Predictors of acute hospital mortality and length of stay in patients with new-onset atrial fibrillation: a first-hand experience from a medical emergency team response provider

Intern Med J. 2019 Aug;49(8):969-977. doi: 10.1111/imj.14236.

Abstract

Background: Atrial fibrillation (AF) occurs frequently following cardiothoracic surgery and treatment decisions are informed by evidence-based clinical guidelines. Outside this setting there are few data to guide clinical management.

Aim: To describe the characteristics, management and outcomes of hospitalised adult patients with new-onset AF.

Methods: The medical emergency team (MET) database was utilised to identify patients who had a 'MET call' activated for tachycardia between 2015 and 2016. Patients with sinus tachycardia, pre-existing AF/atrial flutter or other known tachyarrhythmia were excluded. Primary outcomes were length of hospital stay and in-hospital mortality.

Results: New-onset AF was identified in 137 patients: 68 medically managed; 38 non-cardiothoracic post-operative; and 31 cardiothoracic post-operative. Mean age was 74 ± 11.6 years and 72 (53%) were male. Of 79 patients who underwent echocardiography, 80% had left atrial dilatation and 14% had reduced left ventricular ejection fraction (LVEF). Mean length of stay (LOS) was 12 days and in-hospital mortality rate was 11%. On multivariable analysis, the odds of death during acute hospitalisation was 7.4 times higher in patients with heart failure with reduced LVEF (odds ratio 7.4, 95% confidence interval (CI) 1.23-44.8, P = 0.028). Length of acute hospital stay increased by 36% if the duration of AF was longer than 48 h (beta coefficient 0.36, 95% CI -0.015 to 0.74, P = 0.059).

Conclusion: Left ventricular systolic dysfunction in hospitalised patients with new-onset AF is associated with increased all-cause mortality whereas lower serum potassium levels are associated with an increased LOS. A prospective study is planned to compare outcomes based on in-hospital treatment strategies.

Keywords: atrial fibrillation; length of stay; medical emergency team; mortality.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Atrial Fibrillation / diagnosis*
  • Atrial Fibrillation / mortality
  • Atrial Fibrillation / therapy
  • Australia / epidemiology
  • Echocardiography
  • Emergency Service, Hospital / statistics & numerical data*
  • Female
  • Heart Failure / diagnosis*
  • Heart Failure / mortality
  • Heart Failure / therapy
  • Hospital Mortality*
  • Humans
  • Length of Stay / statistics & numerical data*
  • Male
  • Middle Aged
  • Odds Ratio
  • Risk Factors
  • Ventricular Dysfunction, Left