Risk stratification with attenuation corrected stress Tc-99m sestamibi SPECT myocardial perfusion imaging in the absence of ECG-gating due to arrhythmias

J Nucl Cardiol. 2009 Jul-Aug;16(4):533-9. doi: 10.1007/s12350-009-9071-3. Epub 2009 Mar 14.


Background: Despite growing recognition of attenuation correction (AC) utilizing an external radiation source, prognostic studies using AC are lacking.

Methods: Consecutive patients (n = 419) who underwent stress Tc-99m sestamibi SPECT imaging with AC but without ECG-gating, due to arrhythmia, were followed for cardiac death or non-fatal myocardial infarction (MI). A 17-segment model and the summed stress score (SSS) were used to classify both the non-AC and AC images.

Results: The 419 patients had a mean age of 71.5 +/- 11.7 years and most (70.6%) underwent pharmacologic stress. In follow-up, 35 (8.4%) patients suffered an adverse cardiac event. Patients with AC-SSS 1-3 and AC-SSS 4-8 had similar cardiac event rates (11.4% vs 10.5%, P = NS). Accordingly, AC-SSS cutoffs of 0, 1-8, and >8 were selected to classify perfusion as normal, mildly abnormal, and moderately to severely abnormal with annualized event rates of 2.1%, 10.8%, and 18.7%, respectively (P < .001). In multivariable analysis, AC-SSS >8 was the most powerful predictor of cardiac events followed by AC-SSS 1-8, history of CAD, age >75 and pharmacologic stress.

Conclusions: AC provides powerful risk stratification when added to clinical variables in patients undergoing stress Tc-99m sestamibi SPECT imaging without ECG-gating. Moreover, smaller/less severe defects on AC data are more significant than if the same defects were seen on non-AC data.

MeSH terms

  • Aged
  • Arrhythmias, Cardiac / complications*
  • Coronary Artery Disease / diagnosis
  • Coronary Artery Disease / diagnostic imaging
  • Electrocardiography / instrumentation
  • Electrocardiography / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / diagnostic imaging
  • Myocardial Perfusion Imaging / instrumentation
  • Myocardial Perfusion Imaging / methods*
  • Prognosis
  • Risk
  • Risk Assessment
  • Risk Factors
  • Technetium Tc 99m Sestamibi*
  • Tomography, Emission-Computed, Single-Photon / methods*


  • Technetium Tc 99m Sestamibi