Clinical Research
Cardiac Imaging
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

This study was presented in part at the American Heart Association Annual Scientific Session, New Orleans, Louisiana, November 7–10, 2004. Todd Miller, MD, FACC, acted as guest editor.
https://doi.org/10.1016/j.jacc.2005.11.062Get rights and content
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Objectives

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 ≥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 inversepredictor 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.

Abbreviations and Acronyms

BMI
body mass index
CABG
coronary artery bypass grafting
CAD
coronary artery disease
CHF
chronic heart failure
EDV
end-diastolic volume
EF
ejection fraction
ESV
end-systolic volume
LV
left ventricle/ventricular
LVEF
left ventricular ejection fraction
MPS
myocardial perfusion single-photon emission computed tomography
PCI
percutaneous coronary intervention
SPECT
single-photon emission computed tomography

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Partial funding was provided by grants from Bristol-Myers Squibb Medical Imaging Inc., Billerica, Massachusetts, and Astellas Inc., Deerfield, Illinois. Grant support for the follow-up portion of this project was provided by Bristol-Myers Squibb Medical Imaging and Astellas Inc.