine-treated systemic lupus erythematosus patients

OBJECTIVES

HCQ is recommended for all patients with SLE, but reports of cardiac toxicity in severe acute respiratory syndrome coronavirus 2 patients raised concerns. We aimed to study the relationship between HCQ blood levels and QTc intervals.

METHODS

A retrospective review of 90 SLE patients (cohort 1) was conducted with data collected regarding demographics, QTc interval and chronic kidney disease (CKD). A prospective study of 84 SLE patients (cohort 2) was conducted with data collected regarding demographics, dose of HCQ, duration of HCQ treatment, presence of echocardiographic abnormalities and CKD simultaneous with whole blood HCQ levels measured by HPLC. Statistical analysis utilized one-way analysis of variance, Pearson's correlation coefficient and t tests.

RESULTS

In cohort 1 there was no significant difference in mean QTc based on 75 HCQ-treated [437.91 msec (s.d. 20.02)] as compared with 15 untreated patients [434.6 msec (s.d. 27.49)]. In patients with CKD, the mean QTc in HCQ users [448 (s.d. 23.37)] as compared with non-users [444.5 msec (s.d. 24.61)] also had no significant difference. In cohort 2, HCQ levels did not correlate with QTc interval (r = 0.017) and this applied regardless of the dose prescribed (r = 0.113 for 400 mg and r = 0.06 for 200 mg), duration of exposure (P = 0.36 for 0-5, >5-10 or >10 years), CKD (r = 0.482) or underlying cardiac abnormalities (r = 0.430).

CONCLUSIONS

This is the first study relying on measured blood levels demonstrating the absence of a clinically consequential increase in QTc levels in HCQ-treated SLE patients.

ESC guidance for the diagnosis and management of cardiovascular disease during the COVID-19 pandemic: part 2-care pathways, treatment, and follow-up

AIMS

Since its emergence in early 2020, the novel severe acute respiratory syndrome coronavirus 2 causing coronavirus disease 2019 (COVID-19) has reached pandemic levels, and there have been repeated outbreaks across the globe. The aim of this two part series is to provide practical knowledge and guidance to aid clinicians in the diagnosis and management of cardiovascular (CV) disease in association with COVID-19.

METHODS AND RESULTS

A narrative literature review of the available evidence has been performed, and the resulting information has been organized into two parts. The first, which was reported previously, focused on the epidemiology, pathophysiology, and diagnosis of CV conditions that may be manifest in patients with COVID-19. This second part addresses the topics of: care pathways and triage systems and management and treatment pathways, both of the most commonly encountered CV conditions and of COVID-19; and information that may be considered useful to help patients with CV disease (CVD) to avoid exposure to COVID-19.

CONCLUSION

This comprehensive review is not a formal guideline but rather a document that provides a summary of current knowledge and guidance to practicing clinicians managing patients with CVD and COVID-19. The recommendations are mainly the result of observations and personal experience from healthcare providers. Therefore, the information provided here may be subject to change with increasing knowledge, evidence from prospective studies, and changes in the pandemic. Likewise, the guidance provided in the document should not interfere with recommendations provided by local and national healthcare authorities.

Synergistic Adverse Effects of Azithromycin and Hydroxychloroquine on Human Cardiomyocytes at a Clinically Relevant Treatment Duration

Adverse effects of drug combinations and their underlying mechanisms are highly relevant for safety evaluation, but often not fully studied. Hydroxychloroquine (HCQ) and azithromycin (AZM) were used as a combination therapy in the treatment of COVID-19 patients at the beginning of the pandemic, leading to higher complication rates in comparison to respective monotherapies. Here, we used human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to systematically investigate the effects of HCQ, AZM, and their combination on the structure and functionality of cardiomyocytes, and to better understand the underlying mechanisms. Our results demonstrate synergistic adverse effects of AZM and HCQ on electrophysiological and contractile function of iPSC-CMs. HCQ-induced prolongation of field potential duration (FPDc) was gradually increased during 7-day treatment period and was strongly enhanced by combination with AZM, although AZM alone slightly shortened FPDc in iPSC-CMs. Combined treatment with AZM and HCQ leads to higher cardiotoxicity, more severe structural disarrangement, more pronounced contractile dysfunctions, and more elevated conduction velocity, compared to respective monotreatments. Mechanistic insights underlying the synergistic effects of AZM and HCQ on iPSC-CM functionality are provided based on increased cellular accumulation of HCQ and AZM as well as increased Cx43- and Nav1.5-protein levels.

QTc interval prolongation in patients infected with SARS-CoV-2 and treated with antiviral drugs

Introduction

Many antiviral agents, such as hydroxychloroquine, have been used to treat COVID-19, without being broadly accepted. QTc prolongation is a worrisome adverse effect, scarcely studied in pediatrics.

Patients and methods

Paediatric patients affected from COVID-19 who received antivirals were matched (1:2) with controls not infected nor exposed. Electrocardiograms were prospectively analyzed at baseline, during the first 72 h of treatment and after 72 h.

Results

Eleven (22.9%) out of 48 patients admitted due to COVID-19 (March–July 2020) received antiviral therapy. All had underlying diseases: congenital heart disease (4/11; 36.4%) and immunosuppression (3/11; 27.3%) stand out. 5/11 (45.5%) received treatment at baseline with a potential effect on QTc. There where no differences observed in the baseline QTc between cases and controls: 414.8 ms (49.2) vs 416.5 ms (29.4), (P = .716). Baseline long QT was observed in 2/11 cases and 2/22. Among cases, 10/11 (90.9%) received hydroxychloroquine, mainly associated with azithromycin (8/11; 72.7%), 3 received lopinavir/ritonavir and one remdesivir. The median increase in QTc after 72 h under treatment was 28.9 ms [IQR 48.7] (P = .062). 4/11 (36.4%) patients had a long QTc at 72 h, resulting in 3 patients ≥500 ms; treatment was stopped in one (QTc 510 ms) but ventricular arrhythmias were not documented.

Conclusions

The use of antivirals caused an increase on the QTc interval after 72 h of treatment, being the QTc long in 36.3% of the patients, although no arrhythmic events were observed. The use of hydroxychloroquine and antivirals requires active QTc monitoring and it is recommended to discontinue treatment if QTc > 500 ms.

Use of hiPSC-Derived Cardiomyocytes to Rule Out Proarrhythmic Effects of Drugs: The Case of Hydroxychloroquine in COVID-19

In the early phases of the COVID-19 pandemic, drug repurposing was widely used to identify compounds that could improve the prognosis of symptomatic patients infected by SARS-CoV-2. Hydroxychloroquine (HCQ) was one of the first drugs used to treat COVID-19 due to its supposed capacity of inhibiting SARS-CoV-2 infection and replication in vitro. While its efficacy is debated, HCQ has been associated with QT interval prolongation and potentially Torsades de Pointes, especially in patients predisposed to developing drug-induced Long QT Syndrome (LQTS) as silent carriers of variants associated with congenital LQTS. If confirmed, these effects represent a limitation to the at-home use of HCQ for COVID-19 infection as adequate ECG monitoring is challenging. We investigated the proarrhythmic profile of HCQ with Multi-Electrode Arrays after exposure of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from two healthy donors, one asymptomatic and two symptomatic LQTS patients. We demonstrated that: I) HCQ induced a concentration-dependent Field Potential Duration (FPD) prolongation and halted the beating at high concentration due to the combined effect of HCQ on multiple ion currents. II) hiPSC-CMs from healthy or asymptomatic carriers tolerated higher concentrations of HCQ and showed lower susceptibility to HCQ-induced electrical abnormalities regardless of baseline FPD. These findings agree with the clinical safety records of HCQ and demonstrated that hiPSC-CMs potentially discriminates symptomatic vs. asymptomatic mutation carriers through pharmacological interventions. Disease-specific cohorts of hiPSC-CMs may be a valid preliminary addition to assess drug safety in vulnerable populations, offering rapid preclinical results with valuable translational relevance for precision medicine.

Arrhythmogenic mechanisms of interleukin-6 combination with hydroxychloroquine and azithromycin in inflammatory diseases

Inflammatory diseases including COVID-19 are associated with a cytokine storm characterized by high interleukin-6 (IL-6) titers. In particular, while recent studies examined COVID-19 associated arrhythmic risks from cardiac injury and/or from pharmacotherapy such as the combination of azithromycin (AZM) and hydroxychloroquine (HCQ), the role of IL-6 per se in increasing the arrhythmic risk remains poorly understood. The objective is to elucidate the electrophysiological basis of inflammation-associated arrhythmic risk in the presence of AZM and HCQ. IL-6, AZM and HCQ were concomitantly administered to guinea pigs in-vivo and in-vitro. Electrocardiograms, action potentials and ion-currents were analyzed. IL-6 alone or the combination AZM + HCQ induced mild to moderate reduction in heart rate, PR-interval and corrected QT (QTc) in-vivo and in-vitro. Notably, IL-6 alone was more potent than the combination of the two drugs in reducing heart rate, increasing PR-interval and QTc. In addition, the in-vivo or in-vitro combination of IL-6 + AZM + HCQ caused severe bradycardia, conduction abnormalities, QTc prolongation and asystole. These electrocardiographic abnormalities were attenuated in-vivo by tocilizumab (TCZ), a monoclonal antibody against IL-6 receptor, and are due in part to the prolongation of action potential duration and selective inhibition of Na⁺, Ca²⁺ and K⁺ currents. Inflammation confers greater risk for arrhythmia than the drug combination therapy. As such, in the setting of elevated IL-6 during inflammation caution must be taken when co-administering drugs known to predispose to fatal arrhythmias and TCZ could be an important player as a novel anti-arrhythmic agent. Thus, identifying inflammation as a critical culprit is essential for proper management.

Assessment of proarrhythmogenic risk for chloroquine and hydroxychloroquine using the CiPA concept

Chloroquine and hydroxychloroquine have been proposed recently as therapy for SARS-CoV-2-infected patients, but during 3 months of extensive use concerns were raised related to their clinical effectiveness and arrhythmogenic risk. Therefore, we estimated for these compounds several proarrhythmogenic risk predictors according to the Comprehensive in vitro Proarrhythmia Assay (CiPA) paradigm. Experiments were performed with either CytoPatch™2 automated or manual patch-clamp setups on HEK293T cells stably or transiently transfected with hERG1, hNav1.5, hKir2.1, hKv7.1+hMinK, and on Pluricyte® cardiomyocytes (Ncardia), using physiological solutions. Dose-response plots of hERG1 inhibition fitted with Hill functions yielded IC50 values in the low micromolar range for both compounds. We found hyperpolarizing shifts of tens of mV, larger for chloroquine, in the voltage-dependent activation but not inactivation, as well as a voltage-dependent block of hERG current, larger at positive potentials. We also found inhibitory effects on peak and late INa and on IK1, with IC50 of tens of μM and larger for chloroquine. The two compounds, tested on Pluricyte® cardiomyocytes using the β-escin-perforated method, inhibited IKr, ICaL, INa peak, but had no effect on If. In current-clamp they caused action potential prolongation. Our data and those from literature for Ito were used to compute proarrhythmogenic risk predictors Bnet (Mistry HB, 2018) and Qnet (Dutta S et al., 2017), with hERG1 blocking/unblocking rates estimated from time constants of fractional block. Although the two antimalarials are successfully used in autoimmune diseases, and chloroquine may be effective in atrial fibrillation, assays place these drugs in the intermediate proarrhythmogenic risk group.

Prolonged corrected QT interval in hospitalized patients with coronavirus disease 2019 in Dubai, United Arab Emirates: a single-center, retrospective study

OBJECTIVE

To evaluate the association of a prolonged corrected QT (QTc) interval in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its association with in-patient mortality.

METHODS

A cohort of 745 patients were recruited from a single center between 1 March 2020 and 31 May 2020. We analyzed the factors associated with a prolonged QTc and mortality.

RESULTS

A prolonged QTc interval >450 ms was found in 27% of patients admitted with SARS-CoV-2 infection. These patients were predominantly older, on a ventilator, and had hypertension, diabetes mellitus, or ischemic heart disease. They also had high troponin and D-dimer concentrations. A prolonged QTc interval had a significant association with the requirement of ventilator support and was associated with an increased odds of mortality. Patients who died were older than 55 years, and had high troponin, D-dimer, creatinine, procalcitonin, and ferritin concentrations, a high white blood cell count, and abnormal potassium concentrations (hypo- or hyperkalemia).

CONCLUSIONS

A prolonged QTc interval is common in patients with SARS-CoV-2 infection and it is associated with worse outcomes. Older individuals and those with comorbidities should have an electrocardiogram performed, which is noninvasive and easily available, on admission to hospital to identify high-risk patients.

Electrophysiological and Proarrhythmic Effects of Hydroxychloroquine Challenge in Guinea-Pig Hearts

Hydroxychloroquine (HCQ), clinically established in antimalarial and autoimmune therapy, recently raised cardiac arrhythmogenic concerns when used alone or with azithromycin (HCQ+AZM) in Covid-19. We report complementary, experimental, studies of its electrophysiological effects. In patch clamped HEK293 cells expressing human cardiac ion channels, HCQ inhibited IKr and IK1 at a therapeutic concentrations (IC50s: 10 ± 0.6 and 34 ± 5.0 μM). INa and ICaL showed higher IC50s; Ito and IKs were unaffected. AZM slightly inhibited INa, ICaL, IKs, and IKr, sparing IK1 and Ito. (HCQ+AZM) inhibited IKr and IK1 (IC50s: 7.7 ± 0.8 and 30.4 ± 3.0 μM), sparing INa, ICaL, and Ito. Molecular induced-fit docking modeling confirmed potential HCQ-hERG but weak AZM-hERG binding. Effects of μM-HCQ were studied in isolated perfused guinea-pig hearts by multielectrode, optical RH237 voltage, and Rhod-2 mapping. These revealed reversibly reduced left atrial and ventricular action potential (AP) conduction velocities increasing their heterogeneities, increased AP durations (APDs), and increased durations and dispersions of intracellular [Ca2+] transients, respectively. Hearts also became bradycardic with increased electrocardiographic PR and QRS durations. The (HCQ+AZM) combination accentuated these effects. Contrastingly, (HCQ+AZM) and not HCQ alone disrupted AP propagation, inducing alternans and torsadogenic-like episodes on voltage mapping during forced pacing. O'Hara-Rudy modeling showed that the observed IKr and IK1 effects explained the APD alterations and the consequently prolonged Ca2+ transients. The latter might then downregulate INa, reducing AP conduction velocity through recently reported INa downregulation by cytosolic [Ca2+] in a novel scheme for drug action. The findings may thus prompt future investigations of HCQ's cardiac safety under particular, chronic and acute, clinical situations.

The cardiovascular effects of amodiaquine and structurally related antimalarials: An individual patient data meta-analysis

BACKGROUND

Amodiaquine is a 4-aminoquinoline antimalarial similar to chloroquine that is used extensively for the treatment and prevention of malaria. Data on the cardiovascular effects of amodiaquine are scarce, although transient effects on cardiac electrophysiology (electrocardiographic QT interval prolongation and sinus bradycardia) have been observed. We conducted an individual patient data meta-analysis to characterise the cardiovascular effects of amodiaquine and thereby support development of risk minimisation measures to improve the safety of this important antimalarial.

METHODS AND FINDINGS

Studies of amodiaquine for the treatment or prevention of malaria were identified from a systematic review. Heart rates and QT intervals with study-specific heart rate correction (QTcS) were compared within studies and individual patient data pooled for multivariable linear mixed effects regression. The meta-analysis included 2,681 patients from 4 randomised controlled trials evaluating artemisinin-based combination therapies (ACTs) containing amodiaquine (n = 725), lumefantrine (n = 499), piperaquine (n = 716), and pyronaridine (n = 566), as well as monotherapy with chloroquine (n = 175) for uncomplicated malaria. Amodiaquine prolonged QTcS (mean = 16.9 ms, 95% CI: 15.0 to 18.8) less than chloroquine (21.9 ms, 18.3 to 25.6, p = 0.0069) and piperaquine (19.2 ms, 15.8 to 20.5, p = 0.0495), but more than lumefantrine (5.6 ms, 2.9 to 8.2, p < 0.001) and pyronaridine (-1.2 ms, -3.6 to +1.3, p < 0.001). In individuals aged ≥12 years, amodiaquine reduced heart rate (mean reduction = 15.2 beats per minute [bpm], 95% CI: 13.4 to 17.0) more than piperaquine (10.5 bpm, 7.7 to 13.3, p = 0.0013), lumefantrine (9.3 bpm, 6.4 to 12.2, p < 0.001), pyronaridine (6.6 bpm, 4.0 to 9.3, p < 0.001), and chloroquine (5.9 bpm, 3.2 to 8.5, p < 0.001) and was associated with a higher risk of potentially symptomatic sinus bradycardia (≤50 bpm) than lumefantrine (risk difference: 14.8%, 95% CI: 5.4 to 24.3, p = 0.0021) and chloroquine (risk difference: 8.0%, 95% CI: 4.0 to 12.0, p < 0.001). The effect of amodiaquine on the heart rate of children aged <12 years compared with other antimalarials was not clinically significant. Study limitations include the unavailability of individual patient-level adverse event data for most included participants, but no serious complications were documented.

CONCLUSIONS

While caution is advised in the use of amodiaquine in patients aged ≥12 years with concomitant use of heart rate-reducing medications, serious cardiac conduction disorders, or risk factors for torsade de pointes, there have been no serious cardiovascular events reported after amodiaquine in widespread use over 7 decades. Amodiaquine and structurally related antimalarials in the World Health Organization (WHO)-recommended dose regimens alone or in ACTs are safe for the treatment and prevention of malaria.

Genetic deletion of the Tas2r143/Tas2r135/Tas2r126 cluster reveals that TAS2Rs may not mediate bitter tastant-induced bronchodilation

Bitter taste receptors (TAS2Rs) and their signaling elements are detected throughout the body, and bitter tastants induce a wide variety of biological responses in tissues and organs outside the mouth. However, the roles of TAS2Rs in these responses remain to be tested and established genetically. Here, we employed the CRISPR/Cas9 gene-editing technique to delete three bitter taste receptors-Tas2r143/Tas2r135/Tas2r126 (i.e., Tas2r triple knockout [TKO]) in mice. The fidelity and effectiveness of the Tas2r deletions were validated genetically at DNA and messenger RNA levels and functionally based on the tasting of TAS2R135 and TAS2R126 agonists. Bitter tastants are known to relax airways completely. However, TAS2R135 or TAS2R126 agonists either failed to induce relaxation of pre-contracted airways in wild-type mice and Tas2r TKO mice or relaxed them dose-dependently, but to the same extent in both types of mice. These results indicate that TAS2Rs are not required for bitter tastant-induced bronchodilation. The Tas2r TKO mice also provide a valuable model to resolve whether TAS2Rs mediate bitter tastant-induced responses in many other extraoral tissues.

Contemporary approach to understand and manage COVID-19-related arrhythmia

Arrhythmia, one of the most common complications of COVID-19, was reported in nearly one-third of diagnosed COVID-19 patients, with higher prevalence rate among ICU admitted patients. The underlying etiology for arrhythmia in these cases are mostly multifactorial as those patients may suffer from one or more of the following predisposing mechanisms; catecholamine surge, hypoxia, myocarditis, cytokine storm, QTc prolongation, electrolyte disturbance, and pro-arrhythmic drugs usage. Obviously, the risk for arrhythmia and the associated lethal outcome would rise dramatically among patients with preexisting cardiac disease such as myocardial ischemia, heart failure, cardiomyopathy, and hereditary arrhythmias. Considering all of these variables, the management strategy of COVID-19 patients should expand from managing a viral infection and related host immune response to include the prevention of predictable causes for arrhythmia. This may necessitate the need to investigate the role of some drugs that modulate the pathway of arrhythmia generation. Of these drugs, we discuss the potential role of adrenergic antagonists, trimetazidine, ranolazine, and the debatable angiotensin converting enzyme inhibitors drugs. We also recommend monitoring the level of: unbound free fatty acids, serum electrolytes, troponin, and QTc (even in the absence of apparent pro-arrhythmic drug use) as these may be the only indicators for patients at risk for arrhythmic complications.

Heart Muscle Microphysiological System for Cardiac Liability Prediction of Repurposed COVID-19 Therapeutics

Despite global efforts, it took 7 months between the proclamation of global SARS-CoV-2 pandemic and the first FDA-approved treatment for COVID-19. During this timeframe, clinicians focused their efforts on repurposing drugs, such as hydroxychloroquine (HCQ) or azithromycin (AZM) to treat hospitalized COVID-19 patients. While clinical trials are time-consuming, the exponential increase in hospitalizations compelled the FDA to grant an emergency use authorization for HCQ and AZM as treatment for COVID-19, although there was limited evidence of their combined efficacy and safety. The authorization was revoked 4 months later, giving rise to controversial political and scientific debates illustrating important challenges such as premature authorization of potentially ineffective or unsafe therapeutics, while diverting resources from screening of effective drugs. Here we report on a preclinical drug screening platform, a cardiac microphysiological system (MPS), to rapidly identify clinically relevant cardiac liabilities associated with HCQ and AZM. The cardiac MPS is a microfabricated fluidic system in which cardiomyocytes derived from human induced pluripotent stem cells self-arrange into a uniaxially beating tissue. The drug response was measured using outputs that correlate with clinical measurements such as action potential duration (proxy for clinical QT interval) and drug-biomarker pairing. The cardiac MPS predicted clinical arrhythmias associated with QT prolongation and rhythm instabilities in tissues treated with HCQ. We found no change in QT interval upon acute exposure to AZM, while still observing a significant increase in arrhythmic events. These results suggest that this MPS can not only predict arrhythmias, but it can also identify arrhythmias even when QT prolongation is absent. When exposed to HCQ and AZM polytherapy, this MPS faithfully reflected clinical findings, in that the combination of drugs synergistically increased QT interval when compared to single drug exposure, while not worsening the overall frequency of arrhythmic events. The high content cardiac MPS can rapidly evaluate the cardiac safety of potential therapeutics, ultimately accelerating patients' access to safe and effective treatments.

COVID-19 induced bradyarrhythmia and relative bradycardia: An overview

Novel coronavirus 2019 (COVID-19) has been the focus of the medical community since its emergence in December 2019 and has already infected more than 100 million patients globally. Primarily described to cause a respiratory illness, COVID-19 has been found to affect almost every organ system. Bradycardia is a newly recognized ramification of COVID-19 that still has unknown prognostic value. Studies have shown an increase in the incidence of arrhythmias, cardiomyopathies, myocarditis, acute coronary syndromes, and coagulopathies in infected patients as well as an increased risk of mortality in patients with preexisting cardiovascular disease. While the pathogenesis of bradycardia in COVID-19 may be multifactorial, clinicians should be aware of the mechanism by which COVID-19 affects the cardiovascular system and the medication side effects which are used in the treatment algorithm of this deadly virus. There has yet to be a comprehensive review analyzing bradyarrhythmia and relative bradycardia in COVID-19 infected patients. We aim to provide a literature review including the epidemiology, pathogenesis, and management of COVID-19 induced bradyarrhythmia.

Modelling sudden cardiac death risks factors in patients with coronavirus disease of 2019: the hydroxychloroquine and azithromycin case

AIMS

Coronavirus disease of 2019 (COVID-19) has rapidly become a worldwide pandemic. Many clinical trials have been initiated to fight the disease. Among those, hydroxychloroquine and azithromycin had initially been suggested to improve clinical outcomes. Despite any demonstrated beneficial effects, they are still in use in some countries but have been reported to prolong the QT interval and induce life-threatening arrhythmia. Since a significant proportion of the world population may be treated with such COVID-19 therapies, evaluation of the arrhythmogenic risk of any candidate drug is needed.

METHODS AND RESULTS

Using the O'Hara-Rudy computer model of human ventricular wedge, we evaluate the arrhythmogenic potential of clinical factors that can further alter repolarization in COVID-19 patients in addition to hydroxychloroquine (HCQ) and azithromycin (AZM) such as tachycardia, hypokalaemia, and subclinical to mild long QT syndrome. Hydroxychloroquine and AZM drugs have little impact on QT duration and do not induce any substrate prone to arrhythmia in COVID-19 patients with normal cardiac repolarization reserve. Nevertheless, in every tested condition in which this reserve is reduced, the model predicts larger electrocardiogram impairments, as with dofetilide. In subclinical conditions, the model suggests that mexiletine limits the deleterious effects of AZM and HCQ.

CONCLUSION

By studying the HCQ and AZM co-administration case, we show that the easy-to-use O'Hara-Rudy model can be applied to assess the QT-prolongation potential of off-label drugs, beyond HCQ and AZM, in different conditions representative of COVID-19 patients and to evaluate the potential impact of additional drug used to limit the arrhythmogenic risk.

Does hydroxychloroquine still have any role in the COVID-19 pandemic?

Introduction: The 4-aminoquinolines, chloroquine, and hydroxychloroquine have been used for over 70 years for malaria and rheumatological conditions, respectively. Their broad-spectrum antiviral activity, excellent safety profile, tolerability, low cost, and ready availability made them prime repurposing therapeutic candidates at the beginning of the COVID-19 pandemic.Areas covered: Here, the authors discuss the history of hydroxychloroquine and chloroquine, the in vitro data which led to their widespread repurposing and adoption in COVID-19 and their complex pharmacokinetics. The evidence for the use of these drugs is assessed through in vivo animal experiments and the wealth of conflicting data and interpretations published during COVID-19, including the more informative results from randomized controlled trials (RCTs). The safety aspects of these drugs, in particular cardiotoxicity, are then reviewed.Expert opinion: The evidence from clinical trials in COVID-19 supports the well-established safety record of the 4-aminoquinolines at currently recommended dosage. In hospitalized patients with severe COVID-19 RCTs show clearly that the 4-aminoquinolines are not beneficial. The only treatments with proven benefit at this stage of infection are immunomodulators (dexamethasone, IL-6 receptor antagonists). No antiviral drugs have proven life-saving in late-stage COVID-19.

Comprehensive Cardiotoxicity Assessment of COVID-19 Treatments Using Human Induced Pluripotent Stem Cell-derived Cardiomyocytes

Coronavirus disease 2019 (COVID-19) continues to spread across the globe, with numerous clinical trials underway seeking to develop and test effective COVID-19 therapies, including remdesivir. Several ongoing studies have reported hydroxychloroquine-induced cardiotoxicity, including development of torsade de pointes (TdP). Meanwhile, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are expected to serve as a tool for assessing drug-induced cardiotoxicity, such as TdP and contraction impairment. However, the cardiotoxicity of COVID-19 treatments has not been fully assessed using hiPSC-CMs. In the present study, we focused on drug repurposing with various modes of actions and examined the TdP risk associated with COVID-19 treatments using field potential using multi-electrode array (MEA) system and motion analysis with hiPSC-CMs. Hydroxychloroquine induced early after depolarization, while remdesivir, favipiravir, camostat and ivermectin had little effect on field potentials. We then analyzed electromechanical window (EMw), which is defined as the difference between field potential and contraction-relaxation durations. Hydroxychloroquine decreased EMw of hiPSC-CMs in a concentration-dependent manner. In contrast, other drugs have little effect. Our data suggest that hydroxychloroquine has proarrhythmic risk and other drugs have low proarrhythmic risk. Thus, hiPSC-CMs represent a useful tool for assessing the comprehensive cardiotoxicity caused by COVID-19 treatments in non-clinical settings.

Lack of efficacy of hydroxychloroquine and azithromycin in patients hospitalized for COVID-19 pneumonia: A retrospective study

Background

Hydroxychloroquine combined with azithromycin (HCQ/AZI) has initially been used against coronavirus disease-2019 (COVID-19). In this retrospective study, we assessed the clinical effects of HCQ/AZI, with a 28-days follow-up.

Methods

In a registry-study which included patients hospitalized for COVID-19 between March 15 and April 2, 2020, we compared patients who received HCQ/AZI to those who did not, regarding a composite outcome of mortality and mechanical ventilation with a 28-days follow-up. QT was monitored for patients treated with HCQ/AZI. Were excluded patients in intensive care units, palliative care and ventilated within 24 hours of admission. Three analyses were performed to adjust for selection bias: propensity score matching, multivariable survival, and inverse probability score weighting (IPSW) analyses.

Results

Overall, 203 patients were included: 60 patients treated by HCQ/AZI and 143 control patients. During the 28-days follow-up, 32 (16.3%) patients presented the primary outcome and 23 (12.3%) patients died. Propensity-score matching identified 52 unique pairs of patients with similar characteristics. In the matched cohort (n = 104), HCQ/AZI was not associated with the primary composite outcome (log-rank p-value = 0.16). In the overall cohort (n = 203), survival and IPSW analyses also found no benefit from HCQ/AZI. In the HCQ/AZI group, 11 (18.3%) patients prolonged QT interval duration, requiring treatment cessation.

Conclusions

HCQ/AZI combination therapy was not associated with lower in-hospital mortality and mechanical ventilation rate, with a 28-days follow-up. In the HCQ/AZI group, 18.3% of patients presented a prolonged QT interval requiring treatment cessation, however, control group was not monitored for this adverse event, making comparison impossible.

Association of hydroxychloroquine and cardiac arrhythmia in patients with systemic lupus erythematosus: A population-based case control study

Objectives

Hydroxychloroquine is widely used to treat certain viral and rheumatic diseases including systemic lupus erythematosus. Cardiac arrhythmia is an important safety issue with hydroxychloroquine. The aim of this study was to investigate whether hydroxychloroquine increases new-onset arrhythmia among patients with systemic lupus erythematosus.

Methods

This was a nested case-control study using data from the Longitudinal Health Insurance Database of Taiwan. A conditional logistic regression model was used to analyse differences in the risk of arrhythmia between systemic lupus erythematosus patients with and without hydroxychloroquine treatment after controlling for related variables.

Results

A total of 2499 patients with newly diagnosed systemic lupus erythematosus were identified (81% females), of whom 251 were enrolled in the new-onset arrhythmia group (mean age 50.4 years) and 251 in the non-arrhythmia group (mean age 49.1 years). There was no significantly increased risk of cardiac arrhythmia (adjusted odds ratio = 1.49, 95% confidence interval: 0.98–2.25) or ventricular arrhythmia (adjusted odds ratio = 1.02, 95% confidence interval: 0.19–5.41) between the patients with and without hydroxychloroquine treatment. In addition, there were no significant differences in the risk of arrhythmia between those receiving hydroxychloroquine treatment for <180 days or ≥180 days, with a drug adherence rate of <50% or ≥50%, and receiving a daily dose of <400 mg or ≥400 mg.

Conclusion

In patients with systemic lupus erythematosus, hydroxychloroquine treatment did not significantly increase the risk of cardiac arrhythmia or life-threatening ventricular arrhythmia regardless of the different hydroxychloroquine treatment duration, drug adherence rate, or daily dose.

Effect of Hydroxychloroquine on QTc in Patients Diagnosed with COVID-19: A Systematic Review and Meta-Analysis

BACKGROUND

Hydroxychloroquine or chloroquine with or without the concomitant use of azithromycin have been widely used to treat patients with SARS-CoV-2 infection, based on early in vitro studies, despite their potential to prolong the QTc interval of patients.

OBJECTIVE

This is a systematic review and metanalysis designed to assess the effect of hydroxychloroquine with or without the addition of azithromycin on the QTc of hospitalized patients with COVID-19.

MATERIALS AND METHODS

PubMed, Scopus, Cochrane and MedRxiv databases were reviewed. A random effect model meta-analysis was used, and I-square was used to assess the heterogeneity. The prespecified endpoints were ΔQTc, QTc prolongation > 500 ms and ΔQTc > 60 ms.

RESULTS

A total of 18 studies and 7179 patients met the inclusion criteria and were included in this systematic review and meta-analysis. The use of hydroxychloroquine with or without the addition of azithromycin was associated with increased QTc when used as part of the management of patients with SARS-CoV-2 infection. The combination therapy with hydroxychloroquine plus azithromycin was also associated with statistically significant increases in QTc. Moreover, the use of hydroxychloroquine alone, azithromycin alone, or the combination of the two was associated with increased numbers of patients that developed QTc prolongation > 500 ms.

CONCLUSION

This systematic review and metanalysis revealed that the use of hydroxychloroquine alone or in conjunction with azithromycin was linked to an increase in the QTc interval of hospitalized patients with SARS-CoV-2 infection that received these agents.

[QTc interval prolongation in patients infected with SARS-CoV-2 and treated with antiviral drugs]

INTRODUCTION

Many antiviral agents, such as hydroxychloroquine, have been used to treat COVID-19, without being broadly accepted. QTc prolongation is a worrisome adverse effect, scarcely studied in pediatrics.

PATIENTS AND METHODS

Pediatric patients affected from COVID-19 who received antivirals were matched (1:2) with controls not infected nor exposed. Electrocardiograms were prospectively analyzed at baseline, during the first 72 h in treatment and after 72 h.

RESULTS

Eleven (22.9%) out of 48 patients admitted due to COVID-19 (March-July 2020) received antiviral therapy. All had underlying diseases: congenital heart disease (4/11; 36.4%) and immunosuppression (3/11; 27.3%) stand out. 5/11 (45.5%) received treatment at baseline with a potential effect on QTc. There where no differences observed in the baseline QTc between cases and controls: 414.8 ms (49.2) vs. 416.5 ms (29.4) (p = 0.716). Baseline long QT was observed in 2/11 cases and 2/22. Among cases, 10/11 (90.9%) received hydroxychloroquine, mainly associated with azithromycin (8/11; 72.7%), 3 received lopinavir/ritonavir and one remdesivir. The median increase in QTc after 72 h under treatment was 28.9 ms (IQR 48.7) (p = 0.062). 4/11 (36.4%) patients had a long QTc at 72 h, resulting in 3 patients ≥500 ms; treatment was stopped in one (QTc 510 ms) but ventricular arrhythmias were not documented.

CONCLUSIONS

The use of antivirals caused an increase on the QTc interval after 72 h of treatment, being the QTc long in 36.3% of the patients, although no arrhythmic events were observed. The use of hydroxychloroquine and antivirals requires active QTc monitoring and it is recommended to discontinue treatment if QTc >500 ms.

Cardiac TdP risk stratification modelling of anti-infective compounds including chloroquine and hydroxychloroquine

Hydroxychloroquine (HCQ), the hydroxyl derivative of chloroquine (CQ), is widely used in the treatment of rheumatological conditions (systemic lupus erythematosus, rheumatoid arthritis) and is being studied for the treatment and prevention of COVID-19. Here, we investigate through mathematical modelling the safety profile of HCQ, CQ and other QT-prolonging anti-infective agents to determine their risk categories for Torsade de Pointes (TdP) arrhythmia. We performed safety modelling with uncertainty quantification using a risk classifier based on the qNet torsade metric score, a measure of the net charge carried by major currents during the action potential under inhibition of multiple ion channels by a compound. Modelling results for HCQ at a maximum free therapeutic plasma concentration (free C max) of approximately 1.2 µM (malaria dosing) indicated it is most likely to be in the high-intermediate-risk category for TdP, whereas CQ at a free C max of approximately 0.7 µM was predicted to most likely lie in the intermediate-risk category. Combining HCQ with the antibacterial moxifloxacin or the anti-malarial halofantrine (HAL) increased the degree of human ventricular action potential duration prolongation at some or all concentrations investigated, and was predicted to increase risk compared to HCQ alone. The combination of HCQ/HAL was predicted to be the riskiest for the free C max values investigated, whereas azithromycin administered individually was predicted to pose the lowest risk. Our simulation approach highlights that the torsadogenic potentials of HCQ, CQ and other QT-prolonging anti-infectives used in COVID-19 prevention and treatment increase with concentration and in combination with other QT-prolonging drugs.

Cardiotoxic Potential of Hydroxychloroquine, Chloroquine and Azithromycin in Adult Human Primary Cardiomyocytes

Substantial efforts have been recently committed to develop coronavirus disease-2019 (COVID-19) medications, and Hydroxychloroquine alone or in combination with Azithromycin has been promoted as a repurposed treatment. Although these drugs may increase cardiac toxicity risk, cardiomyocyte mechanisms underlying this risk remain poorly understood in humans. Therefore, we evaluated the proarrhythmia risk and inotropic effects of these drugs in the cardiomyocyte contractility-based model of the human heart. We found Hydroxychloroquine to have a low proarrhythmia risk, whereas Chloroquine and Azithromycin were associated with high risk. Hydroxychloroquine proarrhythmia risk changed to high with low level of K+, whereas high level of Mg2+ protected against proarrhythmic effect of high Hydroxychloroquine concentrations. Moreover, therapeutic concentration of Hydroxychloroquine caused no enhancement of elevated temperature-induced proarrhythmia. Polytherapy of Hydroxychloroquine plus Azithromycin and sequential application of these drugs were also found to influence proarrhythmia risk categorization. Hydroxychloroquine proarrhythmia risk changed to high when combined with Azithromycin at therapeutic concentration. However, Hydroxychloroquine at therapeutic concentration impacted the cardiac safety profile of Azithromycin and its proarrhythmia risk only at concentrations above therapeutic level. We also report that Hydroxychloroquine and Chloroquine, but not Azithromycin, decreased contractility while exhibiting multi-ion channel block features, and Hydroxychloroquine's contractility effect was abolished by Azithromycin. Thus, this study has the potential to inform clinical studies evaluating repurposed therapies, including those in the COVID-19 context. Additionally, it demonstrates the translational value of the human cardiomyocyte contractility-based model as a key early discovery path to inform decisions on novel therapies for COVID-19, malaria, and inflammatory diseases.

Cardiac Corrected QT Interval Changes Among Patients Treated for COVID-19 Infection During the Early Phase of the Pandemic

IMPORTANCE

Critical illness, a marked inflammatory response, and viruses such as SARS-CoV-2 may prolong corrected QT interval (QTc).

OBJECTIVE

To evaluate baseline QTc interval on 12-lead electrocardiograms (ECGs) and ensuing changes among patients with and without COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 3050 patients aged 18 years and older who underwent SARS-CoV-2 testing and had ECGs at Columbia University Irving Medical Center from March 1 through May 1, 2020. Patients were analyzed by treatment group over 5 days, as follows: hydroxychloroquine with azithromycin, hydroxychloroquine alone, azithromycin alone, and neither hydroxychloroquine nor azithromycin. ECGs were manually analyzed by electrophysiologists masked to COVID-19 status. Multivariable modeling evaluated clinical associations with QTc prolongation from baseline.

EXPOSURES

COVID-19, hydroxychloroquine, azithromycin.

MAIN OUTCOMES AND MEASURES

Mean QTc prolongation, percentage of patients with QTc of 500 milliseconds or greater.

RESULTS

A total of 965 patients had more than 2 ECGs and were included in the study, with 561 (58.1%) men, 198 (26.2%) Black patients, and 191 (19.8%) aged 80 years and older. There were 733 patients (76.0%) with COVID-19 and 232 patients (24.0%) without COVID-19. COVID-19 infection was associated with significant mean QTc prolongation from baseline by both 5-day and 2-day multivariable models (5-day, patients with COVID-19: 20.81 [95% CI, 15.29 to 26.33] milliseconds; P < .001; patients without COVID-19: -2.01 [95% CI, -17.31 to 21.32] milliseconds; P = .93; 2-day, patients with COVID-19: 17.40 [95% CI, 12.65 to 22.16] milliseconds; P < .001; patients without COVID-19: 0.11 [95% CI, -12.60 to 12.81] milliseconds; P = .99). COVID-19 infection was independently associated with a modeled mean 27.32 (95% CI, 4.63-43.21) millisecond increase in QTc at 5 days compared with COVID-19-negative status (mean QTc, with COVID-19: 450.45 [95% CI, 441.6 to 459.3] milliseconds; without COVID-19: 423.13 [95% CI, 403.25 to 443.01] milliseconds; P = .01). More patients with COVID-19 not receiving hydroxychloroquine and azithromycin had QTc of 500 milliseconds or greater compared with patients without COVID-19 (34 of 136 [25.0%] vs 17 of 158 [10.8%], P = .002). Multivariable analysis revealed that age 80 years and older compared with those younger than 50 years (mean difference in QTc, 11.91 [SE, 4.69; 95% CI, 2.73 to 21.09]; P = .01), severe chronic kidney disease compared with no chronic kidney disease (mean difference in QTc, 12.20 [SE, 5.26; 95% CI, 1.89 to 22.51; P = .02]), elevated high-sensitivity troponin levels (mean difference in QTc, 5.05 [SE, 1.19; 95% CI, 2.72 to 7.38]; P < .001), and elevated lactate dehydrogenase levels (mean difference in QTc, 5.31 [SE, 2.68; 95% CI, 0.06 to 10.57]; P = .04) were associated with QTc prolongation. Torsades de pointes occurred in 1 patient (0.1%) with COVID-19.

CONCLUSIONS AND RELEVANCE

In this cohort study, COVID-19 infection was independently associated with significant mean QTc prolongation at days 5 and 2 of hospitalization compared with day 0. More patients with COVID-19 had QTc of 500 milliseconds or greater compared with patients without COVID-19.

Cardiac arrhythmias amongst hospitalised Coronavirus 2019 (COVID-19) patients: Prevalence, characterisation, and clinical algorithm to classify arrhythmic risk

OBJECTIVES

A significant proportion of COVID-19 patients may have cardiac involvement including arrhythmias. Although arrhythmia characterisation and possible predictors were previously reported, there are conflicting data regarding the exact prevalence of arrhythmias. Clinically applicable algorithms to classify COVID patients' arrhythmic risk are still lacking, and are the aim of our study.

METHODS

We describe a single-centre cohort of hospitalised patients with a positive nasopharyngeal swab for COVID-19 during the initial Israeli outbreak between 1/2/2020 and 30/5/2020. The study's outcome was any documented arrhythmia during hospitalisation, based on daily physical examination, routine ECG's, periodic 24-hour Holter, and continuous monitoring. Multivariate analysis was used to find predictors for new arrhythmias and create classification trees for discriminating patients with high and low arrhythmic risk.

RESULTS

Out of 390 COVID-19 patients included, 28 (7.2%) had documented arrhythmias during hospitalisation, including 23 atrial tachyarrhythmias, combined atrial fibrillation (AF), and ventricular fibrillation, ventricular tachycardia storm, and 3 bradyarrhythmias. Only 7/28 patients had previous arrhythmias. Our study showed a significant correlation between disease severity and arrhythmia prevalence (P < .001) with a low arrhythmic prevalence amongst mild disease patients (2%). Multivariate analysis revealed background heart failure (CHF) and disease severity are independently associated with overall arrhythmia while age, CHF, disease severity, and arrhythmic symptoms are associated with tachyarrhythmias. A novel decision tree using age, disease severity, CHF, and troponin levels was created to stratify patients into high and low risk for developing arrhythmia.

CONCLUSIONS

Dominant arrhythmia amongst COVID-19 patients is AF. Arrhythmia prevalence is associated with age, disease severity, CHF, and troponin levels. A novel simple Classification tree, based on these parameters, can discriminate between high and low arrhythmic risk patients.

Chloroquine-induced Prolonged QT Interval in COVID-19 Patients in Indonesia: Case Series

The treatment of corona virus disease 2019 (COVID-19)remains in debate, and the use of chloroquine has not been validated by accurate clinical trials.The aim of this study was to provide the possible cardiotoxicity effect of chloroquine in patients with COVID-19. This study was a case-series of prolonged QT interval of COVID-19 patients treated with chloroquine in a hospital in Bali, Indonesia. There were two cases of COVID-19 with exhibited a prolonged QT interval after being administrated of chloroquine. The prolonged QT interval returned to normal after chloroquine was stopped.These cases alert us the cardiotoxicity effect of chloroquine and the need for serial electro-cardiography monitoring before and during therapy. In conclusion, although antiviral and anti-inflammation properties of chloroquine on COVID-19 are promising, its cardiotoxicity effects should be monitored closely for less harm to the patients.

QT prolongation associated with hydroxychloroquine and protease inhibitors in COVID-19

What is known and Objective

Hydroxychloroquine and protease inhibitors were widely used as off‐label treatment options for COVID‐19 but the safety data of these drugs among the COVID‐19 population are largely lacking. Drug‐induced QTc prolongation is a known adverse reaction of hydroxychloroquine, especially during chronic treatment. However, when administered concurrently with potential pro‐arrhythmic drugs such as protease inhibitors, the risk of QTc prolongation imposed on these patients is not known. We aim to investigate the incidence of QTc prolongation events and potential factors associated with its occurrence in COVID‐19 population.

Methods

We included 446 SARS‐CoV‐2 RT‐PCR‐positive patients taking at least one treatment drug for COVID‐19 within a period of one month (March–April 2020). In addition to COVID‐19‐related treatment (HCQ/PI), concomitant drugs with risks of QTc prolongation were considered. We defined QTc prolongation as QTc interval of ≥470 ms in postpubertal males, and ≥480 ms in postpubertal females.

Results and Discussion

QTc prolongation events occurred in 28/446 (6.3%) patients with an incidence rate of 1 case per 100 person‐days. A total of 26/28 (93%) patients who had prolonged QTc intervals received at least two pro‐QT drugs. Multivariate analysis showed that HCQ and PI combination therapy had five times higher odds of QTc prolongation as compared to HCQ‐only therapy after controlling for age, cardiovascular disease, SIRS and the use of concurrent QTc‐prolonging agents besides HCQ and/or PI (OR 5.2; 95% CI, 1.11‐24.49; p = 0.036). Independent of drug therapy, presence of SIRS resulted in four times higher odds of QTc prolongation (OR 4.3; 95% CI, 1.66‐11.06; p = 0.003). In HCQ‐PI combination group, having concomitant pro‐QT drugs led to four times higher odds of QTc prolongation (OR 3.8; 95% CI, 1.53‐9.73; p = 0.004). Four patients who had prolonged QTc intervals died but none were cardiac‐related deaths.

What is new and conclusion

In our cohort, hydroxychloroquine monotherapy had low potential to increase QTc intervals. However, when given concurrently with protease inhibitors which have possible or conditional risk, the odds of QTc prolongation increased fivefold. Interestingly, independent of drug therapy, the presence of systemic inflammatory response syndrome (SIRS) resulted in four times higher odds of QTc prolongation, leading to the postulation that some QTc events seen in COVID‐19 patients may be due to the disease itself. ECG monitoring should be continued for at least a week from the initiation of treatment.

Electrocardiographic modifications and cardiac involvement in COVID-19 patients: results from an Italian cohort

AIM

The aim of this study was to detect predisposing CV risks factors and ECGs changes in COVID-19 patients.

METHODS

The study population included 60 noncritically ill patients with COVID-19 pneumonia admitted to our hospital between 16 March and 11 May 2020. Electrographic changes, evaluated from ECGs acquired at admission and at 7 days after starting COVID-19 therapy, were analysed. We also compared 45 patients without CV involvement with 15 patients with new onset of cardiac adverse events during hospitalization.

RESULTS

ECGs under treatment showed a lower heart rate (HR) (69.45 ± 8.06 vs 80.1 ± 25.1 beats/min, P = 0,001) and a longer QRS (102.46 ± 15.08 vs 96.75 ± 17.14, P = 0.000) and QT corrected (QTc) interval (452.15 ± 37.55 vs 419.9 ± 33.41, P = 0,000) duration than ECGs before therapy. Fifteen patients (25%) showed clinical CV involvement. Within this group, female sex, lower ejection fraction (EF), low serum haemoglobin, high Troponin I levels (TnI), low lymphocytes count, high serum IL-6 levels, or use of Tocilizumab (TCZ) were more represented.

CONCLUSIONS

Patients admitted for SARS-CoV2 infection and treated with anti-COVID-19 drug therapy develop ECG changes such as reduction in HR and increase in QRS duration and QTc interval. One in four patients developed CV events. Gender, EF, heamoglobin values, TnI, lymphocytes count, IL-6 and use of TCZ can be considered as predisposing factors for CV involvement.

Efficacy and safety of hydroxychloroquine as add-on therapy in uncontrolled type 2 diabetes patients who were using two oral antidiabetic drugs

OBJECTIVE

To evaluate the Safety and Efficacy of Hydroxychloroquine as add-on therapy in uncontrolled type 2 diabetes patients who were using two oral antidiabetic drugs.

MATERIALS AND METHODS

This was a double blind, placebo controlled, parallel group study in 304 inadequately controlled type 2 diabetes (T2DM) subjects with two oral antidiabetic drugs (glimepiride 4 mg and metformin 500 mg) were randomised to hydroxychloroquine (HCQ) 200 mg, 300 mg, 400 mg once daily (OD) or placebo. Dose of hydroxychloroquine was selected as per body weight of the subject. Primary end point was glycated haemoglobin (HbA1c) change at week 12 from baseline. Secondary endpoint was change in fasting plasma glucose (FPG), post prandial plasma glucose (PPG), body weight and any adverse reaction including no of hypoglycemic events, as well as a change in the percentage of subjects with A1C < 7.0% and > 6.5% after 12 weeks of treatment.. In follow-up of 400 mg once daily was once again divided to 200 mg twice daily (BD) to study the effect on tolerability profile for further 12 weeks.

RESULTS

Hydroxychloroquine was associated with significant reduction in HbA1c from baseline (7-8.5%) in 12 weeks -0.78%, -0.91% and 1.2% for hydroxychloroquine 200 mg, 300 mg and 400 mg OD, respectively, versus 0.13% with placebo (P < 0.005). FPG and PPG were reduced by -25 to -38 mg/dl and 34-53 mg/dl, respectively. Body weight also reduced in each group of HCQ. Hypoglycemia was reported only with 300 mg (1.2%) and 400 mg (2.1%) group of HCQ. It was observed that patients who complains with mild GI disturbance with HCQ 400 mg glycemic efficacy was maintained with 200 mg BD with significant relief of the symptoms.

CONCLUSION

Hydroxychloroquine added to sulphonylurea and metformin, improves glycemic control significantly in T2DM patients. Glycemic effect of different dose of hydroxychloroquine is dose dependent. The safety/tolerability profile of hydroxychloroquine was favourable except GI disturbance which is more frequent with 400 mg. This can be avoided with 200 mg BD without compromise on efficacy.