title: Clinical and angiographic characteristics of exertion-related acute myocardial infarction.
abstract: BACKGROUND
  Vigorous physical exertion transiently increases the risk of acute myocardial infarction (MI), but little is known about the clinical characteristics of exertion-related MI.
  
  
  OBJECTIVE
  To compare the clinical and angiographic characteristics of patients who had an exertion-related acute MI vs those who experienced an MI not related to exertion.
  
  
  METHODS
  Prospective observational cohort study of patients with an acute MI referred to a tertiary care hospital for primary angioplasty.
  
  
  METHODS
  Of 1048 patients with acute MI, 640 (64 who experienced an exertion-related MI and 576 who did not) were selected for treatment with primary angioplasty and admitted between August 1995 and November 1998.
  
  
  METHODS
  Clinical characteristics of the patients, including their habitual physical activity (determined by the Framingham Physical Activity Index and the Lipid Research Clinic Physical Activity Questionnaire), angiographic findings during coronary angiography, and the relative risk (RR) of MI during exertion.
  
  
  RESULTS
  Patients who experienced exertion-related MI were more frequently men (86% vs 68%), hyperlipidemic (62% vs 40%), and smokers (59% vs 37%), were more likely to present with ventricular fibrillation (20% vs 11%), Killip classification III or IV heart failure (44% vs 22%), single-vessel disease (50% vs 28%), and a large thrombus in the infarct artery (64% vs 35%) and were more likely to be classified as having very low or low activity (84% vs 66%). The RR of experiencing an MI during exertion was 10.1 times greater than the risk at other times (95% confidence interval [CI], 1.6-65.6), with the highest risk among patients classified as very low active (RR, 30.5; 95% CI, 4.4-209.9) and low active (RR, 20.9; 95% CI, 3.1-142.1).
  
  
  CONCLUSIONS
  These results show that exertion-related MIs occur in habitually inactive people with multiple cardiac risk factors. These individuals may benefit from modest exercise training and aggressive risk-factor modification before they perform vigorous physical activity.
authors.affiliation: Division of Cardiology, Hartford Hospital, Conn 06102, USA.
authors.forename: S
authors.initials: S
authors.lastname: Giri
authors.forename: P D
authors.initials: PD
authors.lastname: Thompson
authors.forename: F J
authors.initials: FJ
authors.lastname: Kiernan
authors.forename: J
authors.initials: J
authors.lastname: Clive
authors.forename: D B
authors.initials: DB
authors.lastname: Fram
authors.forename: J F
authors.initials: JF
authors.lastname: Mitchel
authors.forename: J A
authors.initials: JA
authors.lastname: Hirst
authors.forename: R G
authors.initials: RG
authors.lastname: McKay
authors.forename: D D
authors.initials: DD
authors.lastname: Waters
mesh_terms: D006328:Cardiac Catheterization; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D005082:Physical Exertion / Q000502:physiology*; D011446:Prospective Studies; D012306:Risk