Background: Cardiotoxicity as a result of anthracycline chemotherapy has been linked to increased morbidity and mortality in breast cancer patients. There is a need for early detection through risk factor identification. To date, no large multicenter study has been conducted to describe the incidence, risk factors and clinical and demographic profiles of breast cancer patients with anthracycline-induced cardiotoxicity (AIC) in the Philippines.Methods: This was a nationwide multicenter retrospective cohort study among adult breast cancer patients who underwent anthracycline chemotherapy from 2015 to 2020 in 10 sites in the Philippines. Baseline characteristics and possible risk factors for AIC were re-trieved from medical records and cancer registries. AIC was defined as a reduction of left ventricular ejection fraction (LVEF) by > 10% from baseline to a value of < 53% or the development of overt left ventricular systolic dysfunction or heart failure (HF). Odds ratios from logistic regression were computed to determine risk factors associated with AIC using STATA-15.0 software. Results:Out of 341 patients included, 33 had AIC, accounting for an incidence of 9.68%. Nine patients (2.6%) had clinical HF. AIC patients had a mean age of 53.91 ± 10.84 years. Breast cancer AIC patients were significantly older and had lower body mass index (BMI) than those without AIC. AIC patients had significantly more comorbidities, especially hypertension and atrial fibrillation. Multivariate analysis showed that patients with any preexisting comorbidity are approximately 12.37 times as likely to have AIC, while those with concurrent chemotherapy are 0.07 times or 93% less likely to have AIC. Conclusion:Among adult breast cancer patients undergoing anthracycline chemotherapy, we determined a high incidence of cardiotoxicity at 9.68%. Having preexisting comorbidities gave patients 12 times increased odds of developing anthracycline cardiotoxicity. The presence of concurrent non-anthracycline chemotherapy showed an inverse association with the development of AIC which we attribute largely to patient selection in a retrospective study. The significantly higher propensity for AIC development in patients with preexisting comorbidities may warrant closer monitoring and control of patient comorbidities such as hypertension among patients undergoing anthracycline chemotherapy.

IntroductionCOVID-19 is a global pandemic caused by the SARS-CoV-2 virus. Although most COVID-19 cases are asymptomatic or mild, a significant number of patients experienced adverse outcomes. In addition, studies have shown that cardiac abnormalities are associated with increased mortality in hospitalised patients with COVID-19. This finding sets a precedent for the potential use of ECG tracing as an indicator of patient mortality and morbidity. This study aims to determine associations between the 12-lead ECG findings and various clinical outcomes of hospitalised patients with COVID-19, measured as incidence of endotracheal intubation, intensive care unit (ICU) admission and mortality rate.Methods and analysisAn electronic literature search will identify all potentially relevant articles using specific databases and websites. The search will be limited to studies published from December 2019 to May 2021. In addition, studies will include hospitalised patients with COVID-19 with normal and abnormal 12-lead ECG findings assessed for clinical outcomes, including the incidence of endotracheal intubation, ICU admission and mortality rate. The risk of bias in individual studies will be evaluated using the Quality in Prognostic Studies tool or the Cochrane risk of bias tool. A meta-analysis will be conducted if at least two studies indicate a prognostic factor’s effect. Moreover, subgroup and sensitivity analyses will be performed accordingly to address heterogeneity. Reporting the review results will comply with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. The quality of evidence generated will be assessed using the Grades of Recommendation, Assessment, Development and Evaluation system.Ethics and disseminationThis study has been exempted from ethics review. There will be no patient or public involvement in this study. Furthermore, the findings will be disseminated via conferences, seminars, symposia and congresses on top of peer-reviewed journals.PROSPERO registration numberCRD42021257155.