[The capacity of the rest-dobutamine gated SPECT protocol to predict contractile recovery after revascularization of myocardial dysinergic areas].
OBJECTIVE
Gated-SPECT is a promising method to analyze myocardial viability. We have assessed the accuracy of a new protocol of rest/Dobutamine gated-SPECT, based on the evaluation of contractile reserve induced by 10 microg/kg/min of Dobutamine, to predict contractile recovery after revascularization of dysinergic myocardial territories.


METHODS
In a group of 36 patients submitted to percutaneous revascularization, we selected 40 vascular territories (21 left descending artery, 19 right coronary-circumflex) with severely depressed contractility (contrast ventriculography, center line method). Follow up evaluation at 6 months showed the absence of angiographic restenosis and control contrast ventriculography assessed the contractile changes of the selected territories, considering those with contractile restoration as viable. Before revascularization, rest/Dobutamine gated-SPECT study was applied and viability was defined as the presence of contractile reserve (positive or improvement [n = 21] and negative or impairment [n = 7]) with non viability being the absence of contractile reserve (n = 12). We analyzed the evolution of the ejection fraction in a group of 27 patients with impaired ventricular function and complete revascularization.


RESULTS
Gated-SPECT showed a sensitivity of 0.96 (95% CI 0.78-0.99) and a specificity of 0.78 (95% CI 0.48-0.94) in the diagnosis of viability. The ejection fraction (median [interquartile range]) increased after revascularization: 0.42 (0.15) vs 0.55 (0.22), Z = -3.9; p < 0. 001. The diagnosis of viability by gated-SPECT (p < 0.001) and the extent of severely depressed myocardium (p = 0.04) independently predicted the increase of the ejection fraction after revascularization.


CONCLUSIONS
The analysis of contractile reserve by rest/Dobutamine gated-SPECT is adequate to diagnose viability in territories with severely depressed contractility and independently predicts the increase of ejection fraction after revascularization.
Ruiz-Salmerón
R J
RJ
Departamento de Cardiología Intervencionista. Hospital do Meixoeiro. Vigo.
Ponce De León
E
E
López
A
A
Romeo
D
D
del Campo
V
V
Nandayapa
R
R
Guitián
R
R
Mantilla
R
R
Calvo
F
F
Pasalodos
J
J
Goicolea
J
J
D000318:Adrenergic beta-Agonists; D009202:Cardiomyopathies / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D004280:Dobutamine; D005260:Female; D015637:Gated Blood-Pool Imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D009204:Myocardial Revascularization; D011237:Predictive Value of Tests; D012146:Rest / Q000502:physiology*
D000318:Adrenergic beta-Agonists; D004280:Dobutamine