Electrocardiographic safety of daily Hydroxychloroquine 400mg plus Azithromycin 250mg as an ambulatory treatment for COVID-19 patients in Cameroon

Objective : To determine the early electrocardiographic changes in a cohort of ambulatory cameroonian COVID-19 patients treated with hydroxychloroquine and Azithromycin. Design : Prospective study. Setting : Treatment centres of the city of Yaounde, Cameroon, from May 7th to 24th 2020. Participants : We enrolled 51 consecutive confirmed COVID-19 on RT-PCR who having mild forms of COVID-19 and treated by hydroxychloroquine 200mg twice daily during seven days plus Azithromycin 500 mg the first day and 250 mg the remaining 4 days as per national standard. Main outcomes measures : The primary end-point was the change in QTc interval between day 0 (D0), day 3 (D3) and day 7 (D7). Secondary endpoints were changes in all other cardiac electrical conductivity patterns and the occurrence of clinical arrhythmic events during the course of treatment. Results: The population (29 men and 22 women) was aged 39 ± 11 years (range 17 to 61 years). Mean Tisdale score was 3.35±0.48. No significant change from baseline (D0) of QTc was observed at D7 (429±27 ms at D0 versus 396±26 ms at D7; p=0.27). A reduction of heart rate was observed between the D0 and D7 (75±13 bpm versus 70±13 bpm, p = 0.02) with increased QRS duration between D0 and D7 (95±10 ms versus 102±17 ms, p = 0.004). No symptomatic arrhythmic events occurred during the treatment course. Conclusions: No life-threatening modifications of the QT interval was observed in nonsevere COVID-19 patients treated ambulatory with hydroxychloroquine and azithromycin. Studies are needed in critical-ill and older patients.