Acute coronary syndrome in a hospital in southern Brazil: peak of hospitalizations on Mondays and severe cases on weekends and at night.

Introduction: Ischemic heart disease is the leading cause of death in Brazil and worldwide. The term acute coronary syndrome (ACS) generically represents the acute myocardial ischemic events. These events are clinically divided into three types: acute myocardial infarction (AMI) with ST-segment elevation, AMI without ST-segment elevation, and unstable angina. Although cardiovascular ischemic events occur acutely, studies describe cyclic patterns of ACS, mainly on circadian and weekly variation.

Objective: The aim of this study was to analyze the circadian and weekly variation of hospitalizations for ACS in a hospital in southern Brazil in 2019.

Methods: Observational, cross-sectional type study. The population was the patients hospitalized at the Nossa Senhora da Conceição Hospital (NSCH) in Tubarão (SC, Brazil) with the international classification of diseases (ICD) code referring to ACS in the year 2019, corresponding to 579 patients.

Results: After applying the exclusion criteria, 512 patients hospitalized for ACS were analyzed, 55.1% were male with a median (p25-p75) age of 62.0 (56.0-69.0) years. The main ICDs of hospitalization were: I20.0 (76.2%), I21.9 (16.6%), I21.3 (3.1%) and the most prevalent comorbidities were high blood pressure (82.6%), diabetes (30.1%) and previous AMI (23.6%). The median (p25-p75) time of admission was 14 h (10-18) h and length of stay was 5 (3-9) days. Death occurred in 18 hospitalizations (3.5%) of cases.

Conclusion: We conclude that in the present study there was a peak of hospitalizations for ACS on Mondays, proportionally reducing throughout the week and with a significant decrease on the weekend.