title: Cardiovascular outcomes are predicted by exercise-stress myocardial perfusion imaging: Impact on death, myocardial infarction, and coronary revascularization procedures.
abstract: BACKGROUND
  The aim of this study was to determine the impact of myocardial perfusion imaging (MPI) on the outcomes of death, myocardial infarction (MI), and late coronary revascularization procedures.
  
  
  METHODS
  In patients undergoing exercise-stress MPI (January 1, 2003-March 31, 2007), we determined the impact of summed stress score (SSS) and percent left ventricular (LV) ischemia on (a) death or MI and (b) composite of death, MI, or late coronary revascularization occurring more than 90 days post-MPI.
  
  
  RESULTS
  During 35,007 person-years of follow-up among 9,605 patients (mean ± SD age 54.4 ± 13.2 years, 60.3% men), there were 290 deaths, 175 MIs, and 525 coronary revascularization procedures. Of those who attained ≥10 metabolic equivalents (METS) workload, major stress perfusion defects (SSS ≥7) were present in 4.2% overall and in 3.7% without ST-segment shifts, whereas large ischemic defects (≥10% LV ischemia) were present in 1% overall and 0.7% without ST-segment shifts. For those with 1% to 4%, 5% to 9%, and ≥10% LV ischemia, adjusted hazard ratios were 1.40 (95% CI 1.13-1.73, P = .002), 2.07 (95% CI 1.56-2.74, P < .001), and 3.03 (95% CI 2.21-4.16, P < .001) for the outcome of late revascularization, MI, or death versus no ischemia. Summed stress scores ≥7 were associated with increased risk of death or MI, with an adjusted hazard ratio of 1.57 (95% CI 1.16-2.13, P = .004) compared with those with no stress perfusion defects.
  
  
  CONCLUSIONS
  Although workload ≥10 METS conferred lower frequency of major ischemia (≥10%), %LV ischemia predicted the occurrence of cardiovascular events and death (eg, MI, late coronary revascularization, or death). Presence of a large stress perfusion defect (SSS ≥7) predicted increased risk of MI or death.
authors.affiliation: Robert J. Burns Nuclear Cardiology Laboratory, Toronto, Canada. dlee@ices.on.ca
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Lee
authors.forename: Flavia
authors.initials: F
authors.lastname: Verocai
authors.forename: Mansoor
authors.initials: M
authors.lastname: Husain
authors.forename: Darar
authors.initials: D
authors.lastname: Al Khdair
authors.forename: Xuesong
authors.initials: X
authors.lastname: Wang
authors.forename: Michael
authors.initials: M
authors.lastname: Freeman
authors.forename: Robert M
authors.initials: RM
authors.lastname: Iwanochko
mesh_terms: D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000401:mortality / Q000601:surgery; D009204:Myocardial Revascularization / Q000379:methods*; D009864:Ontario / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D015996:Survival Rate / Q000639:trends; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*