Usefulness of distinct activity thresholds according to baseline regional asynergy for predicting functional recovery in patients with chronic coronary artery disease and left ventricular dysfunction: a study with nitrate-enhanced sestamibi gated SPECT.
BACKGROUND
The role of gated single photon emission computed tomography (SPECT) in improving viability detection with the use of perfusion imaging is uncertain. This study aimed to verify whether the classification of baseline regional dysfunction with gated SPECT helps to predict functional recovery with the use of quantitative perfusion imaging.


RESULTS
Resting nitrate-enhanced sestamibi gated SPECT was performed in 31 patients with left ventricular dysfunction, who later underwent coronary revascularization. With the use of a 16-segment model, tracer activity was quantified, and wall motion and thickening were estimated with a 4-point scoring scheme. Reversible dysfunction was assessed with follow-up gated SPECT. According to receiver operating characteristic curve analysis, the best overall cutoff for predicting reversible dysfunction in asynergic segments was 50% of peak activity or greater, with 83% sensitivity, 54% specificity, and 64% accuracy. When the segments were divided according to wall motion in resting gated SPECT, the optimal activity cutoff was greater than 68% for hypokinetic and 50% or greater for adyskinetic segments. With the use of 2 thresholds, the overall sensitivity remained good (76%), whereas specificity increased to 73% (P <.0005) and accuracy to 74% (P <.02).


CONCLUSIONS
Regional dysfunction assessment directly on perfusion images permits use of different activity thresholds with an improvement over a single cutoff for all asynergic segments. Therefore combining perfusion and functional data with nitrate-enhanced gated SPECT at rest appears to be a promising approach for viability detection.
Leoncini
M
M
Division of Cardiology, Misericordia e Dolce Hospital, Prato, Italy. r.sciagra@dfc.unifi.it
Marcucci
G
G
Sciagrà
R
R
Frascarelli
F
F
Bellandi
F
F
Gallopin
M
M
Mennuti
A
A
Dabizzi
R P
RP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
D017256:Technetium Tc 99m Sestamibi