Factors associated with prolonged QTc interval in Iranian population: MASHAD cohort study.

AIM: QTc interval prolongation is a growing global issue which can cause torsades de pointes, a potentially fatal arrhythmia. We aimed to identify risk factors for prolonged QT interval in men and women. METHODS: The Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study collected electrocardiogram interval data. QT was corrected for heart rate using the Bazett's formula. Ordinal logistic regression with crude (univariable) and adjusted (multivariate) association analyses in the form of odds ratio and corresponding 95% confidence interval (CI) were used to identify the factors associated with QTc prolongation. RESULTS: A total of 8878 individuals including 5318 females and 3560 males, aged 35 to 65 years, were included in this cross-sectional study. Participants with QTc prolongation were more likely to be older and have hypercholesterolemia, hypertension (HTN), and Type 2 diabetes mellitus (T2DM), but to have lower levels of physical activity (P < 0.05). Age (OR = 1.68, 95%CI = 1.18-2.39), hypercholesterolemia (OR = 1.77, 95%CI = 1.24-2.51), HTN (OR = 1.36, 95%CI = 1.06-1.73), T2DM (OR = 1.59, 95%CI = 1.19-2.13), severe anxiety (OR = 1.80, 95%CI = 1.05-3.11) and mild depression (OR = 1.38, 95%CI = 1.01-1.88) were independent risk factors for prolonged QTc interval in men. For women, only HTN (OR = 1.29, 95%CI = 1.02-1.63) and T2DM (OR = 1.50, 95%CI = 1.14-1.97) were independent risk factors. CONCLUSIONS: Older age, Hypercholesterolemia, HTN, T2DM, severe anxiety and mild depression in men, and HTN and T2DM in women were associated with high risk of prolonged QTc interval. Healthcare practitioners should be aware of the risk factors of QTc interval prolongation and should exercise caution in the management of certain patients.

Linezolid and the risk of QT interval prolongation: A pharmacovigilance study of the Food and Drug Administration Adverse Event Reporting System.

AIMS: Few studies have investigated linezolid (LZD)-associated cardiotoxicity. This study explored the potential association between LZD and QT interval prolongation. METHODS: Adverse event reports of QT interval prolongation associated with LZD from the Food and Drug Administration Adverse Event Reporting System from January 2013 to December 2021 were analysed and the reporting odds ratio (ROR) with 95% confidence intervals were calculated. RESULTS: A total of 6738 adverse event reports of LZD as the primary and secondary suspected drug were obtained from the database, including 192 reports with electrocardiogram QT prolonged (QTp), and the ROR value was 26.1 (95% CI = 22.6-30.2). There were 8 reports of long QT syndrome, ROR 14.2 (95% CI = 7.1-28.5); 5 reports of torsade de pointes, ROR 3.2 (95% CI = 1.3-7.6); and 5 reports of ventricular tachycardia, ROR 1.9 (95% CI = 0.8-4.5). Subgroup analysis revealed that patients with tuberculosis treated with LZD had a higher reporting rate among all QTp reports, exhibiting an odds ratio of 330.0 (95% CI = 223.1-488.1). The odds ratios of QTp associated with LZD treatments in patients with and without tuberculosis were 4.2 (95% CI = 3.4-5.3) and 1.2 (95% CI = 0.8-1.6), respectively. CONCLUSION: The study showed an association between LZD and QT interval prolongation. In the report on patients with tuberculosis, the incidence of QTp was higher when treated with LZD.

Dostarlimab, an anti-programmed death-1 monoclonal antibody, does not cause QT prolongation in patients with solid tumours: A concentration-QT analysis.

AIMS: Patients with solid tumours were treated with the anti-PD-1 antibody dostarlimab in the Phase I GARNET trial. This study aimed to examine dostarlimab's effect on corrected QT (QTc) interval and the systemic concentration-QTc interval relationship. METHODS: In GARNET Part 2B, patients received 500 mg dostarlimab every 3 weeks (Q3W) for four cycles, then 1000 mg Q6W. Triplicate 12-lead ECGs were recorded and time-matched pharmacokinetic (PK) samples collected at screening, on Day 1 of Cycles 1, 4, 5, 8, 12 (pre-dose and 0.5 h after infusion end), and at treatment end. Concentration-change from baseline QTcF (ΔQTcF) analysis using a linear mixed effects model, summary statistics, incidence of clinically noteworthy ECG values and rhythm abnormalities were evaluated. RESULTS: A total of 377 patients were considered for evaluation (n = 15 excluded from concentration-ΔQTcF). There was a non-significant concentration-ΔQTcF relationship (0.001589 ms/µg/mL; P = .5906). Mean ΔQTcF increase was <6 ms (upper-bound two-sided 90% confidence interval [CI], <10 ms at all post-dose timepoints). Highest geometric mean concentration was 414.1 µg/mL (Cycle 5 Day 1, 0.5 h) with predicted mean ∆QTcF of 3.064 ms (upper-bound two-sided 90% CI: 5.071). Mean QTcF prolongation (all concentrations) was 2.4 ms. QTcF prolongation ≥500 ms occurred in five patients (1.3%); 51 (13.6%) and nine patients (2.4%) had ΔQTcF ≥30 ms and ≥60 ms, respectively. Ten patients (2.7%) reported rhythm abnormalities. No U-wave abnormalities, torsades de pointes, ventricular tachycardia or ventricular fibrillation/flutter were observed. CONCLUSIONS: Dostarlimab does not cause clinically significant QTcF prolongation exceeding the regulatory concern threshold.

Analysis of clinical characteristics and automatic monitoring of drug-induced arrhythmias in 167,546 inpatients.

OBJECTIVE: The purpose of this study was to analyze the occurrence characteristics, clinical manifestations, medication distribution, and incidence of drug-induced arrhythmias in a real-world inpatient population. METHODS: According to the inclusion and exclusion criteria as well as the ADR evaluation criteria, we retrospectively evaluated hospitalized patients in 2019 using the arrhythmia module of the Adverse Drug Event Active Surveillance and Assessment System-II (ADE-ASAS-II). A detailed analysis was performed on the demographic data, ADR manifestations, and medication distribution of 2097 patients with drug-induced arrhythmias and QT interval prolongation. RESULTS: Of the 167,546 hospitalized patients, there were 1809 cases of drug-induced arrhythmias, with an incidence of 1.08%. The ADRs in 45.35% of positive patients occurred within 3 days after medication administration, and 46.73% of the patients were 65 years old or older. The predominant ADRs identified in this study were extrasystole, tachycardia, and QT interval prolongation, of which the incidence was 0.20%. Levofloxacin was the most involved drug, and levofloxacin-associated rates of incidence of arrhythmia and QT interval prolongation were 1.24% and 0.44%, respectively. The risk factors for drug-induced arrhythmias were male sex, advanced age, emaciation, obesity, and underlying illnesses such as cardiovascular diseases, diabetes mellitus, cerebrovascular diseases, and hepatic and renal inadequacy (P < 0.05). CONCLUSION: The incidence of drug-induced arrhythmias was in the range of common, while QTc interval prolongation was occasional. It is necessary to pay attention to patients with risk factors.

QT Prolongation in Dialysis Patients: An Epidemiological Study with a Focus on Malnutrition.

BACKGROUND/AIMS: QT prolongation is a known risk factor for ventricular fibrillation and ventricular tachycardia. Therefore, more refined management is necessary to reduce sudden cardiac death secondary to such arrhythmias. METHODS: Electrocardiographic findings were reviewed in 224 patients, and the associations of QT prolongation with various clinical parameters were examined, including the nutritional state. Correlations were also examined between QT prolongation and body composition measurements determined by multifrequency bioelectrical impedance analysis. RESULTS: Prolongation of the corrected QT (QTc) interval over 0.44 s was seen in 140 patients (62.5%). QT prolongation was independent of age and dialysis therapy duration and was more frequent in diabetics (70.1%) than in nondiabetics (54.2%, p = 0.014) and more frequent in women (78.8%) than in men (53.5%, p < 0.001). Serum levels of albumin (p < 0.001) and Cr (p < 0.001) and the Geriatric Nutritional Risk Index (GNRI, p < 0.001) were negatively correlated with QTc interval; no significant correlation was noted with total protein, urea nitrogen, or uric acid. Negative correlations with QTc interval were found for BMI(p < 0.01), percent total body water (%TBW; p < 0.05), and percent intracellular water (%ICW; p < 0.01) but not with the percent extracellular water/TBW ratio or edema ratio. The longer the QTc interval, the lower the fat-free mass (FFM; p < 0.01) and muscle mass (MM; p < 0.01), but there was no significant correlation with percent fat. CONCLUSION: These results suggest that QT prolongation is a common complication and is more frequent in women and diabetic patients. The decreases in serum albumin and Cr levels, GNRI, BMI, %TBW, %ICW, FFM, and MM together coincided with malnutrition and thus suggest a close relationship of QT prolongation with malnutrition. Management of QT prolongation may be achieved better in the future by understanding these biochemical and biophysical changes, particularly those regarding malnutrition.

QTc prolongation during levofloxacin and triazole combination chemoprophylaxis: Prevalence and predisposing risk factors in a cohort of hematopoietic cell transplantation recipients.

BACKGROUND: QTc interval prolongation has been reported when combining fluoroquinolones and triazoles for chemoprophylaxis in cancer patients. Herein, we aimed to identify the prevalence and contributing factors to QTc prolongation in hematopoietic cell transplantation (HCT) recipients who received these agents during the neutropenic phase. METHODS: This is a retrospective medical chart review conducted at a university hospital in Lebanon from 2017 to 2020. It included all adult HCT inpatients on antimicrobial prophylaxis with fluoroquinolones and triazoles and whose baseline ECG monitoring done prior to chemoprophylaxis administration, then on day-3 and day-6 of therapy, were available. RESULTS: Overall, 68 HCT recipients met our inclusion criteria, of which 22% developed QTc prolongation. Based on bivariate analysis, female gender contributed to QTc prolongation (P = 0.001). There was a trend to QTc prolongation in patients with predisposing thyroid disease (P = 0.12), grade 2 vomiting and diarrhea (P = 0.16, P = 0.46, respectively), baseline hypokalemia (P = 0.18) and hypocalcemia (P = 0.3), hypomagnesemia on day-3 (P = 0.21) and day-6 hyponatremia (P = 0.36). Patients receiving two or more drugs with a known or probable risk of QTc prolongation (other than the fluoroquinolone/ triazole combination) were more prone to experience a prolonged QTc interval (P = 0.09). None of the patients that had QTc prolongation died or developed serious arrhythmias. CONCLUSION: The prevalence of QTc prolongation was 22% among HCT recipients on fluoroquinolone and triazole prophylaxis, yet we did not identify any independent risk factors for this issue. None of the patients that had QTc interval prolongation died or developed serious arrhythmias.

Serial electrocardiogram recordings revealed a high prevalence of QT interval prolongation in patients with tuberculosis receiving fluoroquinolones.

BACKGROUND: Fluoroquinolones, crucial components of treatment regimens for drug-resistant tuberculosis (TB), are associated with QT interval prolongation and risks of fatal cardiac arrhythmias. However, few studies have explored dynamic changes in the QT interval in patients receiving QT-prolonging agents. METHODS: This prospective cohort study recruited hospitalized patients with TB who received fluoroquinolones. The study investigated the variability of the QT interval by using serial electrocardiograms (ECGs) recorded four times daily. This study analyzed the accuracy of intermittent and single-lead ECG monitoring in detecting QT interval prolongation. RESULTS: This study included 32 patients. The mean age was 68.6 ± 13.2 years. The results revealed mild-to-moderate and severe QT interval prolongation in 13 (41%) and 5 (16%) patients, respectively. The incremental yields in sensitivity of one to four daily ECG recordings were 61.0%, 26.1%, 5.6%, and 7.3% in detecting mild-to-moderate QT interval prolongation, and 66.7%, 20.0%, 6.7%, and 6.7% in detecting severe QT interval prolongation. The sensitivity levels of lead II and V5 ECGs in detecting mild-to-moderate and severe QT interval prolongation exceeded 80%, and their specificity levels exceeded 95%. CONCLUSION: This study revealed a high prevalence of QT interval prolongation in older patients with TB who receive fluoroquinolones, particularly those with multiple cardiovascular risk factors. Sparsely intermittent ECG monitoring, the prevailing strategy in active drug safety monitoring programs, is inadequate owing to multifactorial and circadian QT interval variability. Additional studies performing serial ECG monitoring are warranted to enhance the understanding of dynamic QT interval changes in patients receiving QT-prolonging anti-TB agents.

Gefitinib Increases the Incidence of QT Prolongation in Patients with Non-Small Cell Lung Cancer.

Gefitinib (GEF) may increase the risk of corrected QT prolongation (QTc). We aimed to evaluate whether gefitinib increases the risk of corrected QT interval (QTc) prolongation and analyze the associated risk factors.A total of 122 cases of advanced EGFR-mutated non-small cell lung cancer (NSCLC) who received gefitinib therapy from January 2015 to December 2020 were evaluated. The results of at least two resting 12-lead electrocardiogram before and after gefitinib treatment were obtained. The Bazett and Fridericia formulas were used to calculate the QTc interval, and the changes of QTc interval values before and after treatment were evaluated. The correlation between gefitinib and QTc interval prolongation and related risk factors were analyzed.After gefitinib-targeted therapy, 23 patients (18.9%) had a prolonged QTc interval, which increased from a mean of 446 ± 25 ms at baseline to 478 ± 18 ms (P < 0.001). Three of the patients met criteria for Grade 3 QTc prolongation in the common term V5.0 for clinical adverse events. Univariate analysis showed that age (ORR, 1.054; 95% confidence interval [CI], 1.003-1.107; P = 0.038), history of hypertension (ORR, 3.409; 95% CI, 1.334-8.713; P = 0.01), CCB medication history (ORR, 0.259; 95% CI, 0.094-0.712; P = 0.009), history of lung cancer surgery (ORR, 0.231; 95% CI, 0.064-0.829; P = 0.025), and baseline QT interval (ORR, 0.978; 95% CI, 0.964-0.993; P = 0.004) were important predictors of QTc interval prolongation in patients treated with gefitinib. The results of multivariate analysis showed that the history of lung cancer surgery and the baseline QT interval were important factors affecting QTc interval prolongation in patients treated with gefitinib.Gefitinib increases the risk of QTc prolongation in NSCLC patients, which may be more pronounced in patients with advanced age, hypertension, CCB therapy, lung cancer surgery, and a long QT interval at baseline.

Prescribing Practices of QT Interval Prolonging Drugs in Critically Ill Older Adults in South India.

Background It was Dissertenne who first described a cardiac phenomenon known as the Torsades de Pointes (TdP). QT prolongation caused by drugs is one of the most important causes for acquired QT prolongation syndrome. Objective To observe the prescribing practices of QT interval prolonging drugs among a highrisk population of critically ill older adults in a tertiary care hospital in South India The objectives were to identify the most commonly prescribed QT prolonging drugs, to analyse types of QT prolonging drugs based on risk of causing QT prolongation, to study the frequency of occurrence of common risk factors for QT prolongation and to identify presence of any significant relationships among the study variables. Method We have conducted a one-year cross-sectional descriptive study of the prescribing practices of QT interval prolonging drugs among 319 critically ill older adults in a tertiary care hospital in South India. Data was analysed to categorize the most common drugs which prolong QT interval; the type and frequency of use of QT interval prolonging drugs and to find the most common risk factors for QT prolongation in this study population. Result In this study, ondansetron, clarithromycin, azithromycin,and amiodarone were the most prescribed among the drugs with known risk of QTc (Corrected QT interval) prolongation. Among the drugs with conditional risk of QTc prolongation, pantoprazole, frusemide, piperacillin-tazobactam and esomeprazole were the most prescribed. The most common risk factors for QTc prolongation that were identified in this study were bradycardia, acute kidney injury, chronic kidney disease and low serum potassium. Conclusion This study helps to inform our physicians regarding the commonly prescribed QT interval prolonging drugs so that they may reduce co prescription of multiple QT prolonging drugs in high-risk patients. It identifies kidney injury, low potassium, and bradycardia as common risk factors for QT interval prolongation in these patients.

Prevalence and Risk Factors of QTc Prolongation in Prostate Cancer Patients Undergoing Brachytherapy.

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

A Real-World Study of Risk Factors for QTc Prolongation in Schizophrenia Patients Receiving Atypical Antipsychotics.

PURPOSE: The risk of sudden cardiac death in patients receiving atypical antipsychotics may be related to QTc prolongation. The aim of this study was to investigate the risk factors for QTc prolongation to prevent QTc prolongation and guide clinical practice. METHODS: All electrocardiogram recordings of 913 schizophrenia patients who were receiving atypical antipsychotics were reviewed for prolonged QTc and associated conditions. Binary logistic regression analysis was used to investigate risk factors for QTc prolongation. RESULTS: Logistic regression analysis demonstrated that sex (odds ratio [OR], 0.386; P = 0.010), age (OR, 1.047; P = 0.000), high-density lipoprotein (OR, 0.257; P = 0.014), and antipsychotics dose (OR, 1.040; P = 0.036) were significantly associated with QTc prolongation. CONCLUSIONS: In patients with male sex, elder age, low high-density lipoprotein, or large antipsychotics dose, QTc should be monitored more frequently.

The CredibleMeds® list: Usage of QT interval prolonging drugs in Germany and discordances with prescribing information.

AIMS: A substantial number of Summaries of Product Characteristics (SmPCs)/Prescribing Information (PI) have warnings or contraindications on QT interval prolongation. The goal of this work was to quantify usage of QT interval prolonging drugs according to the CredibleMeds® database of the German outpatient drug prescription market and to evaluate discrepancies between German SmPCs/US PI and CredibleMeds® . METHODS: Drugs listed on CredibleMeds® with known, possible or conditional risk for torsade de pointes were evaluated from 2000 to 2020. The German drug prescription report was used as source for defined daily dose- (DDD-) based prescriptions of the German outpatient drug prescription market of the public health insurance system. German SmPCs and US PI of 253 CredibleMeds® -listed drugs were evaluated for contents regarding QT interval prolongation. RESULTS: Of the drugs currently listed on CredibleMeds® , 59.7% (95% confidence interval [CI] 53.5-65.5%) were listed after 2012. Due to newly listed drugs, the proportion of DDDs of CredibleMeds® drugs among all prescriptions increased from 4.6% in 2013 to 21.1% in 2019. DDD-based usage of the CredibleMeds® drugs already listed in 2013 was similar in 2019. Among the drugs with known QT risk according to CredibleMeds® , 7.5% (95% CI 2.6-19.9%) of German SmPCs and 21.1% (95% CI 11.1-36.3%) of US PI had no mention of QT issues whatsoever. CONCLUSION: A significant proportion of all drugs prescribed in the outpatient sector is associated with QT risks according to CredibleMeds® . SmPCs and PI should systematically be evaluated for concordance with the widely used CredibleMeds® database to increase medication safety.

Hydroxychloroquine cardiotoxicity: a case-control study comparing patients with COVID-19 and patients with systemic lupus erythematosus.

OBJECTIVES: Antimalarials have been associated with QT prolongation in COVID-19 patients but are generally safe in systemic lupus erythematosus (SLE).We compared the prevalence of QTc prolongation between COVID-19 and SLE patients treated with hydroxychloroquine (HCQ). METHODS: We included patients with SARS-CoV-2 infection confirmed by nasopharyngeal swab and patients taking HCQ for SLE. A prolonged QTc was defined as an increase in QTc intervals >60 ms (compared with baseline) or as a QTc of ≥500 ms. We performed the univariate and multivariate logistic regression to investigate the risk factors for QTc prolongation in COVID-19 patients. RESULTS: We enrolled 58 COVID-19 patients (median age 70.5 years, IQR 25), grouped into group A (patients with HCQ) group B (patients with HCQ + azithromycin) and group C (not received either drug). Fifty (26%) COVID-19 patients presented a QTc prolongation (12 QTc≥500 ms, 3 patients ΔQTc>60 ms). We did not find any differences in QTc prolongation among the three treatment groups. Baseline QTc (OR 111.5) and D-dimer (OR 78.3) were independently associated to QTc prolongation. Compared to the 50 SLE patients (median age 38.5 years, IQR 22), chronically treated with HCQ, COVID-19 patients showed significantly longer QTc (p<0.001). CONCLUSIONS: This is the first study demonstrating that, unlike COVID-19 patients, patients with SLE are not susceptible to HCQ-induced long QT syndrome and arrhythmia. The combined arrhythmogenic effect of SARS-CoV-2 infection and HCQ could account for the excess of QTc prolongation and fatal arrhythmias described in patients with COVID-19.

Does sports participation increase risk in patients with long QT syndrome? Results from a large French cohort.

AIMS: Sports practice, especially in competition, is usually restrained in patients diagnosed with long QT syndrome (LQTS). Although data are scarce, a low incidence of cardiac arrhythmic events (CAEs) during sports practice is reported. We aim to evaluate the incidence of CAE during sports practice in LQTS patients. METHODS AND RESULTS: All consecutive patients above 18 years of age diagnosed with LQTS and prospectively followed at the referral centre for inherited arrhythmia syndrome received a survey to retrospectively assess their sports practice prior to and after the diagnosis of LQTS. Two hundred and forty-six patients were included (57% females). The median age was 43 years, and the median QTc was 457 ms (428; 482). Patients reported a total of 4092 years [1376 (34%) after diagnosis] of sports practice: 2905 (77%) [1138 (39%) after diagnosis] years of leisure practice and 1187 (23%) [238 (20%) after diagnosis] years of competitive practice. One hundred and eighty (73%) patients practiced sport prior to the diagnosis of LQTS and 170 (69%) after. Prior to the diagnosis, four (2%) patients presented a CAE during leisure sports practice and one during competition. After diagnosis, only one patient presented a CAE, appropriately treated by an implantable cardioverter defibrillator discharge, in the context of beta-blocker non-compliance. The CAE event rate was 0.0007 events/year in the 1376 years of total sports practice after the diagnosis of LQTS. CONCLUSION: After the diagnosis of LQTS, the occurrence of CAE is very low during sports practice, even in competitive practice. There was no CAE in patients properly treated with beta-blocker therapy with good compliance.

Severity of congenital long QT syndrome disease manifestation and risk of depression, anxiety, and mortality: a nationwide study.

AIMS: We examined if a congenital long QT syndrome (cLQTS) diagnosis and severity of cLQTS disease manifestation was associated with increased risk of depression, anxiety, and all-cause mortality. METHODS AND RESULTS: All patients with known cLQTS in Denmark were identified using nationwide registries and specialized inherited cardiac disease clinics (1994-2016) and followed for up to 3 years after their cLQTS diagnosis. Risk factors for depression, anxiety, and all-cause mortality were determined using multivariable Cox proportional-hazards regression. An age- and sex-matched control population was identified (matching 1:4). Overall, 589 patients with cLQTS were identified of which 119/589 (20.2%) developed depression or anxiety during follow-up compared with 302/2356 (12.8%) from the control population (P < 0.001). Severity of cLQTS disease manifestation was identified for 324/589 (55%) of patients with cLQTS; 162 were asymptomatic, 119 had ventricular tachycardia (VT)/syncope, and 43 had aborted sudden cardiac death (aSCD). In multivariable models, patients with aSCD, VT/syncope, or unspecified cLQTS disease manifestation had a higher risk of developing depression or anxiety compared with the control population (hazard ratio [HR]=2.4, 95% confidence interval [CI]: 1.1-5.1; HR = 1.9, 95% CI: 1.2-3.0; HR = 1.6, 95% CI: 1.1-2.3, respectively). Asymptomatic patients had similar risk of developing depression or anxiety as the control population (HR = 1.2, 95% CI: 0.8-1.9). During follow-up, 10/589 (1.7%) patients with cLQTS died compared with 27/2356 (1.1%) from the control population (P = 0.5). Furthermore, 4/10 who died had developed depression or anxiety. CONCLUSION: A severe cLQTS disease manifestation was associated with a greater risk of depression or anxiety. All-cause mortality for patients with cLQTS was low.

Multiple categories of non-cardiac QT-prolonging drugs are associated with increased risk of out-of-hospital cardiac arrest: real-world data from a population-based study.

AIM: Drugs causing QT-prolongation as off-target effect [non-cardiac QT-prolonging drugs (QT-drugs)] increase the risk of out-of-hospital cardiac arrest (OHCA). Such drugs are categorized in multiple clinically widely used CredibleMeds.org lists. Category 1 ('known risk of Torsade de Pointes') and category 2 ('possible risk of Torsade de Pointes') are of particular clinical relevance. However, a category-stratified analysis of OHCA-risk is presently unavailable. METHODS AND RESULTS: We conducted a case-control study with OHCA-cases from presumed cardiac causes included from the ARREST registry in the Netherlands (2009-2018) that was specifically designed to study OHCA, and age/sex/OHCA-date matched non-OHCA-controls. Adjusted odds ratios for OHCA (ORadj) of QT-drugs from categories 1 or 2 were calculated, using conditional logistic regression. Stratified analysis was performed according to sex, age, and presence of cardiovascular drugs (proxy for cardiovascular disease). We included 5473 OHCA-cases (68.8 years, 69.9% men) and matched them to 20 866 non-OHCA-controls. Compared with no use of non-cardiac QT-drugs, drugs of both categories were associated with increased OHCA-risk, but seemingly weaker for category 2 {category 1: case 3.2%, control 1.4%, ORadj 1.7 [95% confidence interval (CI): 1.3-2.1]}; [category 2: case 7.3%, control 4.0%, ORadj 1.4 (95% CI: 1.2-1.6)]. The increased risk occurred in men and women, at all ages (highest in patients aged ≤50 years), and both in the presence or absence of cardiovascular drug use. CONCLUSION: Both category 1 and category 2 QT-drugs are associated with increased OHCA-risk in both sexes, at all ages, and in patients taking or not taking cardiovascular drugs.

QTc prolongation in adolescents with acute alcohol intoxication.

In adults, alcohol intoxication is associated with prolongation of the QT interval corrected for heart rate (QTc). The QTc is influenced by age and sex. Although alcohol intoxication is increasingly common in adolescents, there are no data on the prevalence of QTc prolongation in adolescents with alcohol intoxication. This study aimed to determine the prevalence of QTc prolongation in adolescents with alcohol intoxication and identify at-risk adolescents. In this observational study including adolescents aged 10-18 years, heart rate and QT interval were automatically assessed from an electrocardiogram (ECG) at alcohol intoxication using a validated algorithm. The QTc was calculated using both the Bazett formula (QTcB) and Fridericia formula (QTcF). If present, an ECG recorded within 1 year of the date of admission to the emergency department was obtained as a reference ECG. A total of 317 adolescents were included; 13.3% had a QTcB and 7.9% a QTcF longer than the sex- and age-specific 95th-percentile. None of the adolescents had a QTcB or QTcF > 500 ms, but 11.8% of the adolescents with a reference ECG had a QTcB prolongation of > 60 ms, while no adolescents had a QTcF prolongation of > 60 ms. QTc prolongation was mainly attributable to an increase in heart rate rather than QT prolongation, which underlies the differences between QTcB and QTcF. Male sex and hypokalaemia increased the likelihood of QTc prolongation.Conclusion: QTc prolongation was seen in approximately 10% of the adolescents presenting with alcohol intoxication, and although no ventricular arrhythmias were observed in this cohort, QTc prolongation increases the potential for malignant QT-related arrhythmias. Clinicians must be aware of the possibility of QTc prolongation during alcohol intoxication and make an effort to obtain an ECG at presentation, measure the QT interval, and give an adequate assessment of the findings. We advocate admitting adolescents with alcohol intoxication and QTc prolongation. During hospital admission, we recommend limiting exposure to QTc-prolonging medication, increasing potassium levels to a high-normal range (4.5-5.0 mmol/L) and obtaining a reference ECG at discharge.

QTc interval prolongation in the patients with primary biliary cholangitis.

BACKGROUND: The QT interval prolongation was associated with fatal arrhythmias and cardiac death. However, there were not adequate data to clarify the situation of QT interval prolongation in primary biliary cholangitis (PBC) patients. The aim of this study was to clarify the rate and the associated risk factors of corrected QT (QTc) interval prolongation in PBC patients. METHODS: From January 2016 to December 2020, PBC patients were retrospectively enrolled. The rate of QTc interval prolongation was surveyed and the associated risk factors were clarified by univariate and multivariate analyses. RESULTS: Among the 189 PBC patients, 24.3% (46/189) had the QTc interval prolongation. The univariate analysis showed that age, Child-Pugh classification, creatinine, international normalized ratio (INR), and platelet (PLT) were associated with QTc interval prolongation in the PBC patients. The multivariate analysis further showed only age (p = .028) and Child-Pugh classification (p = .035) were the associated risk factors. It had the highest risk of QTc interval prolongation (as high as 64.3%) in the patients who were more than 62.5 years old and with Child-Pugh C. CONCLUSION: The QTc interval prolongation was frequent in PBC patients, especially in the patients with decompensated cirrhosis. The rate of QTc interval prolongation was as high as 64.3% in the PBC patients who were more than 62.5 years old and classified as Child-Pugh C.

Long QT and Hearing Loss in High-Risk Infants Prospective Study Registry.

The objective of this study is to determine the prevalence of an abnormal electrocardiogram showing a prolonged QTc greater than 450 ms in infants with unilateral or bilateral sensorineural hearing loss. We conducted a prospective study of healthy term infants (≥37 weeks gestational age) who failed their newborn auditory brainstem response hearing screen, were seen by an audiologist and diagnosed as having sensorineural hearing loss during follow-up to 1 year of age. In infants with a diagnosis of hearing loss, we collected a detailed family history and performed an ECG between 2 and 6 months of age. We obtained follow-up for 1 year by calling the parent requesting the hearing and cardiac status of their child. Two of the 40 infants with sensorineural hearing loss (5%) had a QTc greater than 450 ms. Both had mild bilateral hearing loss and genetic testing did not identify a known mutation for long QT syndrome. The remaining 38 infants had QTc intervals of ≤ 450 ms. One patient diagnosed with bilateral severe sensorineural hearing loss had a normal ECG (QTc = 417 ms). Several months after the ECG was performed, the infant's mother contacted the study cardiologist after she learned that the infant's maternal grandmother was diagnosed with a cardiomyopathy and arrhythmias. Genetic testing was recommended even though the child was asymptomatic and was positive for a pathogenic mutation in the KCNQ1 gene. We speculate that molecular genetic testing in infants with hearing loss may become the standard of care rather than targeted electrocardiograms.Clinical Trial Registration NCT02082431 https://www.clinicaltrials.gov/ct2/show/NCT02692521?cond=NCT02692521&rank=1 .

Safety of hydroxychloroquine and darunavir or lopinavir in COVID-19 infection.

BACKGROUND: Combination therapy with hydroxychloroquine and darunavir/ritonavir or lopinavir/ritonavir has been suggested as an approach to improve the outcome of patients with moderate/severe COVID-19 infection. OBJECTIVES: To examine the safety of combination therapy with hydroxychloroquine and darunavir/ritonavir or lopinavir/ritonavir. METHODS: This was an observational cohort study of patients hospitalized for COVID-19 pneumonia treated with hydroxychloroquine and darunavir/ritonavir or lopinavir/ritonavir. Clinical evaluations, electrocardiograms and the pharmacokinetics of hydroxychloroquine, darunavir and lopinavir were examined according to clinical practice and guidelines. RESULTS: Twenty-one patients received hydroxychloroquine with lopinavir/ritonavir (median age 68 years; 10 males) and 25 received hydroxychloroquine with darunavir/ritonavir (median age 71 years; 15 males). During treatment, eight patients (17.4%) developed ECG abnormalities. Ten patients discontinued treatment, including seven for ECG abnormalities a median of 5 (range 2-6) days after starting treatment. All ECG abnormalities reversed 1-2 days after interrupting treatment. Four patients died within 14 days. ECG abnormalities were significantly associated with age over 70 years, coexisting conditions (such as hypertension, chronic cardiovascular disease and kidney failure) and initial potential drug interactions, but not with the hydroxychloroquine concentration. CONCLUSIONS: Of the patients with COVID-19 who received hydroxychloroquine with lopinavir or darunavir, 17% had ECG abnormalities, mainly related to age or in those with a history of cardiovascular disease.