Should imaging at stress always be followed by imaging at rest in Tc-99m MIBI SPECT? A proposal for a selective referral and imaging strategy.
OBJECTIVE
We addressed the question whether in patients with cardiac chest pain referred for stress myocardial perfusion scintigraphy, Tc-99m MIBI SPECT stress imaging should always be followed by a rest imaging procedure.


BACKGROUND
Using Tc-99m MIBI imaging a stress rest sequence is usually performed implying that the resting study always follows the stress study irrespective of the results of the stress study. As a normal stress study would eliminate a subsequent resting study, it appears desirable to potentially define certain subsets of patients in whom a normal stress study can be expected in order to determine a more selective referral approach to the nuclear medicine department. The consequences of such a more streamlined approach would less impose on the logistics of the department of nuclear medicine, with decrease of investigation time, radiation dose, and costs in a time of retrenchment in the medical sector.


METHODS
A consecutive series of 460 patients (mean age 58.2 years) was studied who were stratified to 269 patients without prior myocardial infarction, and to 191 patients with documented evidence of a previously sustained myocardial infarction. All patients underwent Tc-99m MIBI SPECT imaging according to a two-day stress-rest protocol.


RESULTS
Patients with and without a previous myocardial infarction showed suboptimal overall predictive accuracies for the exercise electrocardiograms (58% and 60%, respectively). In the total group of 460 patients, 94 (20%) patients showed a normal stress-rest Tc-99m MIBI SPECT; this occurred in 86/269 (32%) patients without a previous myocardial infarction and in only 8/191 (4%) patients with a previous myocardial infarction.


CONCLUSIONS
Patients with a stress defect at Tc-99m MIBI SPECT imaging should always undergo a resting SPECT study irrespective of the clinical and stress electrocardiographic findings. As patients without a previous myocardial infarction had a normal stress SPECT study in almost one-third (32%) of patients compared to only 4% in patients with a previously myocardial infarction, it may be useful to employ different referral and imaging strategies i.e., a stress-only versus a stress-rest procedure. To schedule referring patients differently according to the presence or absence of a previously sustained myocardial infarction may be cost-saving, less demanding for the nuclear medicine personnel, and patient-convenient. In addition, a stress-only imaging procedure reduces radiation exposure to the individual patient.
Schroeder-Tanka
J M
JM
Department of Cardiology, Academic Medical Centre, Amsterdam, The Netherlands.
Tiel-van Buul
M M
MM
van der Wall
E E
EE
Roolker
W
W
Lie
K I
KI
van Royen
E A
EA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003287:Contrast Media; D003327:Coronary Disease / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D012016:Reference Values; D012146:Rest; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D003287:Contrast Media; D017256:Technetium Tc 99m Sestamibi