Heart rate n-variability (HRnV) measures for prediction of mortality in sepsis patients presenting at the emergency department

Abstract

Sepsis is a potentially life-threatening condition that requires prompt recognition and treatment. Recently, heart rate variability (HRV), a measure of the cardiac autonomic regulation derived from short electrocardiogram tracings, has been found to correlate with sepsis mortality. This paper presents using novel heart rate n-variability (HRnV) measures for sepsis mortality risk prediction and comparing against current mortality prediction scores. This study was a retrospective cohort study on patients presenting to the emergency department of a tertiary hospital in Singapore between September 2014 to April 2017. Patients were included if they were above 21 years old and were suspected of having sepsis by their attending physician. The primary outcome was 30-day in-hospital mortality. Stepwise multivariable logistic regression model was built to predict the outcome, and the results based on 10-fold cross-validation were presented using receiver operating curve analysis. The final predictive model comprised 21 variables, including four vital signs, two HRV parameters, and 15 HRnV parameters. The area under the curve of the model was 0.77 (95% confidence interval 0.70–0.84), outperforming several established clinical scores. The HRnV measures may have the potential to allow for a rapid, objective, and accurate means of patient risk stratification for sepsis severity and mortality. Our exploration of the use of wealthy inherent information obtained from novel HRnV measures could also create a new perspective for data scientists to develop innovative approaches for ECG analysis and risk monitoring.

Adding heart rate n-variability (HRnV) to clinical assessment potentially improves prediction of serious bacterial infections in young febrile infants at the emergency department: a prospective observational study

“…Unlike another study which found higher risk among neonates (11), we found a significant proportion of SBIs (77%) in the group 29-90 days old, highlighting the need for careful assessment and monitoring for all young infants <90 days old. An earlier study among adults presenting to the ED with sepsis demonstrated that HRnV in addition to HRV parameters and vital signs, was superior in predicting for mortality when compared to traditional scores including the acute physiology and chronic health evaluation II (APACHE II) and sequential organ failure assessment (SOFA) (27). The authors propose that HRnV may contribute to rapid, objective and accurate risk stratification for sepsis severity and risk of death.…”

“…An earlier study among adults presenting to the ED with sepsis demonstrated that HRnV in addition to HRV parameters and vital signs, was superior in predicting for mortality when compared to traditional scores including the acute physiology and chronic health evaluation II (APACHE II) and sequential organ failure assessment (SOFA) ( 27 ). The authors propose that HRnV may contribute to rapid, objective and accurate risk stratification for sepsis severity and risk of death.…”

“…HRnV constructs new signals based on the RRI used in the conventional HRV analysis, called RRnIs. As illustrated in Figure S1 (27), when n≤3, we can generate 6 new RRnI signals from the original RRI by combining n consecutive RRIs, with or without overlapping signals, controlled by parameter m. Subsequently, standard HRV parameters (i.e., HRnV parameters) can be calculated using RRnIs, which share similar properties with RRIs but contain additional physiological information such as the long-term correlations within the original RRI. We obtained HRnV parameters in the same domains as the conventional HRV analysis mentioned above.…”

“…Heart rate n-variability (HRnV), constructs new signals based on the R-to-R peak intervals (RRI) used in the conventional HRV analysis. It was more recently invented as a novel tool to augment the number of calculated parameters from the same segment of signals, with the potential to enhance the prognostic information provided by traditional HRV parameters ( 26 , 27 ).…”

“…Heart Rate n-Variability and definition of RR intervals(27). Reprinted with permission from the copyright owner, under the terms of the Creative Commons Attribution License.…”