Clinical and electrocardiographic outcomes evaluated by telemedicine of outpatients with clinical suspicion of COVID-19 treated with chloroquine compounds in Brazil†

Bruno R Nascimento; Gabriela M M Paixão; Luìs Antônio B Tonaco; Ana Carolina D Alves; David C Peixoto; Leonardo B Ribeiro; Mayara S Mendes; Paulo R Gomes; Magda C Pires; Antonio Luiz P Ribeiro

doi:10.3389/fcvm.2023.1028398

Clinical and electrocardiographic outcomes evaluated by telemedicine of outpatients with clinical suspicion of COVID-19 treated with chloroquine compounds in Brazil^†

Front Cardiovasc Med. 2023 Feb 15:10:1028398. doi: 10.3389/fcvm.2023.1028398. eCollection 2023.

Authors

Affiliations

¹ Serviço de Cardiologia e Cirurgia Cardiovascular e Centro de Telessaúde do Hospital das Clínicas da UFMG, Belo Horizonte, MG, Brazil.
² Departamento de Clínica Médica, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
³ Curso de Medicina, Faculdade de Saúde e Ecologia Humana (FASEH), Belo Horizonte, MG, Brazil.
⁴ Departamento de Estatística, Instituto de Ciências Exatas (ICEX) da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.

Abstract

Aims: To evaluate clinical and electrocardiographic outcomes of patients with COVID-19, comparing those using chloroquine compounds (chloroquine) to individuals without specific treatment.

Methods: Outpatients with suspected COVID-19 in Brazil who had at least one tele-electrocardiography (ECG) recorded in a telehealth system were enrolled in two arms (Group 1: chloroquine and Group 2: without specific treatment) and one registry (Group 3: other treatments). Outcomes were assessed through follow-up calls (phone contact, days 3 and 14) and linkage to national mortality and hospitalization databases. The primary outcome was composed of: hospitalization, intensive care admission, mechanical ventilation, and all-cause death, and the ECG outcome was the occurrence of major abnormalities by the Minnesota code. Significant variables in univariable logistic regression were included in 4 models: 1-unadjusted; 2-adjusted for age and sex; 3-model 2 + cardiovascular risk factors and 4-model 3 + COVID-19 symptoms.

Results: In 303 days, 712 (10.2%) patients were allocated in group 1, 3,623 (52.1%) in group 2 and 2,622 (37.7%) in group 3; 1,969 had successful phone follow-up (G1: 260, G2: 871, and G3: 838). A late follow-up ECG was obtained for 917 (27.2%) patients [group 1: 81 (11.4%), group 2: 512 (14.1%), group 3: 334 (12.7%)]. In adjusted models, chloroquine was independently associated with greater chance of the composite clinical outcome: phone contact (model 4): OR = 3.24 (95% CI 2.31-4.54), p < 0.001. Chloroquine was also independently associated with higher mortality, assessed by phone + administrative data (model 3): OR = 1.67 (95% CI 1.20-2.28). However, chloroquine did not associate with the occurrence of major ECG abnormalities [model 3; OR = 0.80 (95% CI 0.63-1.02, p = 0.07)]. Abstracts with partial results of this work was accepted in the American Heart Association Scientific Sessions, November 2022, in Chicago, IL, USA.

Conclusion: Chloroquine was associated with a higher risk of poor outcomes in patients suspected to have COVID-19 when compared to those who received standard care. Follow-up ECGs were obtained in only 13.2% of patients and did not show any significant differences in major abnormalities amongst the three groups. In the absence of early ECG changes, other side effects, late arrhythmias or deferral of care may be hypothesized to explain the worse outcomes.

Keywords: COVID-19; chloroquine; electrocardiogram; outcomes; prognosis; telemedicine; treatment.

Grants and funding

BN was partially supported by CNPq (Research Productivity Grant, 312382/2019-7), the Edwards Lifesciences Foundation (Improving the prevention and detection of Heart Valve disease across the Lifespan, 2021), and FAPEMIG (Grant APQ-000627-20). AR was partially funded by CNPq (310790/2021-2 and 465518/2014-1), FAPEMIG (PPM-00428-17 and RED-00081-16), and CAPES (88887.507149/2020-00). This study was contracted and funded by the Brazilian Ministry of Health (TED 66/2020). The funder did not have any relationship with the conduct of the study, data collection, analysis, and interpretation, and the preparation, review, or approval of this manuscript.