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

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.

Evaluation of Mortality in Atrial Fibrillation: Clinical Outcomes in Digital Electrocardiography (CODE) Study.

Aims: Atrial fibrillation (AF) is a public health problem and its prevalence is increasing worldwide. Electronic cohorts, with large electrocardiogram (ECG) databases linked to mortality data, can be useful in determining prognostic value of ECG abnormalities. Our aim is to evaluate the risk of mortality in patients with AF from Brazil. Methods: This observational retrospective study of primary care patients was developed with the digital ECG database from the Telehealth Network of Minas Gerais, Brazil. ECGs performed from 2010 to 2017 were interpreted by cardiologists and the University of Glasgow automated analysis software. An electronic cohort was obtained linking data from ECG exams and those from a national mortality information system, using standard probabilistic linkage methods. We considered only the first ECG of each patient. Patients under 16 years were excluded. Hazard ratios (HR) for mortality were adjusted for demographic and self-reported clinical factors and estimated with Cox regression. Results: From a dataset of 1,773,689 patients, 1,558,421 were included, mean age 51.6 years; 40.2% male. There were 3.34% deaths from all causes in 3.68 years of median follow up. The prevalence of AF was 1.33%. AF was an independent risk factor for all-cause mortality (HR 2.10, 95%CI 2.03-2.17) and cardiovascular mortality (HR 2.06, 95%CI 1.86-2.29). Females with AF had a higher risk of overall and cardiovascular mortality compared with males (p < 0.001). Conclusions: AF was a strong predictor of cardiovascular and all-cause mortality in a primary care population, with increased risk in women. Condensed abstract: To assess risk of mortality in AF patients, an electronic cohort was obtained linking data from ECG exams of Brazilian primary care patients and a national mortality information system. From 1,558,421 patients, AF (prevalence 1.33%) carried a higher risk of overall and cardiovascular mortality, with increased risk in women. What's New: This is the first study with a large Brazilian electronic cohort to evaluate the risk of mortality linked to AF in primary care patients.AF patients from a Brazilian primary care population had a higher risk of death for all causes (HR 2.10, 95%CI 2.03-2.17) and cardiovascular mortality (HR 2.06, 95%CI 1.86-2.29).Female patients with AF had an increased risk of overall and cardiovascular mortality compared with male patients (p < 0.001).

Evaluation of mortality in bundle branch block patients from an electronic cohort: Clinical Outcomes in Digital Electrocardiography (CODE) study.

BACKGROUND: Left bundle branch block is recognized as a marker of higher risk of death, but the prognostic value of the right bundle branch block in the general population is still controversial. Our aim is to evaluate the risk of overall and cardiovascular mortality in patients with right (RBBB) and left bundle branch block (LBBB) in a large electronic cohort of Brazilian patients. METHODS: This observational retrospective study was developed with the database of digital ECGs from Telehealth Network of Minas Gerais, Brazil (TNMG). All ECGs performed from 2010 to 2017 in primary care patients over 16 years old were assessed. The electronic cohort was obtained by linking data from ECG exams (name, sex, date of birth, city of residence) and those from national mortality information system, using standard probabilistic linkage methods (FRIL: Fine-grained record linkage software, v.2.1.5, Atlanta, GA). Only the first ECG of each patient was considered. Clinical data were self-reported, and ECGs were interpreted manually by cardiologists and automatically by the Glasgow University Interpreter software. Hazard ratio (HR) for mortality was estimated using Cox regression. RESULTS: From a dataset of 1,773,689 patients, 1,558,421 primary care patients over 16 years old underwent a valid ECG recording during 2010 to 2017. We excluded 17,359 patients that didn't have a valid QRS measure from the Glasgow program and 11,091 patients from the control group that had QRS equal or above 120 ms and were not RBBB or LBBB. Therefore, 1,529,971 were included (median age 52 [Q1:38; Q3:65] years; 40.2% were male). In a mean follow-up of 3.7 years, the overall mortality rate was 3.34%. RBBB was more frequent (2.42%) than LBBB (1.32%). In multivariate analysis, adjusting for sex, age and comorbidities, both patients with RBBB (HR 1.32; CI 95% 1.27-1.37) and LBBB (HR 1.69; CI 95% 1.62-1.76) had higher risk of overall mortality. Women with RBBB had an increased risk of all-cause death compared to men (p < 0.001). Cardiovascular mortality was higher in patients with LBBB (HR 1.77; CI 95% 1.55-2.01), but not for RBBB. CONCLUSIONS: Patients with RBBB and LBBB had higher risk of overall mortality. Women with RBBB had more risk of all-cause death than men. LBBB was associated with higher risk of cardiovascular mortality.

Tele-electrocardiography and bigdata: The CODE (Clinical Outcomes in Digital Electrocardiography) study.

Digital electrocardiographs are now widely available and a large number of digital electrocardiograms (ECGs) have been recorded and stored. The present study describes the development and clinical applications of a large database of such digital ECGs, namely the CODE (Clinical Outcomes in Digital Electrocardiology) study. ECGs obtained by the Telehealth Network of Minas Gerais, Brazil, from 2010 to 17, were organized in a structured database. A hierarchical free-text machine learning algorithm recognized specific ECG diagnoses from cardiologist reports. The Glasgow ECG Analysis Program provided Minnesota Codes and automatic diagnostic statements. The presence of a specific ECG abnormality was considered when both automatic and medical diagnosis were concordant; cases of discordance were decided using heuristisc rules and manual review. The ECG database was linked to the national mortality information system using probabilistic linkage methods. From 2,470,424 ECGs, 1,773,689 patients were identified. After excluding the ECGs with technical problems and patients <16 years-old, 1,558,415 patients were studied. High performance measures were obtained using an end-to-end deep neural network trained to detect 6 types of ECG abnormalities, with F1 scores >80% and specificity >99% in an independent test dataset. We also evaluated the risk of mortality associated with the presence of atrial fibrillation (AF), which showed that AF was a strong predictor of cardiovascular mortality and mortality for all causes, with increased risk in women. In conclusion, a large database that comprises all ECGs performed by a large telehealth network can be useful for further developments in the field of digital electrocardiography, clinical cardiology and cardiovascular epidemiology.

Brazilian National Service of Telediagnosis in Electrocardiography.

Access to specialized care remains unsolved in Brazil. The National Telediagnosis Project was created to expand successful telediagnosis experiences nationwide. The Telehealth Network of Minas Gerais (TNMG) was selected as a reference for tele-electrocardiogram (ECG). We aim to describe the experience of TNMG of developing and implementing the Brazilian National Service of Telediagnosis in Electrocardiography. Implementation planning includes discussion of workflows, standard procedures, responsibility definition for stakeholders, and adaptation of TNMG telediagnosis system. Tele-ECG has been implemented in 79 municipalities in 5 states. In a survey with 152 health professionals, 57% noted that ECG was not available in the local public health system before, 63% indicated tele-ECG service utilization ≥3 days per week, 96% considered the service very useful and 89% were very satisfied with it. In conclusion, the service fills a gap in specialized care in the public system and can improve access to a basic exam in remote and underserved regions.

Normal limits of the electrocardiogram derived from a large database of Brazilian primary care patients.

BACKGROUND: Knowledge of the normal limits of the electrocardiogram (ECG) is mandatory for establishing which patients have abnormal ECGs. No studies have assessed the reference standards for a Latin American population. Our aim was to establish the normal ranges of the ECG for pediatric and adult Brazilian primary care patients. METHODS: This retrospective observational study assessed all the consecutive 12-lead digital electrocardiograms of primary care patients at least 1 year old in Minas Gerais state, Brazil, recorded between 2010 and 2015. ECGs were excluded if there were technical problems, selected abnormalities were present or patients with selected self-declared comorbidities or on drug therapy. Only the first ECG from patients with multiple ECGs was accepted. The University of Glasgow ECG analysis program was used to automatically interpret the ECGs. For each variable, the 1st, 2nd, 50th, 98th and 99th percentiles were determined and results were compared to selected studies. RESULTS: A total of 1,493,905 ECGs were recorded. 1,007,891 were excluded and 486.014 were analyzed. This large study provided normal values for heart rate, P, QRS and T frontal axis, P and QRS overall duration, PR and QT overall intervals and QTc corrected by Hodges, Bazett, Fridericia and Framingham formulae. Overall, the results were similar to those from other studies performed in different populations but there were differences in extreme ages and specific measurements. CONCLUSIONS: This study has provided reference values for Latinos of both sexes older than 1 year. Our results are comparable to studies performed in different populations.