title: Relationship between time of day and periprocedural myocardial infarction after elective angioplasty.
abstract: OBJECTIVE
  To test if the time of day significantly influences the occurrence of type 4A myocardial infarction in elective patients undergoing percutaneous coronary intervention (PCI).
  
  
  BACKGROUND
  Recent studies have suggested an influence of circadian rhythms on myocardial infarction size and mortality among patients with ST-elevation myocardial infarction. The aim of the study is to investigate whether periprocedural myocardial infarction (PMI) is influenced by the time of day in elective patients undergoing PCI.
  
  
  METHODS
  All consecutive patients undergoing elective PCI between 2007 and 2011 at our institutions with known post-interventional troponin were retrospectively included. Patients (n = 1021) were divided into two groups according to the starting time of the PCI: the morning group (n = 651) between 07:00 and 11:59, and the afternoon group (n = 370) between 12:00 and 18:59. Baseline and procedural characteristics as well as clinical outcome defined as the occurrence of PMI were compared between groups. In order to limit selection bias, all analyses were equally performed in 308 pairs using propensity score (PS) matching.
  
  
  RESULTS
  In the overall population, the rate of PMI was statistically lower in the morning group compared to the afternoon group (20% vs. 30%, p < 0.001). This difference remained statistically significant after PS-matching (21% vs. 29%, p = 0.03). Multivariate analysis shows that being treated in the afternoon independently increases the risk for PMI with an odds ratio of 2.0 (95%CI: 1.1-3.4; p = 0.02).
  
  
  CONCLUSIONS
  This observational PS-matched study suggests that the timing of an elective PCI influences the rate of PMI.
authors.affiliation: Department of Cardiology, University Hospital Center (CHUV) , Lausanne , Switzerland .
authors.forename: Stephane
authors.initials: S
authors.lastname: Fournier
authors.forename: Serban
authors.initials: S
authors.lastname: Puricel
authors.forename: Beata
authors.initials: B
authors.lastname: Morawiec
authors.forename: Eric
authors.initials: E
authors.lastname: Eeckhout
authors.forename: Fabio
authors.initials: F
authors.lastname: Mangiacapra
authors.forename: Catalina
authors.initials: C
authors.lastname: Trana
authors.forename: Maxime
authors.initials: M
authors.lastname: Tapponnier
authors.forename: Juan F
authors.initials: JF
authors.lastname: Iglesias
authors.forename: Vincent
authors.initials: V
authors.lastname: Michiels
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Stauffer
authors.forename: Ahmed
authors.initials: A
authors.lastname: Beggah
authors.forename: Pierre
authors.initials: P
authors.lastname: Monney
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Gobet
authors.forename: Pierre
authors.initials: P
authors.lastname: Vogt
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cook
authors.forename: Olivier
authors.initials: O
authors.lastname: Muller
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D001071:Appointments and Schedules; D016009:Chi-Square Distribution; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D016017:Odds Ratio; D057216:Propensity Score; D012189:Retrospective Studies; D012307:Risk Factors; D013557:Switzerland; D013997:Time Factors; D016896:Treatment Outcome