title: Patterns of inflammatory activation associated with precipitants of acute coronary syndromes: a case-crossover study.
abstract: OBJECTIVE
  We sought to assess a broad array of possible precipitants of acute coronary syndromes (ACS) and evaluate their association with detectable inflammatory activation.
  
  
  RESULTS
  Within a case-crossover design, using a standardised questionnaire, interviews among 348 ST-elevation myocardial infarction (44%) or high-risk non-ST-elevation ACS patients (56%), explored potential precipitants, including: infection (INF)-temperature >38°C and/or respiratory tract, urinary or skin infection; inflammation (INFL)-exacerbation of inflammatory conditions; exercise (EX)-moderate to heavy exercise; fast food (FF)-consumption of a meal purchased from a fast food company. Risk and control periods were: weekly over 8 weeks for INF and INFL; 24 hourly over 4 days for FF and 4 hourly over 48 h for EX. C-reactive protein (CRP) levels were assessed at admission. These precipitants were identified in 203/348 (58.3%) patients. An increased temporal risk was observed for: INF (0-7 days vs 7-8 weeks odds ratio (OR): 7.5, confidence interval (CI): 1.7-67.6, P = 0.002); INFL (0-7 days vs 7-8 weeks OR: 14.0, CI: 2.13-591.9, P = 0.001); EX (0-4 h vs 24-28 h OR: 2.2, CI: 1.3-3.5, P = 0.001) and FF (0-24 h vs 72-96 h OR: 5.67, CI: 1.6-30.2, P = 0.003). CRP levels were significantly elevated among patients reporting infective and inflammatory potential precipitants, but not among those reporting fast food consumption and unaccustomed moderate-heavy exercise.
  
  
  CONCLUSIONS
  Infection, inflammatory conditions, moderate-heavy exercise and potentially fast food consumption appear to precipitate high-risk ACS. Increased inflammation as measured by CRP was not consistently detected despite the identification of an ACS precipitant. Strategies that target improved overall health may also lead to fewer ACS events through a reduction in triggers.
authors: Flinders University/Flinders Medical Centre, Adelaide, South Australia, Australia. derek.chew@flinders.edu.au
authors: D P
authors: DP
authors: Chew
authors: S
authors: S
authors: Mattschoss
authors: M
authors: M
authors: Horsfall
authors: C
authors: C
authors: Astley
authors: J C
authors: JC
authors: Vaile
authors: M X
authors: MX
authors: Joseph
mesh_terms: D054058:Acute Coronary Syndrome / Q000453:epidemiology* / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D018592:Cross-Over Studies; D005260:Female; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015985:Precipitating Factors; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D002097:C-Reactive Protein