title: Worsening left ventricular performance on serial exercise radionuclide angiography does not identify high-risk patients.
abstract: OBJECTIVE
  To determine whether worsening exercise performance on serial exercise radionuclide angiography identifies patients at increased risk of future cardiac events.
  
  
  METHODS
  One hundred nine medically treated patients with previous Q-wave myocardial infarction underwent two exercise radionuclide angiographic studies at least 6 months apart (median, 16 months) without an intervening clinical event. Worsening exercise performance between the two studies was defined by five criteria: (1) lower (5% or more) peak exercise ejection fraction; (2) worsening peak exercise wall motion score; (3) combination of criteria 1 and 2; (4) worsening serial delta (exercise - rest) ejection fraction; or (5) increasing exercise ST-segment depression of 1 mm or more. Patients were followed up for a median duration of 3.9 years after the second exercise study.
  
  
  RESULTS
  Five cardiac deaths and 10 nonfatal myocardial infarctions occurred during follow-up. A Cox proportional hazards analysis failed to show an association between any of the aforementioned variables and cardiac events. Of the 15 patients with cardiac events, 4 (27%) had a lower (5% or more) exercise ejection fraction and 2 (13%) had a worsening exercise wall motion score. Of the 94 patients without cardiac events, 37 (39%) had a lower (5% or more) exercise ejection fraction and 28 (30%) had a worsening serial exercise wall motion score (not a statistically significant difference).
  
  
  CONCLUSIONS
  Worsening exercise performance on serial exercise radionuclide angiography does not identify patients at increased risk of future cardiac events.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic Rochester, Minnesota 55905, USA.
authors.forename: H P
authors.initials: HP
authors.lastname: Chaliki
authors.forename: T D
authors.initials: TD
authors.lastname: Miller
authors.forename: T F
authors.initials: TF
authors.lastname: Christian
authors.forename: K R
authors.initials: KR
authors.lastname: Bailey
authors.forename: R J
authors.initials: RJ
authors.lastname: Gibbons
mesh_terms: D000368:Aged; D016757:Death, Sudden, Cardiac; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D016016:Proportional Hazards Models; D015635:Radionuclide Ventriculography; D012008:Recurrence; D012189:Retrospective Studies; D012306:Risk; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left