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.

Abstract

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.

• Authors: John J Mahmarian, Leslee J Shaw, Neil G Filipchuk, Habib A Dakik, Sherif S Iskander, Terrence D Ruddy, Milena J Henzlova, Felix Keng, Adel Allam, Lemuel A Moyé, Craig M Pratt, INSPIRE Investigators
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 48 Issue 12 Pg. 2448-57 (Dec 19 2006) ISSN: 1558-3597 [Electronic] United States
• PMID: 17174181 (Publication Type: Clinical Trial, Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)

Chemical References

• Radiopharmaceuticals
• Technetium Tc 99m Sestamibi
• Adenosine

Topics

• 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