Drug-Induced QTc Prolongation: What We Know and Where We Are Going.

Drug-induced QTc prolongation is a concerning electrocardiogram (ECG) abnormality. This cardiac disturbance carries a 10% risk of sudden cardiac death due to the malignant arrhythmia, Torsades de Pointes. The Arizona Center for Education and Research on Therapeutics (AzCERT) has classified QTc prolonging therapeutic classes, such as antiarrhythmics, antipsychotics, anti-infectives, and others. AzCERT criteria categorize medications into three risk categories: "known," "possible," and "conditional risk" of QTc prolongation and Torsades de Pointes. The list of QTc prolonging medications continues to expand as new drug classes are approved and studied. Risk factors for QTc prolongation can be delineated into modifiable or non-modifiable. A validated risk scoring tool may be utilized to predict the likelihood of prolongation in patients receiving AzCERT classified medication. The resultant risk score may be applied to a clinical decision support system, which offers mitigation strategies. Mitigation strategies including discontinuation of possible offending agents with a selection of an alternative agent, assessment of potential drug interactions or dose adjustments through pharmacokinetic and pharmacodynamic monitoring, and initiation of both ECG and electrolyte monitoring are essential to prevent a drug-induced arrhythmia. The challenges presented by the COVID-19 pandemic have led to the development of innovative continuous monitoring technology, increasing protection for both patients and healthcare workers. Early intervention strategies may reduce adverse events and improve clinical outcomes in patients identified to be at risk of QTc prolongation.

Effect of COVID-19 medications on corrected QT interval and induction of torsade de pointes: Results of a multicenter national survey.

BACKGROUND: There are some data showing that repurposed drugs used for the Coronavirus disease-19 (COVID-19) have potential to increase the risk of QTc prolongation and torsade de pointes (TdP), and these arrhythmic side effects have not been adequately addressed in COVID-19 patients treated with these repurposed medications. METHODS: This is the prospective study of 2403 patients hospitalised at 13 hospitals within the COVID-19 epicentres of the Iran. These patients were treated with chloroquine, hydroxychloroquine, lopinavir/ritonavir, atazanavir/ritonavir, oseltamivir, favipiravir and remdesivir alone or in combination with azithromycin. The primary outcome of the study was incidence of critical QTc prolongation, and secondary outcomes were incidences of TdP and death. RESULTS: Of the 2403 patients, 2365 met inclusion criteria. The primary outcome of QTc ≥ 500 ms and ∆QTc ≥ 60 ms was observed in 11.2% and 17.6% of the patients, respectively. The secondary outcomes of TdP and death were reported in 0.38% and 9.8% of the patients, respectively. The risk of critical QT prolongation increased in the presence of female gender, history of heart failure, treatment with hydroxychloroquine, azithromycin combination therapy, simultaneous furosemide or beta-blocker therapy and acute renal or hepatic dysfunction. However, the risk of TdP was predicted by treatment with lopinavir-ritonavir, simultaneous amiodarone or furosemide administration and hypokalaemia during treatment. CONCLUSION: This cohort showed significant QTc prolongation with all COVID-19 medications studied, however, life-threatening arrhythmia of TdP occurred rarely. Among the repurposed drugs studied, hydroxychloroquine or lopinavir-ritonavir alone or in combination with azithromycin clearly demonstrated to increase the risk of critical QT prolongation and/or TdP.

A pharmacovigilance study to quantify the strength of association between the combination of antimalarial drugs and azithromycin and cardiac arrhythmias: implications for the treatment of COVID-19.

Background: Hydroxychloroquine, an antimalarial drug, combined with azithromycin has been considered a potential treatment for COVID-19. However, these drugs may cause electrocardiogram QT prolongation (QTp) and torsade de Pointes (TdP). We examined potential safety signals for these cardiac arrhythmias. Methods: Using the OpenVigil 2.1 MedDRA platform, we mined data from the U.S. Food and Drug Administration's Adverse Event Reporting System (FAERS) from December 2019 to June 2020. We extracted individual case safety reports based on exposures of seven antimalarial drugs, azithromycin, and combinations. All other drugs in FAERS served as controls. Events of interest included QTp and TdP, with associations between drug exposures and events expressed as adjusted Reporting-Odds-Ratios (aRORs) and confidence intervals. The lower end of aROR 95% confidence interval >1 was used as the statistically significant signal detection threshold. Results: QTp safety signals were found for hydroxychloroquine[aROR:11.70 (10.40-13.16)], chloroquine[aROR:18.97 (11.30-31.87)], quinine[aROR:16.66 (10.18-27.25)], atovaquone[aROR:6.91 (4.14-11.56)], azithromycin alone [aROR:28.02 (22.87-34.32)] and hydroxychloroquine + azithromycin [aROR:75.23 (51.15-110.66)]. TdP safety signals were found for hydroxychloroquine [aROR: 5.62 (4.94-6.38)], chloroquine[aROR:49.37 (30.63-79.58)], and hydroxychloroquine + azithromycin[aROR:33.09 (21.22-51.61)]. Conclusion: Hydroxychloroquine/chloroquine and/or azithromycin was associated with QTp/TdP safety signals and their use should be monitored carefully.

Incidence and treatment of arrhythmias secondary to coronavirus infection in humans: A systematic review.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has affected millions of people worldwide resulting in significant morbidity and mortality. Arrhythmias are prevalent and reportedly, the second most common complication. Several mechanistic pathways are proposed to explain the pro-arrhythmic effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A number of treatment approaches have been trialled, each with its inherent unique challenges. This rapid systematic review aimed to examine the current incidence and available treatment of arrhythmias in COVID-19, as well as barriers to implementation. METHODS: Our search of scientific databases identified relevant published studies from 1 January 2000 until 1 June 2020. We also searched Google Scholar for grey literature. We identified 1729 publications of which 1704 were excluded. RESULTS: The incidence and nature of arrhythmias in the setting of COVID-19 were poorly documented across studies. The cumulative incidence of arrhythmia across studies of hospitalised patients was 6.9%. Drug-induced long QT syndrome secondary to antimalarial and antimicrobial therapy was a significant contributor to arrhythmia formation, with an incidence of 14.15%. Torsades de pointes (TdP) and sudden cardiac death (SCD) were reported. Treatment strategies aim to minimise this through risk stratification and regular monitoring of corrected QT interval (QTc). CONCLUSION: Patients with SARS-CoV-2 are at an increased risk of arrhythmias. Drug therapy is pro-arrhythmogenic and may result in TdP and SCD in these patients. Risk assessment and regular QTc monitoring are imperative for safety during the treatment course. Further studies are needed to guide future decision-making.

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.

COVID-19 and cardiac arrhythmias: a global perspective on arrhythmia characteristics and management strategies.

BACKGROUND: Cardiovascular and arrhythmic events have been reported in hospitalized COVID-19 patients. However, arrhythmia manifestations and treatment strategies used in these patients have not been well-described. We sought to better understand the cardiac arrhythmic manifestations and treatment strategies in hospitalized COVID-19 patients through a worldwide cross-sectional survey. METHODS: The Heart Rhythm Society (HRS) sent an online survey (via SurveyMonkey) to electrophysiology (EP) professionals (physicians, scientists, and allied professionals) across the globe. The survey was active from March 27 to April 13, 2020. RESULTS: A total of 1197 respondents completed the survey with 50% of respondents from outside the USA, representing 76 countries and 6 continents. Of respondents, 905 (76%) reported having COVID-19-positive patients in their hospital. Atrial fibrillation was the most commonly reported tachyarrhythmia whereas severe sinus bradycardia and complete heart block were the most common bradyarrhythmias. Ventricular tachycardia/ventricular fibrillation arrest and pulseless electrical activity were reported by 4.8% and 5.6% of respondents, respectively. There were 140 of 631 (22.2%) respondents who reported using anticoagulation therapy in all COVID-19-positive patients who did not otherwise have an indication. One hundred fifty-five of 498 (31%) reported regular use of hydroxychloroquine/chloroquine (HCQ) + azithromycin (AZM); concomitant use of AZM was more common in the USA. Sixty of 489 respondents (12.3%) reported having to discontinue therapy with HCQ + AZM due to significant QTc prolongation and 20 (4.1%) reported cases of Torsade de Pointes in patients on HCQ/chloroquine and AZM. Amiodarone was the most common antiarrhythmic drug used for ventricular arrhythmia management. CONCLUSIONS: In this global survey of > 1100 EP professionals regarding hospitalized COVID-19 patients, a variety of arrhythmic manifestations were observed, ranging from benign to potentially life-threatening. Observed adverse events related to use of HCQ + AZM included prolonged QTc requiring drug discontinuation as well as Torsade de Pointes. Large prospective studies to better define arrhythmic manifestations as well as the safety of treatment strategies in COVID-19 patients are warranted.

Cardiac safety of off-label COVID-19 drug therapy: a review and proposed monitoring protocol.

More than 2,000,000 individuals worldwide have had coronavirus 2019 disease infection (COVID-19), yet there is no effective medical therapy. Multiple off-label and investigational drugs, such as chloroquine and hydroxychloroquine, have gained broad interest due to positive pre-clinical data and are currently used for treatment of COVID-19. However, some of these medications have potential cardiac adverse effects. This is important because up to one-third of patients with COVID-19 have cardiac injury, which can further increase the risk of cardiomyopathy and arrhythmias. Adverse effects of chloroquine and hydroxychloroquine on cardiac function and conduction are broad and can be fatal. Both drugs have an anti-arrhythmic property and are proarrhythmic. The American Heart Association has listed chloroquine and hydroxychloroquine as agents which can cause direct myocardial toxicity. Similarly, other investigational drugs such as favipiravir and lopinavir/ritonavir can prolong QT interval and cause Torsade de Pointes. Many antibiotics commonly used for the treatment of patients with COVID-19, for instance azithromycin, can also prolong QT interval. This review summarizes evidenced-based data regarding potential cardiac adverse effects due to off-label and investigational drugs including chloroquine and hydroxychloroquine, antiviral therapy, monoclonal antibodies, as well as common antibiotics used for the treatment of COVID-19. The article focuses on practical points and offers a point-of-care protocol for providers who are taking care of patients with COVID-19 in an inpatient and outpatient setting. The proposed protocol is taking into consideration that resources during the pandemic are limited.