The identification of reversible dysfunctional myocardium is influenced by the severity of contractile dysfunction and by the length of follow-up.
OBJECTIVE
To evaluate the influence of the severity of regional myocardial dysfunction and of the length of follow-up on the identification of myocardial viability with rest-redistribution Tl single photon emission computed tomography (SPECT) and low-dose dobutamine echocardiography (LDDE).


METHODS
Twenty-six patients with chronic coronary artery disease and wall motion abnormalities, candidates for revascularization, were included in this study. All patients underwent, in the same week, Tl SPECT and LDDE for pre-revascularization evaluation of myocardial viability. Reversibility of regional dysfunction was assessed by two-dimensional echocardiography, 40+/-20 days (early follow-up) and 12+/-5 months (late follow-up) after revascularization.


RESULTS
In a/dyskinetic segments, Tl SPECT showed similar values of sensitivity (78% vs. 71%, P=NS) and slightly higher values of specificity (43% vs. 18%, P<0.01) compared to hypokinetic segments, in predicting functional recovery at early follow-up. No significant changes were observed in the diagnostic accuracy of Tl SPECT at late follow-up. On the contrary, LDDE provided significantly lower values of sensitivity (56% vs. 94%, P<0.05) and higher values of specificity (73% vs. 9%, P<0.01) in a/dyskinetic compared to hypokinetic segments. Specificity of LDDE in a/dyskinetic segments significantly increased from early (73%) to late follow-up (95%; P<0.05). Similarly, positive predictive value in a/dyskinetic segments significantly increased from early (69%) to late follow-up (96%; P<0.05).


CONCLUSIONS
The severity of regional dysfunction and the length of follow-up significantly influence the diagnostic accuracy of LDDE but not of rest-redistribution Tl SPECT in the identification of myocardial viability.
Dellegrottaglie
Santo
S
Department of Clinical Medicine, Cardiovascular & Immunological Sciences, Federico II University of Naples, Italy.
Perrone-Filardi
Pasquale
P
Pace
Leonardo
L
Prastaro
Maria
M
Corrado
Luigi
L
Cafiero
Maria
M
Della Morte
Anna Maria
AM
Zarrilli
Annamaria
A
Camerino
Roberta
R
Polimeno
Michele
M
Chiariello
Massimo
M
D000328:Adult; D000368:Aged; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D004280:Dobutamine; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011379:Prognosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D020127:Recovery of Function; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013793:Thallium; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
D019275:Radiopharmaceuticals; C027549:thallium chloride; D004280:Dobutamine; D013793:Thallium