title: Impact of cardiovascular risk factors and disease on length of stay and mortality in patients with acute coronary syndromes.
abstract: BACKGROUND
  Traditional risk factors for cardiovascular disease (CVD) have been thoroughly investigated. We aimed to investigate the impact of comorbid cardiovascular risk factors and diseases on length of stay (LOS) and mortality in patients presenting with acute coronary syndromes (ACS).
  
  
  METHODS
  We examined prevalence of CVD, LOS and mortality from 25,287 consecutive admissions for ACS from seven hospitals across North West England between 2000 and 2013 using the ACALM (Algorithm for Comorbidities, Associations, Length of stay and Mortality) protocol using ICD-10 and OPCS-4 coding systems.
  
  
  RESULTS
  Mean LOS was 7.0days and there were 9653 (38.2%) deaths in the ACS cohort over the 13-year period. Hypertension and hyperlipidaemia were associated with decreased LOS (6.95 and 4.8days respectively, P<0.001) and mortality (36.8% and 19.4% respectively, P<0.001), as was angina pectoris (5.4days and 33.5%, P<0.001). Type 2 diabetes was associated with increased LOS and mortality (7.8days, P<0.05; 44.4%, P<0.001), whereas type 1 diabetes was associated with increased mortality only (7.0days, P=0.42; 41.3%, P<0.001). Other concomitant CVD was associated with an increased LOS and mortality: peripheral vascular disease (8.6days, P<0.05; 53%, P<0.001), atrial fibrillation (10.9days, P<0.001; 63.5%, P<0.001), cerebrovascular disease (15.9days, P<0.001; 76%, P<0.001), heart failure (11days, P<0.001; 69.9%, P<0.001), and ischaemic heart disease (6.7days, P<0.001; 38.7%, P<0.05).
  
  
  CONCLUSIONS
  CVD risk factors have a significant and varied impact on LOS and mortality in patients with ACS and it may be inappropriate to group them when assessing in-hospital risk. These factors should be used to identify patients at an increased risk of prolonged admissions and death post-ACS, and services should be directed accordingly.
authors.affiliation: Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK.
authors.forename: B L
authors.initials: BL
authors.lastname: Loudon
authors.affiliation: Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK.
authors.forename: N D
authors.initials: ND
authors.lastname: Gollop
authors.affiliation: Royal Free London NHS Trust, London, UK.
authors.forename: P R
authors.initials: PR
authors.lastname: Carter
authors.affiliation: ACALM Study Unit in collaboration with Aston Medical School, Aston University, Birmingham, UK.
authors.forename: H
authors.initials: H
authors.lastname: Uppal
authors.affiliation: Department of Acute Medicine, North Western Deanery, Manchester, UK.
authors.forename: S
authors.initials: S
authors.lastname: Chandran
authors.affiliation: ACALM Study Unit in collaboration with Aston Medical School, Aston University, Birmingham, UK. Electronic address: rahulpotluri@outlook.com.
authors.forename: R
authors.initials: R
authors.lastname: Potluri
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000401:mortality*; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D007902:Length of Stay / Q000639:trends*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Acute coronary syndrome; Cardiovascular risk factors; Length of stay; Mortality