title: Prognostic significance of ischemic electrocardiographic changes during adenosine infusion in patients with normal myocardial perfusion imaging.
abstract: BACKGROUND
  The development of ST-segment depression during adenosine myocardial perfusion imaging (MPI) has been shown to be an independent predictor of subsequent cardiac events and worse outcome, particularly in association with ischemic defects. However, the prognostic significance of ST-segment depression with adenosine in patients with normal MPI is not known.
  
  
  RESULTS
  We performed a retrospective analysis of 3231 patients undergoing adenosine MPI. Patients with baseline electrocardiographic (ECG) abnormalities were excluded. Overall, 228 patients (7%) had ischemic ECG changes develop during adenosine infusion. Of these, 66 (29% [2% of all patients]) had normal MPI (+ECG group). An age- and sex-matched group of 200 patients with normal MPI without ECG changes served as control subjects (-ECG group). During a mean follow-up of 29 +/- 12 months, patients in the +ECG group had significantly more adverse cardiac events than those in the -ECG group (nonfatal myocardial infarction, 7.6% vs 0.5%, respectively, P = .004; subsequent revascularization, 13.6% vs 2.5%, respectively, P = .0015). Although cardiac death alone did not differ between the 2 groups (+ECG, 3.0%, vs -ECG, 1.0%; P = .25), cumulative survival free from cardiac death and nonfatal myocardial infarction was worse in patients with ST-segment depression during adenosine infusion and normal MPI (+ECG, 10.6%, vs -ECG, 1.5%; log-rank chi(2) = 11.82; P = .0006).
  
  
  CONCLUSIONS
  Patients with normal myocardial perfusion images in whom ST-segment depression develops during adenosine administration appear to be at increased risk for future cardiac events compared with similar patients without ECG evidence of ischemia. Ischemic ECG changes during adenosine MPI should warrant further evaluation, even when perfusion images are reassuring.
authors.affiliation: Yale University School of Medicine, Section of Cardiovascular Medicine, New Haven, Conn 06520, USA. brian.abbot@yale.edu
authors.forename: Brian G
authors.initials: BG
authors.lastname: Abbott
authors.forename: Maryam
authors.initials: M
authors.lastname: Afshar
authors.forename: Alan K
authors.initials: AK
authors.lastname: Berger
authors.forename: Frans J Th
authors.initials: FJ
authors.lastname: Wackers
mesh_terms: D000241:Adenosine; D000368:Aged; D000369:Aged, 80 and over; D003327:Coronary Disease / Q000175:diagnosis; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine