title: Clinical characteristics determining the mode of presentation in patients with acute coronary syndromes.
abstract: OBJECTIVE
  The purpose of this study was to examine clinical characteristics of patients with acute coronary syndromes to identify factors that influence the mode of presentation.
  
  
  BACKGROUND
  In acute coronary syndromes, presentation with myocardial infarction or unstable angina has major prognostic implications, yet clinical factors affecting the mode of presentation are not well defined.
  
  
  METHODS
  A prospective cohort study was made of 1,111 patients with acute coronary syndromes. Baseline demographic, clinical and biochemical data were compared in groups with myocardial infarction (n = 633) and unstable angina (n = 478).
  
  
  RESULTS
  The risk of myocardial infarction relative to unstable angina was increased by age >70 years (odds ratio [OR] 2.21; 95% confidence interval [CI] 1.33 to 3.66), male gender (OR 1.56; CI 1.13 to 2.16) and cigarette smoking (OR 1.49; CI 1.09 to 2.03). A rise in admission creatinine from the 10th to the 90th centile of the distribution also increased the odds of myocardial infarction (OR 1.30; CI 1.05 to 1.94). Conversely, the risk of myocardial infarction relative to unstable angina was reduced by previous treatment with aspirin (OR 0.37; CI 0.27 to 0.52), hypertension (OR 0.64; CI 0.47 to 0.86) and previous acute coronary syndromes (OR 0.36; CI 0.26 to 0.51) and revascularization procedures (OR 0.36; CI 0.21 to 0.62).
  
  
  CONCLUSIONS
  The clinical presentation of acute coronary syndromes may be influenced by various factors that have the potential to influence the coagulability of the blood, the collateralization of the coronary circulation and myocardial mass. Myocardial infarction is favored by cigarette smoking, advanced age and renal impairment, while unstable angina is favored by treatment with aspirin, hypertension, previous revascularization and previous coronary syndromes.
authors.affiliation: Department of Cardiology, Royal Hospitals Trust, London, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Kennon
authors.forename: A
authors.initials: A
authors.lastname: Suliman
authors.forename: P K
authors.initials: PK
authors.lastname: MacCallum
authors.forename: K
authors.initials: K
authors.lastname: Ranjadayalan
authors.forename: P
authors.initials: P
authors.lastname: Wilkinson
authors.forename: A D
authors.initials: AD
authors.lastname: Timmis
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000175:diagnosis* / Q000503:physiopathology; D003097:Collateral Circulation; D003326:Coronary Circulation; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
chemical_list: D003404:Creatinine