Impact of body mass index on cardiac mortality in patients with known or suspected coronary artery disease undergoing myocardial perfusion single-photon emission computed tomography.
OBJECTIVE
The purpose of this study was to assess the relationship between body mass index (BMI) and the prognostic value of myocardial perfusion single-photon emission computed tomography (MPS).


BACKGROUND
The prognostic value of MPS in the obese has not been evaluated.


METHODS
We studied 4,720 patients with and 10,019 patients without known coronary artery disease (CAD) who underwent rest Tl-201/stress Tc-99m sestamibi MPS, including 5,233 gated MPS studies and followed up (mean 2.7 to 3.2 years). Patients were categorized as normal weight (BMI 18.5 to 24.9 kg/m2), overweight (BMI 25.0 to 29.9 kg/m2), or obese (BMI > or =30.0 kg/m2).


RESULTS
Unadjusted annual rates of cardiac death (CD) rose versus stress MPS abnormalities in all weight groups (p < 0.001). Obese or overweight patients with or without known CAD who had normal MPS were at low CD risk (<1%/year), similar to normal weight patients. In CAD, obese and overweight patients with abnormal MPS had lower rates of CD compared with normal weight patients (p < 0.01). In patients with low ejection fraction (EF) by gated MPS, those with normal weight had highest CD rate (p = 0.001). Multivariable models revealed that BMI was not a predictor of CD in suspected CAD patients (hazard ratio [HR] 0.99; 95% confidence interval [CI] 0.95 to 1.02) but was an independent inverse predictor of CD in known CAD patients (HR 0.95; 95% CI 0.92 to 0.98), especially in women, adenosine stress, low EF, or abnormal perfusion.


CONCLUSIONS
Normal MPS was associated with low risk of CD in patients of all weight categories. In patients with known CAD undergoing MPS, obese and overweight patients were at lower risk of CD over three years than normal weight patients.
Kang
Xingping
X
Department of Imaging, Division of Nuclear Medicine, and CSMC Burns & Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
Shaw
Leslee J
LJ
Hayes
Sean W
SW
Hachamovitch
Rory
R
Abidov
Aiden
A
Cohen
Ishac
I
Friedman
John D
JD
Thomson
Louise E J
LE
Polk
Donna
D
Germano
Guido
G
Berman
Daniel S
DS
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology / Q000503:physiopathology; D003326:Coronary Circulation; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D050177:Overweight; D011379:Prognosis; D018570:Risk Assessment; D012737:Sex Factors; D016019:Survival Analysis; D015899:Tomography, Emission-Computed, Single-Photon