A multinational study to establish the value of early adenosine technetium-99m sestamibi myocardial perfusion imaging in identifying a low-risk group for early hospital discharge after acute myocardial infarction

J Am Coll Cardiol. 2006 Dec 19;48(12):2448-57. doi: 10.1016/j.jacc.2006.07.069. Epub 2006 Nov 28.


Objectives: The purpose of this study was to determine whether gated adenosine Tc-99m sestamibi single-photon emission computed tomography (ADSPECT) could accurately define risk and thereby guide therapeutic decision making in stable survivors of acute myocardial infarction (AMI).

Background: Controversy continues as to the role of noninvasive stress imaging in stratifying risk early after AMI.

Methods: The INSPIRE (Adenosine Sestamibi Post-Infarction Evaluation) trial is a prospective multicenter trial which enrolled 728 clinically stable survivors of AMI who had gated ADSPECT within 10 days of hospital admission and subsequent 1-year follow-up. Event rates were assessed within prospectively defined INSPIRE risk groups based on the adenosine-induced left ventricular perfusion defect size, extent of ischemia, and ejection fraction.

Results: Total cardiac events/death and reinfarction significantly increased within each INSPIRE risk group from low (5.4%, 1.8%), to intermediate (14%, 9.2%), to high (18.6%, 11.6%) (p < 0.01). Event rates at 1 year were lowest in patients with the smallest perfusion defects but progressively increased when defect size exceeded 20% (p < 0.0001). The perfusion results significantly improved risk stratification beyond that provided by clinical and ejection fraction variables. The low-risk INSPIRE group, comprising one-third of all enrolled patients, had a shorter hospital stay with lower associated costs compared with the higher-risk groups (p < 0.001).

Conclusions: Gated ADSPECT performed early after AMI can accurately identify a sizeable low-risk group who have a <2% death and reinfarction rate at 1 year. Identifying these low-risk patients for early hospital discharge may improve utilization of health care resources at considerable cost savings.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine
  • Aged
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnostic imaging*
  • Patient Discharge
  • Prospective Studies
  • Radiopharmaceuticals*
  • Risk Assessment
  • Technetium Tc 99m Sestamibi*
  • Tomography, Emission-Computed, Single-Photon*


  • Radiopharmaceuticals
  • Technetium Tc 99m Sestamibi
  • Adenosine