title: Clinical features of myocardial infarction and myocarditis in young adults: a retrospective study.
abstract: OBJECTIVE
  To evaluate the prevalence and clinical presentation of myocardial infarction (MI) and myocarditis in young adults presenting with chest pain (CP) and an elevated serum troponin I (TnI) to the emergency department (ED).
  
  
  METHODS
  Retrospective, observational, single-centre study.
  
  
  METHODS
  All consecutive patients 18-40 years old admitted to the ED for CP with an elevated TnI concentration.
  
  
  METHODS
  Prevalence of MI, myocarditis and the characterisation of clinical presentation.
  
  
  RESULTS
  1588 patients between 18 and 40 years old were admitted to the ED with CP during 30 consecutive months. 49 (3.1%) patients with an elevated TnI (>0.09 μg/l) were included. 32.7% (16/49) were diagnosed with MI (11 ST-elevation myocardial infarction (STEMI) and 5 non-ST-elevation myocardial infarction (NSTEMI)) and 59.2% (29/49) with myocarditis. Compared with patients with myocarditis, MI patients were older (34.1±3.8 vs 26.9±6.4, p=0.0002) with more cardiovascular risk factors (mean 2.06 vs 0.69). Diabetes (18.8% vs 0%, p=0.0039), dyslipidaemia (56.2% vs 3.4%, p<0.0001) and family history of coronary artery disease (CAD) (37.5% vs 10.3% p=0.050) were associated with MI. Fever or recent viral illness were present in 75.9% (22/29) of patients with myocarditis, and in 0% of MI patients (p<0.0001). During follow-up, two patients with myocarditis were re-admitted for CP.
  
  
  CONCLUSIONS
  In this study, 32.7% of patients <40-year-old admitted to an ED with CP and elevated TnI had a diagnosis of MI. Key distinctive clinical factors include diabetes, dyslipidaemia, family history of CAD and fever or recent viral illness.
authors.affiliation: Department of Cardiology,  University Hospital of Lausanne, Lausanne,  Switzerland.
authors.forename: Cyril
authors.initials: C
authors.lastname: Pellaton
authors.forename: Pierre
authors.initials: P
authors.lastname: Monney
authors.forename: Andrew James
authors.initials: AJ
authors.lastname: Ludman
authors.forename: Juerg
authors.initials: J
authors.lastname: Schwitter
authors.forename: Eric
authors.initials: E
authors.lastname: Eeckhout
authors.forename: Olivier
authors.initials: O
authors.lastname: Hugli
authors.forename: Olivier
authors.initials: O
authors.lastname: Muller