QT interval and repolarization dispersion changes during the administration of hydroxychloroquine/chloroquine with/without azithromycin in early COVID 19 pandemic: A prospective observational study from two academic hospitals in Indonesia

Abstract Background Hydroxychloroquine/chloroquine (HCQ/CQ) treatment for COVID‐19 was associated with QT interval prolongation and arrhythmia risks. This study aimed to investigate QTc interval and ventricular repolarization dispersion changes, as markers of arrhythmia risks, after HCQ/CQ administration with/without azithromycin (AZT) during COVID‐19 pandemic. Methods A prospective observational study was performed in two academic hospitals in Indonesia. Adult patients who received HCQ/CQ alone and HCQ/CQ + AZT concomitant treatments for COVID‐19 infection were enrolled. Baseline and post HCQ/CQ treatment electrocardiograms were obtained. Baseline and post HCQ/CQ treatment QT interval by Bazett (B‐QTc) and Fridericia (F‐QTc) formulas and ventricular repolarization dispersion indices by Tpeak‐Tend (Tp‐e) interval and Tpeak‐Tend/QT (Tp‐e/QT) ratio were calculated and analyzed. Results The study enrolled 55 (HCQ/CQ alone) and 77 subjects (HCQ/CQ + AZT concomitant). F‐QTc interval significantly lengthened in subjects with HCQ/CQ + AZT (mean difference 11.89 ms [P = .028]). The incidences of severe B‐QTc and F‐QTc lengthening were 13.1% and 12.3%, B‐QTc and F‐QTc prolongation were 25.4% and 12.3%, and severe B‐QTc and F‐QTc prolongation were 6.2% and 3.2%. Tp‐e interval lengthened significantly from baseline to posttreatment in HCQ/CQ alone and HCQ/CQ + AZT (mean difference 10.83 ms [P = .006] and 18.73 ms [P < .001], respectively). Tp‐e/QT ratio increased significantly from baseline to posttreatment in HCQ/CQ + AZT concomitant (mean difference 0.035 [P < .001]). No fatal arrhytmia occurred. Conclusions During COVID‐19 pandemic, HCQ/CQ + AZT concomitant treatment caused significant F‐QTc lengthening, significantly increased Tp‐e interval and increased Tp‐e/QT ratio. HCQ/CQ alone only caused significant increase of Tp‐e interval. Incidences of severe QTc lengthening and prolongation were low in both HCQ/CQ alone and HCQ/CQ + AZT concomitant.


| INTRODUC TI ON
A novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) reached pandemic status in early 2020 due to its fast spreading pneumonia becoming transmitted worldwide. 1,2 This new disease was acronymized as COVID-19 (Coronavirus Disease of 2019). 2 To date, COVID-19 has afflicted as many as 80 million people and caused more than 1.7 million death globally. 3 Indonesia reported its earliest cases of COVID-19 on March 1, 2020 and subsequently the number of cases has increased progressively. 4,5 At the beginning of this pandemic, several drugs were proposed for the management of COVID-19 including hydroxychloroquine (HCQ), chloroquine (CQ), and azithromycin (AZT). 6 Either HCQ or CQ hinders viral replication and reduces viral load, which is reinforced by adding AZT in the treatment regimen. 7,8 Over time, the evidence shows unconvincing data regarding the effectiveness of this treatment regimen for COVID-19. 9, 10 The regimens of HCQ/CQ with/without AZT have very limited documented clinical benefit for COVID-19. [11][12][13] Therefore, World Health Organization (WHO) recommends against the use of HCQ/CQ in the latest guideline for management of COVID- 19. 14 Moreover, HCQ and CQ as well as AZT are QT-prolonging drugs which pose a risk of malignant ventricular arrhythmia, Torsade de Pointes (TdP), and cardiac arrest. [15][16][17] The synthesis of several studies indicate the increased incidence of corrected QT (QTc) prolongation and TdP in COVID-19 patients using HCQ/CQ alone or in combination with AZT. 18,19 Furthermore, in about 13% COVID-19 patients suffer from QTc prolongation due to this illness. 20 Similar to what had occurred in other parts of the world, in Indonesia the use of HCQ/CQ in combination with AZT as a treatment regimen for COVID-19 had been implemented in the national protocol since March 2020. 21 Despite many evidences of QTc prolongation due to HCQ/CQ administration, there are still insufficient data of other markers of ventricular arrhythmia in relation to this regimen. A Tpeak -Tend (Tp-e) interval and Tpeak-Tend/QT (Tp-e/QT) ratio reflect ventricular repolarization dispersion, which are regarded as markers of ventricular arrhythmia and sudden cardiac death. 22,23 These parameters, in addition to QTc changes, may indicate the cardiac toxicities of HCQ/CQ in COVID-19 treatment regimen. Despite warnings regarding cardiac side effects, evidence at that time was scarce and our physicians were accustomed to administering HCQ/CQ for malaria without any significant side effects. Our data on QTc interval and ventricular repolarization dispersion changes due to HCQ/CQ treatment for COVID-19 will provide additional data from Southeast Asian countries, which are still underrepresented in scientific literatures, despite the huge number of HCQ/CQ usage in the region. We conducted a prospective observational study to investigate the changes of QTc interval, Tp-e interval and Tp-e/QT ratio, and the incidence of QTc prolongation and cardiac arrhythmias in Indonesian patients who received HCQ/CQ alone or HCQ/CQ + AZT concomitant treatment during COVID-19 pandemic.

| Study design and subjects
This study design was a prospective observational study. Subjects were adult patients enrolled from March 2020 to September 2020.
The subjects were patients with the diagnosis of high-probability-

| Subject enrollment and baseline measurements
The diagnosis and treatment protocol for patients with suspected COVID-19 in our hospitals were based on the national protocol increased Tp-e/QT ratio. HCQ/CQ alone only caused significant increase of Tp-e interval. Incidences of severe QTc lengthening and prolongation were low in both HCQ/CQ alone and HCQ/CQ + AZT concomitant. The demographic data, history of illness, cardiovascular comorbidities, and current medications were collected and recorded in an electronic case report form on admission and during observation.
The laboratory data were obtained from hospital central laboratories. The Tisdale score and its risk categories were calculated based on baseline parameters and divided into three categories: low risk (score <7), moderate risk (score 7-10), and highrisk (score ≥11). 24 The disease severity was determined based on the national protocol classification. 21

Tpeak-Tend interval, and Tpeak-Tend/QT ratio
The measurement of QT interval was performed by two cardiologists (R.A.G. and A.B.H.) independently and blindly. The coefficient correlation of the ratings of these two cardiologists was >90%. The QT interval was measured visually from the onset of the first deflection of QRS complex from isoelectric line to the end of T wave. The end of the T wave was determined by the tangent point of its steepest return to isoelectric line. The QT measurement was performed mainly in lead II, if the T-wave could not be determined in lead II then lead I, V5 or V6 were used. In a case of a bundle-branch block, the J-T interval was measured and 120 ms was added to obtain the QT interval duration. 25 Three beats of QT were measured and mean value was used. All measurements were performed manually by standard calipers and aided by computer. The QTc interval was calculated based on the Bazett's formula and Fridericia's formula. The Tp-e interval was measured in V5 lead, 26 and the Tp-e/QT ratio was measured by dividing Tp-e interval from V5 lead with measured QT interval as described above. However, the decision of HCQ/CQ treatment, concomitantly with/ without AZT, and the duration of treatment were made at the discretion of the attending physicians. Other medications were also given by the attending physicians and recorded in our electronic case report form. The decisions of attending physicians were not interfered by this study.

| Primary and secondary outcomes
The primary outcomes of the study were the changes of QTc interval, Tp-e interval, and Tp-e/QT ratio after HCQ/CQ alone and HCQ/ CQ + AZT concomitant treatments. These changes were analyzed by measuring QTc interval, Tp-e interval, and Tp-e/QT ratio differences from baseline to post HCQ/CQ treatment.
The secondary outcomes were the incidences of severe QTc lengthening, QTc prolongation, and severe QTc prolongation. A QTc lengthening was defined as any increased of QTc interval from baseline to post HCQ/CQ treatment. A severe QTc lengthening was defined as QTc changes ≥60 ms from baseline to post HCQ/CQ treatment. A QTc prolongation was defined as QTc value >450 ms (males) and QTc value >460 ms (females) at post HCQ/CQ treatment. A severe QTc prolongation was defined as QTc value ≥500 ms at post HCQ/CQ treatments. The presence of any arrhythmias was also reported.

| Statistics analysis
The continuous data were reported as mean ± standard deviation (mean ± SD). The categorical data were reported as count and percentage (n (%)). The continuous data were tested for normality by the Kolmogorov-Smirnov test or Shapiro-Wilk test in every group allocated for analysis. This normality test determined the parametric or nonparametric analysis for continuous data. The comparison of continuous data between paired groups (baseline vs posttreatment) was analyzed using paired-T test or Wilcoxon-Signed rank test. The comparison of continuous data between nonpaired groups (HCQ/CQ alone vs HCQ/CQ + AZT concomitant) was performed with Student T-test or Mann-Whitney test. The comparison between categorical data was analyzed by chi-squared test or Fischer exact test. A P < .05 was considered as statistically significant. Statistical analyses were performed using SPSS version 22.0 (IBM Corp., USA).

| Baseline characteristics
From 142 patients who satisfied the inclusion criteria, 12 of them were excluded due to incompleteness of electrocardiogram data.
Most of the reason of incompleteness was the self-imposed constraint on exposure or contact with the patients by staffs on duty. In our observational data, all of the 12 excluded patients were clinically well until post HCQ/CQ treatment. Figure 1 shows the flowchart of subjects' enrollment and analysis. Table 1 presents the characteristics of the subjects eligible for analysis in this study. Of 130 subjects, mean of age was 48 years old and 60% were males. Subjects with confirmed-COVID-19-PCR positive were 68.5%. The majority of disease severity at diagnosis was moderate disease (40%). The HCQ was more frequently administered than CQ with the mean duration of both treatments was 5.8 ± 1.5 days and cumulative dose was 1816.3 mg. The Tisdale risk category mostly fell into low risk, and only 6.9% were in high-risk category. The most common cardiovascular comorbidity was hypertension (28.5%).  (Table 1).

| Primary outcome
The QTc interval lengthened for both B-QTc and F-QTc in subjects with HCQ/CQ alone and those received HCQ/CQ + AZT concomitant. The significant QTc lengthening was found in F-QTc of subjects with HCQ/CQ + AZT concomitant group, with F-QTc change mean difference of 11.89 ms (P = .028). There were no significant differences in the value of baseline QTc interval, posttreatment QTc interval, and QTc interval changes in both treatment groups. Table 2 showed the QTc interval and its changes between groups.  and Tp-e/QT ratio change mean difference was 0.035 (P < .001), from baseline to posttreatment. There were no differences in baseline value, posttreatment value, and mean changes of Tp-e interval and Tp-e/QT ratio between both groups.

| Secondary outcomes
In all subjects, the incidence of severe B-QTc and F-QTc lengthening

TA B L E 3 The Tpeak-Tend (Tp-e) and
Tp-e/QT ratio from baseline to posttreatment of HCQ/CQ alone and HCQ/CQ + AZT concomitant treatments   Table 4).
The characteristics associated with severe B-QTc and F-QTc lengthening were depicted in Table 5 The characteristics associated with severe B-QTc and F-QTc prolongation were depicted in Table 6. There was a significant shorter  .262

(4.4)
.553 b Chronic kidney disease (n, %) 0 (0) 6 (5.3) .424 b 0 (0) 6 (5.3) .  peaked at day 4. 33 The incidence of QTc prolongation was 38.5% without any TdP or other cardiac arrhytmias. 33 The meta-analysis which included studies until September 2020 concluded that HCQ/ CQ-associated cardiac toxicity in COVID-19 was infrequent; however, it necessitated electrocardiogram monitoring especially in elderly and/or patients receiving other QT-prolonging drugs, such as AZT. [34][35][36][37] A large, multicenter cohort study in Europe with various clinical settings, home management, medical ward, and ICU also revealed that HCQ in short-term administration for COVID 19 only caused modest QTc increment and did not relate with arrhythmic death. 38 Our study corroborated previous data and enriched the solid findings from the Southeast Asian region. Notably, subjects with concomitant AZT tend to be younger and have milder disease that those without AZT. As this was an observational study that was a coincidence, there was no tendency from physician to give concomitant AZT in younger and milder clinical presentation. However, there was a potential bias of data analysis due to these significant differences baseline data.
There is scarce evidence related to the effects of HCQ/CQ in Tp-e interval changes in COVID-19 patients. The underlying mechanism on how HCQ/CQ causes Tp-e interval and Tp-e/QT ratio increased, as observed in our study, has not been clearly elucidated. 39 There are several hypothesizes underly why we choose Tp-e and Tp-e/QT ratio in this study, as stated by Prenneret al. In this study, there was one arrhytmia observed, ie the deterioration of first-degree AV block into second degree AV block during HCQ + AZT treatments. The worsening of AV block did not associate with prolonged QTc interval, but probably due to tachycardia . of HCQ treatment and standard care on the low incidence of arrhythmia. 44

| Limitations of study
In this study, we could not examine objective data such as echocardiography and cardiac biomarkers to elucidate cardiac function of the patients and to exclude the concomitant myocarditis.

| CON CLUS IONS
This prospective observational study indicates that HCQ/CQ + AZT

CO N FLI C T O F I NTE R E S T
Authors declare no conflict of interests for this article.