Clinical correlates of Tc-99m sestamibi lung uptake.
BACKGROUND
Increased lung uptake of thallium 201 during myocardial perfusion scintigraphy is related to severe coronary artery disease (CAD), but a similar relationship for technetium 99m sestamibi has not been clearly established.


RESULTS
Resting and stress lung-heart ratios (LHR) were retrospectively determined in 96 patients who underwent Tc-99m sestamibi stress testing and coronary angiography within 4 months of each other. A semiquantitative CAD severity score (CADSS) was derived from the coronary angiogram. Left ventricular (LV) function was assessed in a subgroup of 42 subjects. CADSS of 24 or higher was associated with increased stress LHR compared with angiographically normal individuals (P =.009). Patients with severely impaired LV function also had a higher mean stress LHR than those with normal LV function (P =.01). Stress LHR was significantly greater than resting LHR in patients with coronary disease (0.32 +/- 0.07 vs 0.30 +/- 0.07; P =.003) and impaired LV function (0.35 +/- 0.08 vs 0.31 +/- 0.07; P <.02). CADSS correlated with stress, but not resting, LHR (P =.006), whereas the degree of LV dysfunction correlated with both resting (P =.046) and stress (P =.004) LHR. Left anterior descending (P =.017) and left main (P =.03) stenoses were independent predictors of increased stress LHR.


CONCLUSIONS
An increase in stress Tc-99m sestamibi lung uptake is a marker for severe CAD. Correlation of stress LHR, but not resting LHR, with CAD severity supports exercise-induced pulmonary congestion as the underlying mechanism.
Choy
J B
JB
Division of Cardiology, University of Alberta Hospital, Edmonton, Alberta, Canada.
Leslie
W D
WD
D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D012146:Rest / Q000502:physiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi