QTc Interval of Healthcare Workers from India: Baseline and Effect of Hydroxychloroquine Prophylaxis during the COVID-19 Pandemic
Indian Journal of Community Medicine, doi:10.4103/ijcm.ijcm_663_22
IntRoductIon During the recent coronavirus disease 2019 (COVID-19) pandemic, before the availability of vaccine in the year 2020 itself, the National Task Force by the Indian Council of Medical Research (ICMR) recommended the use of hydroxychloroquine (HCQ) as chemoprophylaxis for asymptomatic healthcare workers (HCWs) involved in the care of suspected or confirmed cases of COVID-19 and asymptomatic household contacts of laboratory-confirmed cases.  Their recommendation was based on in vitro studies, which found that HCQ is effective against COVID-19. [2, 3] In view of ICMR recommendations, the Indian Heart Rhythm Society (IHRS) proposed a scientific statement for the use of HCQ and strongly discouraged its use for the general public without medical supervision and prescription.  As there is a scarcity of known prevalence of QT interval prolongation in nonhospitalized population in general, and none in specific population such as HCWs from India, we conducted this study to assess the baseline-corrected QT (QTc) interval, the incidence of prolonged QTc interval, and changes, if any, among HCWs taking HCQ prophylaxis while managing COVID-19-confirmed or COVID-19-suspected cases.
Methods This was a prospective observational study conducted at a tertiary care university hospital in North India, after approval from the Background: The aim of this study was to access the incidence of prolonged QTc interval and changes, if any, among Indian healthcare workers (HCWs) taking hydroxychloroquine (HCQ) prophylaxis while managing coronavirus disease 2019 (COVID-19) cases. Methods: At the beginning of the COVID-19 pandemic, as per the Indian Council of Medical Research (ICMR) policy, HCWs were advised to take HCQ as prophylaxis after getting an electrocardiogram (ECG) while being posted to look after COVID-19 patients. A follow-up ECG was repeated for those who took HCQ. The normal upper limit for QTc interval of 460 milliseconds (ms) for females and 450 ms for males was considered. Results: A baseline ECG was analyzed for 250 HCWs with a median age of 35 (30-43) years. The median QTc was 410 (395-421) ms with the prevalence of prolonged QTc of 1.8% in females and 0% in males. A follow-up ECG after HCQ intake for 43 HCWs was further analyzed. They had a median age of 35 (31-39) years and took an average dose of HCQ of 2372 ± 839 mg. Pre-and post-HCQ chemoprophylaxis QTc interval (ms) was as follows: 408 (386-419) and 405 (387-417), with P = 0.434, respectively. Conclusion: Among Indian HCWs, the prevalence of prolonged QTc is 1.8% and 0% in females and males, respectively. HCQ intake as chemoprophylaxis for COVID-19 did not affect their QTc interval.
Conflicts of interest There are no conflicts of interest.
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