title: Relationship between time of day, day of the week and in-hospital mortality in patients undergoing emergency percutaneous coronary intervention.
abstract: BACKGROUND
  Previous studies have reported circadian variation in the rate of post-percutaneous coronary intervention (PCI) complications and mortality.
  
  
  OBJECTIVE
  To assess whether in-hospital outcomes during the first 48h after admission are related to the time or the day when PCI is performed.
  
  
  METHODS
  Emergency PCIs (2266 total; 1396 during regular hours and 870 during off hours) performed consecutively during a 3.5-year-period (2005-2008) were evaluated. The primary endpoint was death and the secondary endpoint was a composite score based on cardiovascular complications. The association between PCI start time and in-hospital outcome was assessed using multivariable logistic regression and propensity score analysis.
  
  
  RESULTS
  The patients' mean age was 64.8 years and 77.3% were men. The highest death rate was for night-time PCI (3.6%), with a 5.1% occurrence rate for PCI performed between 00:00 and 03:59, and a 3.0% occurrence rate for weekend daytime PCI compared with 1.5% for weekday daytime (regular-hours) PCI. The frequency of occurrence of other clinical events did not vary significantly throughout the day. Compared with weekday daytime PCI, the odds ratio for mortality was 2.95 for night-time PCI (95% confidence interval [CI] 1.58-6.01; p=0.0007) and 2.42 for weekend daytime PCI (95% CI 0.97-6.01; p=0.06).
  
  
  CONCLUSIONS
  Our study shows a significant time-dependent effect on in-hospital deaths in patients treated with emergency PCI. Healthcare organization and circadian variation of ischaemic processes could explain this variation in mortality.
authors: Department of Cardiology, CHU Rangueil, Toulouse, France.
authors: Olivier
authors: O
authors: Lairez
authors: Jérôme
authors: J
authors: Roncalli
authors: Didier
authors: D
authors: Carrié
authors: Meyer
authors: M
authors: Elbaz
authors: Michel
authors: M
authors: Galinier
authors: Stéphane
authors: S
authors: Tauzin
authors: Dominique
authors: D
authors: Celse
authors: Jacques
authors: J
authors: Puel
authors: Jean-Marie
authors: JM
authors: Fauvel
authors: Jean-Bernard
authors: JB
authors: Ruidavets
mesh_terms: D000328:Adult; D039602:After-Hours Care; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000401:mortality*; D002940:Circadian Rhythm; D004638:Emergency Treatment; D005260:Female; D005602:France / Q000453:epidemiology; D006331:Heart Diseases / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010561:Personnel Staffing and Scheduling; D057216:Propensity Score; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult