Mechanisms of Progression and Regression of Coronary Artery Disease by PET Related to Treatment Intensity and Clinical Events at Long-Term Follow-up

Schematic of stress PET images after dipyridamole at baseline compared with follow-up PET in various quadrant pairings. Small orange area signifies a mild small dipyridamole-induced perfusion defect. Green medium-sized area signifies a moderate medium-sized dipyridamole-induced perfusion defect. Large blue area signifies a severe large dipyridamole-induced defect. BW at follow-up may be worse (arrow A) or better (arrow B). FuW may be the same quadrant as baseline (arrow A) or a different quadrant than at baseline (arrow C). MCh may be a different quadrant than the baseline worst, either worse (arrow C) or better (arrow D).

(A) PET perfusion images at rest (top row) and after dipyridamole (middle row) at baseline and after dipyridamole at follow-up (bottom row) illustrating progression. In color bar, white indicates the highest myocardial uptake of radionuclide reflecting the highest myocardial perfusion, with red being the next highest and progressively lower perfusion indicated by color gradations from red to yellow, green, and blue. At baseline, the lateral quadrant has the worst defect, whereas at follow-up, the inferior wall has the worst defect, illustrating that most patients had changes in quadrants other than the baseline worst quadrant. (B) PET perfusion images after dipyridamole at baseline and at follow-up illustrating regression.

Percentage of patients in whom the quadrant pair with the maximal change from baseline to follow-up (MCh) improved (better) or became more severe (worse) for each treatment group (P < 0.001).

Percentage of patients with the FuW in a different region than at baseline that was also more severe than at baseline for each treatment group (P = 0.01).

Percentage of patients in whom the BW became better, worse, or showed no change in each treatment group (P = 0.02).