Low-dose dobutamine nitrate-enhanced technetium 99m sestamibi gated SPECT versus low-dose dobutamine echocardiography for detecting reversible dysfunction in ischemic cardiomyopathy.
BACKGROUND
The simultaneous assessment of perfusion and function with the use of technetium 99m sestamibi gated single photon emission computed tomography (SPECT) is helpful for the detection of myocardial viability, but its value in comparison with more established methods is not yet defined.


RESULTS
This study compared low-dose dobutamine (LDD) nitrate-enhanced gated SPECT with LDD echocardiography for predicting recovery of regional ventricular function after revascularization in 25 patients with ischemic cardiomyopathy. In both studies, regional function (wall motion and thickening) at rest, during inotropic stimulation, and after revascularization was scored by a 4-point scale. In LDD echocardiography, the prediction of reversible dysfunction was based on the recognition of contractile reserve in asynergic (hypokinetic or a-dyskinetic) segments. In LDD gated sestamibi SPECT, reversible dysfunction was predicted on the basis of perfusion quantification (sestamibi uptake >or= 50%) in a-dyskinetic segments and on the basis of contractile reserve in hypokinetic segments. LDD echocardiography predicted reversible dysfunction with sensitivity, specificity, and global accuracy of 57%, 85%, and 75%, respectively. The sensitivity and specificity of LDD gated SPECT for identifying dysfunctional segments capable of functional recovery were 77% and 88%, respectively, with a diagnostic accuracy of 84% (P <.02 vs LDD echocardiography).


CONCLUSIONS
The combined use of 2 different markers of viability, such as cellular integrity in a-dyskinetic segments and contractile reserve in hypokinetic segments, as permitted by LDD gated sestamibi SPECT, showed higher predictive accuracy for reversible dysfunction than the assessment of contractile reserve in all asynergic segments with LDD echocardiography.
Leoncini
Mario
M
Division of Cardiology, Misericordia e Dolce Hospital, Prato, Italy. r.sciagra@dfc.unifi.it
Sciagrà
Roberto
R
Bellandi
Francesco
F
Maioli
Mauro
M
Sestini
Stelvio
S
Marcucci
Gabriella
G
Coppola
Angela
A
Frascarelli
Fabio
F
Mennuti
Alberto
A
Dabizzi
Roberto P
RP
D000368:Aged; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002316:Cardiotonic Agents / Q000008:administration & dosage*; D002908:Chronic Disease; D004280:Dobutamine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D025401:Echocardiography, Stress; D005260:Female; D015637:Gated Blood-Pool Imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009566:Nitrates / Q000008:administration & dosage; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D020127:Recovery of Function / Q000502:physiology; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D018754:Ventricular Dysfunction / Q000000981:diagnostic imaging* / Q000503:physiopathology
D002316:Cardiotonic Agents; D009566:Nitrates; D019275:Radiopharmaceuticals; D004280:Dobutamine; D017256:Technetium Tc 99m Sestamibi