Prognostic performance of quantitative PET tools for stratification of patients with ischemic cardiomyopathy undergoing myocardial viability assessment.
OBJECTIVE
This study was performed to determine the prognostic performance of quantitative PET tools in the stratification of patients with ischemic cardiomyopathy undergoing myocardial viability assessment.


METHODS
We applied four different quantitative tools to 104 consecutive patients with coronary artery disease and previous myocardial infarction who had undergone rest Rb/gated F-fluorodeoxyglucose (FDG) PET, to assess myocardial viability for potential revascularization. One of these tools was based on the FDG study alone and the other three tools assessed the extent of match/mismatch defects using FDG in comparison with a perfusion reference database. The four quantitative tools used in this research to define viability were (i) FDG alone, which calculates the percentage of left ventricular myocardium (LVM) that is above the 50% of the maximum LVM FDG counts, (ii) low flow match/mismatch, which determines the area with a 5% increase in normalized FDG counts in relation to defined resting perfusion defects as compared with a reference database, (iii) all regions match/mismatch, which computes the area with a 10% increase in normalized FDG counts in relation to the left ventricle resting perfusion distribution, and (iv) percentage max FDG match/mismatch, which defines the area with FDG uptake greater than 60% of the maximum LVM FDG counts within defined perfusion defects as determined by the reference database. The primary endpoint for this analysis was cardiac death.


RESULTS
During the follow-up period (22+/-14 months), 19 patients (18%) died; in 17 of these the cause of death was cardiac. Using univariate analysis, none of the methods were predictive of cardiac death. Receiver operating characteristic analysis defined the optimal thresholds for the extent of myocardial viability for the four tools in the prediction of cardiac death: FDG alone=20%, low flow match/mismatch=15%, all regions match/mismatch=35%, and percentage max FDG match/mismatch=20%. A censored survival analysis using a Kaplan-Meier method showed a statistically significant difference between patients with cardiac death and those with no cardiac death using only the low flow match/mismatch (hazard ratio=0.29, P=0.01) and percentage max FDG match/mismatch criteria (hazard ratio=0.23, P=0.005) tools.


CONCLUSIONS
The low flow match/mismatch and percentage max FDG match/mismatch quantitative PET tools are useful for prognostic stratification of patients with ischemic cardiomyopathy undergoing myocardial viability assessment.
Emory University School of Medicine, Department of Radiology, Atlanta, Georgia 30322, USA. csantan@emory.edu
Cesar A
CA
Santana
Tracy L
TL
Faber
Marina
M
Soler-Peter
Rupan
R
Sanyal
Fabio P
FP
Esteves
Mario
M
Ornelas
Russell D
RD
Folks
Liudmila
L
Verdes
Leonela F
LF
Santana
Jaume
J
Candell-Riera
Ernest V
EV
Garcia
D000368:Aged; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D003326:Coronary Circulation; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012414:Rubidium Radioisotopes; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology
D019275:Radiopharmaceuticals; D012414:Rubidium Radioisotopes; D019788:Fluorodeoxyglucose F18