title: The impact of circadian variation on outcomes in emergency acute anterior myocardial infarction percutaneous coronary intervention.
abstract: OBJECTIVE
  We investigated the impact of primary coronary angioplasty performed during night and compared to the impact of that performed during day-time on outcomes of patients with acute ST elevation anterior wall myocardial infarction (AMI).
  
  
  METHODS
  We prospectively followed 273 consecutive patients of whom 160 (58.6%) were treated during day time (8:00 a.m. to 6 p.m.) and 113 (41.4%) were treated "off hours"/at night (6 p.m. to 8 a.m.). Baseline demographics, angiographic factors, and clinical outcomes (death, recurrent AMI, and need for repeat revascularization) were compared between the groups.
  
  
  RESULTS
  Baseline clinical characteristics were similar between the two groups. Unadjusted mortality at one-month was significantly higher among patients who were treated during night compared with those treated at day-time (9.7% vs. 3.1% P = 0.03), as was adverse cardiac event rate (15.9% vs. 6.9%; P = 0.02). Multiple logistic regression analysis adjusted for the CADILLAC risk score demonstrated that this score, which includes baseline LVEF, renal failure, Killip class, final TIMI flow, age>65 years, anemia, and the number of coronary vessel diseases, is a significant predictor of one-month mortality, while the effect of time of treatment was borderline (night vs. day; odds ratio 2.7; 95% confidence interval, 0.8-9.4; P = 0.095).
  
  
  CONCLUSIONS
  The results of this study indicate that patients with anterior myocardial infarction treated during night time have worse unadjusted short-term clinical outcomes despite no delay from onset of symptoms to actual treatment. Larger studies are needed in order to identify potential contributors to this phenomenon.
authors.affiliation: The Cardiac Catheterization Laboratories, Cardiology Department, Rabin Medical Center, Petach-Tikva, Sackler School of Medicine, Tel-Aviv University, Israel.
authors.forename: Abid R
authors.initials: AR
authors.lastname: Assali
authors.forename: David
authors.initials: D
authors.lastname: Brosh
authors.forename: Hana
authors.initials: H
authors.lastname: Vaknin-Assa
authors.forename: Shmuel
authors.initials: S
authors.lastname: Fuchs
authors.forename: Igal
authors.initials: I
authors.lastname: Teplitsky
authors.forename: Ofer
authors.initials: O
authors.lastname: Sela
authors.forename: Ran
authors.initials: R
authors.lastname: Kornowski
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D016009:Chi-Square Distribution; D002940:Circadian Rhythm; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000628:therapy*; D011446:Prospective Studies; D012307:Risk Factors; D015607:Stents; D016896:Treatment Outcome