Patterns of inflammatory activation associated with precipitants of acute coronary syndromes: a case-crossover study

Aims We sought to assess a broad array of possible precipitants of acute coronary syndromes (ACS) and evaluate their association with detectable inflammatory activation. Methods and 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 degrees 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 (07 days vs 78 weeks odds ratio (OR): 7.5, confidence interval (CI): 1.767.6, P = 0.002); INFL (07 days vs 78 weeks OR: 14.0, CI: 2.13591.9, P = 0.001); EX (04?h vs 2428?h OR: 2.2, CI: 1.33.5, P = 0.001) and FF (024?h vs 7296?h OR: 5.67, CI: 1.630.2, 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. Conclusion 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.