Prediction of improvement in global left ventricular function in patients with chronic coronary artery disease and impaired left ventricular function: rest thallium-201 SPET versus low-dose dobutamine echocardiography.
Accurate assessment of myocardial viability permits selection of patients who would benefit from myocardial revascularization. Currently, rest-redistribution thallium-201 scintigraphy and low-dose dobutamine echocardiography are among the most used techniques for the identification of viable myocardium. Thirty-one consecutive patients (all men, mean age 60 +/- 8 years) with chronic coronary artery disease and reduced left ventricular ejection fraction (31% +/- 7%) were studied. Rest 201Tl single-photon emission tomography (SPET), low-dose dobutamine echocardiography and radionuclide angiography were performed before revascularization. Radionuclide angiography and echocardiography were repeated after revascularization. An a/dyskinetic segment was considered viable on 201Tl SPET when tracer uptake was >65%, while improvement on low-dose dobutamine echocardiography was considered a marker of viability. Increase in global ejection fraction was considered significant at > or = 5%. In identifying viable segments, rest 201Tl SPET showed higher sensitivity than low-dose dobutamine echocardiography (72% vs 53%, P<0.05), while specificity was not significantly different (86% vs 88%). In 17 patients, global ejection fraction increased > or = 5% (group 1) while in 14 it did not (group 2). A higher number of a/dyskinetic segments were viable on 201Tl SPET in group 1 than in group 2 (2.6 +/- 1.9 vs 0.6 +/- 1.2, P < 0.005), while no significant differences were observed on low-dose dobutamine echocardiography (1.7 +/- 1.6 vs 1.1 +/- 1.6). A significant correlation was found between the number of a/dyskinetic segments viable on 201Tl SPET and post-revascularization changes in ejection fraction (r = 0.52, P < 0.05), but such a correlation was not observed for low-dose dobutamine echocardiography. Using as the cut-off the presence of at least one viable a/dyskinetic segment, rest 201Tl SPET had a higher sensitivity (82% vs 53%, P = 0.07) and showed a trend towards higher accuracy and specificity (77% vs 58%, and 71% vs 64%, respectively) as compared with low-dose dobutamine echocardiography. In conclusion, these findings suggest that when severely reduced global function is present, rest 201Tl SPET evaluation of viability is more accurate than low-dose dobutamine echocardiography for the identification of patients who will benefit most from revascularization.
Pace
L
L
Cattedra di Medicina Nucleare, Istituto di Scienze Biomorfologiche e Funzionali, Facoltà di Medicina, Università Federico II, Napoli, Italy.
Perrone-Filardi
P
P
Storto
G
G
Della Morte
A M
AM
Dellegrottaglie
S
S
Prastaro
M
M
Crisci
T
T
Ponticelli
M P
MP
Piscione
F
F
Chiariello
M
M
Salvatore
M
M
D000318:Adrenergic beta-Agonists; D000368:Aged; D002908:Chronic Disease; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004280:Dobutamine; D004452:Echocardiography; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D013318:Stroke Volume; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left
D000318:Adrenergic beta-Agonists; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D004280:Dobutamine