Prediction of mortality in patients with coronary artery disease undergoing vasodilator stress testing: a comparison between 99mTc-tetrofosmin and 99mTc-sestamibi.
OBJECTIVE
To compare the prognostic ability of the imaging agents 99mTc-sestamibi versus 99mTc-tetrofosmin to predict mortality outcomes in patients with documented coronary artery disease and undergoing vasodilator stress testing.


METHODS
The study included 2147 consecutive patients who underwent rest and stress single photon emission computed tomographic (SPECT) examination with either 99mTc-sestamibi (n=1128) or 99mTc-tetrofosmin (n=1019). Information relating to all-cause death and cardiovascular death was collected over a 4-year study period. Unadjusted Kaplan-Meier estimates were compared for the two imaging agents. Cox proportional hazard models were examined to determine the incremental contribution of SPECT sum stress score (SSS) and the imaging agent after adjusting for clinical and demographic characteristics. Additionally, the interaction between SSS and agent was examined to determine if the effect of SSS on prognosis was different for the two agents.


RESULTS
Vasodilator agents were used for stress testing in all patients who received 99mTc-tetrofosmin and 99mTc-sestamibi. Despite differences in patient risk factors Kaplan-Meier estimates were similar for the two groups of patients. Resulting P-values for differences between models for the end points of (1) death from any cause and (2) cardiovascular death showed that SSS combined with clinical index was significantly better than a model that adjusted for only baseline characteristics (P<0.0001 for both endpoints). The addition of imaging agent (99mTc-tetrofosmin or 99mTc-sestamibi) to the model containing both SSS and the clinical characteristics did not show further significant improvement (P=0.62, P=0.96 for death from any cause and cardiovascular death, respectively).


CONCLUSIONS
The type of clinically available 99mTc-labelled myocardial perfusion agents did not affect interpretation of results for prognostic assessment.
Adams
George L
GL
Department of Medicine (Cardiology), Duke University Medical Center, Durham, North Carolina 27710, USA.
Shaw
Linda K
LK
Tuttle
Robert H
RH
Hanson
Michael W
MW
Pagnanelli
Robert
R
Borges-Neto
Salvador
S
D000368:Aged; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014665:Vasodilator Agents
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; C078700:technetium tc-99m tetrofosmin; D017256:Technetium Tc 99m Sestamibi