Effect of mean heart rate on 30-day mortality in older patients with sepsis: Data from the MIMIC-IV database

Abstract

BackgroundSepsis is a critical condition with a significant risk of mortality. Advanced age is one factor in increasing mortality in intensive care. ObjectivesThe aim of this study is to investigate the association between mean heart rate (MHR) and 30-day mortality among older patients with sepsis in the intensive care unit (ICU). MethodsAll older patients (age 65 or older) with sepsis for first time in ICU admission in Medical Information Mart for Intensive Care-IV (MIMIC-IV) were included in this retrospective study. The effect of MHR within 24 h of ICU admission on 30-day mortality was assessed according to multivariable Cox regression models, restricted cubic splines and two-piecewise Cox regression models. ResultsThe total number of participants was 6598 (mean heart rate, 83.8 ± 14.3 bpm). A total of 1295 (19.6 %) patients died within 30 days after ICU admission. MHR within 24 h of admission was associated with 30-day mortality (J-shaped association) in older patients with sepsis in the ICU, with an inflection point at about 74 bpm and a minimal risk observed at 73 to 82 bpm of MHR. ConclusionsIn this retrospective cohort study, there was a J-shaped association between MHR and 30-day mortality in older patients with sepsis admitted to the ICU and a minimal risk observed at 73 to 82 bpm of MHR. If further confirmed, this association may provide a theoretical basis for formulating the target strategy of heart rate therapy for these patients.