[Reversibility in perfusion scintigraphy after myocardial infarct: a comparison between the protocol of single-day rest-stress with 99mTc sestamibi and reinjection with thallium-201].
OBJECTIVE
To compare thallium-201 stress-reinjection SPECT (TL) and single-day rest-stress 99mTc-sestamibi SPECT (MIBI) for detection of reversibility of perfusion defects after Q-wave myocardial infarction.


METHODS
Prospective study with the two scintigraphic methods.


METHODS
We studied 31 patients with previous Q-wave myocardial infarction referred for assessment of myocardial viability.


METHODS
Patients were studied with thallium-201 stress-reinjection SPECT and single-day rest-stress 99mTc-sestamibi SPECT. Tracer uptake was classified in a 0 to 4 intensity scale in each of 13 myocardial segments.


RESULTS
Segmental comparison indicated that the identification of perfusion defects was similar by the two methods. Some reversibility was present in 51% of TL perfusion defects and in 26% of MIBI perfusion defects (p < 0.001). Twenty-seven percent of fixed perfusion defects in MIBI showed some reversibility by TL, but only 8% of the fixed perfusion defects by TL were reversible by MIBI (p < 0.001). In infarct-related perfusion defects, TL showed reversibility in 46% and MIBI in 22% (p < 0.001). TL detected reversibility in 84% of patients and MIBI in 48% (p = 0.007).


CONCLUSIONS
Although the two methods were similar for perfusion defects identification, the present study suggests that thallium-201 reinjection is superior to single-day rest-stress 99mTc-sestamibi for the detection of reversibility. Clinical relevance of these differences, as a marker of viability, requires further evaluation of these patients after successful revascularization.
Ferreira
J
J
Serviço de Cardiologia, Hospital de Santa Cruz, Carnaxide.
Gil
V M
VM
Ventosa
A
A
Calqueiro
J
J
Seabra-Gomes
R
R
D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D004176:Dipyridamole; D005080:Exercise Test / Q000706:statistics & numerical data; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000453:epidemiology; D012146:Rest; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data
D013794:Thallium Radioisotopes; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi
Reversibilidade na cintigrafia de perfusão após enfarte do miocárdio: comparação entre o protocolo de dia único repouso-sobrecarga com 99mTc-sestamibi e a reinjecção com tálio-201.