Transient ischemic dilation ratio of the left ventricle is a significant predictor of future cardiac events in patients with otherwise normal myocardial perfusion SPECT.
OBJECTIVE
This study evaluated the prognostic value of transient ischemic dilation (TID) of the left ventricle (LV) in patients with normal stress myocardial perfusion single photon emission computed tomography (MPS).


BACKGROUND
The prognostic value of TID in patients with an otherwise normal MPS has not been defined.


METHODS
We identified 1,560 patients who had normal stress MPS (436 vasodilator and 1,124 exercise stress), and no rest LV enlargement (Population 1) and followed up for 2.30 +/- 0.67 years for hard events (HE) (cardiac death or myocardial infarction) and soft events (SE) (revascularization). Prediction of first HE or SE (total events [TE]) was evaluated by multivariable Cox analysis, which was also applied to a broader group of 2,037 patients (including patients with minimal defects (Population 2).


RESULTS
In Population 1, there were 13 HE, 36 SE, and 42 TE. Patients in the highest TID quartile (TID > or =1.21) had a higher TE rate than others, regardless of stress type. By multivariable analysis, highest TID quartile was predictive of TE (p = 0.008). Other independent predictors of TE were age, typical angina, and diabetes. In Population 2, TID was also predictive of TE.


CONCLUSIONS
An entirely normal stress MPS study does not always imply an excellent prognosis. In patients with otherwise normal MPS, TID is an independent and incremental prognostic marker of TE even after significant clinical variables--age, typical angina, and diabetes--are accounted for. When TID is present, caution in making low-risk prognostic statements may be warranted, especially in patients with typical angina, the elderly, and diabetics. Our findings also appear to apply to the broader population of "normal" MPS, which included patients with minimal perfusion defects.
Abidov
Aiden
A
Department of Imaging, Division of Nuclear Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
Bax
Jeroen J
JJ
Hayes
Sean W
SW
Hachamovitch
Rory
R
Cohen
Ishac
I
Gerlach
James
J
Kang
Xingping
X
Friedman
John D
JD
Germano
Guido
G
Berman
Daniel S
DS
D000368:Aged; D003643:Death; D004108:Dilatation, Pathologic; D005080:Exercise Test / Q000379:methods; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology*; D017202:Myocardial Ischemia / Q000150:complications* / Q000628:therapy; D009204:Myocardial Revascularization; D011237:Predictive Value of Tests; D011379:Prognosis; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000628:therapy