A reverse perfusion pattern during Technetium-99m stress myocardial perfusion imaging does not predict flow limiting coronary artery disease.

Background: A reverse redistribution pattern during myocardial perfusion imaging is most widely described using thallium (Tl-201), when stress images exhibit greater perfusion than rest. Technetium (Tc-99 m) radiopharmaceuticals may also yield a reverse perfusion (RP) pattern, but its significance is uncertain. This study tested the hypothesis that RP correlates with the presence and location of flow limiting coronary stenosis(es).

Method: We reviewed 842 consecutive Tc-99 m tetrofosmin SPECT stress studies performed at a cardiothoracic centre over a 15 month period. 69 (8.2%) demonstrated RP. Thirty-three patients (age 32-79 mean 56, 17 female) had undergone cardiac catheterisation within 12 months of the scan. Correlation was sought between the presence and location of angiographic stenoses and RP pattern.

Results: 10/33 (30.3%) had significant (>60%) coronary stenosis(es); 5 single-vessel, 2 two-vessel and 3 three-vessel disease (3VD). Stenosis location correlated poorly with the RP territory (LAD/Anterior 5/17, RCA/Inferior 1/10, Cx/lateral 0/4 (p = 0.57)). Of the 6 patients with a lesion in the RP territory, 3 had 3VD; 2 of these had a simultaneous reversible defect. All 5 patients with previous myocardial infarction had a simultaneous fixed defect. However only 3/12 with co-existent reversible defects had significant disease.

Conclusion: The reverse perfusion pattern is a poor predictor of flow limiting coronary disease, and does not correlate with stenosis location in those with significant lesions. Such patients should not undergo invasive investigation purely on the basis of this result.