[Prognostic value of cardiac perfusion scintigraphy associated with the dobutamine test in acute coronary syndromes].
OBJECTIVE
This study aimed to establish the value of myocardial ischemia induced by the dobutamine infusion test associated to 99m technetium isonitrile single photon emission computed tomography in patients with unstable angina or non Q-wave infarction during the first days in the Coronary Care Unit.


METHODS
Fifty three patients with unstable coronary syndromes and common medical treatment were studied with a moderate-dose dobutamine test (5 to 20 microgram/Kg/min) using a 99mTc-MIBI SPECT. The results were correlated with the incidence of recurrent angina, infarction, death or revascularization.


RESULTS
The dobutamine test induced a reversible perfusion defect in 36 patients (68%) and angina in 12 of them (12/36, 33%). However, the patients who had a positive test had a similar incidence of events as those with a negative test (58% vs 59%). Thus, while the sensitivity of the dobutamine test to identify patients at risk was relatively high (68%), its specificity (32%) and its negative predictive value (41%) were low. The patients with dobutamine-induced angina, however, had a higher scintigraphy score (3.0 +/- 1,7 vs 1.6 +/- 1.8, p < 0.02) and a higher incidence of recurrent angina (8/12, 67% vs 13/41, 31%, p < 0.04) than those without, at a comparable double product.


CONCLUSIONS
In conventionally treated patients with unstable coronary syndromes, the specificity of the inducible scintigraphic ischemia with moderate dose of dobutamine performed during the first days is too low to be used as a marker for in-hospital events. However, inducible angina with dobutamine suggests an extensive jeopardized area and/or a particularly reduced ischemic threshold.
Cortadellas
J
J
Servicio de Cardiología Hospital General Vall d'Hebron, Barcelona.
Figueras
J
J
Aguadé
S
S
Castell
J
J
González
T
T
Soler Soler
J
J
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000368:Aged; D000787:Angina Pectoris / Q000139:chemically induced; D000789:Angina, Unstable / Q000000981:diagnostic imaging*; D003326:Coronary Circulation / Q000187:drug effects; D004280:Dobutamine / Q000008:administration & dosage / Q000494:pharmacology; D004569:Electroencephalography; D005080:Exercise Test; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D009204:Myocardial Revascularization; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012008:Recurrence; D012306:Risk; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome
D000318:Adrenergic beta-Agonists; D019275:Radiopharmaceuticals; D004280:Dobutamine; D017256:Technetium Tc 99m Sestamibi