Assessment of diastolic function using 16-frame 99mTc-sestamibi gated myocardial perfusion SPECT: normal values.
The purposes of this study were (a) to assess the feasibility of diastolic function (DFx) evaluation using standard 16-frame postexercise gated (99m)Tc-sestamibi myocardial perfusion SPECT (MPS), (b) to determine the relationship of the 2 common DFx parameters, peak filling rate (PFR) and time to peak filling (TTPF), to clinical and systolic function (SFx) variables in patients with normal myocardial perfusion and SFx, and (c) to derive and validate normal limits.


METHODS
Ninety patients (71 men; age, 30-79 y) with normal exercise gated MPS were studied. None had hypertension, diabetes, rest electrocardiogram abnormality, or known cardiac disease. All patients reached > or = 85% of maximum predicted heart rate (HR). The population was randomized into derivation (n = 50) and validation (n = 40) groups. Univariable and multivariable approaches were deployed to assess the influence of clinical and functional variables on DFx parameters.


RESULTS
PFR and TTPF were assessed in all patients. Mean values of PFR and TTPF in the whole study population were 2.62 +/- 0.46 end-diastolic volumes per second (EDV/s) and 164.6 +/- 21.7 ms, respectively. By applying a 2-SD cutoff to the mean values in the derivation group, the threshold for abnormal PFR and the threshold for abnormal TTPF were < 1.71 EDV/s and > 216.7 ms, respectively. The normalcy rates in the validation group for PFR and TTPF were both 100%. The PFR showed weak but significant correlations with age, EDV, end-systolic volume, left ventricular ejection fraction (LVEF), and poststress HR. However, TTPF did not correlate with these parameters. Final normal thresholds determined from the combined populations were PFR = 1.70 EDV/s and TTPF = 208 ms. Multivariable analysis showed that age, sex, LVEF, and HR are strong predictors for PFR, whereas TTPF was not influenced by any clinical or SFx variable.


CONCLUSIONS
With a new algorithm in QGS, assessment of LV DFx is feasible using 16-frame gated MPS even without bad-beat rejection, resulting in normal limits similar to those reported with gated blood-pool studies. However, due to the dependency of PFR on SFx parameters, sex, HR, and age, TTPF appears to be a stable and more useful parameter with this approach. The clinical usefulness of these findings requires further study.
Department of Imaging and Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
Cigdem
C
Akincioglu
Daniel S
DS
Berman
Hidetaka
H
Nishina
Paul B
PB
Kavanagh
Piotr J
PJ
Slomka
Aiden
A
Abidov
Sean
S
Hayes
John D
JD
Friedman
Guido
G
Germano
D000328:Adult; D000367:Age Factors; D000368:Aged; D005080:Exercise Test; D005240:Feasibility Studies; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology*; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016276:Ventricular Function; D016277:Ventricular Function, Left / Q000502:physiology*
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi